Neutropenia due to Parvovirus B19 Infections in Patients with Paroxysmal Nocturnal Hemoglobinuria

Two patients with paroxysmal nocturnal hemoglobinuria (PNH) and parvovirus B19 (PVB19) infection are reported. One was infected by PVB19-contaminated blood transfusion, whereas the other had become infected naturally. Both patients completely recovered after transient pancytopenia, but showed severe and intermediate neutropenia (0.216 and 0.768 × 109/l, respectively) at the nadirs of aplastic crises. In the literature, PNH cases also showed neutropenia (0 and 0.54 × 109/l) at aplastic crises. When patients with PNH are infected by PVB19, they may show severe neutropenia and mild thrombocytopenia in addition to severe reticulocytopenia. Therefore, these patients might have to be treated with granulocyte colony-stimulating factor to be able to recover from severe neutropenia.