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PLATELETS AS IMMUNOGENS

Alloantigens on platelets may be shared with other cells or platelet specific. Of the shared antigens the most important clinically are the HLA-A,B and blood group A,B antigens. There are a number of well defined human platelet (specific) antigen (HPA) systems. These have been identified serologically by antibodies from patients who have been pregnant or transfused, usually associated with NAlT or PTP. The HPA allotypes are associated with a single DNA base change that causes an amino-acid substitution in the polypeptide chain of the platelet membrane glycoprotein (GP) that bears the epitope of the antigen.[6]