Advanced therapy in thoracic surgery - part 7 pps

We have shown that the transtra-cheal administration of the gene coding for the anti-inflammatory cytokine human interleukin-10 to the donor 12 and 24 hours prior to lung retrieval reduc

Trang 1

tice, the allograft is gently reinflated before reperfusion

and ventilated with an FiO2of 0.5, PEEP of 5 cm H2O,

and a pressure-control ventilation limiting the peak

airway pressures to 25 cm H2O.100,101

Gene Therapy

The utilization of gene therapy in the transplantation

setting is advantageous because immunosuppressive

ther-apy may potentially allow repeated transfection with the

same viral vector without developing immunization.102,103

Multiple strategies have been used experimentally to

trans-fect donor lungs with variable success Genes have been

administered to the donor before lung retrieval, on the

back table during the cold ischemic time, and to the

recipi-ent after reperfusion They have been delivered

intravascu-larly, intramuscuintravascu-larly, and transtracheally as naked

deoxyribonucleic acid (DNA) or with the help of a vector,

either viral or nonviral, such as cationic liposomes.102–108

We have demonstrated that transfection of the donor

lung is possible through the transtracheal route using a

second-generation adenoviral vector without

contami-nating other organs such as the heart, liver, or kidneys.104

Since the transfection rate is significantly decreased at

cold temperatures, this mode of administration is useful

in that it allows for efficient transfection before retrieving

and cooling the lungs We have shown that the

transtra-cheal administration of the gene coding for the

anti-inflammatory cytokine (human interleukin-10) to the

donor 12 and 24 hours prior to lung retrieval reduces

ischemia-reperfusion injury and improves lung function

in a rat single lung transplant model.108A high dose of

steroids given before the administration of the adenoviral

vector can reduce the inflammation induced by the

aden-oviral vector and allow the transfection time to be

reduced to 6 hours before retrieving the lungs We are

currently performing similar experiments in a large

animal study Once similar results can be reproduced,

human lung protection from reperfusion injury by gene

therapy may be possible

Mechanisms of Ischemia-Reperfusion

Lung InjuryCalcium Overload

Hypothermic storage alters calcium metabolism in cells

both by release of calcium from intracellular depots and

by pathological influx through the plasma membrane

The alteration of pH and intracellular calcium

concen-tration disrupts many intracellular functions causing

cellular damage, leading to the activation of

phospholi-pase A2 and to the production of free radicals by

macrophages Elevated cytosolic calcium can also

enhance the conversion of xanthine dehydrogenase toxanthine oxidase and potentiate the damaging effect offree radicals on mitochondria

Verapamil, a calcium channel blocker, was found toprotect the lung from warm- and cold-preservationinjury.109,110If the drug is administered just before reper-fusion or immediately after reperfusion, arterial oxygena-tion may not be improved, although the lung watercontent has been found to be significantly lower in allgroups receiving verapamil In an isolated rabbit lungperfusion model, Yokomise and colleagues observed thatverapamil had the most dramatic effect when it wasadministered to the donor before lung retrieval.110 Theadministration of verapamil to the donor can reducelipid peroxidation during the ischemic time and preventendothelial damage after reperfusion.111,112In the longterm, however, the administration of the drug to thedonor and to the recipient did not seem to improvesurvival.112Similar results have been observed with othercalcium blockers such as nifedipine and diltiazem.113

Commonly, ischemia-reperfusion corresponds toanoxia–reoxygenation However, the lung has to beconsidered differently because it contains oxygen in thealveoli during ischemia Alveolar oxygen helps maintainaerobic metabolism and prevents hypoxia.84,116Hence, inthe lung, the oxidative stress resulting from ischemiashould be distinguished from the oxidative stress result-ing from hypoxia

Hypoxia and, ultimately, anoxia results in a sharpdecrease of ATP and a corresponding increase in theATP-degradation product hypoxanthine, which generatessuperoxide when oxygen is reintroduced with reperfu-sion or ventilation This phenomenon can occur in thelung when alveolar oxygen tension drops below 7 mm Hgduring ischemia.117 The mechanism can be blocked byinhibitors of the xanthine oxidase such as allopurinol butnot by inhibitors of the reduced form of nicotinamideadenine dinucleotide phosphate (NADPH) oxidase.118–120Ischemia is characterized by the absence of blood flowinto the lung and can cause lipid peroxidation and

Trang 2

oxidant injury despite the absence of hypoxia.84,120The

mechanism of oxidative stress is different from that

occurring during anoxia–reoxygenation, because it is not

associated with ATP depletion and it can occur during

the storage period.84,116,120

The endothelium appears to be the predominant

source of oxidants during nonhypoxic lung ischemia.121

Endothelial cells are highly sensitive to the physical forces

resulting from blood flow variation and are able to

trans-form these mechanical forces into electrical and

biochem-ical signals (mechanotransduction).122,123The absence of

the mechanical component of flow during lung ischemia

stimulates membrane depolarization of endothelial cells

with the activation of NADPH oxidase, nuclear factor

kappa-B (NF-B), and calcium/calmodulin-dependent

nitric oxide synthase (NOS).121,124,125Other cells such as

macrophages and marginated polymorphonuclear

leuko-cytes, which are known to have high NADPH oxidase

activity, could also contribute to the lung oxidant burden

that takes place during storage.126,127

Several antioxidants and free radical scavengers have

been developed and incorporated into preservation

solu-tions to minimize lung injury from the oxidative stress

that takes place during ischemia-reperfusion These

include xanthine oxidase inhibitors such as lodoxamide

and allopurinol, superoxide dismutase, catalase,

glutathione, dimethylsulfoxide, and alpha

toco-pherol.119,128,129 While experimental evidence supporting

their use is strong, they have not made a major clinical

impact on reperfusion injury

Pulmonary Surfactant Dysfunction

Surfactant dysfunction has been shown to occur during

ischemia-reperfusion injur y of the lung.1 3 0 – 1 3 4

Ultrastructural analyses have shown an increase in the

small to large surfactant aggregate ratio, an increase in

sphingomyelin, and a decrease in phosphatidylglycerol

and phosphatidylcholine, which correlated with

detri-mental changes in pulmonary compliance and lung

oxygenation.130–132,135These changes were also associated

with a deficit in surfactant adsorption and a decrease in

surfactant protein A (SP-A).131,134,136Alveolar surfactant

dysfunction may occur despite the absence of plasma

protein leakage or changes in lamellar bodies of type II

pneumocytes.130,137 The dysfunction is most likely the

result of numerous insults occurring during lung storage

such as production of phospholipase A2, mechanical

distorsion, altered phospholipid metabolism, reduced

production of SP-A, and accumulation of C-reactive

protein.132,134,138Although some alterations in surfactant

can be observed immediately after pulmonary artery

flushing, most of the alterations have been shown to

progressively increase during ischemic storage and to be

significantly less with extracelullar-type preservationsolutions.132,133,135,136

Experimental studies and anecdotal clinical tions have found that exogenous surfactant therapy canimprove pulmonary function after lung transplanta-tion.139–142The administration of exogenous surfactant isassociated with a higher amount of total surfactant phos-pholipids, a higher percentage of the heavy subtype ofsurfactant, a normalized percentage of phosphatidyl-choline, and a higher amount of endogenous SP-A—which has been shown to improve oxygenation andcompliance of the transplanted lung.140Exogenous surfac-tant has also been shown to enhance immediate recoveryfrom transplantation injury and to be persistently benefi-cial for endogenous surfactant metabolism for up to 1week after transplantation.143Exogenous surfactant given

observa-to the donor before retrieval has been associated withbetter and more reliable results than when it was adminis-tered just before or immediately after reperfusion.141,144Since 1995, Struber and coworkers have successfully used

a nebulized synthetic surfactant in several patients withreperfusion injury after lung transplantation.142,145 Theyobserved a rapid improvement in pulmonary complianceand in alveolar–arterial oxygen difference (A-aDO2), lead-ing to extubation within a few days after surgery.142In thefuture, these promising results need to be confirmed with

a prospective, randomized trial

Cell Death

In human lung transplantation, we have observed thatlungs with excellent function and good clinical outcomehave up to 30% of their cells undergoing apoptosis after 2hours of reperfusion.1 4 6 Similar findings have beenobserved experimentally after 6 and 12 hours of coldischemic time in rats, whereas longer ischemic times wereassociated with a preponderance of necrotic cell death inlung tissue.147 In contrast to necrosis, which may occurprior to reperfusion, apoptosis appears after reoxygena-tion, peaks rapidly after reperfusion, and does not corre-late with lung function.146,147

Whether apoptotic cells have a deleterious impact onorgan function remains controversial Some authors havedemonstrated that ischemia-reperfusion injury ofkidneys and hearts is reduced when antiapoptotic agentsare injected prior to reperfusion in mice models of warmischemia.148However, other investigators have argued that

by blocking the apoptotic molecular cascade after aperiod of brain ischemia, injured cells may not be able torecover but may instead continue to release proinflam-matory agents and subsequently die by necrosis, a mode

of cell death more injurious to surrounding tissue.149Wehave observed that for a similar amount of dead cells inthe transplanted lung, the presence of apoptotic cells was

Lung Preservation for Transplantation / 331

Trang 3

associated with better lung function than if the cells had

died by necrosis Clearly agents and techniques that

prevent cell death in the transplanted lung will play an

important role in future strategies for lung preservation

The Cytokine Network

Experimental studies have shown that

ischemia-reperfusion of the lung150–152induces a rapid release of

proinflammatory cytokines including tumor necrosis

factor ( TNF)-, interferon (IFN)-, IL-1, IL-6,

membrane cofactor protein (MCP)-1, and IL-8

(Table 26-2) In human lung transplantation, we have

demonstrated a striking relationship between IL-8 levels

and graft function after lung transplantation IL-8, which

is a potent chemokine promoting neutrophil migration

and activation, is rapidly released following reperfusion,

and levels in lung tissue 2 hours after reperfusion

corre-lated with lung function assessed by the PaO2/FiO2ratio,

the mean airway pressure, and the acute physiology and

chronic health evaluation (APACHE) score during the

first 24 postoperative hours The potential importance of

IL-8 has also been demonstrated in patients with acute

respiratory distress syndrome and in human liver

trans-plantation In addition, Sekido and colleagues have

shown that the intravenous administration of anti-IL-8

antibody at the beginning of the reperfusion period

markedly reduced lung injury and neutrophil infiltration

3 hours after reperfusion in a rabbit model of warm lung

ischemia.153

In contrast to liver transplantation, we did not find a

significant release of the anti-inflammatory cytokine

IL-10 after reperfusion in lung transplantation.154However,

we did observe a significant decline in the release of

IL-10 in lung tissue after reperfusion in older donors

Interestingly, the release of IL-10 has also been shown to

be decreased in older mice subjected to the stressful event

of trauma-hemorrhage.155This finding may thus, in part,

explain why lungs from older donors are more

suscepti-ble to ischemic injury and are associated with a higher

mortality rate than lungs from younger donors.10

Lentsch and colleagues156and Daemen and colleagues157have recently shown in a murine model of warm ischemiathat IL-12 and IL-18 cytokines play a significant role inischemia-reperfusion injury of the liver and kidney byinducing the release of TNF- and IFN- and by enhanc-ing the expression of MHC class I and II In human lungtransplantation, we observed that both IL-12 and IL-18were significantly higher during the ischemic time thanafter reperfusion In addition, IL-18 was the onlycytokine that correlated with the length of ischemic time

in our study Since longer ischemic times have beenshown to induce the expression of MHC class II, ourfinding suggests that long ischemic times may influenceacute rejection and subsequent chronic allograft dysfunc-tion through the release of IL-18 Clearly, cytokine-medi-ated injury can have important early and late effects onthe lung and further study is ongoing in this area

Lipid Mediated Network

Cell injury is accompanied by a rapid remodeling ofmembrane lipids with the generation of bioactive lipidsthat can serve as both intra- and extracellular media-tors.158 Phospholipases such as phospholipase A2have apivotal role in the generation of these lipid mediators.Phospholipase A2has been detected in a wide variety ofinflammatory conditions such as ischemia-reperfusion.The activation of phospholipase A2induces the produc-tion of platelet-activating factor (PAF), an extraordinarilypotent mediator of inflammation, and mobilizes arachi-donic acid from the membrane lipid pool, which is thendegraded by two major pathways into eicosanoids Thepotent vaso- and bronchoconstrictor thromboxane A2(TXA2) and various prostaglandins (PGs), such as PGD2,PGE2, PGF2, and PGI2, are produced via the cyclooxygenasepathway The lipoxygenase pathway, on the other hand,catalyzes leukotrienes (LTs) such as LTB4, LTC4, LTD4, andLTE4, which can increase capillary permeability

To date, only a few studies have analyzed the effect ofphospholipase A2inhibitors in lung ischemia-reperfusioninjury Shen and colleagues found that mepacrineTABLE 26-2 Source and Function of Cytokines Potentially Involved in Ischemia-Reperfusion Injury

Cytokine Main Cell Source Function

Tumor necrosis factor- Macrophages, lymphocytes Cell activation

Interferon- Lymphocytes Cell activation

Macrophage chemoattractant protein-1 Immune cells, lung epithelial cells Macrophage chemotaxis Interleukin-1 Macrophages, fibroblasts Cell activation

Interleukin-2 Lymphocytes Lymphocyte proliferation Interleukin-6 Macrophages, endothelial cells, epithelial cells Cell activation

Interleukin-8 Immune cells, lung epithelial cells, fibroblasts Neutrophil chemotaxis Interleukin-10 Macrophages, lymphocytes Anti-inflammatory Interleukin-12 Macrophages Proinflammatory Interleukin-18 Macrophages Proinflammatory

Trang 4

reduces lung injury after hypoxia–reoxygenation of the

lung, and Nagahiro and colleagues observed that the

administration of EPC-K1 in the flush and preservation

solution can enhance lung function after reperfusion.159,160

PAF can be released by a wide variety of cells

includ-ing macrophages, platelets, endothelial cells, mast cells,

and neutrophils.158It exerts its biological effects by

acti-vating the PAF receptors, which consequently activates

leukocytes, stimulates platelet aggregation, induces the

release of cytokines and the expression of cell adhesion

molecules.161PAF has been shown to play a critical role in

initiating lung injury The most direct evidence was

published by Nagase and colleagues, who demonstrated

that PAF receptor knockout mice developed a mild form

of acute lung injury after acid aspiration whereas the

overexpression of PAF receptor in transgenic mice

exag-gerated the acute lung injury when compared with

control mice.162A number of studies have demonstrated

that the administration of PAF antagonists during the

ischemic storage and after reperfusion reduces

ischemia-reperfusion injury and improves lung function.163–166

Similar results have been observed when PAF

acetylhy-drolase was administered to the flush solution and after

reperfusion to increase the rate of degradation of PAF.167

Wittwer and colleagues have recently reported their

clinical experience with a PAF antagonist in 24 patients

randomly assigned to a high dose of PAF antagonist in

the flush solution and after reperfusion (n = 8), a low

dose of PAF antagonist in the flush solution and after

reperfusion (n = 8), and a control group (n = 8).168They

observed a trend towards better A-aDO2within the first

32 hours after reperfusion and better chest radiograph

score However, the postoperative ventilation time did

not show any significant difference between groups In

clinical kidney transplantation, a randomized,

double-blind single center trial with 29 recipients showed a

significant reduction in the incidence of primary graft

failure after transplantation in the group of patients

receiving the PAF antagonist.169These interesting results

from single centers will hopefully stimulate large

multi-center trials

Arachidonic acid metabolites such as leukotrienes and

thromboxanes have been shown to increase in the lung

during ischemia-reperfusion in a dog model of warm

ischemia Thromboxanes may contribute to reperfusion

injury and exacerbate lung edema; however, their role in

the development of pulmonary hypertension after

reper-fusion remains controversial Zamora and colleagues

observed in an isolated perfused rabbit lung model that a

TXA2receptor antagonist administered before ischemia

and after reperfusion attenuated the degree of lung

edema.170Similar results have been observed with the

simultaneous administration of cyclooxygenase

inhibitors before and after ischemia in different models

of warm ischemia-reperfusion of the lung.171,172However,Ljungman and colleagues and Kukkonen and colleaguesfound that the administration of cyclooxygenase orthromboxane inhibitors after reperfusion only did notprevent the development of pulmonary hyperten-sion.171,173Hence, thromboxane inhibitors may reduce thedegree of reperfusion injury when given during storage,but do not appear to affect pulmonary artery pressurewhen administered after reperfusion only

