Dapsone for thrombocytopenic purpura related to human immunodeficiency virus infection

PURPOSE: The purpose of this study was to determine the effect of dapsone on platelet count in patients with human immunodeficiency virus (HIV)-related autoimmune thrombocytopeniag. PATIENTS AND METHODS: Eleven patients with HIV-related thrombocytopenia received dapsone (50 to 125 mg/day) for 2 to 43 months. Patients with the acquired immunodericiency syndrome were not enrolled. RESULTS: Of the 11 patients, six developed platelet counts above 50 X 10.sup.9/L and did not require any other specific therapy. No significant side effects were observed. CONCLUSION: We conclude that dapsone may be effective in some patients with HIV-related thrombocytopenia.
Autoimmune thrombocytopenic purpura (AITP) is a systemic illness in which the platelet (cells which help preserve clotting mechanism in blood) count decreases and easy bruising of the skin occurs, along with a tendency to bleed. It is often seen in patients infected with the human immunodeficiency virus (HIV). A suitable treatment for this problem has not yet been found. This study examined the effectiveness of the drug dapsone to treat AITP in HIV-infected patients. The idea behind such therapy is that dapsone might be able to inhibit the destruction of platelets by macrophages, cells of the immune system that engulf cells and other matter identified as 'foreign'. Eleven HIV-infected patients with AITP were treated with 50 to 125 mg dapsone/day for between 2 and 43 months. The patients did not yet have AIDS and had not received antiviral therapy. Platelet counts were measured before, during, and after drug therapy. Results showed that platelet counts rose after therapy in 9 of the 11 patients, with counts rising above 50 billion per liter of blood - significantly better than the counts of 27 billion/L before therapy. Increases were persistent in eight of the nine patients that responded. There were no significant side effects of the drug therapy beyond some mild hemolysis (red cell destruction). The results indicate dapsone may be useful for treating some HIV-related cases of AITP. The mechanism by which it works is not clear. (Consumer Summary produced by Reliance Medical Information, Inc.)