Survivin promoter polymorphisms and autoantibodies in endometriosis

Expression of survivin, an inhibitor of apoptosis, is increased in endometriotic lesions and probably favors the survival of endometrial fragments in the peritoneal cavity. The aim of this study was to evaluate associations between survivin promoter polymorphisms and the risk of endometriosis, as well as to compare the immunoreactivity to survivin in sera of patients with and without endometriosis. We studied 149 women with endometriosis, 196 fertile women from the general population (control group A) and 47 women who had undergone diagnostic laparoscopy and had no evidence of endometriosis (control group B). There were no significant differences in the genotypic distribution of the survivin gene promoter region -241C/T, -235G/A and -31G/C single nucleotide polymorphisms (SNP) between endometriosis patients and the two control groups. In addition, also median anti-survivin autoantibody levels were similar among patients and controls (group B). However, anti-survivin antibody concentrations seemed to be influenced by cigarette smoking, being significantly lower in sera of actively smoking women compared to non-smokers (median OD: 0.019 vs. 0.155, respectively, P<0.001), and by the -235G/A SNP, as A allele carriers were significantly more frequent among women with a high antibody level (OD≥2.0) compared to those with lower concentrations (OD<2.0) (23.1% vs. 4.1%, respectively, P=0.008). Based on these results, we conclude that survivin promoter polymorphisms are not associated with susceptibility to endometriosis in the Estonian population, and though the expression of survivin is increased in endometriotic lesions, autoimmune reactivity against it is similar in women with and without the disease.