Background : Detection of neutrophil antigen is not routinely performed in transfusion medicine. The gold standard of antigen detection is a serological test, nonetheless, lack of antibody to white cell antigens is one of its limitations.

Objective : This research aimed to identify human neutrophil antigen-3 (HNA-3) genotypes in southern Thai blood donors using high resolution melting (HRM) analysis. Allele frequencies of HNA-3 were also compared to other populations.

Materials and methods : DNA from 443 blood donors from southern Thailand was amplified by two-step PCR and then genotypically classified by HRM analysis. Allele frequencies of solute carrier family 44 member 2 ( SLC44A2 ) gene and distribution of HNA-3 genotypes were compared with other populations. Forty-seven samples were subsequently sequenced to generate concordance date between HRM and Sanger sequencing.

Results : Frequencies of SLC44A2*01 and SLC44A2*02 were 0.812 and 0.188, respectively. HNA-3a/3a homozygous was the most common genotype at 62.3%, followed by 37.7% of HNA-3a/3b heterozygous, whereas HNA-3b/3b homozygous genotype was not observed. Distribution of genotype frequencies in the present study was significantly different from other populations worldwide including other parts of Thailand but matched to the same population reported previously by multiplex PCR. HRM genotyping was strong agreement with sequencing method (Kappa score = 0.87).

Conclusion : This report identified three genotypes of HNA-3 in Thailand using PCR-HRM. PCR-HRM is a rapid, sensitive, and cost-effective genotyping tool suitable for large-scale donor screening.