Characteristics of quinine- and quinidine-induced antibodies specific for platelet glycoproteins IIb and IIIa.

摘要: Recent studies have shown that antibodies characteristic of quinine- and quinidine-induced thrombocytopenia sometimes recognize the platelet membrane glycoprotein (GP) complex IIb/IIIa in addition to their well known target, GPIb/IX. We investigated frequency with which drug-induced bind GPIIb/IIIa nature target epitopes. In sera from 13 patients sensitive quinidine or quinine, we found 10 contained IgG specific for both GPIb/IX GPIIb/IIIa, two reacted alone, one alone. all cases, presence drug was required binding GPs. By immunoabsorption, each five polyspecific at least different antibodies, reactive GPb/IX other GPIIb/IIIa. Further eight drug- dependent (DDAb) showed three recognized only, GPIIb GPIIIa The eighth serum appeared alone an epitope determined by complex. also deglycosylated endo-H, major (61 Kd) fragment obtained chymotryptic digestion but failed react reduced GPIIIa. These findings demonstrate that, induced, immunologic thrombocytopenia, anti-platelet immune response is typically directed against epitopes on DDAb studied were resistant chymotrypsin endo-H treatment are intrachain disulfide bonding.