An Evaluation of HLA-matched Platelet Transfusion Effect in Patients with Platelet Refractoriness

Park, Hyung Doo; Kim, Yang Hyun; Park, Yoon June; Han, Kyou Sup; Park, Myoung Hee

Abstract

BACKGROUND
Patients with platelet refractoriness as a result of human leukocyte antigen (HLA) alloimmunization can be effectively managed by transfusion of HLA-matched platelets. In this study, we have retrospectively evaluated the effect of HLA-matched platelet transfusion using a hospital based donor pool of 450 HLA typed donors. METHODS: For 17 patients showing platelet refractoriness to random donor platelets [1 hr corrected count increment (CCI) <7, 500/microliter/m2; mean 1, 887/microliter/m2] and HLA alloimmunization, 78 single-donor apheresis platelets from 62 donors were transfused. HLA compatible donors were selected based on HLA match and patients' HLA antibody specificities. RESULTS: An average of 4.6 transfusions per patient were done and effective post-transfusion platelet increments were obtained with a mean 1 hr CCI of 17, 813/microliter/m2. In 76% (59/78) of the total transfusions, an effective platelet increment (1 hr CCI > or =7, 500/microliter/m2) was obtained. HLA crossmatch (NIH method) negative patients showed a significantly higher platelet increment compared with crossmatch positive patients (23, 877 vs 10, 823; P=0.000). Although better transfusion effect was obtained in higher grade HLA match of A-B2U by selection of HLA compatible donors according to patients' HLA antibody specificities, an effective platelet increment was obtained in lower grade matches as well. Platelets transfused < or =24 hours after collection showed a significantly higher platelet increment compared with those stored >24 hours (20, 325 vs 11, 417; P=0.029). CONCLUSIONS: Although many low grade matched donors were selected due to a relatively small size of HLA typed donor pool, effective platelet increments were obtained by selecting platelet donors on the basis of HLA antibody specificity.