Leukotrienes have not been systematically studiedduring ischemia-reperfusion of the lung However, mastcells, which are known to release large amounts ofleukotrienes and histamine, are increased in numberafter lung ischemia and reperfusion.174 In addition, theadministration of mast cell membrane–stabilizing agentsbefore cold or warm ischemia has been shown toimprove lung function.175The effect was associated with adecreased expression of adhesion molecules and anincreased expression of NOS-2 and tissue cyclic guano-sine monophosphate (cGMP) levels

Adhesion Molecules

Adhesion molecules can be upregulated on endothelialcells in the lung during the ischemic period Severalexperiments have shown a reduction in lung ischemia-reperfusion injury by alternatively blocking selectins,intracellular adhesion molecule (ICAM) 1, and CD18before initiating reperfusion

Moore and colleagues demonstrated that blockade ofP-selectin, ICAM-1, and the integrin CD18 using mono-clonal antibodies can reduce lung reperfusion injury asdetermined by the coefficient of filtration in an in vivomodel of warm ischemia.176The role of P-selectin in theearly phase of reperfusion has been confirmed by otherstudies using monoclonal antibodies and knockout micedeleted for the P-selectin gene.177In contrast to P-selectin,E-selectin and L-selectin may have little influence in theearly phase of reperfusion, while having an establishedrole in late reperfusion.176 This effect may relate to thepredominant role of neutrophils in the second phase ofreperfusion The use of biostable analogs of the oligosac-charides Lewis X and Lewis A, which are potent ligandsfor selectin adhesion molecules, has also been shown toreduce ischemia-reperfusion injury and to improve lungfunction when given before reperfusion in severalstudies.178–180

ICAM-1 blockade by monoclonal antibody tered in the flush solution or immediately prior to reper-fusion has been shown to reduce leukocyte sequestrationand to improve lung function.181Similar results have beenobserved with an antisense oligodeoxyribonucleotide,which selectively prevented the synthesis of ICAM-1

adminis-Lung Preservation for Transplantation / 333

Trang 5

during lung preservation.182 Blockade of CD18 with

monoclonal antibody also improved lung function with

an increasing effect after a prolonged period of

reperfu-sion.183A phase I clinical trial of immunosuppression

with anti-ICAM-1 monoclonal antibody in 18 renal

allo-graft recipients showed that the drug could be used safely

and that an adequate serum level of antibody was

associ-ated with significantly less graft dysfunction and less

acute rejection in the postoperative period.184No clinical

trials have been performed in lung transplantation yet

Metals and Metalloenzymes

Although iron is an essential element for all living cells, it

can be highly toxic under pathophysiologic or stress

conditions because of its ability to participate in the

generation of powerful oxidants Free iron can be

released from the ferritin core and from cytochrome

P-450 during ischemia by a number of factors such as

acidosis, proteolysis, and superoxide In addition to tissue

oxidation, iron can be released into the circulation and

potentially activate platelet aggregation.120

The importance of iron in promoting injury during

ischemia-reperfusion has been demonstrated by the

increased injury observed in iron-supplemented tissue

and conversely, by the protection offered with the iron

chelator deferoxamine Recently, a novel iron chelator

(desferriexochelin 772SM) has been shown to enhance

the effect of a P-selectin antagonist in preventing

ischemia-reperfusion injury in a rat liver model

Laz-aroids, which are aminosteroids that inhibit

iron-dependent lipid peroxidation, have also shown good

results in protecting the lung from ischemia-reperfusion

injury in all but one study.185–187

Metals other than iron have been less extensively

stud-ied in the setting of ischemia-reperfusion injury Zinc has

been shown to have a protective effect on the lungs

during hyperbaric oxygenation and on the kidneys after a

period of ischemia The protective effect may be

medi-ated through the induction of metallothionein or

through its interaction with free iron and copper.188Zinc

and copper are both constituents of

copper/zinc-superoxide dismutase–an antioxidant enzyme that has

been shown to be important in ischemia-reperfusion of

the gut and brain Copper may also be involved in the

production of the protective antioxidant enzyme heme

oxygenase 1 (HO-1).1 8 9 Selenium is involved in the

glutathione antioxidant system, and some authors have

shown that its addition to the preservation solution can

be beneficial in ischemia-reperfusion of the lung.190

Prothrombotic and Antifibrinolytic Agents

Hypoxia can induce endothelial cells and macrophages to

develop procoagulant properties, which may contribute

to the formation of microvascular thrombosis andimpede the return of blood flow after reperfusion Invitro studies have shown that endothelial cells subjected

to hypoxia can suppress their production of the ulant cofactor thrombomodulin and increase theirproduction of a membrane-associated factor X activa-tor.191 Tissue factor has also been shown to be upregu-lated on endothelial cells and macrophages by hypoxiaand to play a significant role in modulating ischemia-reperfusion injury in a model of liver warm ischemia.192The administration of C1-esterase inhibitor, whichinhibits the classical pathway of the complement system

anticoag-as well anticoag-as the contact phanticoag-ase and the intrinsic pathway ofthe coagulation system, has been shown to improve earlylung function and to reduce ischemia-reperfusion injury

in a dog lung transplantation model.1 9 3 C1-esteraseinhibitor has also been used successfully to treat lunggraft failure in two patients, but further clinical studiesare required to prove its efficacy.194

Recent experiments have demonstrated that miceplaced in a hypoxic environment suppressed their fibri-nolytic axis by increasing macrophage release of plas-minogen activator inhibitor 1 (PAI-1) and decreasingmacrophage release of tissue plasminogen activator (t-PA) and urinar y plasminogen activator (u-PA).Additional studies in mice have shown that the beneficialeffects of HO-1, carbon monoxide, and IL-10 duringlung ischemia are partially mediated by their ability topotentiate the fibrinolytic axis.195,196 Recombinant tissueplasminogen activator (rt-PA) has also been shown toimprove early lung function in a canine model of lungtransplantation from a non–heart-beating donor.197Further studies should determine more precisely the role

of fibrinolytic agents in ischemia-reperfusion of the lung

vasoconstric-Endothelins (ETs) are powerful vasoconstrictors—10times more active than angiotensin II or vasopressin.198Three isoforms have been described in human and othermammals, ET-1, ET-2, and ET-3, among which ET-1 hasbeen most extensively studied because it is released byendothelial cells and smooth muscle cells and its expres-sion is predominant in the lung In addition to being a

Trang 6

potent vasoconstrictor, ET-1 can stimulate the

produc-tion of cytokines by monocytes and promote the

reten-tion of leukocytes in the lung

Studies in human liver transplantation have shown

that ET-1 accumulates in the vascular space during

harvesting and cold storage Similar findings have been

observed in lung transplantation with ET-1 levels being

elevated in lavage fluid of transplanted allografts or in

plasma during the first few hours after reperfusion when

compared with preischemic values.199–201

The role of ET-1

in ischemia-reperfusion injury is supported by the

improvement in lung function when endothelin receptor

antagonists were administered before or during

reperfu-sion.202,203The administration of ET-1 receptor antagonist

is associated with a reduction in the expression of

inducible NOS (iNOS) and with a lower proportion of

apoptotic cells in the lung.204

Paradoxically, in vitro studies with pulmonar y

endothelial cells have shown that hypoxia and oxidant

stress can decrease the production of ET-1.205This finding

suggests that the production of ET-1 in vivo could result

from stimuli other than hypoxia or oxidant stress and

could be related to, for instance, the absence of blood

flow into the vascular bed during ischemia

NO is a messenger gas molecule with many

physio-logic effects, including potent vasoregulatory and

immunomodulatory properties.206It is produced by a

family of enzymes—the NOSs, which catalyze the

conversion of l-arginine to l-citrulline with the help of

five cofactors

Endogenous NO has been found to be decreased after

ischemia and reperfusion of the lung in human and

animal studies.207The fall in detectable endogenous NO

may be due to an accelerated destruction of NO by

oxygen free radicals or the presence of NOS inhibitors

that may be produced during ischemia-reperfusion of the

lung.207,208

Multiple strategies have been developed to

compen-sate for the fall in endogenous NO during lung

trans-plantation These strategies have been applied in the

donor and in the recipient and have targeted each step of

the pathway described above, including the

administra-tion of the upstream molecule l-arginine,209the

incre-ment of the downstream molecule cGMP,2 0 7 or the

administration of exogenous NO Exogenous NO has

been given directly by inhalation (inhaled NO),210,211 or

indirectly by infusion of an NO-donating agent (NO

donor), such as FK409,212 nitroprusside,213,214glyceryl

trinitrate,215 nitroglycerin,216,217or SIN-1.218 Other

strate-gies have been directed at increasing the activity of the

NOS enzyme by the addition of one of its cofactors

(tetrahydrobiopterin) to the preservation solution,219or

by transfecting the donor with an adenovirus containing

endothelial derived NOS (eNOS) before lung retrieval.107These experimental strategies have been shown to beeffective and to have a prolonged effect if they are initi-ated before the occurrence of reperfusion injur y.However, NO can react with superoxide anion and formperoxynitrous acid (ONOOH), which is a highly reactiveoxidant that can induce the release of ET-1, damage alve-olar type II cells even after a short period of ischemia,and cause structural and functional alterations of surfac-tant.220

Hence, this reaction may explain some of theconflicting reports in the literature, where some authorshave shown that NO administered during ischemia orearly reperfusion may be ineffective or even harmful, inparticular when it is given with a high fraction ofinspired oxygen at the time of reperfusion.210,221,222

Inhaled NO has been extremely useful clinically totreat ischemia-reperfusion injury of the lung because itcan improve ventilation-perfusion mismatch anddecrease pulmonary artery pressures without affectingsystemic pressures.223However, the role of inhaled NO inpreventing ischemia-reperfusion injury during clinicallung transplantation remains controversial Ardehali andcolleagues have shown that the application of inhaled

NO to 28 consecutive recipients after lung tion did not prevent the occurrence of reperfusioninjury.224We have recently completed a randomized andblinded placebo-controlled trial of inhaled NO adminis-tered to lung transplant recipients, starting 10 minutesafter reperfusion for a minimum of 6 hours.2 2 5 Weobserved no significant differences in the immediateoxygenation, time to extubation, and length of stay in theintensive care unit (ICU) or 30-day mortality In conclu-sion, while our clinical experience indicates that inhaled

transplanta-NO therapy appears to be useful in improving gasexchange in cases of established reperfusion injury, therole for NO in the prevention of ischemia-reperfusioninjury remains unproven in clinical lung transplantation

attrib-The continuous intravenous administration of PGE1

to the recipient during the early phase of reperfusion has

Trang 7

been shown to reduce ischemia-reperfusion injury of the

lung.227Although this effect can be partially attributed to

the vasodilatative property of PGE1during the initial 10

minutes of reperfusion,228after a longer period of

reper-fusion PGE1achieved significantly better lung function

than other vasodilatative agents such as prostacyclin and

nitroprusside.229Hence, the continuous infusion of PGE1

clearly has a beneficial role on ischemia-reperfusion

injury, some of which can be attributable to its beneficial

action on pro- and anti-inflammatory cytokines.230,231

Wehave recently demonstrated that the continuous adminis-

tration of PGE1during reperfusion is associated with a

shift from proinflammatory cytokines such as TNF-,

IFN-, and IL-12 to anti-inflammatory cytokines such as

IL-10 in a rat lung transplant model Other effects of

PGE1, such as its antiaggregant action on platelets,232have

not been specifically explored in the setting of lung

trans-plantation but may also potentially contribute to its

beneficial role

Although experimental studies suggest a beneficial

effect of PGE1after reperfusion, no randomized clinical

trial has yet been reported in lung transplantation to

demonstrate that it prevents ischemia-reperfusion injury

In human liver transplantation, two randomized trials

have shown a significant reduction in the duration of

ICU stay, although no difference in the incidence of

primary graft dysfunction was detected.233,234Studies in

clinical lung transplantation are required to determine

whether PGE1has a beneficial effect in the postoperative

course Such studies should probably use the newly

developed aerosolized form of PGE1, which has been

shown experimentally to reduce ischemia-reperfusion

injury of the lung without having the systemic side

effects of intravenous PGE1.235

Macrophages

Alveolar macrophages have been shown to produce a

large number of cytokines, cell surface receptors, and

procoagulant agents in vitro in response to oxidative

stress or hypoxia In an in vivo model of warm ischemia,

Eppinger and colleagues demonstrated the importance of

TNF-, IFN-, and MCP-1 in the early phase of

reperfu-sion and suggested that alveolar macrophages could play

an important role during that period.2 3 6 Fiser and

colleagues recently confirmed this hypothesis by

specifi-cally inhibiting pulmonary passenger macrophages with

gadolinium chloride before a period of cold ischemia,

showing significant improvement in lung function

immediately after reperfusion.237,238

The Complement System

Complement is a collective term used to designate a group

of plasma and cell membrane proteins that play a key role

in the cell defense process Studies in ischemia-reperfusion

of the lung have shown an activation of the complementsystem after reperfusion that may lead to cellular injurythrough direct and indirect mechanisms.239,240Products ofcomplement activation cause smooth muscle contractionand increase vascular permeability as well as degranulation

of phagocytic cells, mast cells, and basophils The activatedcomplement product C5a is also capable of amplifying theinflammatory response via its chemoattractant properties,its induction of granule secretion from phagocytes, and itsability to induce neutrophil and monocyte or macrophagegeneration of toxic oxygen metabolites Activation of C3and C5 via their respective convertases is essential for acti-vation of the complement cascade and generation of themembrane attack complex, which leads to direct cell lysis.241Complement receptor 1 is a natural complementantagonist present on erythrocytes and leukocytes Thisprotein was cloned and the transmembrane portion wasremoved to obtain a soluble form of CR1 (sCR1) sCR1suppresses complement activation in vivo by inhibitingC3 and C5 convertases, which prevent the activation ofboth the classical and alternative pathways In a swinesingle lung transplant model, we and others have shownthat the administration of sCR1 to the recipient beforereperfusion reduced lung edema as well as the accumula-tion of neutrophils in BAL and improved oxygena-tion.242,243 Similar findings have been observed in a ratsingle lung transplant model.239Following these results, amulticenter randomized, double-blinded, placebo-controlled trial with 59 lung transplant recipients wascarried out.244Among 29 patients receiving a dose ofsCR1 before reperfusion, 14 (48%) were extubatedwithin 24 hours, which was significantly better than inthe control arm, with only 6 patients of a total of 30(20%) In addition, the overall duration of mechanicalventilation and length of ICU stay tended to be shorter inthe group receiving sCR1, but the PaO2/FiO2ratio wasnot different between groups Recently, Stammberger andcolleagues have demonstrated that the administration of

a molecule combining sCR1 with sialyl Lewis X (aselectin receptor antagonist), can achieve significantlybetter results than the adminsitration of sCR1 alone.245

Neutrophils

Neutrophils progressively infiltrate the transplanted lungduring the initial 24 hours of reperfusion Although theycertainly play an important role in perpetuating reperfu-sion injury, their function in the early phase of reperfu-sion remains more controversial Several experimentshave been performed with the use of a leukocyte filter todeplete the blood at the time of reperfusion, demonstrat-ing a beneficial effect of leukocyte depletion even aftershort periods of reperfusion.246,247However, few studies

Trang 8

have examined the specific role of neutrophils.

