Gonzalez-Conejero R, Rivera J, Rosillo M C, Cano A, Rodriguez T, Vicente V
Unit of Haematology and Haemotherapy, Hospital General Universitario, Murcia, Spain.
Br J Haematol. 1996 May;93(2):464-71. doi: 10.1046/j.1365-2141.1996.00502.x.
The levels of platelet-associated Igs (PAIgs) and plasma circulating antiplatelet antibodies were evaluated by a flow cytometric immunofluorescence assay (FCIFA), an enzyme-linked immunoassay (ELISA), and a platelet radioactive antiglobulin test (PRAT), in a group of 45 human immunodeficiency virus (HIV)-infected intravenous drug users (IVDUs), with or without thrombocytopenia (TCP). Direct tests demonstrated an increased amount of PAIgs in 40% of the patients, irrespective of their platelet count. These PAIgs were mainly of IgG class and could not be eluted with ether. Plasma IgG with antiplatelet activity was found in 70% of the thrombocytopenic individuals, whereas it was detected in only one patient without TCP. The relative frequencies of antibodies against the platelet glycoproteins (GPs) Ib/IX and IIb/IIIa were assessed in plasma from all patients by means of the monoclonal antibody-specific immobilization of platelet antigens assay (MAIPA). Plasmas from all non-thrombocytopenic patients were negative when tested by indirect MAIPA. In contrast, 10/23 plasma from thrombocytopenic patients reacted with either GP IIb/IIIa, GP Ib/IX, or both GPs. Finally, aiming to investigate whether HIV antibodies from these patients are reactive with normal platelets, we performed absorption-elution experiments, followed by evaluation of HIV antibodies in the indirect eluates by ELISA and Western blot. Interestingly, we detected anti-HIV antibodies that bind to normal platelet antigens in 50% of the ether eluates prepared from control platelets sensitized with plasma from patients with TCP, but in only 5% of eluates obtained from platelets sensitized with plasma from non-thrombocytopenic patients. The present study provides direct evidence that specific autoantibodies against platelet membrane GPs Ib/IX and IIb/IIIa are common in HIV positive thrombocytopenic individuals. The finding in these patients of HIV antibodies cross-reactive with normal platelets, suggests that mimicry of human antigens by HIV could play a key role in the pathophysiology of the HIV-related TCP.
采用流式细胞免疫荧光分析（FCIFA）、酶联免疫吸附测定（ELISA）和血小板放射性抗球蛋白试验（PRAT），对45名感染人类免疫缺陷病毒（HIV）的静脉吸毒者（IVDU）进行了评估，这些患者有或没有血小板减少症（TCP）。直接检测显示，40%的患者血小板相关免疫球蛋白（PAIg）量增加，与血小板计数无关。这些PAIg主要为IgG类，不能用乙醚洗脱。70%的血小板减少患者血浆中发现具有抗血小板活性的IgG，而在无TCP的患者中仅1例检测到。通过血小板抗原单克隆抗体特异性固定试验（MAIPA）评估了所有患者血浆中抗血小板糖蛋白（GP）Ib/IX和IIb/IIIa抗体的相对频率。所有非血小板减少患者的血浆经间接MAIPA检测均为阴性。相反，23名血小板减少患者中有10名的血浆与GP IIb/IIIa、GP Ib/IX或两者均发生反应。最后，为了研究这些患者的HIV抗体是否与正常血小板发生反应，我们进行了吸收 - 洗脱实验，随后通过ELISA和蛋白质印迹法评估间接洗脱液中的HIV抗体。有趣的是，我们在50%由TCP患者血浆致敏的对照血小板制备的乙醚洗脱液中检测到与正常血小板抗原结合的抗HIV抗体，但在由非血小板减少患者血浆致敏的血小板获得的洗脱液中仅5%检测到。本研究提供了直接证据，表明针对血小板膜GP Ib/IX和IIb/IIIa的特异性自身抗体在HIV阳性血小板减少个体中很常见。这些患者中发现HIV抗体与正常血小板交叉反应，表明HIV对人类抗原的模拟可能在HIV相关TCP的病理生理学中起关键作用。
