Development of hypogammaglobulinemia in a patient with systemic lupus erythematosus

This report describes a young girl in whom systemic lupus erythematosus (SLE) with normogammaglobulinemia but high serum DNA binding developed at age 10. She was subsequently treated with prednisone and intermittent cyclophosphamide for six years, and severe hypogammaglobulinemia associated with recurrent infections developed; disease remained active and serum DNA binding high. The possible contribution of treatment with cyclophosphamide to the development of hypogammaglobulinemia is discussed.