Human parvovirus B19-induced pancytopenia with progressive anemia during maintenance therapy in a patient with mixed-phenotype acute leukemia

Abstract

A 6-year-old boy with mixed-phenotype acute leukemia in his first remission with chemotherapy developed pancytopenia with progressive anemia and fever during his maintenance therapy. The maintenance therapy was discontinued, and he was admitted to our hospital for further investigation. The bone marrow aspirate smears revealed erythroid hypoplasia with a few giant pre-erythroblasts and no obvious leukemic cells. Antibiotics, immunoglobulin, and red blood cell transfusion were administered. His pyrexia resolved in 3 days and the pancytopenia gradually improved. Laboratory tests showed elevated levels of human parvovirus (HPV) B19-IgM in serum and positivity for HPVB19 DNA in the bone marrow, leading to the diagnosis of HPVB19-induced pancytopenia. When pancytopenia accompanying progressive anemia develops in patients with leukemia during maintenance therapy, HPVB19 infection should be considered, in addition to recurrence of the primary disease.