Pure Red Cell Aplasia

Acquired disease is rare; in adults, it is usually idiopathic

Cases have been seen in association with systemic lupus erythematosus, chronic lymphocytic leukemia (CLL), lymphomas, or thymoma

Some drugs (phenytoin, chloramphenicol) may cause red cell aplasia

Rarely, anti-erythropoietin antibodies cause pure red cell aplasia in patients who are treated with recombinant erythropoietin

The only signs are those of anemia unless the patient has an associated autoimmune or lymphoproliferative disorder

Transient episodes of red cell aplasia are probably common in response to viral infections, especially parvovirus infections

Acute episodes go unrecognized unless the patient has a chronic hemolytic disorder or a chronic immunocompromised state, in which case the hematocrit may fall precipitously

Anemia is often severe and normochromic, with low or absent reticulocytes

Red blood cell morphology is normal, and the myeloid and platelet lines are unaffected

Bone marrow

• Normocellular with markedly reduced or absent erythroid progenitors

• All non-erythroid elements are present and normal

The bone marrow karyotype is normal on standard banding cytogenetics

Chest imaging may reveal a thymoma

Possible offending drugs should be stopped

Most patients will require red blood cell transfusion support

Resection of thymoma may result in amelioration of anemia

High-dose intravenous immune globulin has produced responses in a small number of cases, mainly during parvovirus infections

Treatment of choice for idiopathic cases is immunosuppressive therapy with a calcineurin inhibitor (ie, cyclosporine)

Monotherapy with corticosteroids produce responses in 30–60% of cases, but relapses are common once corticosteroids are discontinued

Anti-CD20 monoclonal antibody (rituximab) is the treatment of choice in the setting of anti-erythropoietin antibodies

In patients with an associated lymphoproliferative disorder, treating the neoplasm should also treat the anemia