Curtis B R, Aster R H
Blood Center of Southeastern Wisconsin, Milwaukee, Wisconsin 53201-2178, USA.
Transfusion. 1996 Apr;36(4):331-4. doi: 10.1046/j.1537-2995.1996.36496226147.x.
About 5 to 10 percent of Asians have platelets that lack the major membrane glycoprotein (GP) IV (CD36, GPIIIb) that carries the isoantigen Naka. The GPIV-negative platelet phenotype is extremely rare among whites, but its frequency in persons of African ancestry has not yet been determined. Isoimmunization against GPIV can occur in GPIV-negative persons and can lead to platelet transfusion refractoriness. Therefore, the expression of GPIV on platelets from unrelated African Americans was studied.
Platelets were obtained from 250 African American and 280 white blood donors. Flow cytometry was used to determine the ability of these platelets to bind a monoclonal antibody that reacted with GPIV. Platelets that failed to react with this probe were tested with other GPIV-specific monoclonal antibodies and with anti-Naka, an isoantibody that recognizes an epitope on GPIV.
Platelets from 6 of the 250 African American donors (2.4%) lacked GPIV and failed to bind anti-Naka, whereas platelets from all of the white donors were GPIV positive (p>0.05). No platelet-reactive antibodies were identified in the serum of the GPIV-negative donors.
The frequency of the GPIV-negative platelet phenotype in African Americans is comparable to that in Asians and much greater than that in whites. Studies are needed to determine the frequency with which African Americans become isoimmunized to GPIV by transfusions and the possible contribution of this isoimmunization to platelet transfusion refractoriness in this population.
约5%至10%的亚洲人血小板缺乏携带异抗原中河的主要膜糖蛋白（GP）IV（CD36，GPIIIb）。GPIV阴性血小板表型在白人中极为罕见，但在非洲裔人群中的频率尚未确定。GPIV阴性个体可发生针对GPIV的同种免疫，可导致血小板输注无效。因此，对无关非裔美国人血小板上GPIV的表达进行了研究。
从250名非裔美国人和280名白人献血者中获取血小板。采用流式细胞术测定这些血小板与与GPIV反应的单克隆抗体结合的能力。未与该探针反应的血小板用其他GPIV特异性单克隆抗体和抗中河（一种识别GPIV上一个表位的同种抗体）进行检测。
250名非裔美国献血者中有6人（2.4%）的血小板缺乏GPIV且未结合抗中河，而所有白人献血者的血小板GPIV均为阳性（p>0.05）。在GPIV阴性献血者的血清中未鉴定出血小板反应性抗体。
非裔美国人中GPIV阴性血小板表型的频率与亚洲人相当，远高于白人。需要开展研究以确定非裔美国人因输血而对GPIV产生同种免疫的频率，以及这种同种免疫对该人群血小板输注无效可能产生的影响。
