Promoter -817C>T variant of B lymphocyte stimulator gene (BLyS) and susceptibility to endometriosis-related infertility and idiopathic infertility in Brazilian population.

Many theories have been proposed to explain the development of endometriosis, and recently, autoimmune aetiology has been suggested. Besides, it is well known that endometriosis, especially the advanced disease, may impair fertility. B lymphocyte stimulator (BLyS) is a cytokine produced by macrophages and is necessary for normal B cell development. One of the most studied polymorphisms is the -817C/T in the promoter region of the gene. We aimed to assess the association between endometriosis-related infertility and idiopathic infertility and the BLyS -817C/T polymorphism in a Brazilian population. We performed a case-control study comprising 165 infertile women with endometriosis, 83 with idiopathic infertility and 145 fertile and assessed the association with BLys -817C/T polymorphism. BLyS -817C/T polymorphism was detected using TaqMan PCR. The results were analysed statistically, and a P-value < 0.05 was considered significant. The results disclosed similar genotype and allelic frequencies between endometriosis-related infertility (P = 0.225) and control group, regardless of the disease stage (P = 0.213 and P = 0.462, respectively). However, a statistically significant difference was observed regarding idiopathic infertile group (P = 0.048) compared with controls. Considering the dominant and recessive inheritance models, no significant differences in both endometriosis and idiopathic infertility group were found. The genotype frequencies were in Hardy-Weinberg equilibrium in all studied groups. The results point to a possible association between BLyS -817C/T polymorphism and idiopathic infertility in Brazilian population.

Analysis of CTLA4 gene variant in infertile Brazilian women with and without endometriosis.

An autoimmune aetiology has been suggested for endometriosis mostly on the basis of an increased prevalence of autoimmune diseases in affected women. Cytotoxic T lymphocyte antigen (CTLA) 4 gene is recognized as a primary determinant for autoimmunity, since specific polymorphisms have been associated with predisposition to most autoimmune disorders. Thus, the objective of the study was to evaluate CTLA4 polymorphism (+49A/G) in a group of infertile women with and without endometriosis and controls. Case-control study comprising 244 infertile women (177 with endometriosis and 67 without endometriosis) and 172 fertile women as controls. CTLA4 polymorphism was identified by qPCR. The results were analysed statistically and a P-value <0.05 was considered significant. We found relatively similar CTLA4 polymorphisms genotype frequencies in women with and without endometriosis and controls (P=0.158 and P=0.262, respectively). When the patients with minimal/mild endometriosis and moderate/severe endometriosis were studied separately, no difference was also found related to controls (P=0.560 and P=0.11, respectively). The data suggest that the CTLA4 polymorphism is not associated with endometriosis and/or infertility in Brazilian women.