Associations of Killer Cell Immunoglobulin-Like Receptor Genes with Rheumatoid Arthritis

Objective: Rheumatoid Arthritis (RA) is an autoimmune and chronic inflammatory disease of unknown etiology. Killer cell immunoglobulin-like receptors are expressed on the surface of natural killer cells and CD28nullT-cells, both present in synovial membrane of RA. Therefore we evaluated the associations ofKIRgenes with RA.Methods: 16KIRgenes were genotyped in 100 healthy subjects (HS) and 100 RA patients from Western Mexico using PCR-SSP. Differences inKIRgenotypes and gene frequencies were assessed using theX2test.Results: Gene frequency ofKIR2DL3was lower in RA than in HS (p= 0.0019), whereasKIR2DL2andKIR2DS2were higher in RA than HS (p= 0.0004 andp= 0.0487, respectively). In addition were identified 38 genotypes (from G1-G38) in both studied groups, and the genotype frequencies of G1, G6 and G14 showed significant differences (p= 0.0001,p= 0.0208 andp= 0.0300, respectively).Conclusions: The presence ofKIR2DL2,KIR2DS2and absence ofKIR2DL3are associated with RA. Moreover, two genotypes BX are associated with RA. These results suggest thatKIRscan be involved in RA susceptibility.