Research on the Relationship Between Interleukin-1 Receptor Antagonist and Endometriosis

Objective To analyze whether the expression level of interleukin-1 receptor antagonist(IL-1Ra) or gene polymorphism of IL-1Ra is associated with endometriosis(EMs).Methods Blood sample and peritoneal fluid were collected from 138 patients with EMs and 100 controls without EMs.The level of IL-1Ra in serum and peritoneal fluid was detected with ELISA.And the gene of IL-1Ra was amplified with PCR.Results No significant difference was found for IL-1Ra level in serum between two groups(P0.05).However,the IL-1Ra level in peritoneal fluid of patients with EMs was significantly lower than that of controls,the median is 102.64pg/ml and 175.18pg/ml respectively(P0.05).According to staging criteria of r-AFS,the IL-1Ra level in peritoneal fluid of patients with Ⅲ-Ⅳstage EMs was lower than with Ⅰ-Ⅱ stage EMs and significantly lower than in controls(P0.05).The frequencies of genotype A1/A1,A1/A2,A1/A4 and A2/A2 for IL-1Ra were 84.1%,12.3%,2.9% and 0.7% in EMs and 95%,4%,1% and 0% in controls,respectively(P0.05).The frequencies of A1,A2,and A4 allele were 91.7%,6.9% and 1.4% in patients and 97.5%,2%,0.5% in controls(P0.05).The variant genotype A1/A2 significantly increased EMs risk compared with the wild genotype A1/A1(OR=3.48 95%CI: 1.13-10.69).And allele A2 also increased EMs risk compared with allele A1.(OR=3.66 95%CI: 1.23-10.94).Conclusions The IL-1Ra level in EMs,especially in Ⅰ-Ⅱ stage EMs,was significantly lower than that in controls.It suggests that the IL-1Ra may be involved in the pathogenesis of EMs and correlated with the severity of EMs.The A2 allele of IL-1Ra may be one of the risk factors for the Chinese women to suffer EMs.