Intravenous gammaglobulin (Gaminume) for treatment of chronic idiopathic thrombocytopenic purpura (ITP): a two-year follow-up.
Thirteen subjects 5-20 years of age with the chronic, autoimmune form of idiopathic thrombocytopenic purpura (ITP) were given intravenous gammaglobulin (Gamimune; Cutter Biological, Berkeley, CA) in a dose of 400 mg/kg per day for 5 consecutive days. Two of the 13 children had undergone splenectomy; the other 11 had not. Eight of these 13 children had also received corticosteroid therapy with no sustained increase in platelet counts. Six of 13 children had a good or excellent response to the first 5 day course of gammaglobulin therapy, and one had a fair response. The peak platelet count occurred within 7 days of the start of therapy except in one patient, whose platelet count peaked on day 12. Six of seven patients who initially responded to Gamimune required booster doses to maintain platelet counts at a safe level. All children had marked increases in serum IgG following Gamimune except one (who had undergone splenectomy for chronic ITP), who had high baseline levels of immunoglobulin G (IgG). No untoward reactions necessitating cessation of therapy were encountered during this study. The most common side effect observed was headache. During the first year of follow-up after Gamimune, three of seven initial responders became refractory to Gamimune therapy. Two of these three refractory subjects later underwent splenectomy with excellent response. The third refractory patient who was splenectomized prior to gammaglobulin therapy had spontaneous remission of his ITP 5 months after the last dose of Gamimune. Three of the four other initial responders have continued to do well and have maintained platelet counts above 40,000/mm3 (one without booster). The fourth subject dropped out of the study. Thus our observations indicate that Gamimune is an effective form of treatment for some children with chronic ITP, and can be considered as an alternative to splenectomy or as a potential therapeutic modality in those who have failed to respond to splenectomy.