Using an isolated rat lung perfusion model, Deeb and

colleagues demonstrated that the addition of neutrophils

to the perfusion system was not necessary for the

induc-tion of reperfusion injury after a period of warm

ischemia.248With an antineutrophil antibody, the same

group went on to demonstrate that reperfusion injury

exhibited a bimodal pattern, consisting of

neutrophil-independent events during the early phase of reperfusion

and of neutrophil-mediated events in the late phase of

reperfusion.249Other studies with specific antibodies

against neutrophils confirm these findings and show that

other leukocytes such as macrophages have a more

important role in the early phase of reperfusion.238,250,251

Clinical Lung Preservation at the

University of Toronto

When a potential lung donor is identified, 1 g of

intra-venous Solumedrol is administered After the lungs have

been assessed and the other procurement teams have

finished their dissection, the donor is fully heparinized,

and the main pulmonary artery is cannulated with a 20

French cannula Prostaglandin PGE1 (Prostin VR,

UpJohn) 500 µg is added to the preservation solution

(Perfadex), and 500 µg is injected directly into the main

pulmonary artery just prior to flushing the lungs The

lungs are recruited with 25 cm H2O prior to flushing to

remove atelectasis After inflow occlusion, the left atrial

appendage is transected for drainage and the lungs are

flushed antegrade with 50 mL/kg of Perfadex solution at

4°C, with the bag hung approximately 30 cm above the

heart The lungs are ventilated throughout the flush with

a tidal volume of 10 mL/kg, a PEEP of 5 cm H2O, and an

FiO2of 50% A retrograde flush is then performed in situ

with ventilation being continued (250 mL Perfadex into

each pulmonary vein orifice) After completion of the

flush, the heart and then the lungs are extracted We

inflate the lungs with a pressure of approximately 20 cm

H2O before tracheal cross-clamping to obtain lung

expansion but avoid overdistension The lungs are then

packaged floating in 2 L of flush solution and stored on

ice for transport (Table 26-3)

At the beginning of the recipient operation we ister 500 mg of Solumedrol The donor lung is kept coolwith a cooling jacket in the chest during implantation.After implantation, the lung is gently recruited and venti-lated: FiO2= 0.5, PEEP = 5 cm H2O, and pressure controlventilation limiting the peak airway pressure to a maxi-mum of 25 cm H2O The lung is then reperfused slowlyover a 10-minute period by gradually removing thepulmonary artery clamp or by allowing the right heart toeject in a controlled fashion if on cardiopulmonarybypass We give no other routine pharmacologic therapyfollowing reperfusion—nitric oxide or PGE1are usedonly for clinical indications of reperfusion injury

admin-Summary

It is now 20 years since the first successful single lungtransplant Considerable progress has been made in lungpreservation since that time The development of aspecific lung preservation solution has been an impor-tant advance and the clinical introduction of the low-potassium dextran solution has been a long time coming

In general the lung transplant community has beenslow to translate the findings from animal experimentalwork to the bedside, but this is changing Ischemia-reperfusion injury is still a significant clinical problem,and our goals for the future are to be able to better assessthe degree of injury, to predict the degree of dysfunction,and hopefully to develop strategies to treat or prevent theinjury in the first place Ultimately, we strive towardsrepairing or modifying a donor lung, allowing time forrepair of the injuries, and then testing the lungs ex vivo toensure good function before transplanting the organ intothe recipient

References

1 Hosenpud JD, Bennett LE, Keck BM, et al The registry of the international society for heart and lung transplantation: seventeenth official report-2000 J Heart Lung Transplant 2000;19:909–31.

2 Anderson DC, Glazer HS, Semenkovich JW, et al Lung transplant edema: chest radiography after lung transplantation—the first 10 days Radiology 1995;195:275–81.

3 Kundu S, Herman SJ, Winton TL Reperfusion edema after lung transplantation: radiographic manifestations Radiology 1998;206:75–80.

4 King RC, Binns OA, Rodriguez F, et al Reperfusion injury significantly impacts clinical outcome after pulmonary transplantation Ann Thorac Surg 2000;69:1681–5.

5 Meyers CH, Purut CM, D’Amico TA, et al Pulmonary arterial impedance after single lung transplantation J Surg Res 1992;52:459–65.

TABLE 26-3 Current Recommendations for Lung

Preservation

Volume of flush solution 50 mL/kg

Pressure during flush solution 10–15 mm Hg

Temperature of flush solution 4°C–8°C

Lung ventilation 10 mL/kg

Lung inflation (airway pressure) 20 cm H2O

Oxygenation ≤ 50% FiO 2

Storage temperature 4°C–8°C

Trang 9

6 Qayumi AK, Nikbakht-Sangari MN, Godin DV, et al The

relationship of ischemia-reperfusion injury of

transplant-ed lung and the up-regulation of major histocompatibility

complex II on host peripheral lymphocytes J Thorac

Cardiovasc Surg 1998;115:978–89.

7 Toronto Lung Transplant Group Unilateral lung

trans-plantation for pulmonary fibrosis N Engl J Med

1986;314:1140–5.

8 Sommers KE, Griffith BP, Hardesty RL, Keenan RJ Early

lung allograft function in twin recipients from the same

donor: risk factor analysis Ann Thorac Surg

1996;62:784–90.

9 Madill J, Gutierrez C, Grossman J, et al Nutritional

assess-ment of the lung transplant patient: body mass index as a

predictor of 90-day mortality following transplantation J

Heart Lung Transplant 2001;20:288–96.

10 Meyer DM, Bennett LE, Novick RJ, Hosenpud JD Effect of

donor age and ischemic time on intermediate survival and

morbidity after lung transplantation Chest

2000;118:1255–62.

11 Pierson RN, Milstone AP, Loyd JE, et al Lung allocation in

the United States, 1995–1997: an analysis of equity and

utility J Heart Lung Transplant 2000;19:846–51.

12 deMeester J, Smits JM, Persijn GG, Haverich A Lung

transplant waiting list: differential outcome of type of

end-stage lung disease, one year after registration J Heart

Lung Transplant 1999;18:563–71.

13 Cohen RG, Starnes VA Living donor lung transplantation.

World J Surg 2001;25:244–50.

14 Steen S, Sjoberg T, Pierre L, et al Transplantation of lungs

from a non-heart-beating donor Lancet 2001;357:825–9.

15 Pierre AF, Sekine Y, Hutcheon M, et al Evaluation of

extended donor and recipient criteria for lung

transplan-tation J Heart Lung Transplant 2001;20:256.

16 Sundaresan S, Trachiotis GD, Aoe M, et al Donor lung

procurement: assessment and operative technique Ann

Thorac Surg 1993;56:1409–13.

17 Gabbay E, Williams TJ, Griffiths AP, et al Maximizing the

utilization of donor organs offered for lung

transplanta-tion Am J Respir Crit Care Med 1999;160:265–71.

18 Sundaresan S, Semenkovich J, Ochoa L, et al Successful

outcome of lung transplantation is not compromised by

the use of marginal donor lungs J Thorac Cardiovasc Surg

1995;109:1075–9.

19 Bhorade SM, Vigneswaran W, McCabe MA, Garrity ER.

Liberalization of donor criteria may expand the donor

pool without adverse consequence in lung

transplanta-tion J Heart Lung Transplant 2000;19:1199–204.

20 Bittner HB, Kendall SW, Chen EP, et al The effects of brain

death on cardiopulmonary hemodynamics and pulmonary

blood flow characteristics Chest 1995;108:1358–63.

21 Follette DM, Rudich SM, Babcock WD Improved genation and increased lung donor recovery with high- dose steroid administration after brain death J Heart Lung Transplant 1998;17:423–9.

oxy-22 Takada M, Nadeau KC, Hancock WW, et al Effects of explosive brain death on cytokine activation of peripheral organs in the rat Transplantation 1998;65:1533–42.

23 Pratschke J, Wilhelm MJ, Kusaka M, et al Accelerated rejection of renal allografts from brain-dead donors Ann Surg 2000;232:263–71.

24 DerHoeven JA, TerHorst GJ, Molema G, et al Effects of brain death and hemodynamic status on function and immunologic activation of the potential donor liver in the rat Ann Surg 2000;232:804–13.

25 Koo DD, Welsh KI, McLaren AJ, et al Cadaver versus living donor kidneys: impact of donor factors on antigen induction before transplantation Kidney Int 1999;56:1551–9.

26 Schwarz C, Regele H, Steininger R, et al The contribution

of adhesion molecule expression in donor kidney biopsies

to early allograft dysfunction Transplantation 2001;71:1666–70.

27 Fisher AJ, Donnelly SC, Hirani N, et al Elevated levels of interleukin-8 in donor lungs is associated with early graft failure after lung transplantation Am J Respir Crit Care Med 2001;163:259–65.

28 Hopkinson DN, Bhabra MS, Hooper TL Pulmonary graft preservation: a worldwide survey of current clinical prac- tice J Heart Lung Transplant 1998;17:525–31.

29 Fujimura S, Handa M, Kondo T, et al Successful 48-hour simple hypothermic preservation of canine lung transplants Transplant Proc 1987;19:1334–6.

30 Keshavjee SH, Yamazaki F, Cardoso PF, et al A method for safe twelve-hour pulmonary preservation J Thorac Cardiovasc Surg 1989;98:529–34.

31 Yamazaki F, Yokomise H, Keshavjee SH, et al The ity of an extracellular fluid solution over Euro-Collins’ solution for pulmonary preservation Transplantation 1990;49:690–4.

superior-32 Keshavjee SH, Yamazaki F, Yokomise H, et al The role of dextran 40 and potassium in extended hypothermic lung preservation for transplantation J Thorac Cardiovasc Surg 1992;103:314–25.

33 Date H, Matsumura A, Manchester JK, et al Evaluation of lung metabolism during successful twenty-four hour canine lung preservation J Thorac Cardiovasc Surg 1993;105:480–91.

34 Steen S, Kimbald PO, Sjoberg T, et al Safe lung tion for twenty-four hours with Perfadex Ann Thorac Surg 1994;57:336–41.

preserva-35 Date H, Izumi S, Miyade Y, et al Successful canine

bilater-al single-lung transplantation after 21-hour lung tion Ann Thorac Surg 1995;59:336–41.

Trang 10

preserva-36 Spaggiari L, Bobbio P Dextran 40 at 2% versus 5% in

low-potassium solutions: which is best? Ann Thorac Surg

1994;58:1784–6.

37 Miyoshi S, Shimokawa S, Schreinemakers HH, et al.

Comparision of the University of Wisconsin perservation

solution and other crystalloid perfusates in a 30-hour

rab-bit lung preservation model J Thorac Cardiovasc Surg

1992;103:27–32.

38 Wagner FM, Jamieson SW, Fung J, et al A new concept for

successful long-term pulmonary preservation in a dog

model Transplantation 1995;59:1530–6.

39 Chien S, Zhang F, Niu W, et al Comparison of university

of wisconsin, euro-collins, low-potassium dextran, and

krebs-henseleit solutions for hypothermic lung

preserva-tion J Thorac Cardiovasc Surg 2000;119:921–30.

40 Roberts RF, Nishanian GP, Carey JN, et al A comparison

of the new preservation solution Celsior to Euro-Collins

and University of Wisconsin solutions in lung reperfusion

injury Transplantation 1999;67:152–5.

41 Wittwer T, Wahlers T, Fehrenbach A, et al Improvement of

pulmonary preservation with Celsior and Perfadex:

impact of storage time on early post-ischemic lung

func-tion J Heart Lung Transplant 1999;18:1198–201.

42 Keshavjee SH, McRitchie DI, Vittorini T, et al Improved

lung preservation with dextran 40 is not mediated by a

superoxide radical scavenging mechanism J Thorac

43 Kimbald PO, Sjoberg T, Massa G, et al High potassim

con-tents in organ preservation solutions cause strong

pul-monary vasocontraction Ann Thorac Surg

1991;52:523–8.

44 Fukuse T, Albes JM, Wilhelm A, et al Influence of dextrans

on lung preservation: is the molecular weight important? J

45 Sakamaki F, Goffmann H, Munzing S, et al Effects of lung

preservation solutions on PMN activation in vitro.

Transplant Int 1999;12:113–21.

46 Maccherini M, Keshavjee SH, Slutsky AS, et al The effect

of low-potassium-dextran versus Euro-Collins solution

for preservation of isolated type II pneumocytes.

Transplantation 1991;52:621–6.

47 Suzuki S, Inoue K, Sugita M, et al Effects of EP4 solution

and LPD solution vs Euro-Collins solution on

Na(+)/K(+)-ATPase activity in rat alveolar type II cells

and human alveolar epithelial cell line A549 cells J Heart

48 Struber M, Hohlfeld JM, Fraund S, et al Low-potassium

dextran solution ameliorates reperfusion injury of the

lung and protects surfactant function J Thorac Cardiovasc

Surg 2000;120:566–72.

49 Sakamaki F, Hoffmann H, Muller C, et al Reduced lipid

peroxidation and ischemia-reperfusion injury after lung

transplantation using low-potassium dextran solution for

lung preservation Am J Respir Crit Care Med

1997;156:1073–81.

50 Hopkinson DN, Odom JJ, Bridgewater BJ, Hooper TL University of Wisconsin solution for lung graft preservation: which components are important? J Heart Lung Transplant 1994;13:990–7.

51 Fischer S, Hopkinson D, Liu M, Keshavjee SH Raffinose improves the function of rat pulmonary grafts stored for twenty-four hours in low-potassium dextran solution J Thorac Cardiovasc Surg 2000;119:488–92.

52 Fischer S, Hopkinson D, Liu M, et al Raffinose improves 24-hour lung preservation in low potassium dextran glucose solution: a histologic and ultrastructural analysis Ann Thorac Surg 2001;71:1140–5.

53 Muller C, Furst H, Reichenspurner H, et al Lung ment by low-potassium dextran and the effect on preservation injury Munich Lung Transplant Group Transplantation 1999;68:1139–43.

procure-54 Struber M, Wilhelmi M, Harringer W, et al Flush sion with low potassium dextran solution improves early graft function in clinical lung transplantation Eur J Cardiothorac Surg 2001;19:190–4.

perfu-55 Fischer S, Matte-Martyn A, DePerrot M, et al potassium dextran preservation solution improves lung function after human lung transplantation J Thorac Cardiovasc Surg 2001;121:594–6.

Low-56 Haverich A, Aziz S, Scott WC, et al Improved lung vation using Euro-Collins solution for flush-perfusion Thorac Cardiovasc Surg 1986;34:368–76.

preser-57 Sasaki M, Muraoka R, Chiba Y, Hiramatu Y Influence of pulmonary arterial pressure during flushing on lung preservation Transplantation 1996;61:22–7.

