Relationship between obstructive sleep apnea and human leukocyte antigen variants

Background and aim: The obstructive sleep apnea (OSA) is a common, complex and polygenic disease and it has high risk of serious complications. The human leukocyte antigen (HLA) system plays a crucial role in the regulation of immune function by discriminating self from non-self. In recent years there has been rapid advancement in "Next Generation Sequencing" technology. It enables the detection of HLA alleles in four or even six digits, providing a high level of precision. The aim of the present study was to investigate the genetic variants at HLA-A,-B,-C,-DQB1 and -DRB1 loci in OSA patients and unrelated healthy individuals by targeted NGS in the Turkish population. Materials methods: Fifty newly diagnosed patients with OSA and 50 control subjects were enrolled in the study. OSA diagnosis was made by utilizing the apnea-hypopnea index (AHI)≥5 in overnight polysomnography (PSG). Blood samples were obtained in the morning, after PSG. Controls were randomly selected from healthy volunteers who had a low risk for OSA. Genotyping of HLA-A, B, C, DRB1 and DQB1 genes were performed by using next generation sequencing. Results: HLA-A*02:01, HLA-C*03:03:01, HLA-C*14:03, HLA DRB1*04:05 alleles were found more frequently in OSA patients, but not in the controls (p=0.036, p=0.007, p=0.043 and 0.013, respectively). The allele frequencies of HLA-A*03:01 and HLA-B*35:02 were significantly higher in controls compared to OSA patients (p=0.024 and p=0.043). Conclusion: These results suggest that HLA-A*02:01, HLA-C*03:03:01, HLA-C*14:03, HLA DRB1*04:05 alleles may play a predisposing role in the Turkish population with OSA. In addition, HLA-A*03:01 and HLA-B*35:02 alleles may be protective in this population.