Interferon-alpha therapy in idiopathic thrombocytopenic purpura

BACKGROUND: Acute idiopathic thrombocytopenic purpura (ITP) represents the most frequent hemorrhagic diathesis in childhood. Up to 30% of patients with ITP are regarded as refractory to standard therapy. The rare mortality from acute ITP in childhood is almost exclusively due to intracranial hemorrhage. This complication occurs in less than 1% of ITP patients. This study was designed to evaluate the effect of alpha-interferon (IFN-alpha) in eight patients whom did not respond to conventional therapy. METHOD: In spite of conventional therapies, the patient whose platelet count could not be increased to 50;10(9)/L were accepted as refractory ITP. Eight of these patients whose platelet count lower than 20;10(9)/L were included in the prospective cohort study. Interferon alpha 2b 5 MU/m(2) was administered subcutaneously three times a week, totalling 12 times in a month. According to the platelet count on the 28th day of therapy, we grouped the patients into three categories. After 60 days, the survey was re-evaluated according to the platelet count. RESULTS: The mean age of children was 3.5+/-2.5 (ranged between 3.5 and 9) years. Six of them were boys and two were girls. There was no response in one patient, partial response in one, and good response in six patients on the 28th day of therapy. The maximum rise in platelet count was observed from 7 to 14 days after the initiation of interferon. The median platelet count which was 15+/-5;10(9)/L before therapy, raised to 60+/-12;10(9)/L after therapy. However, on the 60th day of therapy, there were only two patients who had a platelet count over 100;10(9)/L. CONCLUSION: In our study, we did not observe the long-term benefit of IFN-alpha therapy in refractor ITP in childhood. However, in good responding patients, platelet levels were increased in a short time. Alpha-interferon may be alternative therapy for patients whom had a platelet count below 20;10(9)/L and not responding to standard therapy, or for patients whom immunosuppressive therapy is contraindicated.