58 Tanaka H, Chiba Y, Sasaki M, et al Relationship between flushing pressure and nitric oxide production in preserved lungs Transplantation 1998;65:460–4.

59 Andrade RS, Wangensteen OD, Jo JK, et al Effect of hypothermic pulmonary artery flushing on capillary filtration coefficient Transplantation 2000;70:267–71.

60 Kimbald PO, Sjoberg T, Steen S Pulmonary vascular tance related to endothelial function after lung transplantation Ann Thorac Surg 1994;58:416–20.

resis-61 Wang LS, Nakamoto K, Hsieh CM, et al Influence of perature of flushing solution on lung preservation Ann Thorac Surg 1993;55:711–5.

tem-62 Albes JM, Fischer F, Bando T, et al Influence of the fusate temperature on lung preservation: is there an opti- mum? Eur Surg Res 1997;29:5–11.

per-63 Steen S, Ingemansson R, Budrikis A, et al Successful plantation of lungs topically cooled in the non-heart-beating donor for 6 hours Ann Thorac Surg 1997;63:345–51.

trans-64 VanRaemdonck DE, Jannis NC, Rega FR, et al External cooling of warm ischemic rabbit lungs after death Ann Thorac Surg 1996;62:331–7.

65 Hall SM, Odom N, McGregor CG, Haworth SG Transient ultrastructural injury and repair of pulmonary capillaries

in transplanted rat lung: effect of preservation and fusion Am J Respir Cell Mol Biol 1992;7:49–57.

reper-Lung Preservation for Transplantation / 339

Trang 11

66 Steen S, Sjoberg T, Ingemansson R, Lindberg L Efficacy of

topical cooling in lung preservation: is a reappraisal due?

Ann Thorac Surg 1994;58:1657–63.

67 Toronto Lung Transplant Group Experience with

single-lung transplantation for pulmonary fibrosis JAMA

1988;259:2258–62.

68 Sakuma T, Takahashi K, Ohya N, et al

Ischemia-reperfusion injury in rabbits: mechanisms of injury and

protection Am J Physiol 1999;276:L137–45.

69 VanRaemdonch DE, Jannis NC, Rega FR, et al Extended

preservation of ischemic pulmonary graft by postmortem

alveolar expansion Ann Thorac Surg 1997;64:801–8.

70 Veith FJ, Sinha SB, Graves JS, et al Ischemic tolerance of

the lung The effect of ventilation and inflation J Thorac

71 Kuang JQ, VanRaemdonck DE, Jannis NC, et al.

Pulmonary cell death in warm ischemic rabbit lung is

related to the alveolar oxygen reserve J Heart Lung

Transplant 1998;17:406–14.

72 Date H, Matsumura A, Manchester JK, et al Changes in

alveolar oxygen and carbon dioxide concentration and

oxygen consumption during lung preservation The

main-tenance of aerobic metabolism during lung preservation J

Thorac Cardiovasc Surg 1993;105:492–501.

73 Fukuse T, Hirata T, Nnakamura T, et al Influence of

deflated and anaerobic conditions during cold storage on

rat lungs Am J Respir Crit Care Med 1999;160:621–7.

74 DeCampos KN, Keshavjee S, Liu M, Slutsky AS Optimal

inflation volume for hypothermic preservation of rat

lungs J Heart Lung Transplant 1998;17:599–607.

75 Sakuma T, Tsukano C, Ishigaki M, et al Lung deflation

impairs alveolar epithelial fluid transport in ischemic

rab-bit and rat lungs Transplantation 2000;69:1785–93.

76 Puskas JD, Hirai T, Christie N, et al Reliable thirty-hour

lung preservation by donor lung hyperinflation J Thorac

77 Baretti R, Bitu-Morsdorf J, Beyersdorf F, et al Distribution

of lung preservation solutions in parenchyma and airways:

influence of atelectasis and route of delivery J Heart Lung

Transplant 1995;14:80–91.

78 Aoe M, Okabayashi K, Cooper JD, Patterson GA.

Hyperinflation of canine lung allografts during storage

increases reperfusion pulmonary edema J Thorac

79 Haniuda M, Hasegawa S, Shiraishi T, et al Effects of

infla-tion volume during lung preservainfla-tion on pulmonary

cap-illary permeability J Thorac Cardiovasc Surg

1996;112:85–93.

80 Kayano K, Toda K, Naka Y, Pinsky DJ Identification of

optimal conditions for lung graft storage with

Euro-Collins solution by use of a rat orthotopic lung transplant

model Circulation 1999;100:II257–61.

81 Weder W, Harper B, Shimokawa S, et al Influence of intraalveolar oxygen concentration on lung preservation in

a rabbit model J Thorac Cardiovasc Surg 1991;101:1037–43.

82 Fukuse T, Hirata T, Hitomi S, Wada H Influence of lar gas during pulmonary preservation on reperfusion injury Transplant Proc 2000;32:334–5.

alveo-83 Haniuda M, Dresler CM, Mizuata T, et al Free mediated vascular injury in lungs preserved at moderate hypothermia Ann Thorac Surg 1995;60:1376–81.

radical-84 Fisher AB, Dodia C, Tan ZT, et al Oxygen-dependent lipid peroxidation during lung ischemia J Clin Invest 1991;88:674–9.

85 Ueno T, Yokomise H, Oka T, et al The effect of PGE1 and temperature on lung function following preservation Transplantation 1991;52:626–30.

86 Date H, Lima O, Matsumura A, et al In a canine model, lung preservation at 10 degrees C is superior to that at 4 degrees C A comparision of two preservation temperatures on lung function and on adenosine triphosphate level measured by phosphorus 31-nuclear magnetic reso- nance J Thorac Cardiovasc Surg 1992;103:773–80.

87 Mayer E, Puskas JD, Cardoso PF, et al Reliable hour lung preservation at 4 degrees and 10 degrees C by pulmonary artery flush after high-dose prostaglandin E1 administration J Thorac Cardiovasc Surg 1992;103:1136–42.

eighteen-88 Varela A, Montero C, Cordoba M, et al Clinical experience with retrograde lung preservation Transplant Int 1996;9:S296–8.

89 Wittwer T, Fehrenbach A, Meyer D, et al Retrograde flush perfusion with low-potassium solutions for improvement

of experimental pulmonary preservation J Heart Lung Transplant 2000;19:976–83.

90 Varela A, Montero CG, Cordoba M, et al Improved ution of pulmonary flush solution to the tracheobronchial wall in pulmonary transplantation Eur Surg Res 1997;29:1–4.

distrib-91 Chen CZ, Gallagher RC, Ardery P, et al Retrograde flush and cold storage for twenty-two to twenty-five hours lung preservation with and without prostaglandin E1 J Heart Lung Transplant 1997;16:658–66.

92 Parrott NR, Forsythe JL, Matthews JN, et al Late sion A simple remedy for renal allograft primary non- function Transplantation 1990;49:913–5.

perfu-93 Serrick CJ, Jamjoum A, Reis A, et al Amelioration of monary allograft injury by administering a second rinse solution J Thorac Cardiovasc Surg 1996;112:1010–6.

pul-94 Venuta F, Rendina EA, Bufi M, et al Preimplantation rograde pneumoplegia in clinical lung transplantation J Thorac Cardiovasc Surg 1999;118:107–14.

Trang 12

ret-95 Bhabra MS, Hopkinson DN, Shaw TE, et al Controlled

reperfusion protects lung grafts during a transient early

increase in permeability Ann Thorac Surg

1998;65:187–92.

96 Clark SC, Sudarshan C, Khanna R, et al Controlled

reper-fusion and pentoxifylline modulate reperreper-fusion injury

after single lung transplantation J Thorac Cardiovasc Surg

1998;115:1335–41.

97 Pierre AF, DeCampos KN, Liu M, et al Rapid reperfusion

causes stress failure in ischemic rat lungs J Thorac

98 Bhabra MS, Hopkinson DN, Shaw TE, Hooper TL Critical

importance of the first 10 minutes of lung graft

reperfu-sion after hypothermic storage Ann Thorac Surg

1996;61:1631–5.

99 DosSantos CC, Slutsky AS Invited review: Mechanisms of

ventilator-induced lung injury: a perspective J Appl

Physiol 2000;89:1645–55.

100 McRae K Con: lung transplantation should not be

rou-tinely performed with cardiopulmonary bypass J

Cardiothorac Vasc Anesth 2000;14:746–50.

101 DeCampos KN, Keshavjee S, Slutsky AS, Liu M Alveolar

recruitment prevents rapid-reperfusion-induced injury of

lung transplants J Heart Lung Transplant

1999;18:1096–102.

102 Cassivi SD, Liu M, Boehler A, et al Transgene expression

after adenovirus-mediated retransfection of rat lungs is

increased and prolonged by transplant

immunosuppres-sion J Thorac Cardiovasc Surg 1999;117:1–7.

103 Cassivi SD, Liu M, Boehler A, et al Transplant

immuno-suppression increases and prolongs transgene expression

following adenoviral-mediated transfection of rat lungs J

104 Cassivi SD, Cardella JA, Fischer S, et al Transtracheal gene

transfection of donor lungs prior to organ procurement

increases transgene levels at reperfusion and following

transplantation J Heart Lung Transplant 1999;18:1181–8.

105 Yano M, Hiratsuka M, Mora BN, et al Transfection of

pul-monary artery segments in lung isografts during storage.

106 Yano M, Mora BN, Ritter JM, et al Ex vivo transfection of

transforming growth factor-beta1 gene to pulmonary

artery segments in lung grafts J Thorac Cardiovasc Surg

1999;117:705–13.

107 Suda T, Mora BN, D’Ovidio F, et al In vivo

adenovirus-mediated endothelial nitric oxide synthase gene transfer

ameliorates lung allograft ischemia-reperfusion injury J

Thorac Cardiovasc Surg 2000;119:297–304.

108 Fischer S, Liu M, MacLean AA, et al In vivo transtracheal

adenovirus-mediated transfer of human interleukin-10

gene to donor lungs ameliorates ischemia-reperfusion

injury and improves early posttransplant graft function in

the rat Hum Gene Ther 2001;12:1513–26.

109 Wickersham NE, Johnson JJ, Meyrick BO, et al Lung ischemia-reperfusion injury in awake sheep: protection with verapamil J Appl Physiol 1991;71:1554–62.

110 Yokomise H, Ueno T, Yamazaki F, et al The effect and mal time of administration of verapamil on lung preservation Transplantation 1990;49:1039–43.

opti-111 Pickford MA, Gower JD, Dore C, et al Lipid peroxidation and ultrastructural changes in rat lung isografts after single-passage organ flush and 48-hour cold storage with and without one-hour reperfusion in vivo Transplantation 1990;50:210–8.

112 Pickford MA, Gower JD, Simpkin S, et al Function of gle rat lung isografts after 48-hour cold storage The effect

sin-of treatment with free radical antagonists and prostacyclin PGI2 Transplantation 1991;51:733–49.

113 Haverich A, Karck M Role of calcium channel blockers in postischemic lungs Ann N Y Acad Sci 1994;723:51–8.

114 McCord JM Oxygen-derived free radicals in postischemic tissue injury N Engl J Med 1985;312:159–63.

115 AlMehdi AB, Shuman H, Fisher AB Intracellular tion of reactive oxygen species during nonhypoxic lung ischemia Am J Physiol 1997;272:L294–300.

genera-116 Eckenhoff RG, Dodia C, Tan Z, Fisher AB dependent reperfusion injury in the isolated rat lung J Appl Physiol 1992;72:1454–60.

Oxygen-117 Fisher AB, Dodia C Lung as a model for evaluation of ical intracellular PO 2 and PCO Am J Physiol 1981;241:E47–50.

crit-118 Adkins WK, Taylor AE Role of xanthine oxidase and trophils in ischemia-reperfusion injury in rabbit lung J Appl Physiol 1990;69:2012–8.

neu-119 Kennedy TP, Rao NV, Hopkins C, et al Role of reactive oxygen species in reperfusion injury of the rabbit lung J Clin Invest 1989;83:1326–35.

120 Zhao G, AlMehdi AB, Fisher AB Anoxia-reoxygenation versus ischemia in isolated rat lungs Am J Physiol 1997;273:L1112–7.

121 AlMehdi AB, Zhao G, Dodia C, et al Endothelial NADPH oxidase as the source of oxidants in lungs exposed to ischemia or high K+ Circ Res 1998;83:730–7.

122 Davies PF, Tripathi SC Mechanical stress mechanisms and the cell An endothelial paradigm Circ Res 1993;72:239–45.

123 Lansman JB Endothelial mechanosensors Going with the flow Nature 1988;331:481–2.

124 AlMehdi AB, Zhao G, Fisher AB ATP-independent brane depolarization with ischemia in the oxygen-ventilated isolated rat lung Am J Respir Cell Mol Biol 1998;18:653–61.

mem-125 Wei Z, Costa K, AlMehdi AB, et al Simulated ischemia in flow-adapted endothelial cells leads to generation of reactive oxygen species and cell signaling Circ Res 1999;85:682–9.

Trang 13

126 Henderson LM, Chappell JB, Jones OT Superoxide

gener-ation by the electrogenic NADPH oxidase of human

neu-trophils is limited by the movement of compensating

charge Biochem J 1988;255:285–90.

127 Kitagawa S, Johnston RB Relationship between

mem-brane potential changes and superoxide-releasing capacity

in resident and activated mouse peritoneal macrophages J

Immunol 1985;135:3417–23.

128 Kelly RF Current strategies in lung preservation J Lab

Clin Med 2000;136:427–40.

129 Baker CJ, Longoria J, Gade PV, et al Addition of a

water-sol-uble alpha-tocopherol analogue to University of Wisconsin

solution improves endothelial viability and decreases lung

reperfusion injury J Surg Res 1999;86:145–9.

130 Ochs M, Nenadic I, Fehrenbach A, et al Ultrastructural

alterations in intraalveolar surfactant subtypes after

exper-imental ischemia and reperfusion Am J Respir Crit Care

Med 1999;160:718–24.

131 Veldhuizen RA, Lee J, Sandler D, et al Alterations in

pul-monary surfactant composition and activity after

experi-mental lung transplantation Am Rev Respir Dis

1993;148:208–15.

132 Erasmus ME, Petersen AH, Oetomo SB, Prop J The

func-tion of surfactant is impaired during the reimplantafunc-tion

response in rat lung transplants J Heart Lung Transplant

1994;13:791–802.

133 Andrade RS, Solien EE, Wangensteen OD, et al Surfactant

dysfunctionin lung preservation Transplantation

1995;60:536–41.

134 Casals C, Varela A, Ruano ML, et al Increase of C-reactive

protein and decrease of surfactant protein A in surfactant

after lung transplantation Am J Respir Crit Care Med

1998;157:43–9.

135 Ochs M, Fehrenbach H, Nenadic I, et al Preservation of

intraalveolar surfactant in a rat lung

ischaemia/reperfu-sion injury model Eur Respir J 2000;15:526–31.

136 Fehrenbach A, Ochs M, Warnecke T, et al Beneficial effect

of lung preservation is related to ultrastructural integrity

of tubular myelin after experimental ischemia and

reper-fusion Am J Respir Crit Care Med 2000;161:2058–65.

137 Ochs M, Fehrenbach H, Richter J Ultrastructure of canine

type II pneumocytes during hypothermic ischemia of the

lung: a study by means of conventional and energy

filter-ing transmission electron microscopy and stereology Anat

Rec 2001;263:118–26.

