BIOCHEMICAL-CHARACTERIZATION OF ANTIGENS DETECTED WITH ANTIPLATETLET MONOCLONAL-ANTIBODIES

A panel of 18 monoclonal antibodies (mAbs) defined by the third worksh op as specific for platelets, clustered in three preliminary groups: P C7, PC13 and PC27, These mAbs were further analysed by immunoprecipita tion using extracts of iodinated and biotinylated peripheral blood mon onucleated cells (PBMC) and platelets. We could confirm the existence of mAbs with specificities to WC9 (in PC7) and CD41/61 (in PC13). Two mAbs formed a new cluster, WC13, which may be homologous to human CD31 (in PC27). The influence of EDTA and thrombin on the expression of th e different antigens on the platelet membrane was assessed by flow cyt ometry (FCM) analysis, as well as cross-reactivity with platelets from different species.