Human platelet-specific antigen frequencies in Indonesian population

BackgroundAlloantibodies against human platelet antigens (HPAs) are responsible for the development of alloimmune thrombocytopenia including platelet transfusion refractoriness (PTR) and neonatal alloimmune thrombocytopenia (NAIT). Therefore, transfusion of HPA-compatible platelets is of importance for the management of these diseases. AimDetermination of the allele frequency of the major HPA systems for Indonesian blood donors and the development of the first HPA-typed donor registry in Indonesia. MethodsDNA derived from 500 Indonesian healthy blood donors was genotyped for HPA-1 to HPA-6 and HPA-15 alleles by the use of polymerase chain reaction sequence-specific primer method. ResultsThe gene frequencies of the rare allelic variants HPA-1b, -2b, -3b, -4b, -5b, -6b and -15b were 0<bold>023</bold>, 0<bold>060</bold>, 0<bold>493</bold>, 0<bold>052</bold>, 0<bold>032</bold>, 0<bold>044</bold> and 0<bold>049</bold>, respectively. However, donors homozygous for the HPA-1b, -2b and -6b were not found in this cohort, indicating that the risks of alloimmunisation caused by incompatibility of these three HPA systems are extremely low. In contrast, alloimmunisation against HPA-3, -4, -5 and -15 systems is anticipated. ConclusionThe development of an HPA-genotyped registry for donors homozygous for HPA-1b, -2b and -6b is desired for the optimum management of PTR patients and children with NAIT.