Chapter 102. Aplastic Anemia, Myelodysplasia, and Related Bone Marrow Failure Syndromes (Part 12) pot

Aplastic Anemia, Myelodysplasia, and Related Bone Marrow Failure Syndromes Part 12 Pure Red Cell Aplasia: Treatment History, physical examination, and routine laboratory studies may d

Chapter 102 Aplastic Anemia, Myelodysplasia, and

Related Bone Marrow Failure Syndromes

(Part 12)

Pure Red Cell Aplasia: Treatment

History, physical examination, and routine laboratory studies may disclose

an underlying disease or a suspect drug exposure Thymoma should be sought by radiographic procedures Tumor excision is indicated, but anemia does not necessarily improve with surgery The diagnosis of parvovirus infection requires detection of viral DNA sequences in the blood (IgG and IgM antibodies are commonly absent) The presence of erythroid colonies has been considered predictive of response to immunosuppressive therapy in idiopathic PRCA

Red cell aplasia is compatible with long survival with supportive care alone: a combination of erythrocyte transfusions and iron chelation For persistent B19 parvovirus infection, almost all patients respond to intravenous immunoglobulin therapy (for example, 0.4 g/kg daily for 5 days), although relapse and retreatment may be expected, especially in patients with AIDS The majority

of patients with idiopathic PRCA respond favorably to immunosuppression Most

first receive a course of glucocorticoids Also effective are cyclosporine, ATG, azathioprine, cyclophosphamide, and the monoclonal antibodydaclizumab, an antibody to the IL-2 receptor PRCA developing on erythropoietin therapy should

be treated with immunosuppression and withdrawal of erythropoietin

Myelodysplasia

Definition

The myelodysplasias (MDSs) are a heterogeneous group of hematologic disorders broadly characterized by cytopenias associated with a dysmorphic (or abnormal appearing) and usually cellular bone marrow, and by consequent ineffective blood cell production A clinically useful nosology of these entities was first developed by the French-American-British Cooperative Group in 1983 Five entities were defined: refractory anemia (RA), refractory anemia with ringed sideroblasts (RARS), refractory anemia with excess blasts (RAEB), refractory anemia with excess blasts in transformation (RAEB-t), and chronic myelomonocytic leukemia (CMML) The World Health Organization classification (2002) recognizes that the distinction between RAEB-t and acute myeloid leukemia is arbitrary and groups them together as acute leukemia, notes that CMML behaves as a myeloproliferative disease, and separates refractory anemias with dysmorphic change restricted to erythroid lineage from those with multilineage changes (Table 102-5)

Table 102-5 World Health Organization Classification of Myelodysplastic Syndromes

ncy

Blood Findings

Bone Marrow Findings

Prognos

is

Refractory

anemia (RA)

No or rare blasts

Erythro

id dysplasia only

<5%

blasts

<15%

ringed sideroblasts

Protract

ed course

Leukem

ic transformation

in ~6%

Refractory

anemia with ringed

sideroblasts

No blasts

Erythro

id dysplasia only

Protract

ed course

Leukem

(RARS) ≥15%

ringed sideroblasts

<5%

blasts

ia in ~1–2%

Refractory

cytopenia with

multilineage

dysplasia (RCMD)

nias (2 or 3 lineages)

No or rare blasts

No Auer rods

<1 x

109/L monocytes

Dysplas

ia in ≥10% of cells in ≥2 lineages

<5%

blasts

No Auer rods

<15%

ringed sideroblasts

Variable clinical course

Leukem

ia in ~11%

ringed sideroblasts

(RCMD-RS)

nias (2 or 3 lineages)

No or rare blasts

No Auer rods

<1 x

109/L monocytes

ia in ≥10% of cells in ≥2 lineages

≥15%

ringed sideroblasts

<5%

blasts

No Auer rods

Refractory

anemia with excess

blasts-1 (RAEB-1)

40%

(RAEB-1 +2)

Cytope nias

<5%

blasts

No Auer rods

<1 x

Uniline

multilineage dysplasia

5–9%

blasts

No

Progress ive BM failure

Leukem

ia in ~25%

109/L monocytes

Auer rods

Refractory

anemia with excess

blasts-2 (RAEB-2)

nias

5–19%

blasts

±Auer rods

<1 x

109/L monocytes

Uniline

multilineage dysplasia

10–

19% blasts

±Auer rods

Progress ive BM failure

Leukem

ia in ~33%

Myelodyspl

astic syndrome,

unclassified

(MDS-U)

Unkno

wn

Cytope nias

No or rare blasts

No

Dysplas

ia in myeloid

or platelet lineage

<5%

blasts

Unknow

n

Auer rods No

Auer rods

MDS with

isolated del(5q)

Unkno

wn

Anemia

<5%

blasts

Platelet

increased

Nl or increased megakaryocyt

hypolobated nuclei

<5%

blasts

No Auer rods

Isolated del(5q)

Long survival

Note: BM, bone marrow

Source: Extracted from Jaffe ES et al (eds): Pathology and Genetics of

Tumors of Haematopoietic and Lymphoid Tissues Lyon, IARC Press, 2001