Gene frequency of human platelet alloantigens‐1 to ‐6 and ‐15 in Saudi blood donors

Abstract

Human platelet antigens (HPAs) are involved in the pathogenesis of several clinical conditions, such as platelet transfusion purpura (PTP), refractoriness to platelet transfusion and neonatal alloimmune thrombocytopenia (NAITP). Typing of HPA (1-6 and 15) has not been carried on the Saudi population. This is the first study of all the seven HPA systems on Arabs. The aim of this prospective study was to determine the frequency of HPA (1-6 and 15) in Saudis. A total of 100 randomly selected Saudi blood donor samples were genotyped using the polymerase chain reaction with sequence-specific primers (PCR-SSP). The most common HPA genotypes among Saudis were HPA-1 a + b- (75%), HPA-2 a + b- (62%), HPA-3 a + b- (51·5%), HPA-4 a + b- (99%), HPA-5 a + b- (76·5%), HPA-6 a + b- (100%) and HPA-15 a + b + (50%). The prevalent allele among the HPA systems was (a), except in the HPA-15 system where the (b) allele was found in 52% of the subjects. Comparisons with other ethnic populations uncovered marked differences in the distribution of HPA alleles. Studying the prevalence of HPA antigens in Saudi population will help in the understanding of its role in platelet-related disorders. It will also enable the blood bank to establish an HPA-based donor registry that will be a valuable source of compatible platelet-therapeutic products to alloimmunised patients. This will also enhance the safety and efficacy of platelet transfusion. This data obtained will form an addition to the existing body of literature in transfusion research.