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

[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 combinations can enhance cancer predisposition by promoting immune evasion. Studying the relationship between 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 and genes (OR = 0.15, 95% CI = 0.05-0.41, = 0.0001; OR = 0.06, 95% CI = 0.02-0.2, = 0.000, respectively) and in the presence of the gene (OR = 0.05, 95% CI = 0.02-0.14, = 0.0000) in the TC group compared to the HC group. The frequency of the allotype was significantly higher in HC compared to patients with TC ( = 0.02). The KIR haplotype group A and AB genotypes revealed a protective effect against TC ( = 0.0003 and = 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 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.