Promoter ‐817C>T Variant of B Lymphocyte Stimulator Gene (BLyS) and Susceptibility to Endometriosis‐Related Infertility and Idiopathic Infertility in Brazilian Population

Abstract

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.

CYP19 gene variant confers susceptibility to endometriosis-associated infertility in Chinese women

“…It was previously reported in the Brazilian population that polymorphisms in the nuclear factor-κB gene promoter, B lymphocyte stimulator gene promoter and TYK2 were associated with endometriosis-related infertility. 33, 34, 35 Nevertheless, we report here for the first time that in the Chinese Han population the CYP19 rs700518 AA genotype is associated with endometriosis-related infertility. This result indicates clinical relevance with regard to two aspects.…”

The possible role of genetic variants in autoimmune-related genes in the development of endometriosis

“…In contrast, Christofolini et al (2011) [126] performed a casecontrol study in 165 infertile women with endometriosis, 83 women with idiopathic infertility, and 145 fertile women; the results disclosed similar genotype and allelic frequencies between the endometriosis-related infertility and control group, regardless the disease stage. However, a statistically significant difference was observed regarding the idiopathic infertile group compared with controls.…”

“…Once, in a study by Graaff et al (2010) [125], the genotype frequencies of patients with deep infiltrating endometriosis were not in Hardy-Weinberg equilibrium, and the authors did not mention the reproductive status of their patients. Christofolini et al (2011) [126] supposed that, maybe, in the Graaff et al sample, some patients presented with infertility associated with endometriosis. The authors concluded that BLyS Ϫ817C/T polymorphism may play a role in the pathogenesis of infertility in Brazilian population.…”

Peritoneal immune microenvironment of endometriosis: Role and therapeutic perspectives

“…Numerous studies have reported that the number of B cells increased in the PF of patients with endometriosis (144, 145). In contrast, some reports demonstrated that there is no significant difference in the B cells count of PF between endometriosis patients and patients in the control group (146). A few other studies have also demonstrated decreased numbers of B cells (147).…”