Refractory anemia in human immunodeficiency virus: Expect the unexpected.

Pure red cell aplasia (PRCA) is an uncommon hematological disorder affecting selectively the erythroid cell lines. PRCA is defined as anemia with normal leukocyte and platelet counts, a corrected reticulocyte count <1%, <5% erythroid precursors in the bone marrow and an absence of hemolysis. We describe a case of Zidovudine (AZT) induced PRCA causing severe anemia in a patient taking antiretroviral therapy (ART) after 4 months of starting therapy and in whom all other causes were excluded. The hematological abnormalities resolved after AZT was replaced with tenofovir and the patient remained transfusion independent thereafter. A slowly progressive normocytic-normochromic anemia and reticulocytopenia, without leukopenia and thrombocytopenia in a patient, should raise the suspicion of PRCA. Search for underlying diseases, infections and drugs may help in the diagnosis and etiology of acquired PRCA. Elimination of potentially causative factors may induce complete recovery. AZT is a well-known cause of anemia and thus should be used with caution in the initiation of ART.