Rheumatoid Arthritis Susceptibility Is Associated with the KIR2DS4-Full of Killer-Cell Immunoglobulin-Like Receptor Genes in the Lur Population of Iran

Background: The pathophysiology underlying the progression and development of autoimmune conditions, such as Rheumatoid Arthritis (RA), is a result of dysregulations of the immune system. Research has explored the genetic alterations present in RA; however, limited studies have examined the role of Killer cell Immunoglobulin-like Receptors (KIR) and Human Leukocyte Antigen (HLA) molecules in RA. Therefore, the aim of this study was to examine KIR genes, their HLA ligands, and KIR-HLA compounds in patients with RA. Methods: In this case-control study, a total of 50 patients with RA and 100 healthy individuals were enrolled. DNA samples were evaluated using PCR with sequence specific Primers (PCR-SSP). Odds ratio (OR) with a 95% confidence interval (CI) were reported. Results: Among the KIR genes examined, KIR2DLA (p= 0.0255, OR= 0.389, 95% CI= 0.210-0.722) and KIR2DS4-full (p< 0.0001, OR= 6.163, 95% CI= 3.174-11.968) were observed to have a statistically significant correlation with disease susceptibility to RA. As an inhibitory gene, KIR2DLA was observed to have a protective effect against RA while KIR2DS4-full as an activating gene, was found to increase risk for RA. No significant associations were found between any of the other KIR genotypes, HLA ligands, or KIR-HLA compounds examined in this study to RA susceptibility. Conclusions: In this study of RA in the Lur population of Iran, KIR2DS4-full was observed to increase susceptibility to RA, while KIR2DL5A was found to act as a protecting factor based on both the cross Table and regression analyses. Further research should focus on repeating this study in additional populations.