138 Klepetko W, Lohninger A, Wisser W, et al Pulmonary

sur-factant in bronchoalveolar lavage after canine lung

trans-plantation: effect of L-carnitine application J Thorac

139 Buchanan SA, Mauney MC, Parekh VI, et al Intratracheal

surfactant administration preserves airway compliance

during lung reperfusion Ann Thorac Surg

1996;62:1617–21.

140 Erasmus ME, Petersen AH, Hofstede G, et al Surfactant treatment before reperfusion improves the immediate function of lung transplants in rats Am J Respir Crit Care Med 1996;153:665–70.

141 Hohlfeld JM, Struber M, Ahlf K, et al Exogenous tant improves survival and surfactant function in ischaemia-reperfusion injury in minipigs Eur Respir J 1999;13:1037–43.

surfac-142 Struber M, Hirt SW, Cremer J, et al Surfactant ment in reperfusion injury after clinical lung transplantation Intensive Care Med 1999;25:862–4.

replace-143 Erasmus ME, Hofstede GJ, Petersen AH, et al Effects of early surfactant treatment persisting for one week after lung transplantation in rats Am J Respir Crit Care Med 1997;156:567–72.

144 Novick RJ, Veldhuizen RA, Possmayer F, et al Exogenous surfactant therapy in thirty-eight hour lung graft preservation for transplantation J Thorac Cardiovasc Surg 1994;108:259–68.

145 Struber M, Cremer J, Harringer W, et al Nebulized thetic surfactant in reperfusion injury after single lung transplantation J Thorac Cardiovasc Surg 1995;110:563–4.

syn-146 Fischer S, Cassivi SD, Xavier AM, et al Cell death in human lung transplantation: apoptosis induction in human lungs during ischemia and after transplantation Ann Surg 2000;231:424–31.

147 Fischer S, Maclean AA, Liu M, et al Dynamic changes in apoptotic and necrotic cell death correlate with severity of ischemia-reperfusion injury in lung transplantation Am J Respir Crit Care Med 2000;162:1932–9.

148 Yaoita H, Ogawa K, Maehara K, Maruyama Y Attenuation

of ischemia/reperfusion injury in rats by a caspase inhibitor Circulation 1998;97:276–81.

149 Hartmann A Antiapoptotic agents in brain ischemia N Engl J Med 2000;342:823.

150 Serrick C, Adoumie R, Giaid A, Shennib H The early release of interleukin-2, tumor necrosis factor-alpha and interferon-gamma after ischemia reperfusion injury in the lung allograft Transplantation 1994;58:1158–62.

151 Chang DM, Hsu K, Ding YA, Chiang CH Interleukin-1 in ischemia-reperfusion acute lung injury Am J Respir Crit Care Med 1997;156:1230–4.

152 Khimenko PL, Bagby GJ, Fuseler J, Taylor AE Tumor necrosis factor-alpha in ischemia and reperfusion injury in rat lungs J Appl Physiol 1998;85:2005–11.

153 Sekido N, Mukaida N, Harada A, et al Prevention of lung reperfusion injury in rabbits by a monoclonal antibody against interleukin-8 Nature 1993;365:654–7.

154 LeMoine O, Marchant A, Durand F, et al Systemic release

of interleukin-10 during orthotopic liver transplantation Hepatology 1994;20:889–92.

Trang 14

155 Kahlke V, Angele MK, Ayala A, et al Immune dysfunction

following trauma-haemorrhage: influence of gender and

age Cytokine 2000;12:69–77.

156 Lentsch AB, Yoshidome H, Kato A, et al Requirement for

interleukin-12 in the pathogenesis of warm hepatic

ischemia/reperfusion injury in mice Hepatology

1999;30:1448–53.

157 Daemen MA, van’t Veer C, Wolfs TG, Buurman WA.

Ischemia/reperfusion induced IFN-gamma up-regulation:

involvement of IL-12 and IL-18 J Immunol

1999;162:5506–10.

158 Heller A, Koch T, Schmeck J, vanAckern K Lipid

media-tors in inflammatory disorders Drugs 1998;55:487–96.

159 Shen CY, Wang D, Chang ML, Hsu K Protective effect of

mepacrine on hypoxia-reoxygenation-induced acute lung

injury in rats J Appl Physiol 1995;78:225–31.

160 Nagahiro I, Aoe M, Yamashita M, et al EPC-K1 is effective

in lung preservation in an ex vivo rabbit lung perfusion

model Ann Thorac Surg 1997;63:954–9.

161 Miotla JM, Jeffery PK, Hellewell PG Platelet-activating

factor plays a pivotal role in the induction of experimental

lung injury Am J Respir Cell Mol Biol 1998;18:197–204.

162 Nagase T, Ishii S, Kume K, et al Platelet-activating factor

mediates acid-induced lung injury in genetically

engi-neered mice J Clin Invest 1999;104:1071–6.

163 Kawahara K, Tagawa T, Takahashi T, et al The effect of the

platelet-activating factor inhibitor TCV-309 on

reperfu-sion injury in a canine model of ischemic lung.

164 Wahlers T, Hirt SW, Haverich A, et al Future horizons of

lung preservation by application of a platelet-activating

factor antagonist compared with current clinical

stan-dards Euro-Collins flush perfusion versus donor core

cooling J Thorac Cardiovasc Surg 1992;103:200–4;

discus-sion 5.

165 Qayumi AK, English JE, Duncan S, et al Extended lung

preservation with platelet-activating factor-antagonist

TCV-309 in combination with prostaglandin E1 J Heart

166 Qayumi AK, Jamieson WR, Poostizadeh A Effects of

platelet-activating factor antagonist CV-3988 in

preserva-tion of heart and lung for transplantapreserva-tion Ann Thorac

Surg 1991;52:1026–32.

167 Kim JD, Baker CJ, Roberts RF, et al Platelet activating

fac-tor acetylhydrolase decreases lung reperfusion injury Ann

Thorac Surg 2000;70:423–8.

168 Wittwer T, Grote M, Oppelt P, et al Impact of PAF

antag-onist BN 52021 (Ginkolide B) on post-ischemic graft

function in clinical lung transplantation J Heart Lung

Transplant 2001;20:358–63.

169 Grino JM BN 52021: a platelet activating factor antagonist

for preventing post-transplant renal failure A

double-blind, randomized study Ann Intern Med

1994;121:345–7.

170 Zamora CA, Baron DA, Heffner JE Thromboxane tributes to pulmonary hypertension in ischemia-reperfusion lung injury J Appl Physiol 1993;74:224–9.

con-171 Ljungman AG, Grum CM, Deeb GM, et al Inhibition of cyclooxygenase metabolite production attenuates ischemia- reperfusion lung injury Am Rev Respir Dis 1991;143:610–7.

172 Segiet W, Krieter H, Stieber C, et al Effect of nase inhibition in a canine model of unilateral pulmonary occlusion and reperfusion Intensive Care Med 1995;21:817–25.

cyclooxyge-173 Kukkonen S, Heikkila L, Verkkala K, et al Thromboxane receptor blockade does not attenuate pulmonary pressor response in porcine single lung transplantation J Heart Lung Transplant 1996;15:409–14.

174 Su M, Chi EY, Bishop JJ, Henderson WR Lung mast cells increase in number and degranulate during pulmonary artery occlusion/reperfusion injury in dogs Am Rev Respir Dis 1993;147:448–56.

175 Vural KM, Liao H, Oz MC, Pinsky DJ Effects of mast cell membrane stabilizing agents in a rat lung ischemia- reperfusion model Ann Thorac Surg 2000;69:228–32.

176 Moore TM, Khimenko P, Adkins WK, et al Adhesion ecules contribute to ischemia and reperfusion-induced injury in the isolated rat lung J Appl Physiol 1995;78:2245–52.

mol-177 Naka Y, Toda K, Kayano K, et al Failure to express the selectin gene or P-selectin blockade confers early pulmonary protection after lung ischemia or transplantation Proc Natl Acad Sci U S A 1997;94:757–61.

P-178 Reignier J, Sellak H, Lemoine R, et al Prevention of ischemia-reperfusion lung injury by sulfated Lewis(a) pentasaccharide The Paris-Sud University Lung Transplantation Group J Appl Physiol 1997;82:1058–63.

179 Schmid RA, Yamashita M, Boasquevisque CH, et al Carbohydrate selectin inhibitor CY-1503 reduces neutrophil migration and reperfusion injury in canine pulmonary allografts J Heart Lung Transplant 1997;16:1054–61.

180 Brandt M, Boeke K, Phillips ML, et al Effect of charides on rejection and reperfusion injury after lung transplantation J Heart Lung Transplant 1997;16:352–9.

oligosac-181 Horgan MJ, Ge M, Gu J, et al Role of ICAM-1 in trophil mediated lung vascular injury after occlusion and reperfusion Am J Physiol 1991;261:H1578–84.

neu-182 Toda K, Kayano K, Karimova A, et al Antisense lar adhesion moleule-1 (ICAM-1) oligodeoxyribonucleotide delivered during organ preservation inhibits post- transplant ICAM-1 expression and reduces primary lung isograft failure Circ Res 2000;86:166–74.

intercellu-183 Kapelanski DP, Iguchi A, Niles SD, Mao HZ Lung sion injury is reduced by inhibiting a CD18-dependent mechanism J Heart Lung Transplant 1993;12:294–306; discussion 7.

Trang 15

reperfu-184 Haug CE, Colvin RB, DelMonico FL, et al A phase I trial of

immunosuppression with anti-ICAM-1 (CD54) mAb in

renal allograft recipients Transplantation 1993;55:766–72.

185 Qayumi AK, Jamieson WR, Poostizadeh A, et al.

Comparison of new iron chelating agents in the

preven-tion of ischemia/reperfusion injury: a swine model of

heart-lung transplantation J Invest Surg 1992;5:115–27.

186 Hillinger S, Schmid RA, Stammberger U, et al Donor and

recipient treatment with the Lazaroid U-74006F do not

improve post-transplant lung function in swine Eur J

Cardiothorac Surg 1999;15:475–80.

187 Kuwaki K, Komatsu K, Sohma H, Abe T The effect of

var-ious doses of lazaroid U74389G on lung ischemia

reperfu-sion injury Thorac Cardiovasc Surg 1999;47:67–72.

188 Ogawa T, Mimura Y Antioxidant effect of zinc on acute

renal failure induced by ischemia-reperfusion injury in

rats Am J Nephrol 1999;19:609–14.

189 Vanacore RM, Eskew JD, Morales PJ, et al Role for copper

in transient oxidation and nuclear translocation of

MTF-1, but not of NF-kappa B, by the heme-hemopexin

trans-port system Antioxid Redox Signal 2000;2:739–52.

190 Soncul H, Kaptanoglu M, Oz E, et al The role of selenium

added to pulmonary preservation solutions in isolated

guinea pig lungs J Thorac Cardiovasc Surg

1994;108:922–7.

191 Ogawa S, Gerlach H, Esposito C, et al Hypoxia modulates

the barrier and coagulant function of cultured bovine

endothelium Increased monolayer permeability and

induction of procoagulant properties J Clin Invest

1990;85:1090–8.

192 Yoshimura N, Kobyashi Y, Nakamura K, et al The effect of

tissue factor pathway inhibitor on hepatic ischemic

reper-fusion injury of the rat Transplantation 1999;67:45–53.

193 Salvatierra A, Velasco F, Rodriguez M, et al C1-esterase

inhibitor prevents early pulmonary dysfunction after lung

transplantation in the dog Am J Respir Crit Care Med

1997;155:1147–54.

194 Struber M, Hagl C, Hirt SW, et al C1-esterase inhibitor in

graft failure after lung transplantation Intensive Care Med

1999;25:1315–8.

195 Fujita T, Toda K, Karimova A, et al Paradoxical rescue

from ischemic lung injury by inhaled carbon monoxide

driven by derepression of fibrinolysis Nat Med

2001;7:598–604.

196 Okada K, Fujita T, Minamoto K, et al Potentiation of

endogenous fibrinolysis and rescue from lung

ischemia/reperfusion injury in interleukin (IL)-10

recon-stituted IL-10 null mice J Biol Chem 2000;275:21468–76.

197 Akasaka S, Nishi H, Aoe M, et al The effects of

recombi-nant tissue-type plasminogen activator (rt-PA) on canine

cadaver lung transplantation Surg Today 1999;29:747–54.

198 Boscoe MJ, Goodwin AT, Amrani M, Yacoub MH Endothelins and the lung Int J Biochem Cell Biol 2000;32:41–62.

199 Shennib H, Serrick C, Saleh D, et al Plasma endothelin-1 levels in human lung transplant recipients J Cardiovasc Pharmacol 1995;26:S516–8.

200 Shennib H, Serrick C, Saleh D, et al Alterations in choalveolar lavage and plasma endothelin-1 levels early after lung transplantation Transplantation 1995;59:994–8.

bron-201 Okada M, Yamashita C, Okada M, Okada K Contribution

of endothelin-1 to warm ischemia/reperfusion injury of the rat lung Am J Respir Crit Care Med 1995;152:2105–10.

202 Shennib H, Lee AG, Kuang JQ, et al Efficacy of tering an endothelin-receptor antagonist (SB209670) in ameliorating ischemia-reperfusion injury in lung allografts Am J Respir Crit Care Med 1998;157:1975–81.

adminis-203 Mizutani H, Minamoto K, Aoe M, et al Expression of endothelin-1 and effects of an endothelin receptor antagonist, TAK-044, at reperfusion after cold preservation in a canine lung transplantation model J Heart Lung Transplant 1998;17:835–45.

204 Shaw MJ, Shennib H, Bousette N, et al Effect of lin receptor antagonist on lung allograft apoptosis and NOSII expression Ann Thorac Surg 2001;72:386–90.

endothe-205 Markewitz BA, Kohan DE, Michael JR Hypoxia decreases endothelin-1 synthesis by rat lung endothelial cells Am J Physiol 1995;269:L215–20.

206 Meyer KC, Love RB, Zimmerman JJ The therapeutic potential of nitric oxide in lung transplantation Chest 1998;113:1360–71.

207 Pinsky DJ, Naka Y, Chowdhury NC, et al The nitric oxide/cyclic GMP pathway in organ transplantation: critical role in successful lung preservation Proc Natl Acad Sci USA 1994;91:12086–90.

208 Liu M, Tremblay L, Cassivi SD, et al Alterations of nitric oxide synthase expression and activity during rat lung transplantation Am J Physiol Lung Cell Mol Physiol 2000;278:L1071–81.

209 Vainikka T, Heikkila L, Kukkonen S, Toivonen HJ Arginine in lung graft preservation and reperfusion J Heart Lung Transplant 2001;20:559–67.

L-210 Murakami S, Bacha EA, Mazmanian GM, et al Effects of various timings and concentrations of inhaled nitric oxide

in lung ischemia-reperfusion The Paris-Sud University Lung Transplantation Group Am J Respir Crit Care Med 1997;156:454–8.

211 Bhabra MS, Hopkinson DN, Shaw TE, Hooper TL dose nitric oxide inhalation during initial reperfusion enhances rat lung graft function Ann Thorac Surg 1997;63:339–44.

Trang 16

Low-212 Takeyoshi I, Otani Y, Yoshinari D, et al Beneficial effects of

novel nitric oxide donor (FK409) on pulmonary

ischemia-reperfusion injury in rats J Heart Lung Transplant

2000;19:185–92.

213 Yamashita M, Schmid RA, Ando K, et al Nitroprusside

ameliorates lung allograft reperfusion injury Ann Thorac

Surg 1996;62:791–6; discussion 6–7.

