Reiner A P, Teramura G, Nelson K A, Slichter S J
Puget Sound Blood Center, University of Washington School of Medicine, Seattle 98104-1256, USA.
J Immunol Methods. 1995 Aug 18;184(2):153-62. doi: 10.1016/0022-1759(95)00083-m.
Post-transfusion purpura (PTP) and neonatal alloimmune thrombocytopenia (NAT) result from formation of alloantibodies to platelet membrane glycoprotein-associated antigens. The detection and identification of platelet-specific alloantibodies in patient sera is often complicated by the presence of co-existing HLA antibodies and/or more than one platelet specificity in the same serum. We describe a solid phase assay that specifically detects antibodies to platelet membrane associated alloantigens by measuring the ability of patient antisera to inhibit the binding of glycoprotein GPIIb or GPIIIa monoclonal antibodies to intact platelets. When tested in the GPIIIa assay against a panel of random platelet donors, the reactivities of two known PLAI antisera that also contained different HLA antibodies were highly correlated (r = 0.99) and allowed PLA phenotyping of the population. A standard direct binding platelet ELISA, on the other hand, was unable to accurately PLA phenotype the same population. The reactivities of two known Baka antisera (one containing additional anti-PLA2 and the other anti-Brb specificities) were highly correlated (r = 0.95) in the GPIIb assay, and Bak phenotype determination was similarly accomplished for a random platelet panel. Furthermore, a comparison of platelet phenotype results (using the monoclonal inhibition assay) and genotype results (using DNA analysis) for the PLA and Bak systems showed a concordance of 98% for 146 alleles tested. In conclusion, the platelet monoclonal antibody inhibition assay: (1) allows determination of platelet-specific alloantibodies in the presence of contaminating HLA antibodies and/or in sera containing multiple platelet alloantibodies; (2) allows accurate platelet phenotyping for the GPIIIa-associated PLA and GPIIb-associated Bak antigen systems; and (3) may be applicable to the detection of other known or even novel platelet glycoprotein-associated antigens.
输血后紫癜（PTP）和新生儿同种免疫性血小板减少症（NAT）是由针对血小板膜糖蛋白相关抗原的同种抗体形成所致。患者血清中血小板特异性同种抗体的检测和鉴定常常因同时存在的HLA抗体和/或同一血清中存在一种以上血小板特异性而变得复杂。我们描述了一种固相检测方法，通过测量患者抗血清抑制糖蛋白GPIIb或GPIIIa单克隆抗体与完整血小板结合的能力，特异性检测针对血小板膜相关同种抗原的抗体。当在针对一组随机血小板供体的GPIIIa检测中进行测试时，两种已知的PLAI抗血清（也含有不同的HLA抗体）的反应性高度相关（r = 0.99），并能够对该群体进行PLA表型分析。另一方面，标准的直接结合血小板ELISA无法准确地对同一群体进行PLA表型分析。两种已知的Baka抗血清（一种含有额外的抗PLA2特异性，另一种含有抗Brb特异性）在GPIIb检测中的反应性高度相关（r = 0.95），并且对一组随机血小板也同样完成了Bak表型的确定。此外，对PLA和Bak系统的血小板表型结果（使用单克隆抑制检测法）和基因型结果（使用DNA分析）进行比较，在检测的146个等位基因中显示一致性为98%。总之，血小板单克隆抗体抑制检测法：（1）能够在存在污染的HLA抗体和/或含有多种血小板同种抗体的血清中确定血小板特异性同种抗体；（2）能够对与GPIIIa相关的PLA和与GPIIb相关的Bak抗原系统进行准确的血小板表型分析；（3）可能适用于检测其他已知的甚至新的血小板糖蛋白相关抗原。
