A functional promoter polymorphism in interleukin-10 gene influences susceptibility to endometriosis.

OBJECTIVE

To investigate the involvement of inflammation in the development of endometriosis.

DESIGN

Case-control study to investigate the association between endometriosis and four inflammation-related genes: interleukin (IL)-6, IL-10, IL-1 beta, and cyclooxygenase-2.

SETTING

University hospital.

PATIENT(S): We had 196 cases with pathologically proved endometriosis and 397 disease-free women as control subjects.

INTERVENTION(S): A total of 12 single nucleotide polymorphisms (SNPs) were selected for genotyping, including functional SNPs and common tagging SNPs.

MAIN OUTCOME MEASURE(S): Logistic regression and haplotype analyses were performed to evaluate the genetic effect with adjustment for other covariates.

RESULT(S): Genotypes at each SNP were in Hardy-Weinberg equilibrium in either case or control subjects, except for rs1800871 at IL-10 in the case subjects (P=.04). We found that the individuals carrying minor allele C of a functional promoter SNP rs1800871 at IL-10 was associated with a reduced risk by approximately twofold compared with the common TT genotype. The T allele was reported to have a lower gene expression level than the C allele, suggesting inadequate suppression of inflammation leading to endometriosis development. Haplotype analysis of the IL-10 gene did not yield a better result. Other genes were not associated with endometriosis.

CONCLUSION(S): This study suggests that the functional promoter polymorphism at IL-10 may play a role in the development of endometriosis.