214 Fujino S, Nagahiro I, Yamashita M, et al Preharvest

nitro-prusside flush improves posttransplantation lung

func-tion J Heart Lung Transplant 1997;16:1073–80.

215 Bhabra MS, Hopkinson DN, Shaw TE, Hooper TL.

Attenuation of lung graft reperfusion injury by a nitric

oxide donor J Thorac Cardiovasc Surg 1997;113:327–33;

discussion 33–4.

216 Kawashima M, Bando T, Nakamura T, et al.

Cytoprotective effects of nitroglycerin in

ischemia-reper-fusion-induced lung injury Am J Respir Crit Care Med

2000;161:935–43.

217 Kayano K, Toda K, Naka Y, et al Superior protection in

orthotopic rat lung transplantation with cyclic adenosine

monophosphate and nitroglycerin-containing

preserva-tion solupreserva-tions J Thorac Cardiovasc Surg

1999;118:135–44.

218 Clark SC, Sudarshan C, Roughan J, et al Modulation of

reperfusion injury after single lung transplantation by

pentoxifylline, inositol polyanions, and sin-1 J Thorac

219 Hillinger S, Sandera P, Carboni GL, et al Survival and graft

function in a large animal lung transplant model after 30 h

preservation and substitution of the nitric oxide pathway.

Eur J Cardiothorac Surg 2001;20:508–13.

220 Eichert K, Hamacher J, Wunder MA, Wendel A Intravasal

peroxynitrite generation causes dysfunction in the isolated

perfused rat lung via endothelin J Pharmacol Exp Ther

2001;297:128–32.

221 Bhabra MS, Hopkinson DN, Shaw TE, Hooper TL.

Modulation of lung reperfusion injury by nitric oxide:

impact of inspired oxygen fraction Transplantation

1999;68:1238–43.

222 Eppinger MJ, Ward PA, Jones ML, et al Disparate effects of

nitric oxide on lung ischemia-reperfusion injury Ann

Thorac Surg 1995;60:1169–75.

223 Date H, Triantafillou AN, Trulock EP, et al Inhaled nitric

oxide reduces human lung allograft dysfunction J Thorac

224 Ardehali A, Laks H, Levine M, et al A prospective trial of

inhaled nitric oxide in clinical lung transplantation.

225 Meade M, Granton JT, Matte-Martyn A, et al A

random-ized trial of inhaled nitric oxide to prevent reperfusion

injury following lung transplantation J Heart Lung

Transplant 2001;20:254–5.

226 Naka Y, Roy DK, Liao H, et al cAMP-mediated vascular protection in an orthotopic rat lung transplant model Insights into the mechanism of action of prostaglandin E1

to improve lung preservation Circ Res 1996;79:773–83.

227 Aoe M, Trachiotis GD, Okabayashi K, et al Administration

of prostaglandin E1 after lung transplantation improves early graft function Ann Thorac Surg 1994;58:655–61.

228 DeCampos KN, Keshavjee SH, Liu M, Slutsky AS Prevention of rapid reperfusion-induced lung injury with prostaglandin E1 during the initial period of reperfusion.

J Heart Lung Transplant 1998;17:1121–8.

229 Matsuzaki Y, Waddell TK, Puskas JD, et al Amelioration of post-ischemic lung reperfusion injury by prostaglandin E1 Am Rev Respir Dis 1993;148:882–9.

230 Renz H, Gong JH, Schmidt A, et al Release of tumor necrosis factor-alpha from macrophages Enhancement and suppression are dose-dependently regulated by prostaglandin E2 and cyclic nucleotides J Immunol 1988;141:2388–93.

231 Tannenbaum CS, Hamilton TA induced gene expression in murine peritoneal macrophages is selectively suppressed by agents that ele- vate intracellular cAMP J Immunol 1989;142:1274–80.

Lipopolysaccharide-232 Himmelreich G, Hundt K, Neuhaus P, et al Evidence that intraoperative prostaglandin E1 infusion reduces impaired platelet aggregation after reperfusion in orthotopic liver transplantation Transplantation 1993;55:819–26.

233 Henley KS, Lucey MR, Normolle DP, et al A double-blind, randomize, placebo-controlled trial of prostaglandin E1 in liver transplantation Hepatology 1995;21:366–72.

234 Klein AS, Cofer JB, Bruiett TL, et al Prostaglanding E1 administration following orthotopic liver transplantation:

a randomized prospective multicenter trial Gastroenterology 1996;111:710–5.

235 Lockinger A, Schutte H, Walmrath D, et al Protection against gas exchange abnormalities by pre-aerosolized PGE1, iloprost and nitroprusside in lung ischemia- reperfusion Transplantation 2001;71:185–93.

236 Eppinger MJ, Deeb GM, Bolling SF, Ward PA Mediators of ischemia-reperfusion injury of rat lung Am J Pathol 1997;150:1773–84.

237 Fiser SM, Tribble CG, Long SM, et al Pulmonary macrophages are involved in reperfusion injury after lung transplantation Ann Thorac Surg 2001;71:1134–8; discussion 8–9.

238 Fiser SM, Tribble CG, Long SM, et al Lung transplant reperfusion injury involves pulmonary macrophages and circulating leukocytes in a biphasic response J Thorac Cardiovasc Surg 2001;121:1069–75.

239 Naka Y, Marsh HC, Scesney SM, et al Complement tion as a cause for primary graft failure in an isogenic rat model of hypothermic lung preservation and transplantation Transplantation 1997;64:1248–55.

activa-Lung Preservation for Transplantation / 345

Trang 17

240 Bishop MJ, Giclas PC, Guidotti SM, et al Complement

activation is a secondary rather than a causative factor in

rabbit pulmonary artery ischemia/reperfusion injury Am

Rev Respir Dis 1991;143:386–90.

241 Frank MM Complement in the pathophysiology of

human disease N Engl J Med 1987;316:1525–30.

242 Pierre AF, Xavier AM, Liu M, et al Effect of complement

inhibition with soluble complement receptor 1 on pig

allotransplant lung function Transplantation

1998;66:723–32.

243 Schmid RA, Zollinger A, Singer T, et al Effect of soluble

complement receptor type 1 on reperfusion edema and

neutrophil migration after lung allotransplantation in

swine J Thorac Cardiovasc Surg 1998;116:90–7.

244 Zamora MR, Davis RD, Keshavjee SH, et al Complement

inhibition attenuates human lung transplant reperfusion

injury: a multicenter trial Chest 1999;116:46S.

245 Stammberger U, Hamacher J, Hillinger S, Schmid RA.

sCR1sLe ameliorates ischemia/reperfusion injury in

experimental lung transplantation J Thorac Cardiovasc

Surg 2000;120:1078–84.

246 Levine AJ, Parkes K, Rooney S, Bonser RS Reduction of endothelial injury after hypothermic lung preservation by initial leukocyte-depleted reperfusion J Thorac Cardiovasc Surg 2000;120:47–54.

247 Ross SD, Tribble CG, Gaughen JR Jr, et al Reduced trophil infiltration protects against lung reperfusion injury after transplantation Ann Thorac Surg 1999;67:1428–33; discussion 1434.

neu-248 Deeb GM, Grum CM, Lynch MJ, et al Neutrophils are not necessary for induction of ischemia-reperfusion lung injury J Appl Physiol 1990;68:374–81.

249 Eppinger MJ, Jones ML, Deeb GM, et al Pattern of injury and the role of neutrophils in reperfuison injury of rat lung J Surg Res 1995;58:713–8.

250 Lu YT, Hellewell PG, Evans TW Ischemia-reperfusion lung injury: contribution of ischemia, neutrophils, and hydrostatic pressure Am J Physiol 1997;273:L46–54.

251 Steimle CN, Guynn TP, Morganroth ML, et al Neutrophils are not necessary for ischemia-reperfusion lung injury Ann Thorac Surg 1992; 53:64–72; discussion 73.

Trang 18

Immunosuppression for solid organ transplantation has

evolved over the past decade Corticosteroids and

azathioprine were the initial primary

immunosuppres-sive agents that were used in solid organ transplantation

in the late 1950s and the early 1960s However, it wasn’t

until the discovery of cyclosporine A that success rates

after solid organ transplantation truly began to rise Over

the past decade, further development of biologic agents

and newer immunosuppressive agents (tacrolimus,

mycophenolate mofetil, sirolimus) has continued to

improve outcomes after transplantation

Cyclosporin A

Cyclosporin A (CsA) is a natural, highly aliphatic cyclic

peptide that was initially isolated from the fungus

Tolypocladium inflatum Gams in 1979.1

Its pressive properties were subsequently discovered in 1972;

immunosup-however, it was not until the early 1980s that CsA gained

widespread use and, ultimately, revolutionized the

success of renal transplantation One-year renal graft

survival increased from approximately 50 to 90% with

the addition of CsA to the azathioprine and prednisone

based immunosuppressive regimen.2 In addition, the

advent of CsA has enabled liver, heart, and lung

trans-plantation to become a reality The unique structure of

CsA impacts upon its delivery system, absorptive

proper-ties, and dosing regimens

of activated T cells (NFAT) Therefore, CsA arrests thelymphocyte cell cycle in the early phase of activation(G0-G1 phase) Inhibition of NFAT blocks transcription

of other cytokine growth factors, including formation ofinterleukin (IL)-2, IL-3, IL-4, IL-5, tumor necrosis factor(TNF), and granulocyte macrophage colony stimulatingfactor as well as costimulatory molecules including CD40ligand Decreased elaboration of cytokines and growthfactors subsequently leads to decreased antigen recogni-tion and clonal expansion of lymphocytes.2 However,cytokines and growth factors may be elaborated by cellsother than T lymphocytes, which may account for refrac-tory rejection episodes on CsA

Pharmacology

The chemical structure of CsA, specifically, its aqueousinsolubility, has made reliable formulations and deliverysystems of this immunosuppressive medication more

Trang 19

complicated Two formulations of CsA currently exist in

the marketplace The initial oral formulation was an

oil-based formulation (Sandimmune) that resulted in

vari-able absorption due to dependence on bile flow and the

timing and nature of oral intake In addition, certain

patient populations including cystic fibrosis patients,

African Americans, and diabetics tend to absorb this

agent erratically More recently, a microemulsion

formu-lation of cyclosporine has been developed (Neoral) In

general, absorption of Neoral tends to be independent of

interactions with food and bile It has reduced the

intra-and interpatient variability compared with Sintra-andimmune

Both Sandimmune and Neoral are available in gel and

liquid capsules

The efficacy and safety profile of CsA correlate best

with the total drug exposure as measured by area under

the curve (AUC) However, because the technique of

obtaining AUC is cumbersome, most transplant

programs generally tend to dose CsA twice daily with

measurement of 12-hour trough levels Cyclosporine

trough levels are measured by either specific monoclonal

antibody (mAb) or high-pressure liquid

chromatogra-phy The latter is more cumbersome and is only

performed in specialized laboratories AUC

measure-ments with Sandimmune reveal slow absorption with

low peak concentrations and an overall decreased

bioavailability As a result, 12-hour trough levels for

Sandimmune tend to correlate poorly with drug

expo-sure meaexpo-sured by AUC (correlation coefficient r = 0.4).

On the other hand, Neoral has been shown to increase

peak concentration (Cmax) by more than 60% and

increase overall bioavailability by 30 to 50%.3Therefore,

12-hour trough levels for Neoral are more consistent

with AUC measurements (correlation coefficient r = 0.8).

Overall, Neoral has a more rapid, complete, and

consis-tent absorption compared with Sandimmune Recently,

two-point sampling (0 and 2 hours) of cyclosporine

levels showed a correlation of 95% with AUC

measure-ments This approach may be appropriate in those

patients with a greater heterogeneity of absorption of

cyclosporine.4In some programs, levels 2 hours postdose

are routinely measured, rather than the trough

Dosage and Administration

Induction and maintenance immunosuppression of CsA is

generally between 4 and 5 mg/kg/d orally in divided doses

If intravenous cyclosporine is necessary, the daily dose is

3 mg/kg/d via continuous infusion over 24 hours The

trough target levels during the first month after lung

trans-plant should be maintained between 350 and 500 ng/mL

during the first month, between 300 and 350 ng/mL during

the first year and between 200 and 300 ng/mL thereafter

Aerosolized CsA has been used in lung transplant recipients

with refractory acute rejection with the hope of increasingdrug delivery to the areas of rejection without increasingoverall systemic toxicity Although initial results appearpromising, further larger randomized studies are necessary

to confirm these preliminary findings

CsA is metabolized via the hepatic cytochrome P-450system Therefore any alteration of the P-450 systemeither by medications or hepatic dysfunction will result

in variable CsA trough levels In the presence of severehepatic dysfunction, CsA dosing should be withheld untilstabilization of hepatic function Additionally, severalmedications may interact with the P-450 system andresult in variability in CsA levels (Table 27-1) More care-ful monitoring of CsA levels is warranted if any of thesemedications are added to a patient’s regimen CsA should

be dose adjusted for renal dysfunction

There are several side effects and toxicities that areassociated with CsA The most significant side effect isnephrotoxicity Nephrotoxicity is dose related to CsA andhas been best described in renal transplantation Ingeneral, there appear to be three forms of renal injury due

to CsA The initial insult is intrarenal vasoconstrictionearly after transplantation The second form of injury isendothelial injury and microangiopathic hemolyticanemia, which usually occurs 2 to 3 weeks post-transplantation Occasionally, CsA-induced nephrotoxic-ity may manifest as a form of hemolytic uremicsyndrome Lastly, chronic renal dysfunction related toCsA may be the result of chronic interstitial fibrosis andarteriolar sclerosis associated with persistent deterioration

of renal function.5Other common side effects include hypertension,gingival hyperplasia, hypertrichosis, hyperkalemia, hyper-glycemia, hyperlipidemia, and elevated uric acid levels

TABLE 27-1A Drugs That May Increase Cyclosporine A Levels

Calcium Channel Blockers Antibiotics or Antifungals Other Diltiazem Erythromycin Colchicine Nicardipine Clarithromycin Cimetidine Verapamil Doxycycline Tacrolimus

Fluconazole Tamoxifen Itraconazole Metoclopramide Ketoconazole

TABLE 27-1B Drugs That May Decrease Cyclosporine A Levels

Anticonvulsants Antibiotics Other Carbamazepine Rifabutin Omeprazole Phenobarbital Rifampin Sulfinpyrazone Phenytoin Nafcillin

