AN EVALUATION OF INTRAVENOUS IMMUNOGLOBULIN IN THE TREATMENT OF HUMAN IMMUNODEFICIENCY VIRUS-ASSOCIATED THROMBOCYTOPENIA

Background: Anecdotal evidence suggests that high-dose intravenous immunoglobulin (IVIG) is useful in the management of human Immunodeficiency virus (HIV)associated thrombocytopenia. Study Design and Methods: To rigorously evaluate this therapy, a crossover study was designed to compare IVIG, given at 1 g per kg per day for 2 consecutive days each week for 4 weeks, with intravenous saline placebo administered according to the same schedule. Subjects were randomly assigned to receive either IVIG or saline during the first 4 weeks; if IVIG was given, there was a 4-week period of no therapy before beginning placebo administration. Criteria for eligibility were platelet count of less than 50,000 per mu L (50 x 10(9)/L), elevated platelet-associated IgG levels, increased megakaryocytes In the bone marrow, and positive HIV antibody test. Twelve patients (11 men, 1 woman) were studied. Seven patients completed the full protocol. Four dropped out: after 2, 5 (2 patients), and 8 weeks that included at least 2 weeks of IVIG. Results: All patients sustained an increase in platelet count in response to IVIG, with increments ranging from 15,000 to 358,000 per mu L (15 to 350 x 10(9)/L) (mean, 180,000/mu L [180 x 10(9)/L]; median, 174,000/mu L [174 x 10(9)/L]). No patient had an increase after placebo infusions. There were no adverse effects of treatment, and weekly chemical analyses showed no new abnormalities except for mild elevations in the serum protein. The duration of responses ranged from 2 to 10 weeks. No patient demonstrated refractoriness to IVIG. Conclusion: IVIG consistently raises platelet counts in patients with HIV-associated thrombocytopenia.