Walsh C M, Nardi M A, Karpatkin S
N Engl J Med. 1984 Sep 6;311(10):635-9. doi: 10.1056/NEJM198409063111004.
Thrombocytopenic purpura has recently been noted in sexually active homosexual men. To elucidate the pathogenesis of thrombocytopenic purpura in this population, we compared the disorder in 33 homosexual men with that in 23 patients (15 women and 8 men) thought to have classic autoimmune thrombocytopenic purpura. The homosexual group had 3.8-fold higher levels of platelet-bound IgG and 4.2-fold higher levels of platelet-bound complement than the patients with autoimmune thrombocytopenic purpura. Eluates from the platelets of only 1 of 10 homosexual patients reacted in vitro with normal platelets, as compared with those from the platelets of 12 of 15 patients with autoimmune thrombocytopenic purpura. Twenty-one of 24 homosexual patients (88 per cent) had elevated serum levels of immune complexes that were capable of binding to platelets, whereas none of 5 patients with autoimmune thrombocytopenic purpura had circulating immune complexes. The IgG fraction of positive serum samples from three homosexual patients did not bind to normal platelets, whereas that from the positive serum of two patients with autoimmune thrombocytopenic purpura and one woman in whom isoimmune antiplatelet antibody developed during pregnancy (studied as a positive control) did bind to normal platelets. We conclude that, whereas classic autoimmune thrombocytopenic purpura involves antiplatelet IgG directed against platelet antigenic determinants, the thrombocytopenic purpura that occurs in sexually active homosexual men is usually caused not by antiplatelet IgG but probably by the nonspecific deposition of complement and immune complexes on platelets.
近期在有性活动的同性恋男性中发现了血小板减少性紫癜。为阐明该人群中血小板减少性紫癜的发病机制，我们将33名同性恋男性患者的这种疾病与23名被认为患有典型自身免疫性血小板减少性紫癜的患者（15名女性和8名男性）进行了比较。同性恋组血小板结合IgG水平比自身免疫性血小板减少性紫癜患者高3.8倍，血小板结合补体水平高4.2倍。10名同性恋患者中只有1人的血小板洗脱液在体外与正常血小板发生反应，而15名自身免疫性血小板减少性紫癜患者中有12人的血小板洗脱液能发生反应。24名同性恋患者中有21人（88%）血清中能与血小板结合的免疫复合物水平升高，而5名自身免疫性血小板减少性紫癜患者均无循环免疫复合物。3名同性恋患者阳性血清样本的IgG组分不与正常血小板结合，而2名自身免疫性血小板减少性紫癜患者及1名孕期发生同种免疫性抗血小板抗体的女性（作为阳性对照）的阳性血清IgG组分可与正常血小板结合。我们得出结论，典型的自身免疫性血小板减少性紫癜涉及针对血小板抗原决定簇的抗血小板IgG，而有性活动的同性恋男性中发生的血小板减少性紫癜通常并非由抗血小板IgG引起，而可能是补体和免疫复合物非特异性沉积于血小板所致。