Trang 20

Neurological side effects are well-described, and range

from mild tremor to frank delirium and seizures

Gastrointestinal complications include dyspepsia, nausea,

and diarrhea may also occur with CsA Most side effects

are dose-related and improve with reduction of CsA dose

Tacrolimus

Tacrolimus (FK506, Prograf ) is a macrolide antibiotic

that was initially isolated from the soil microorganism

Streptomyces tsukubaensis in Northern Japan in 1984 Its

immunosuppressive properties were subsequently

dis-covered by Ochiai in 1985.6Further investigations at the

University of Pittsburgh and in Japan helped to define its

mechanism of action and its therapeutic benefit in solid

organ transplantation Tacrolimus was initially evaluated

as salvage therapy for refractory acute rejection and as an

alternate for CsA-induced toxicity Currently, tacrolimus

is being utilized as both a rescue agent and an alternative

to cyclosporine for primary immunosuppression after

solid organ transplantation

Mechanism of Action

Tacrolimus is a potent inhibitor of T lymphocyte

prolif-eration The mechanism of action for tacrolimus is very

similar to that of CsA Tacrolimus binds intracellularly

with cytoplasmic immunophilin, FK binding protein

(FKBP) The tacrolimus–FKBP complex then engages

and inhibits calcineurin, a calcium-dependent

phos-phatase Calcineurin inhibition prevents the

dephospho-rylation of NFAT; thereby, inhibiting the transcription of

several T cell growth cytokines Tacrolimus is

approxi-mately 100 times more potent than CsA However, when

administered to provide equivalent levels of calcineurin

inhibition, the efficacy of the two drugs is similar

Clinical Trials Involving Tacrolimus

The majority of multicenter clinical trials involving

tacrolimus were performed in liver and kidney

transplan-tation in the early 1990s In two large randomized trials

in liver transplantation, tacrolimus was found to be

supe-rior to CsA in decreasing the overall incidence of acute

rejection, the incidence of steroid resistant rejection and

the incidence of refractory rejection However, there was

no difference in patient or graft survival at 1 year

between the two groups Although there was no

differ-ence in the number of adverse events between tacrolimus

and CsA, the types of adverse events differed between the

two groups Neurotoxicity and glucose intolerance

seemed to be more prevalent in patients who received

tacrolimus, while hypertension and hyperlipidemia were

more apparent in patients treated with CsA.7,8

In addition, there have been several large multicenter

trials evaluating tacrolimus in renal and heart plantation There have been similar findings of a reduc-tion in the incidence of acute rejection with the use oftacrolimus in renal transplantation Again, there was nodemonstrable difference between tacrolimus and CsA inpatient or graft survival Adverse events and infectionrates were comparable with the two immunosuppressiveagents.9 Interestingly, neither of the two multicenterheart transplant studies comparing tacrolimus to CsAhas shown a significant decrease in acute or chronicrejection with the use of tacrolimus.10A limitation ofseveral of the trials is that tacrolimus was comparedwith Sandimmune, a formulation of CsA that has vari-able absorption compared with Neoral

trans-In lung transplantation, there has been only oneprospective randomized study comparing CsA andtacrolimus At the University of Pittsburgh 133 lungtransplant recipients (54 bilateral lung transplants and 79single lung transplants) were randomized to receiveeither CsA or tacrolimus The study demonstrated adecreased risk of obliterative bronchiolitis with a trendtowards decreased acute rejection with tacrolimuscompared with CsA There was no difference in survivalrates at 1 or 2 years between the two groups In addition,there was a slightly higher incidence of bacterial infec-tions in the CsA group and a higher incidence of fungalinfection in the tacrolimus group There were morepatients in the CsA arm who required crossover totacrolimus because of persistent rejection rather thanvice versa.11,12

Several small reports evaluate conversion from CsA totacrolimus in lung transplant recipients with refractoryacute rejection or chronic rejection These reportssuggest that tacrolimus may be beneficial in decreasingthe number of acute rejection episodes and, possibly,decreasing the rate of decline of pulmonary function inobliterative bronchiolitis These studies show promise forthe use of tacrolimus in lung transplantation Currently,approximately 20% of lung transplant programs usetacrolimus as primary immunosuppression in their lungtransplant recipients.13–15

Dosage and Administration

The suggested initial dosage for oral tacrolimus is 0.1 to0.15 mg/kg/d administered in divided doses Sincegastrointestinal absorption is bile-independent and isgenerally not affected by food intake, intravenousadministration is rarely required In certain situations,including in patients who remain on mechanical venti-lation in the early postoperative period and those whohave gastrointestinal difficulties, sublingual administra-tion may be useful by opening the capsule and placingthe powder under the tongue The sublingual dosing isModern Concepts of Immunosuppression for Lung Transplantation / 349

Trang 21

similar to the oral dosing regimen Preliminary studies

suggest similar absorption with sublingual

administra-tion compared with oral administraadministra-tion of tacrolimus

If intravenous tacrolimus becomes necessary in certain

situations, the current recommended intravenous

dosage is 0.01 to 0.05 mg/kg via continuous infusion

over 24 hours.16

Due to increased variability of absorption among

individuals, tacrolimus levels should be monitored

care-fully by measuring whole blood trough levels Target

levels should be 10 to 25 ng/mL for the first 2 weeks

post-transplantation, followed by levels of 10 to 20 ng/mL for

the next 6 to 10 weeks and 10 to 15 ng/mL thereafter

Appropriate dosing should be based upon evidence of

rejection, toxicity, and infection Since tacrolimus

bio-availability depends upon hepatic metabolism, patients

who develop hepatic dysfunction should have their levels

monitored more closely and decreased appropriately In

certain situations of sudden deterioration of liver

func-tion, tacrolimus should be withheld completely until

nontoxic levels have been reached Importantly, there are

several drug interactions that may increase or decrease

tacrolimus levels that may require more intensive

moni-toring (Table 27-2)

The most frequent adverse events associated with

tacrolimus include neuropathy, glucose intolerance, and

nephropathy Toxicity is clearly associated with higher

trough levels and may be treated with dose adjustments

In general, the most common side effects tend to be

minor neurotoxicity, including tremor and paresthesias

Other side effects include nausea, diarrhea, dyspepsia,

hypertension, hyperkalemia, hypomagnesemia, and more

severe neurological toxicities

Azathioprine

Developed in the 1960s, azathioprine (AZA) in

combina-tion with steroids transformed organ transplantacombina-tion

from an experimental science to an acceptable therapy

for end-stage organ disease The combination of CsA,

AZA, and prednisone has now become the primary

immunosuppressive regimen in many lung transplant

centers

AZA is an imidazole derivative of 6-mercaptopurine The

drug is well absorbed from the gastrointestinal tract and

is metabolized in vivo to mercaptopurine AZA acts as a

purine analog to inhibit deoxyribonucleic acid (DNA)

replication It also suppresses de novo purine synthesis

AZA inhibits the proliferation of T and B lymphocytes

and reduces the number of circulating monocytes

Dosing and Administration

The initial dose of AZA post-transplantation is 2 mg/kg/dgiven as a single oral dose For those unable to tolerateoral intake, AZA can be given intravenously at the samedose The dose may be titrated as necessary to keep thewhite blood cell count over 4,000/mm3 The main adverseeffects related to AZA are bone marrow suppression,gastrointestinal distress, and hepatic dysfunction

Mycophenolate Mofetil

Mycophenolate mofetil (MMF) is a prodrug that whenhydrolyzed by the liver produces the active compoundmycophenolic acid (MPA) Discovered in 1986, MPA didnot surface as an immunosuppressive agent until the early1990s Development of the drug was based on the princi-ple that defects of the de novo purine biosynthesis lead toimmunosuppression without affecting other tissues

MPA is a noncompetitive inhibitor of inosinemonophosphate dehydrogenase (IMPDH) The inhibi-tion of IMPDH blocks the conversion of inosinemonophosphate to xanthosine 5- monophosphate, therate limiting enzyme in the de novo synthesis of guano-sine monophosphate (GMP) Although resting lympho-cytes and other proliferating tissues can rely on thesalvage pathway for purine biosynthesis alone, T and Blymphocytes depend on both the salvage and the de novopathway for proliferation Therefore, by blocking the denovo pathway for GMP production, T and B lymphocyteclonal expansion is selectively inhibited Because of itsinhibition of both T and B lymphocytes, MMF has theadvantage that it inhibits cell-mediated immunity andhumoral immunity Since humoral immunity has been

TABLE 27-2A Drugs That May Increase Tacrolimus Blood Levels

Calcium Channel Blockers Antibiotics or Antifungals Other Diltiazem Clotrimazole Bromocriptine Nicardipine Erythromycin Cimetidine Verapamil Clarithromycin Cyclosporine

Fluconazole Danazol Itraconazole Metoclopramide Ketoconazole Grapefruit juice

TABLE 27-2B Drugs That May Decrease Tacrolimus Blood Levels

Anticonvulsants Antibiotics Other Carbamazepine Rifabutin Omeprazole Phenobarbital Rifampin Sulfinpyrazone Phenytoin

Trang 22

implicated in the development of chronic rejection, the

inhibition of B cell proliferation may be beneficial in the

prevention of bronchiolitis obliterans

Pharmacokinetics

MMF has double the bioavailability when compared with

MPA After conversion by the liver from MMF, MPA is

metabolized to the inactive metabolite mycophenolic

acid glucuronide, which is then excreted in the urine and

bile There is some enterohepatic circulation; however, it

is unclear how much will be converted back to the active

drug MPA is highly protein-bound and has a half-life of

approximately 16 to 18 hours Renal impairment does

not affect the pharmacokinetics of MPA, but it does

increase the levels of MPAG in the blood Dose

adjust-ment in renal failure has not been recommended

Clinical Trials

The effectiveness of MMF as an immunosuppressant

agent has been validated in renal and cardiac

transplanta-tion MMF in combination with a calcineurin inhibitor

(CI) has been shown to be effective for the prevention of

acute allograft rejection and for treatment of refractory

rejection in both of these groups There have been few

studies investigating the use of MMF in lung

transplanta-tion In a small non-randomized study, Ross and

colleagues compared MMF with azathioprine in

combi-nation with a CI and prednisone Their findings showed

a reduction in the episodes of acute rejection and better

spirometric function in the MMF-treated group There

was also a trend towards a decrease in the incidence of

bronchiolitis obliterans in the MMF-treated group.17

These results were supported by data from Zuckermann

and colleagues and O’Hair and coworkers, who also

reported a decrease in the rate of acute rejection when

using MMF as part of the immunosuppressive regimen

in lung transplant recipients.18,19These data along with

the renal and cardiac literature on MMF, suggest that the

drug may be superior to AZA in lung transplantation An

ongoing randomized multicenter trial will further

eluci-date the role of MMF in lung transplantation

Because of its specific effects on lymphocyte proliferation,

MMF was introduced as an immunosuppressive agent

with less toxicity than its predecessors Indeed it has no

renal or liver toxicity, no effect on lipids, and minimal

drug interactions The primary toxicities of MMF are

gastrointestinal and hematologic The most common

adverse reactions reported in renal transplant recipients

were abdominal pain, diarrhea, and leukopenia These

reactions appear to be dose-related Patients receiving

3 g/d of MMF were more likely to develop these adverse

effects when compared with the 2 g/d dose With regards

to infectious complications, MMF-treated patients may be

at increased risk for tissue invasive cytomegalovirus(CMV) than those treated with AZA It is unclear if thisrisk is higher in patients treated with the 3 g/d than inthose treated with the 2 g/d The incidence of malignancyappears to be comparable between AZA and MMF.20–22The required immunosuppressive dose of MMF isbetween 2 and 3 g/d in divided doses Studies on the use

of MMF in lung and renal transplantation support theuse of the 2 g/d dose since it is effective and has less toxi-city than MMF at 3 g/d No dose adjustment is necessary

in renal failure; however, the dose should be kept under

2 g/d in patients with a glomerular filtration rate lessthan 25 mL/min/1.73 m2

Corticosteroids

Corticosteroids (CS) have been an integral aspect ofimmunosuppression in solid organ transplantation sincethe inception of renal transplantation in the late 1950s

CS have been used as both induction and maintenanceimmunosuppressive therapy in solid organ transplanta-tion in conjunction with a combination of the CIs, AZA,and mycophenolate mofetil In addition, CS have beenutilized successfully as rescue therapy after episodes ofacute rejection While CS remain a mainstay of immuno-suppression in lung transplantation, several transplantcenters have minimized the dose of CS in order to atten-uate the toxicities of steroid use Currently, steroid with-drawal is not advocated in lung transplantation because

of the high risk of developing acute or chronic rejection

CS affects both leukocytes (lymphocytes, neutrophils, andmacrophages and monocytes) as well as endothelial cells

CS freely diffuse across cell membranes into cytes and bind to specific glucocorticoid receptors TheCS–glucocorticoid receptor complex then translocatesinto the nucleus and binds to glucocorticoid receptorelements (GREs) This interaction may either suppress orinduce the transcription of target genes In this way, CSinhibit the action of transcription factors activatorprotein 1 (AP-1) and nuclear factor kappa B (NFB).Inhibition of AP-1 represses the transcription of variouscytokines and growth factors, subsequently inhibiting TModern Concepts of Immunosuppression for Lung Transplantation / 351

Trang 23

leuko-cell and macrophage proliferation NFB, an important

regulator of cytokines and cell adhesion molecules, is also

a key factor in the immunosuppressive properties of CS

In addition, CS are potent anti-inflammatory agents as

manifested by inhibition of leukotrienes and

prostaglandins via a variety of different pathways.23

The most common steroid preparations in

transplanta-tion include oral prednisone, oral prednisolone,

intra-venous methylprednisolone, and intravenous

hydrocortisone In general, many transplant centers use

steroid induction therapy (methylprednisolone 500 to

1000 mg intravenously) intraoperatively prior to

implan-tation This dose is usually followed by a prednisone

taper This steroid taper generally begins with prednisone

0.25 mg/kg twice daily while in the hospital followed by

prednisone 40 mg/d for 2 weeks This dose is decreased

by 5 mg on a weekly basis to a final goal of prednisone

10 mg/d However, the initial dose of steroids and length

of steroid taper varies by center and type of transplanted

organ In lung transplantation, complete steroid

with-drawal is not recommended because of the high rates of

acute and chronic rejection

CS continue to be the most important first-line agent

in the treatment of acute rejection In general, once the

diagnosis of acute rejection is confirmed, typically

intra-venous methylprednisolone 500 to 1000 mg intraintra-venously

is administered for 3 days This dose is usually followed by

a rapid prednisone taper to the previous maintenance

dose of CS In cases of milder rejection, high dose

pred-nisone (80 to 100 mg/d) may be considered for

approxi-mately 7 to 10 days followed by a rapid steroid taper

The side effects of CS are numerous and are associated

with considerable morbidity CS have been associated with

Cushingoid features (acne, moon facies, buffalo hump,

truncal obesity), weight gain, fluid retention, diabetes

mellitus, peptic ulcer disease hypertension, cataracts,

emotion lability, osteoporosis, poor wound healing, and

growth retardation in children The side effects associated

with CS are clearly dose-related and may be attenuated by

decreasing the dose of CS whenever possible

Sirolimus

Sirolimus, an inhibitor of T lymphocyte activation and

proliferation, has been used successfully to prevent

allo-graft rejection in renal transplantation First discovered

in the mid-1970s, sirolimus was initially evaluated as an

antifungal medication Because of its effects on lymphoid

tissue, further research into its antifungal properties was

abandoned.24It was not until 1989 that researchers

real-ized its potential as an immunosuppressive agent.25,26

Sirolimus is a macrocyclic lactone produced by the

actin-omycete Streptomyces hygroscopicus It inhibits T cell

acti-vation and proliferation by a pathway distinct from otherimmunosuppressive medications Sirolimus binds toFKBP-12 inside cells to form an immunosuppressivecomplex This complex then binds to and inhibits theactivation of the mammalian target of rapamycin, a regu-latory kinase This inhibition prevents T cell proliferation

by inhibiting cell-cycle progression from the G1 to the Sphase In addition, sirolimus may also inhibit the prolif-eration of mesenchymal and endothelial cells.2 7 – 2 9Sirolimus is metabolized in the liver by the cytochromeP-450 system (CYP3A4) Data suggest that sirolimus mayhave synergistic immunosuppressive effects when used incombination with tacrolimus.30

