Pure red cell aplasia caused by parvovirus B19 in two patients without chronic hemolysis

Infection with human parvovirus B19 (PVB19) induces acquired pure red cell aplasia (PRCA). Chronic hemolytic anemia is well known as an underlying condition. However, additional factors have been recognized to accompany parvoviral PRCA; however, there are only limited reports on iron-deficiency anemia (IDA) and rituximab-induced B-cell dysfunction. We report two patients with PVB19-associated PRCA confirmed by positivity of viral DNA. Although they had no chronic hemolysis, patient 1 had IDA, and patient 2 had remitted small-lymphocytic lymphoma treated with rituximab-containing chemotherapy. Absence of reticulocytes in peripheral blood and marked depletion of erythroid precursors in bone marrow were observed both. Whereas patient 1 received only symptomatic therapy because anemia was not severe, patient 2 was treated with steroids, as PRCA etiology was at first uncertain, and immunological PRCA was not excluded. Both showed rapid increase of reticulocyte counts and recovery from anemia. Although immunoglobulin is considered effective for parvoviral PRCA, notable adverse reactions have been reported. When anemic symptom is not severe, reticulocyte observation only is recommended. The effects of steroids should also be re-evaluated. Optimal treatment according to disease severity remains to be established.