Stricker R B, Shuman M A
Blood. 1986 May;67(5):1377-81.
Quinidine-induced thrombocytopenia has been associated with both immune complex and autoantibody binding to platelets. In the present study, serum antibody from six of six patients with quindine purpura was shown by immunoblotting to bind to a single platelet membrane protein of mol wt 80,000. This target protein was absent from Bernard-Soulier (BSS) platelets. F(ab)2 prepared from one patient's serum also bound to this protein, indicating autoantibody rather than immune complex binding to the target antigen. Antibody binding to the 80-kd protein was preserved after treatment of platelets with concentrations of trypsin or chymotrypsin that completely removed glycoprotein Ib (GPIb). Preincubation of platelet proteins with one patient's serum blocked binding of a polyclonal rabbit antibody against glycoprotein V (GPV), indicating that these antibodies recognize the same antigen. By wheat germ affinity chromatography, GPV was shown to copurify with GPIb. Quinidine-induced antibody bound to the wheat germ-purified GPV but not to GPIb. We conclude that quinidine purpura is associated with autoantibody directed against platelet GPV.
奎尼丁诱导的血小板减少症与免疫复合物和自身抗体与血小板的结合均有关。在本研究中，通过免疫印迹法显示，6例奎尼丁紫癜患者的血清抗体均与一种分子量为80,000的单一血小板膜蛋白结合。伯纳德-索利尔（BSS）血小板中不存在这种靶蛋白。从一名患者血清制备的F(ab)2也与该蛋白结合，表明是自身抗体而非免疫复合物与靶抗原结合。用能完全去除糖蛋白Ib（GPIb）的胰蛋白酶或糜蛋白酶浓度处理血小板后，抗体与80-kd蛋白的结合得以保留。用一名患者的血清对血小板蛋白进行预孵育，可阻断抗糖蛋白V（GPV）的多克隆兔抗体的结合，表明这些抗体识别相同的抗原。通过麦胚亲和层析法，显示GPV与GPIb共纯化。奎尼丁诱导的抗体与麦胚纯化的GPV结合，但不与GPIb结合。我们得出结论，奎尼丁紫癜与针对血小板GPV的自身抗体有关。
