The association of IL-33 and Foxp3 gene polymorphisms with recurrent pregnancy loss in Egyptian women.

Deregulated immunity is one of the most important factors implicated in recurrent pregnancy loss (RPL). The possible role of interleukin-33 (IL-33) and forkhead/winged helix transcription factor (Foxp3) in RPL have not been fully investigated. We aimed to evaluate IL-33 rs1929992 and Foxp3 rs2232365 single nucleotide polymorphisms (SNPs) and their serum levels in Egyptian RPL females. Blood samples were collected from 142 RPL patients and 123 women as healthy controls. IL-33 rs1929992 SNP was determined by polymerase chain reaction restriction fragment length polymorphism and Foxp3 rs2232365 SNP was determined using allele specific polymerase chain reaction. The serum IL-33 and Foxp3 levels were measured by enzyme linked immunosorbent assay. Foxp3 rs2232365 SNP showed statistically significant association with RPL. The risk of RPL was significantly higher in women carrying Foxp3 G allele than those carrying A allele. Lower serum levels of Foxp3 and IL-33 were observed in RPL patients than controls (P < 0.001). Foxp3 serum levels were much lower in carriers of G allele than those carrying A allele in all studied groups. Foxp3 rs2232365 SNP could be considered as a risk factor for RPL. The lowered serum levels of IL-33 and Foxp3 in RPL patients suggested that they might have an important role in the pathogenesis of the disease. Therefore, we hypothesized that Foxp3 polymorphisms may be important in RPL pathogenesis.