Intravenous immunoglobulin (i.v. IgG) for previously treated acute or for chronic idiopathic thrombocytopenic purpura (ITP) in childhood: a prospective multicenter study.

In a prospective multicenter study 42 thrombocytopenic (less than 30 X 10(9) platelets/l) children with chronic idiopathic thrombocytopenic purpura (ITP) or with acute ITP, dependent on or refractory to corticosteroids, were given 0.4 g i.v. IgG/kg body weight/day on 5 consecutive days and thereafter once a week if the platelet count fell to less than 20 X 10(9)/l or if the patient bled. After the initial 5 days of i.v. IgG the platelets rose within a mean of 7-8 days to greater than 30 X 10(9)/l in all and to greater than 150 X 10(9)/l in 33 of 42 patients (79%). After a mean observation time of 26.6 months 26 of 42 patients (62%) showed a satisfactory long-term effect, i.e. no need for treatment for at least 6 months without bleeding and with no platelet counts below 20 X 10(9)/l. No difference in response rate was found between children with chronic and those with previously treated acute ITP. These results indicate that i.v. IgG could be used to control emergency situations, e.g. to stop bleeding or to prepare a patient for surgery. I.v. IgG also represents a good alternative to treatment modalities, such as splenectomy and/or the administration of cytostatic immunosuppressants with potentially serious side effects. In addition to the expected transient rise in serum IgG levels, i.v. IgG induced a more prolonged elevation of serum IgM. Platelet associated IgG, elevated before therapy, was correlated with the clinical long-term outcome.