The Association Between Endometriosis and Polymorphisms in the Interleukin-1 Family Genes in Korean Women

Problem: To investigate the association between polymorphisms of the interleukin-1 (IL-1) family genes and endometriosis in Korean women. Method of study: In this case-control study, the IL-1α -889C>T, IL-1 receptor antagonist (IL-1RA) 86-bp microsatellite, IL-1 receptor 1 (IL-1R1) 52C>A, 294C>T, 1498T>C, 1632A>G, IL-1R2 rs2072472 C>T and rs7561460 C>T polymorphisms were analyzed in women with (n = 138) and without (n = 214) endometriosis using restriction fragment length polymorphism (RFLP) analysis, TaqMan assay, or DNA sequencing. Serum IL-1α, soluble IL-1RA (sIL-1RA), and sIL-1R2 levels were measured by enzyme-linked immunosorbent assay (ELISA). Results: Among the polymorphisms measured, the 1498T>C polymorphisms in the IL-1R1 gene were found to be related with early-stage endometriosis but not with advanced-stage endometriosis. The genotypes with at least one T allele (CT + TT) were less frequently observed in early-stage endometriosis compared with normal controls (OR = 0.44, 95% CI = 0.22-0.87, P = 0.02). Serum sIL-1R2 levels were significantly lower (P < 0.01) in women with endometriosis than in normal controls, whereas no difference in serum sIL-1RA levels between these two groups was noted. The single and haplotype genotypes of the IL-1R2 and IL-1RA microsatellite polymorphisms were not related with these serum levels. Conclusion: The IL-1R1 1498T>C polymorphism is associated with early-stage endometriosis in Korean women.