Association of the IL-6 gene rs1800796 polymorphism with recurrent pregnancy loss in a population of women from northwestern China: a case-control study

Abstract

We aimed to identify whether IL-1β (rs1143627, rs1143634 and rs16944), IL-6 (rs1800796), IL-10(rs1800872 and rs1800896), and vascular endothelial growth factor (VEGF) (rs1570360) gene polymorphisms were risk factors for recurrent pregnancy loss (RPL) in a population of women in northwestern China. A total of 150 women with a history of two or more unexplained and consecutive spontaneous abortions before their 24th gestational week and 150 age-matched women with at least two normal pregnancies and no history of pregnancy loss were included in the present study as cases and controls, respectively. We extracted genomic DNA from peripheral blood, and executed genotyping with the SNaPshot technique. Logistic regression analysis was conducted to determine the odds ratios (ORs) of the associations between the polymorphisms and RPL. Of the seven polymorphisms we studied, only IL-6 rs1800796 showed a statistically significant association with RPL, as we noted an elevated risk of RPL with the G allele (OR = 1.57; 95% CI, 1.10–2.24; p = .01). The risk of RPL in women with the GG + CG genotype (OR = 1.96; 95% CI, 1.19–3.21; p = .01) was also higher than that in women with the CC genotype. The present study thus indicated that the IL-6 gene rs1800796 polymorphism may serve as an important risk factor for RPL in this group of women from northwestern China. IMPACT STATEMENT What is already known on this subject? Cytokine and vascular endothelial growth factor (VEGF) gene polymorphisms may affect the risk of recurrent pregnancy loss (RPL) by modulating cytokine and VEGF expression. What do the results of this study add? The study results showed that the IL-6 rs1800796 single-nucleotide polymorphism constituted a risk factor for RPL in a population of women in northwestern China. What are the implications of these findings for clinical practice and/or further research? This study clearly reflects clinical significance as it provides a theoretical basis for the early screening of RPL by revealing that the IL-6 gene rs1800796 polymorphism increased the risk of RPL in women in northwestern China.