Chapter 126. Infections in Transplant Recipients (Part 1) pdf

Infections in Transplant Recipients Part 1 Harrison's Internal Medicine > Chapter 126.. Infections in Transplant Recipients Infections in Transplant Recipients: Introduction The eval

Chapter 126 Infections in Transplant Recipients

(Part 1)

Harrison's Internal Medicine > Chapter 126 Infections in Transplant

Recipients

Infections in Transplant Recipients: Introduction

The evaluation of infections in transplant recipients involves consideration

of both the donor and the recipient of the transplanted organ Infections following transplantation are complicated by the use of drugs that are necessary to enhance the likelihood of survival of the transplanted organ but that also cause the host to

be immunocompromised Thus, what might have been a latent or asymptomatic infection in an immunocompetent donor or in the recipient prior to therapy can

become a life-threatening problem when the recipient becomes immunosuppressed

Pretransplantation Evaluation

A variety of organisms have been transmitted by organ transplantation (Table 126-1) Careful attention to the sterility of the medium used to process the organ combined with meticulous microbiologic evaluation reduces rates of transmission of bacteria that may be present or grow in the organ culture medium From 2% to >20% of donor kidneys are estimated to be contaminated with bacteria—in most cases, with the organisms that colonize the skin or grow in the tissue culture medium used to bathe the donor kidney while it awaits implantation The reported rate of bacterial contamination of transplanted stem cells (bone marrow, peripheral blood, cord blood) is as high as 17% but is most commonly

~1% The use of enrichment columns and monoclonal-antibody depletion procedures results in a higher incidence of contamination In one series of patients receiving contaminated products, 14% had fever or bacteremia, but none died Results of cultures performed at the time of cryopreservation and at the time of thawing were helpful in guiding therapy for the recipient

Table 126-1 Organisms Transmitted by Organ Transplantation and Their Primary Sites of Reactivation Diseasea

Bl

ood

L ungs

H eart

B rain

Liver/S pleen

S kin

Viruses

Cytomega

lovirusb

Epstein-Barr virusc

Herpes

simplex virus

Human

herpesvirus type 6

Kaposi's

sarcoma–

associated

herpesvirus

Hepatitis

B and C viruses

Rabies

virusd

West Nile

virus

Fungi

Candida

albicans

Histoplas

ma capsulatum

Cryptococ

cus neoformans

Parasites

Toxoplas

ma gondii e

Strongyloi

des stercoralis f,g

Trypanoso

ma cruzi g

Plasmodiu

m falciparum g

Prion Diseases

Creutzfeld

t-Jakob disease

(CJD)h

Variant

CJD/bovine

spongiform

encephalopathyi

a

+, well documented; ±, probably occurs

b

Cytomegalovirus reactivation is prone to occur in the transplanted organ The same may be true for Kaposi's sarcoma–associated herpesvirus

c

Epstein-Barr virus reactivation usually presents as an extranodal proliferation of transformed B cells and can be present either as a diffuse disease

or as a mass lesion in a single organ

d

Rabies virus has been transmitted through corneal transplants

e

T gondii usually causes disease in the brain In hematopoietic stem cell

transplant recipients, acute pulmonary disease may also occur Heart transplant recipients develop disease in the allograft

f

Strongyloides "hyperinfection" may present with pulmonary disease—

often associated with gram-negative bacterial pneumonia

g

While transmission with organs has been described, it is unusual

h

CJD (sporadic and familial) has been transmitted with corneal transplants Whether it can be transmitted with blood is not known

i

Variant CJD can be transmitted with transfused non-leukodepleted blood, posing a theoretical risk to transplant recipients