Association of killer cell immunoglobulin-like receptor genotypes with susceptibility to endometriosis

PROBLEM: Endometriosis is an immune-related chronic inflammatory disease with a polygenic predisposition. The aim of this study was to investigate whether polymorphisms in killer cell immunoglobulin-like receptors (KIRs) is responsible, in part, for genetic susceptibility to endometriosis. METHOD OF STUDY: The KIRs genotype was determined in 186 patients with endometriosis and 165 control women using polymerase chain reaction with sequence-specific primers. RESULTS: The frequency of KIR3DS1 was significantly decreased in patients compared with controls (32% versus 44%, P=0.028). KIR data were analyzed using a model comprised of three large groups, in which a gradient of activation/inhibitory potential derived from the combination of KIR and human leukocyte antigen (HLA) ligand genes was taken into account. The frequency of inhibitory KIRs/HLA-class I combination genotypes was significantly higher in patients than in controls (chi2=6.010, 2 df, P=0.0496). CONCLUSION: Our results suggest that polymorphism in KIRs may be associated with susceptibility for endometriosis.