Changes in the Molecular Genetic Profile of IL-1β, TNFα, and Endothelial Nitric Oxide Synthase in Women with Recurrent Miscarriage

Recurrent pregnancy loss is a complex and multifactorial disorder, of unknown origin in approximately 50% of cases. The aim of this study was to investigate the association of eNOS gene polymorphisms with a risk of recurrent pregnancy loss, as well as to evaluate the correlations between eNOS gene polymorphisms and IL-1 β and TNF α gene expression levels. Biological material was taken from 163 patients with reproductive losses (vaginal and cervical mucosal scrapings, venous blood). Detection of the studied markers was performed using real-time PCR. Statistical analysis of the results was performed using the Mann-Whitney U test and Fisher's exact test. The study revealed differences in gene expression of proinflammatory cytokines depending on the type of recurrent pregnancy loss. In patients with recurrent miscarriage, a statistically significant increase in IL-1 β and TNF α gene expression was observed in cervical mucosal cells compared to the sporadic miscarriage cases and control groups. In sporadic miscarriages, the trends to increased IL-1 β gene expression were observed in peripheral leukocytes, and TNF α gene expression, in cervical mucosal cells. It should be noted that IL-1 β gene expression in vaginal mucosal cells was detected exclusively in sporadic miscarriage group, which may reflect some specific features of local immune response in this disorder. The results of our study also revealed a prognostic significance of eNOS gene variants ( G894T, C774T, and T786C ) of the GTCTTC haplotype as a risk factor for the development of sporadic miscarriage. Meanwhile, the GTCTTT haplotype and the T/T genotype of the G894T and C774T gene variants demonstrated protective properties in this disorder. An association has been revealed between IL-1 β gene expression levels and the G894T, C774T , and T786C polymorphic markers of the eNOS gene. It was found that the TT genotype ( T786C ) is associated with low IL-1β expression, while the CC genotype (T786C) correlated with increased expression of this gene in peripheral leukocytes. A link between IL-1β expression in cervical mucosal cells and these eNOS polymorphic markers was also confirmed. IL-1β expression was shown to be genotype-dependent on the T786C polymorphism: IL-1 β gene expression was absent in carriers of the TT genotype, being detectable in carriers of the TC genotype. These findings may serve as a basis for predicting the miscarriage risk.