Immunological effects of intravenous gammaglobulin treatment in childhood idiopathic thrombocytopenic purpura.
The effects of high-dose intravenous IgG treatment on circulating and bound platelet antibodies, immunoglobulin synthesis and lymphocyte subpopulations were studied in children with idiopathic thrombocytopenic purpura (ITP). The levels of circulating IgM platelet antibodies increased in 3 patients and remained unaffected in 9 others after treatment. Platelet-associated IgM levels decreased in all patients, while platelet-associated IgG decreased in 10 out of 12 patients. The spontaneous non-specific immunoglobulin synthesis by peripheral lymphocytes determined with a protein-A plaque assay was rather increased than suppressed. There was no consistent effect on the frequency of surface immunoglobulin-positive lymphocytes (B cells), although an increase was seen after treatment in 5 out of 8 patients, due to an increased number of surface IgM-positive cells. The frequencies of T cells and T cell subpopulations determined with the help of monoclonal antisera (OKT 3, 4, 8) were not affected. No major side effects were observed and serum transaminase levels were normal during and after the treatment. It is suggested that the short-term effect of IgG treatment in ITP is not due to an immunomodulating or suppressive action. It might, in some patients, be due to interaction of the IgG with antibody or immune complex binding to platelets.
D000293:Adolescent; D000906:Antibodies / Q000032:analysis; D000917:Antibody Formation; D001792:Blood Platelets / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007111:Immunity, Cellular; D007116:Immunization, Passive; D007074:Immunoglobulin G / Q000008:administration & dosage / Q000627:therapeutic use*; D007075:Immunoglobulin M / Q000032:analysis; D007275:Injections, Intravenous; D008297:Male; D011696:Purpura, Thrombocytopenic / Q000276:immunology / Q000628:therapy*; D013601:T-Lymphocytes / Q000145:classification
D000906:Antibodies; D007074:Immunoglobulin G; D007075:Immunoglobulin M