Dapsone for autoimmune thrombocytopenic purpura.

Twenty-one human immunodeficiency virus (HIV)-free and six HIV-infected adults with autoimmune thrombocytopenic purpura (AITP) were treated with dapsone (100 mg/day). A response was observed in 13 patients (median platelet count before 25 x 10(9)/L, range 3-49; after 109 x 10(9)/L, range 69-241). Thrombocytopenia recurred in four of the responders in whom dapsone was discontinued. No response was observed in 12 patients. Dapsone had to be withdrawn after two weeks of treatment in the remaining two patients and after six to eight weeks in three other patients due to intolerance. No serious hematological complications were observed. These results confirm that dapsone is a safe, inexpensive, and effective treatment of AITP.