Human parvovirus B19 infection during the inactive stage of systemic lupus erythematosus.

A 42-year-old woman with systemic lupus erythematosus (SLE) had an episode of fever, arthralgia and anemia. In order to treat the suspected activation of SLE, the daily dose of steroid was increased, however, the anemia progressed and pancytopenia developed. Both IgM anti-B19 antibodies to human parvovirus B19 (B19) and B19 DNA were positive, and bone marrow analysis revealed pure red cell aplasia with giant proerythroblasts. High dose gamma globulin was administered and the daily dose of steroid was tapered, resulting in the improvement of her condition. B19 infection should be ruled out in cases with reactivation of autoimmune diseases.