The recommended dose of sirolimus is 2 mg/d givenorally once daily At our institution, we have opted not togive a loading dose when converting patients from anantimetabolite to sirolimus Serum drug levels ofsirolimus are available and can help with dosing Atpresent our target drug level is between 6 and 10 ng /mL

of blood with an associated reduction of the CI dose byone-third

The toxicities associated with sirolimus includeleukopenia, thrombocytopenia, rash, nausea, hyperlipi-demia, and mouth ulcers There have also been reports ofrenal transplant recipients developing interstitial pneu-monitis related to sirolimus Because of its interactionwith CsA and tacrolimus, patients on sirolimus may expe-rience adverse effects related to potentiation of the CI

Trang 24

Biologic Agents

The use of cytolytic therapy for immunosuppression

dates to the very beginnings of solid organ

transplanta-tion It has been used for both induction agents and for

treatment of acute rejection with a great deal of success

in kidney, liver, and heart transplantation These

suc-cesses, however, have not been as well demonstrated in

lung transplantation

In renal and liver transplantation the use of induction

immunosuppression is well established The incidence of

acute rejection has declined as antibody therapy has

evolved over the past two decades The introduction of

directed therapy with anti-CD25 mAbs has increased the

safety of induction immunosuppression without

sacrific-ing efficacy Similarly in heart transplant there is growsacrific-ing

support for biologic agents to prevent early acute rejection

The use of antibody therapy in lung transplantation

is much more controversial Lung transplantation

presents several unique problems not associated with

other solid organ transplants Infection is both more

commonplace and more severe CMV infection in

particular presents a more serious problem Antibody

therapy induces profound immunosuppression Patients

are more susceptible to Epstein-Barr virus and CMV,

which can cause pneumonia, acute rejection, chronic

rejection, and post-transplant lymphoproliferative

disease Although these problems are present in other

solid organ transplants, they present a greater dilemma

in lung transplantation Little literature about use in

lung transplantation exists and most knowledge is

derived from other solid organ transplants

Polyclonal Antibodies

The first induction agent used was antilymphocyte

serum (ALS) created by immunizing animals with

human lymphoid cells It was a very nonspecific agent

with low potency and significant toxicity This was

refined into several purified antilymphocyte and

antithymocyte immunoglobulin (Ig) preparations:

anti-lymphocyte globulin (ALG); antithymocyte globulin

(ATGAM, horse); Thymoglobulin, rabbit); and

Minnesota antilymphoblast globulin (MALG) Currently

only ATGAM and Thymoglobulin are commercially

available in the United States

Polyclonal antibodies act by inducing profound

gener-alized lymphocyte depletion The action is nonspecific

and is directed against a wide range of lymphocyte

surface antigens They have had considerable success in

the treatment of rejection, particularly steroid-resistant

rejection Several studies show significant reduction in

the incidence of acute rejection in renal and cardiac

allo-grafts with induction therapy.3 7 – 3 9 A double-blind

controlled trial comparing Thymoglobulin and ATGAM

in renal transplant recipients demonstrated the cant superiority of Thymoglobulin over ATGAM.39Therewere both a lower rate of acute rejection and increasedgraft survival in the Thymoglobulin group Palmer andcolleagues displayed a reduced incidence of acute rejec-tion in lung transplant recipients treated with rabbitantithymocyte globulin compared with patients treatedwith standard triple therapy.40 However, Wiebe andcolleagues found no difference in the incidence ofbronchiolitis obliterans (BO) in patients receiving induc-tion versus those who did not.41

signifi-These agents can be used for both induction and totreat acute rejection When used for induction, the firstdose is given intraoperatively before implantation of theallograft Both agents have half-lives of 2 to 7 days and aregiven as daily doses They must be infused through acentral venous catheter Skin testing is needed beforeusing ATGAM because of potential cross-reactivity to thehorse sera, but is not needed for Thymoglobulin.Following infusion, T-cell levels should be checked andthe dose increased if they are greater than 100/mL.Patients should have routine monitoring of blood counts.Treatment should be suspended if platelets fall below50,000/mL or if the white blood count falls below2,000/mL

The most significant toxicity can be attributed to therelease of TNF- , IL-1, IL-6, and interferon (IFN)-after the first dose This “cytokine release syndrome”causes fever, chills, diarrhea, nausea, and vomiting.Increased vascular permeability can result in significantfluid shifts causing pulmonary edema and hemodynamicinstability This can be prevented by prophylaxing withanti-inflammatory agents

In up to 30% of cases the recipient can form animmune response to the foreign antibodies The mostcommon consequence is a partial or complete negation ofthe beneficial effect depending on the strength of theimmune response The formation of anti-rabbit or anti-horse antibodies does not necessarily preclude continueduse Serum sickness is relatively rare, which is likely a result

of the combination of steroids and other sive agents given with the sera Serum sickness is treated bydiscontinuing the agent and infusing high-dose steroids

immunosuppres-Anti-CD3 Monoclonal Antibodies

Kohler and Milstein created muromonab-CD3 byproducing a murine myeloma and human B cellhybridoma that manufactured IgG2a mAb (OKT3) Thisantibody targets the epsilon ()chain of the CD3 in theCD3–T cell antigen receptor (TCR) complex It activates alarge number of T cells, releasing massive amounts ofcytokines There is a rapid depletion of T cells caused byModern Concepts of Immunosuppression for Lung Transplantation / 353

Trang 25

cytolysis and sequestration in the reticuloendothelial

system Binding to the CD3–TCR OK may also induce

apoptosis in activated T cells Muromonab induces

anti-genic modulation by internalizing the CD3–TCR

complex The reexpressed CD3–TCR molecule is

nonfunctional The result of these actions is a profound

immunosuppression in patients receiving therapy

The introduction of OKT3 created the ability to delay

CsA therapy, reducing the risk of nephrotoxicity in the

fresh transplant A large multicenter trial comparing

OKT3 plus triple drug therapy with standard triple

ther-apy in renal transplants showed that the OKT3-treated

patients had delayed onset to first rejection episode, fewer

rejection episodes, and fewer patients with multiple

rejec-tion episodes.42It also was used successfully to treat acute

rejection and in particular steroid-resistant acute rejection

These results have been repeated in liver and cardiac

trans-plants It became a standard for both prophylaxis for and

treatment of acute rejection in the 1980s and early 1990s

Early trials in lung transplantation were limited to

single-center retrospective analyses of OKT3 with and

without historical control subjects Ross and colleagues

reported a longer latency to the development of BO with

OKT3 when compared with historical control subjects

using MALG or rabbit antithymocyte globulin (RATG).43

Wain and colleagues reported a decreased incidence of

acute rejection in OKT3 treated recipients compared

with historical control subjects who received no

induc-tion therapy.44

Like polyclonal preparations, OKT3 is given as a daily

infusion Its peak response is within 2 to 3 hours of

infu-sion Therapy should be monitored by measuring drug

levels or, more commonly, by measuring CD3 levels The

goal is to achieve CD3 counts of 10 to 25 cells/mL Like

polyclonal antibodies, patients should be pretreated with

steroids, antihistamines, and acetaminophen

The toxicities of OKT3 are similar to polyclonal

anti-bodies Cytokine release following the first dose can cause

hemodynamic insufficiency, pulmonary edema, renal

fail-ure, and encephalopathy It can be more pronounced than

with polyclonal agents Close attention should be paid to

fluid status in an effort to avoid pulmonary edema, and

patients frequently need treatment with diuretics

Treatment includes discontinuation of the drug,

high-dose steroids, and occasionally anti-TNF mAbs

Another complication is the formation of human

anti-mouse antibodies (HAMAs) The incidence is 30 to

50% but clinical effects are less frequent Assays should

be drawn 3 to 4 weeks after treatment is initiated The

main effect is the interference of the anti-OKT3

antibod-ies with the drug This response is attenuated, but not

eliminated, by the use of other immunosuppressants in

conjunction with OKT3 Retreatment of patients who are

HAMA-positive is typically ineffective, and patientsshould be assayed prior to starting

Anti-CD25 Monoclonal Antibodies

Great promise has more recently been shown in the use

of anti-CD25 mAbs for induction They offer severaladvantages over both polyclonal and OKT3 therapy Theyare more specific inhibitors of T cell proliferation and donot interact with the entire T cell population Two agentsare currently available, daclizumab (Zenapax), amurine–human hybrid mAb, and basiliximab (Simulect),

a chimeric human mAb They are currently the onlyagents approved by the US Food and DrugAdministration for the induction of immunosuppression

in transplantation

The T cell activating antigen serves as the primaryreceptor for IL-2 to induce T cell activation and subse-quent proliferation It has three subunits,, , and expressed on the cell surface IL-2 binds to and subunits and transforms it from a low-affinity to a high-affinity receptor Anti-CD25 mAbs bind to the subunitand inhibit this transformation The antigen-presentingcell is thus inactivated, and T-cell proliferation is inhib-ited

Multiple studies have shown that daclizumab is cious in reducing the incidence of acute rejection in renal,liver, and heart allografts with limited toxicity.4 1 – 4 7Langrehr and colleagues showed that daclizumab hasequal efficacy with both OKT3 and antithymocyte globu-lin in reducing the incidence of acute rejection in livertransplants with a safer side effect profile.48 Data on theuse of anti-CD25 mAbs in lung transplant is sparse Mostrecently, Brock and colleagues prospectively comparedpatients treated with a cyclosporine-based regimen andeither ATGAM, OKT3, or daclizumab They demon-strated equal efficacy in preventing acute rejection amongthe three agents.49Garrity and colleagues reported asignificantly decreased incidence of acute rejection in lungallografts receiving a tacrolimus-based regimen withdaclizumab when compared with historical controlsubjects that received a tacrolimus-based regimen withoutinduction therapy.50There was no difference in the rate ofinfection or post-transplant lymphoproliferative disease.Both agents have relatively long half-lives and can bedosed less frequently Daclizumab can be given intraop-eratively and then biweekly and basiliximab intraopera-tively and then weekly Because they only block a specificsegment of the immune cascade, they should be given as

effica-an adjunct to steffica-andard triple-drug therapy There are nolevels to monitor Because both drugs are humanizedmAbs, there is no risk of cross-reactivity

Trang 26

1 Wenger RM Structures of cyclosporine and its metabolites.

Transplant Proc 1990;22:1104–9.

2 Kahan BD Cyclosporine N Engl J Med 1989;321:1725–38.

3 Kovarik JM, Mueller EA, van Bree JB, et al Reduced

inter-and intraindividual variability in cyclosporine

pharmacoki-netics from a microemulsion formulation J Pharmaceut Sci

1994;83:444–6.

4 Keown P, Landsberg D, Halloran P, et al A randomized

prospective multicenter pharmacoepidemiologic study of

cyclosporine microemulstion in stable renal graft

recipi-ents Report of the Canadian Neoral Renal Transplantation

Study Group Transplantation 1996;62:1744–52.

5 Goldstein DJ, Zuech N, Sehgal V, et al

Cyclosporine-associated end stage nephropathy after cardiac

transplanta-tion Transplantion 1997;63:664–8.

6 Kino T, Hatanaka H, Miyata S, et al FK-506, a novel

immunosuppressant isolated from a Streptomyces II.

Immunosuppressive effect of FK-506 in vitro J Antibiotics

1987;40:1256–65.

7 The US Multicenter FK506 Liver Study Group A comparison

of tacrolimus (FK506) and cyclosporine for

immunosuppres-sion in liver transplantation N Engl J Med 1994;331:1110–5.

8 European FK506 Multicentre Liver Study Group.

Randomized trial comparing tacrolimus (FK506) and

cyclosporine in prevention of liver allograft rejection.

Lancet 1994;344:423–8.

9 European Tacrolimus Multicenter Renal Study Group.

Multicenter randomized trial comparing tacrolimus

(FK-506) in the prevention of renal allograft rejection.

10 Reichart B, Meiser B, Vigano M, et al European Multicenter

Tacrolimus (FK506) Heart Pilot Study: one year results—

European Tacrolimus Multicenter Heart Study Group J

11 Keenan RJ, Konishi H, Kawai et al Clinical trial of

tacrolimus versus cyclosporine in lung transplantation.

12 Keenan RJ, Dauber JH, Iacono AT, et al Long-term

follow-up clinical trial of tacrolimus versus cyclosporine in lung

transplantation J Heart Lung Transplant 1998;17:59A.

13 Ross DJ, Lewis MI, Kramer M, et al FK 506 ‘rescue’

immunosuppression for obliterative bronchiolitis after lung

transplantation Chest 1997;112:1175–9.

14 Horning NR, Lynch JP, Patterson GA, et al Tacrolimus

rescue therapy for persistent or recurrent acute lung

allo-graft rejection J Heart Lung Transplant 1998;17:761–7.

15 Onsanger DR, Love RB, Jahania MS, et al Efficacy of

tacrolimus in the treatment of refractory rejection in heart

and lung transplant recipients J Heart Lung Transplant

1999;18:448–55.

16 Garrity ER, Hertz MI, Trulock EP, et al Suggested lines for the use of tacrolimus in lung transplant recipients.

guide-J Heart Lung Transplant 1999;18:175–6.

17 Ross DJ, Waters PF, Levine M, et al Mycophenolate mofetil versus azathioprine immunosuppressive regimens after lung transplantation: preliminary experience J Heart Lung Transplant 1998;17:768–74.

18 Zuckermann A, Klepetko W, Birsan T, et al Comparison between mycophenolate mofetil and azathioprine based immunosuppressions in clinical lung transplantation J Heart Lung Transplant 1999;18:423–40.

19 O’Hair DP, Cantu E, McGregor C, et al Preliminary ence with mycophenolate mofetil used after lung transplantation J Heart Lung Transplant 1998;17:864–8.

experi-20 European Mycophenolate Mofetil Cooperative Study Group Placebo controlled study of mycophenolate mofetil combined with cyclosporin and steroids for prevention of acute rejection Lancet 1995;345:1321–5.

21 The Tricontinental Mycophenolate Mofetil Renal Transplantation Study Group A blinded, randomized clinical trial of mycophenolate mofetil for the prevention of acute rejection in cadaveric renal transplantation Transplantation 1996;61:1029–37.

22 Sollinger HW, for the US Renal Transplant Mycophenolate Mofetil Study Group Mycophenolate mofetil for the prevention of acute rejection in primary cadaveric renal allograft recipients Transplantation 1995;60:225–32.

23 Schimmer BP, Parker KL Adrenocorticotrophic hormone; adrenocortical steroids and their synthetic analogs; inhibitors of the synthesis and actions of adrenocortical hormones In: Hardman JG, Goodman Gilman A, Limbard

LE, editors Goodman and Gilman’s the pharmacological basis of therapeutics 9th ed New York: McGraw Hill; 1996.

27 Cao W, Mohacsi P, Shorthouse R, et al Effects of rapamycin

on growth factor-stimulated vascular smooth muscle cell DNA synthesis Inhibition of basic fibroblast growth factor and platelet-derived growth factor action and antagonism

of rapamycin by FK506 Transplantation 1995;59:390–5.

28 Gregory CR, Huang X, Pratt RE, et al Treatment with rapamycin and mycophenolic acid reduces arterial intimal thickening produced by mechanical injury and allows endothelial replacement Transplantation 1995;59:655–61.

29 Akselband Y, Harding MW, Nelson PA Rapamycin inhibits spontaneous and fibroblast growth factor beta-stimulated proliferation of endothelial cells and fibroblasts Transplantation Proceedings 1991;23:2833–6.

Modern Concepts of Immunosuppression for Lung Transplantation / 355

Tiêu đề	Advanced Therapy in Thoracic Surgery - Part 7 PPS
Trường học	University of Example
Chuyên ngành	Thoracic Surgery
Thể loại	lecture notes
Năm xuất bản	2023
Thành phố	Sample City

Định dạng
Số trang	52
Dung lượng	843,09 KB