Severe anemia of rapid onset in an inmunocompromised host.

We describe a case of pure red cell aplasia developing within two months after kidney transplant in a patient who was actively receiving immunosuppression. His hemoglobin was 9.5 g/dL and his reticulocyte count was 0%. WBC and platelet counts were normal and a bone marrow showed hypercellularity with normal myelocytic and megakaryocytic elements. The erythrocytic series was completely absent except for an increased number of giant proerythronormoblasts with cytoplasmic vacuolization. The titers for IgG and IgM for Parvovirus were negative. However, DNA PCR for Parvovirus B19 was positive. After receiving IV human immunoglobulin, the patient's hemoglobin increased in 4-6 weeks to 13.1 g/dL and his reticulocyte count became normal. The cause of his anemia was attributed to Parvovirus B19. Parvovirus B19 should be considered as a cause of unexplained progressive anemia in this setting and in any immunosuppressed patient. The reticulocyte count, bone marrow picture and PCR for DNA for Parvovirus B19 are essential for diagnosis.