title: Influences of antiplatelet autoantibodies on platelet function in immune thrombocytopenic purpura.
abstract: We investigated the characteristics of the antiplatelet autoantibodies in 60 patients with ITP. Using flow cytometry, the binding of monoclonal antibodies to the platelet glycoprotein (GP) IIb/IIIa complex and to GPIb was examined in these patients. The extent of binding was decreased in 15 patients (anti-GPIIb/IIIa in 12 patients and both anti-GPIIb/IIIa and anti-GPIb in 3 patients). Western blotting revealed that 10 of these 15 patients had either anti-GPIIb or anti-GPIIIa and 2 had anti-GPIb autoantibodies, ADP-induced aggregation of normal platelets was inhibited by autoantibodies in 12 of 60 patients, and 11 of these had anti-GPIIb/IIIa antibodies. Ristocetin-induced aggregation was inhibited in 4 of these patients, and 2 with prominent inhibition had anti-GPIb antibodies. There was a significant relationship between platelet-associated IgG value and ATP secretion. These results suggest that some antiplatelet autoantibodies can affect platelet function and thus have an influence on the pathophysiology of ITP.
authors.affiliation: First Department of Internal Medicine, Kansai Medical University, Osaka, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Yanabu
authors.forename: M
authors.initials: M
authors.lastname: Suzuki
authors.forename: T
authors.initials: T
authors.lastname: Soga
authors.forename: N
authors.initials: N
authors.lastname: Sone
authors.forename: H
authors.initials: H
authors.lastname: Nagata
authors.forename: S
authors.initials: S
authors.lastname: Nomura
authors.forename: T
authors.initials: T
authors.lastname: Kokawa
authors.forename: K
authors.initials: K
authors.lastname: Yasunaga
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000097:blood; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000276:immunology*; D001792:Blood Platelets / Q000276:immunology* / Q000502:physiology; D015153:Blotting, Western; D002648:Child; D003094:Collagen / Q000494:pharmacology; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation / Q000187:drug effects; D010980:Platelet Membrane Glycoproteins / Q000276:immunology; D011696:Purpura, Thrombocytopenic / Q000276:immunology*; D012310:Ristocetin / Q000494:pharmacology
chemical_list: D001323:Autoantibodies; D010980:Platelet Membrane Glycoproteins; D012310:Ristocetin; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D003094:Collagen