Polimorfismos das glicoproteínas plaquetárias em doadores de sangue do Amazonas

Abstract

Humans platelets Antigens (HPA) are specific alloantigens of platelets resulting from single nucleotide polymorphism (SNP) that lead to substitution of an amino acid protein level defined by polymorphisms of platelet surface glycoproteins. These polymorphisms may trigger immune or nonimmune clinical manifestations, as occurrence of thrombocytopenia and bleeding. The aim of this study was to determine the allele frequencies of HPA-1 systems - 9, HPA-11 and HPA-15 in blood donors of Amazonas and compare with the allele frequencies of other populations studied. The genotyping was performed through a PCR multiplex technique associated with DNA Microarray Technology, BeadChip® . A universe of 200 donors was included in the study since 140 (70%) were male and 60 (30%) female. The donor's age ranged from 19 to 65 years, with an average age of 36 years. However, no significant differences were found between genotype frequencies of men and women for all antigens HPA. All results were consistent and showed balance with Hard-Weinberg, except for the HPA-9 where it was observed a single homozygous HPA-9b. The allele ``b´´ occurred at low frequencies in HPA systems tested except for HPA-3 and -15, which showed higher prevalence of heterozygous genotypes AB (47% and 49.5%, respectively), unlike other systems where AA was the genotype of low occurrence. In addition, no b allele was found for HPA-6, -7, -8 or -11, also not homozygous genotypes were detected BB to the HPA-4, -6, -7, -8 or -11. Five individuals have been identified yet (2.5%) that carry associations of rare alleles. Comparisons between population groups, through the X2 test, revealed significant differences in all systems, but the HPA similar results in statistical analysis (p > 0.005) drew our attention, suggesting a level of genetic proximity between European peoples. The findings allowed the description of genotypic profile of donors and thus predict the risk of alloimmunization to the antigens most commonly involved in transfusion practice.