한국인의 혈소판 특이항원계 유전자형 및 유전자 빈도

Abstract

Background: According to the rapidly increasing demand of platelet transfusion in clinical medicine, knowledge of platelet immunology has rapidly expanded by the introduction of new molecular biological technology. Especially the ability to generate large amounts of cDNA from platelet-specific mRNA sequences should make possible direct molecular characterization of normal platelet proteins. All platelet-specific alloantigens as yet investigated are due to single DNA base changes leading to single amino acid substitution at the protein level and all HPA systems to date have been found to be localized on platelet membrane glycoproteins. Up to now, five distinct diallelic human platelet alloantigen systems, HPA I(P1A, Zw), HPA II(Ko, Sib), HPA III(Bak, Lek), HPA IV(Pen, Yuk) and HPA V(Br, Zav, Hc) were known to be important causes of alloimmune thrombocytopenia. Method: To determine the genotype and gene frequencies for the HPA I-V, DNA from 51-154 healthy men were isolated from peripheral blood mononuclear leukocytes and specific sequences were amplified using polymerase chain reaction(PCR). DNA-based restriction fragment length polymorphism(RFLP) analysis using PCR product for HPA I, II, V and allele-specific PCR(ASA) for HPA III, IV were done. Results: The obtained genotype frequencies of normal Korean population were 100.0%, 0.0%, 0.0% for HPA I a+b-, a+b+, a-b+ and 87.4%, 12.0%, 0.6% for HPA II a+b-, a+b+, a-b+ and 17.6%, 68.6%, 13.8% for HPA III a+b-, a+b+, a-b+ and 100.0%, 0.0%, 0.0% for HPA IV and 98.1%, 1.9%, 0.0% for HPA V a+b-, a+b+, a-b+, respectively. And the gene frequencies were 1.000, 0.000 for HPA I a, b and 0.934, 0.066 for HPA II a, b and 0.520, 0.480 for HPA III a, b and 1.000, 0.000 for HPA IV a, b and 0.990, 0.010 for HPA V a, b respectively. Conclusion: Comparing with Caucasians, Koreans have single genotype(a+b-) in HPA I, IV systems and gene frequency of 'a' was much higher in HPA V system. Genotype patterns of HPA systems are similar with other Orientals, but much lower incidence of a-b+ genotype in HPA V system was investigated.