Interleukin-10 Gene Polymorphisms Modulate the Risk of Infertility in Chlamydia trachomatis Positive Kurdish Women in Erbil Province

Abstract

Background: There is evident inter-individual variability in women's responses to Chlamydial infections and reproductive tract problems. Women's genetic variations within the Interleukin-10 (IL-10) gene have been linked to variances in response to Chlamydia trachomatis infection. This study was aimed to demonstrate the profound association of IL-10 with infertility and demonstrate the role of IL-10 (-592 C/A rs1800872) and (-1082 A>G rs1800896) single nucleotide polymorphism (SNPs) gene in the susceptibility and severity of a C. trachomatis infection.

Methods: In this evaluation study, serum IL-10 concentration was measured in 134 women diagnosed with infertility and 50 healthy volunteers by enzyme-linked immunosorbent assay (ELISA). The tetra-amplification refractory mutation system-PCR (T-ARMS-PCR) analysis was performed to detect the genotyping of the rs1800872 and rs1800896 SNPs genes.

Results: Both female groups were positive for anti-chlamydial IgM antibody, but the intensity of response differed between cases. At the same time, the incidence of genital C. trachomatis by PCR was 46.2% in infertile women. The serum concentration of IL10 was lower in infertile women than healthy participants and higher in infertile C. trachomatis -positive women compared to infertile C. trachomatis-negative in all groups except endometriosis (Endo) infertility. In rs1800872, the CA genotype and C allele are associated with an increased risk for infertility, except in polycystic ovarian syndrome (PCOS), which is an A allele. In the case of rs1800896, the AG genotype and G allele show a greater risk for infertility.

Conclusions: Our results confirmed that rs1800872 and rs1800896 gene polymorphisms were associated with an increased risk of C. trachomatis infection.

Keywords: Chlamydia trachomatis; Female infertility; IL-10; SNP.

Fig. 1

PCR amplification of MOMP gene of C. trachomatis. The first lane indicates a 100 bp DNA ladder; lanes 2, 3, 5, 7, 8, and 9 indicate positive C. trachomatis samples; lanes 3 and 5 indicate negative C. trachomatis samples; lane 10 indicates negative control.

Fig. 2

Amplification bands of the different genotypes of SNP rs1800872: first lane 100 bp DNA ladder; lanes 2-7, 9, 11-14, 16-18, 20-22 indicate AA genotype; lanes 8, 10, 15 indicate CA genotype; lane 19 indicate CC genotype. Genotyping interpretation (CC: N: 211, 425 bp; CA: HE: 211, 268,425 bp; AA: MH: 268, 425 bp). NH: Normal homozygote; HE: Heterozygote; MH: Mutant homozygote.

Fig. 3

Amplification bands of the different genotypes of SNP rs1800896: first lane 100 bp DNA ladder; lanes 2, 10 indicate AG genotype; lanes 3-5, 7-9, 11, 12 indicate AA genotype; lane 6 indicate GG genotype. Genotyping interpretation (AA: NH: 292, 433 bp; AG: HE: 199, 292, 433 bp; GG: MH: 199, 433 bp). NH: Normal homozygote; HE: Heterozygote; MH: Mutant homozygote.

Fig. 4

Mean distribution of serum anti-chlamydial IgM with standard deviation and their correlation with Endo, PCOS, TFI, and UI women infertile groups. *P < 0.05 was considered statistically significant; ns indicate non-significant.

Fig. 5

Mean distribution of serum anti-chlamydial IgM with standard deviation and C. trachomatis PCR results in Endo, PCOS, TFI, and UI women infertile groups; –ve indicate negative C. trachomatis group, +ve show negative C. trachomatis group.

Fig. 6

Mean distribution of serum IL-10 with standard deviation among fertile and infertile participants; *P < 0.05 was considered statistically significant; ns indicate non-significant.

Fig. 7

Mean distribution and standard deviation of serum IL-10 concentration according to IL-10 (-592C/A) genotype among fertile and infertile participants.

Fig. 8

Mean distribution and standard deviation of serum IL-10 concentration according to -1082 A /G genotypes among fertile and infertile participants.

Fig. 9

Mean distribution and standard deviation of serum IL-10 concentration according to C. trachomatis PCR results among infertile participants; –ve indicates negative C. trachomatis group, +ve indicates negative C. trachomatis group.

Fig. 10

Estimating serum anti-chlamydial IgM according to IL-10 -592 C/A and − 1082 A /G genotypes among different infertile groups.