Effect of intravenous gammaglobulin on circulating and platelet-bound antibody in immune thrombocytopenia.
Ten patients with idiopathic thrombocytopenic purpura (ITP) were studied before and following a rise in circulating platelets subsequent to infusions of intravenous gammaglobulin (400 mg/kg/day x 5 days). We quantitated the amount of circulating IgG capable of binding to normal donor platelets in vitro using an 125I-monoclonal anti-human IgG assay, as well as the amount of IgG associated with the patients' platelets before and following therapy. We found no evidence for a decrease in platelet-specific IgG antibodies in these patients undergoing an acute response to therapy. These data suggest that the short-term efficacy of intravenous gammaglobulin is due to effects other than a substantive reduction in platelet reactive antibodies, such as the alteration of IgG-coated platelet destruction.
Barbano
G
G
Department of Medicine, University of Alabama, Birmingham 35294.
Saleh
M N
MN
Mori
P G
PG
LoBuglio
A F
AF
Shaw
D R
DR
D001323:Autoantibodies / Q000276:immunology*; D001327:Autoimmune Diseases / Q000628:therapy*; D001792:Blood Platelets / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism; D010976:Platelet Count; D011696:Purpura, Thrombocytopenic / Q000628:therapy*; D005719:gamma-Globulins / Q000627:therapeutic use*
D001323:Autoantibodies; D007074:Immunoglobulin G; D005719:gamma-Globulins