Association of the Genetic Diversity of Killer Cell Immunoglobulin-like Receptor Genes and HLA-C Ligand in Saudi Women With Thyroid Cancer

Abstract

Introduction Genetic diversity in the killer immunoglobulin-like receptor (KIR) gene composition and human leukocyte antigen (HLA) class I ligands, such as HLA-C, can affect the activity of natural killer cells and determine anti-cancer immunity. Specific KIR-HLA combinations can enhance cancer predisposition by promoting immune evasion. Studying the relationship between KIR-HLA polymorphisms and thyroid cancer (TC) risk can offer insights into how natural immunity fails, leading to disease development. Therefore, we investigated the association between KIR and HLA-C genotypes and TC risk in Saudi women. Methods In this retrospective study, sixteen KIR genotypes and 2 HLA-C allotypes were determined using the polymerase chain reaction-sequence-specific primer (PCR-SSP) method, and the genotypes of 50 Saudi female patients with TC were compared with those of 50 Saudi female healthy controls (HC). Results We observed a highly significant decrease in the presence of the KIR2DS2 and KIR2DS4 genes (OR = 0.15, 95% CI = 0.05-0.41, P = 0.0001; OR = 0.06, 95% CI = 0.02-0.2, P = 0.000, respectively) and in the presence of the KIR2DL5A gene (OR = 0.05, 95% CI = 0.02-0.14, P = 0.0000) in the TC group compared to the HC group. The frequency of the HLA-C2C2 allotype was significantly higher in HC compared to patients with TC ( P = 0.02). The KIR haplotype group A and AB genotypes revealed a protective effect against TC ( P = 0.0003 and P = 0.000, respectively), while the BB genotype showed a risk effect on TC compared to HC. Our results showed significant differences in the KIR gene combinations and KIR-HLA combinations between Saudi female TC patients and HC. Conclusion These results suggest that the expression of KIR genes and their HLA-C ligands may influence the risk of TC development in Saudi women.