RESUMEN
BACKGROUND: Microlymphocytotoxicity test is most widely used for HLA Class I typing but almost all laboratories depend on imported HLA Class I typing trays. Matching criteria for the selection of HLA-matched platelets to treat platelet refractoriness is not as strict as for bone marrow transplantation. Therefore, with the acquisition of various antisera against high frequency HLA antigens, self-made HLA typing trays can be used for HLA typing of HLA-matched platelet donors. METHODS: 140 samples obtained during placental delivery were tested for the presence of HLA antibodies against a well-characterized panel of 90 cells. Specificity of HLA antisera were determined by evaluating the correlation coefficient r of the 2x2 table, kappa2 test. Antisera strength was evaluated by the strength index. RESULTS: HLA antibodies were detected in 25 samples by primary screening and 23 samples also showed a positive reaction in secondary screening (16%). Among 23 samples, 11 antisera were of reagent grade quality and 7 were monospecific antisera. DISCUSSION: Imported HLA typing trays can be replaced by harvesting HLA antisera against HLA antigens which are relatively common in Koreans through continuous HLA antibody screening using gushed out blood during placental delivery.