Investigating the Role of HLA-A, -B, -DRB1 Genes in Periodontitis Disease

Periodontitis is one of the periodontal inflammatory diseases ‎and is the most ‎common cause of tooth loss. Although bacterial infections play a major role in the ‎pathobiology of periodontitis, the severity of these diseases is determined by the severity of the ‎host's immune response to these infections. Human leukocyte antigens (HLAs) play roles in various ‎biological processes, including histocompatibility, inflammation, regulation of immune response, and ‎the complement cascade. In the following study, we investigated the difference in the frequency of HLA ‎locus alleles in patients with periodontitis compared to healthy controls.

This is a case- control study. Tissue samples were taken from 40 patients with periodontitis and 40 healthy controls. Case and control samples were collected based on the inclusion and exclusion criteria of the study. HLA-A, HLA-B, and HLA-DRB1 loci were genotyped by the SSP method and Olerup company kit. Allelic frequency was determined by the direct counting method, and multinomial regression models were used for statistical analysis between the two groups. Arlequin software package, version 3.5.2.2 (Excoffier and Lischer, 2010), and R software, version 3.6.1, were used to perform statistical analyses. Chi-square and OR statistical tests were also calculated.

This study was conducted on 40 cases and 40 controls. The two ‎groups were similar. The frequency of the DRB1*04 allele in the cases (28 cases) was significantly higher than the controls (16 controls) (P < 0.01). The odd ratio for this allele was equal to 2.3 (OR = 2.3). The frequency of other alleles had no statistically significant difference between the case and control groups (P > 0.05).

HLA- DRB1 locus could play a role in the pathogenesis of periodontitis. Conducting similar studies with a larger population and high-resolution HLA typing methods could help to clarify the mechanisms involved in the pathogenesis of periodontitis.