Acute transient hemolytic anemia with a positive Donath-Landsteiner test following parvovirus B19 infection

Purpose: A case of childhood acute hemolytic anemia following parvovirus infection provided an hypothesis for the high frequency of Donath-Landsteiner antibodies and inappropriately low reticulocyte counts in this disease. Patients and Methods: A 3-year-old boy with hematuria and jaundice was found to have autoimmune hemolytic anemia due to a biphasic IgG Donath-Landsteiner antibody. Despite profound anemia (hematocrit 14.5%), the reticulocyte count was low (1.0%) and examination of his normocellular bone marrow showed erythroid hypoplasia. Results: A clinical diagnosis 2 weeks earlier of acute parvovirus B19 was serologically confirmed as the associated antecedent infection. Hemolytic anemia resolved with packed red cell transfusion, and intravenous immune globulin and steroid treatment. Conclusions: The high-frequency red cell P antigen is both the usual specificity of Donath-Landsteiner antibody and the viral receptor for parvovirus infection of red cell precursors. We speculate that interaction of the virus with its receptor may change antigenicity such that anti-P autoantibody forms. Parvovirus B19 may be a primary cause of reticulocytopenic postinfectious hemolytic anemia in children.