Chronic autoimmune thrombopenia/neutropenia in a boy with persistent parvovirus B19 infection

Objective: We report an 11-year-old boy presenting with splenomegaly, chronic thrombocytopenia and concordant neutropenia. Results: In contrast to autoantibodies against platelets, there were no detectable neutrophil-specific autoantibodies present in this patient. Extensive serologic investigations revealed increased IgM- and IgG-antibody titers against parvovirus B19. A nested polymerase chain reaction (PCR) showed parvovirus B19-specific sequences in the patient's bone-marrow cells but not in the serum. Specific antibodies against the structural proteins VP1 and VP2 in addition to those against non-structural protein NS1 of parvovirus B19 were detected by Western blot analysis. Thrombocytopenia and neutropenia responded to immunosuppressive therapy and subsequent splenectomy, the latter being necessary due to severe side-effects of steroid medication. Conclusion: Autoimmune thrombocytopenia/neutropenia may have been triggered and/or sustained by a chronic parvovirus B19 infection. Patients with this very rare disorder should be screened for this virus.