Analyses of polymorphisms in the inflammasome-associated NLRP3 and miRNA-146A genes in the susceptibility to and tubal pathology of Chlamydia trachomatis infection.

Susceptibility to Chlamydia trachomatis infections is 40% host based. microRNA-146a is a negative regulator of Tolllike receptor (TLR) signaling and possesses functional polymorphisms which decrease the production of premiR-146a and mature miR-146a. Single nucleotide polymorphisms (SNPs) in NLRP3 are associated with decreased NLRP3 expression and hypoproduction of interleukin (IL)-1beta. We investigated whether the SNPs miR-146a G>C (rs2910164), NLRP3 C>T (rs4925663) and G>A (rs12065526) are associated with the susceptibility to and severity of C. trachomatis infection. The genotypes of three SNPs were tested in two cohorts: cohort 1 consists of Dutch women (n = 318) attending a sexually transmitted disease (STD) clinic and cohort 2 (n = 277) consists of subfertile (n = 184) and healthy Finnish women (n=93). While in cohort 1 the analyzed SNPs were not associated with the susceptibility to C. trachomatis infections (C. trachomatis-positive vs. C. trachomatis-negative), we showed in C. trachomatis-positive women that the NLRP3 mutant AG and AA genotypes were a risk factor for the development of symptoms (P = 0.047, OR = 2.9) and more specifically for having lower abdominal pain (genotype AA: P = 0.022, OR = 31.3). In the Finnish tubal pathology group versus the control group no statistical significant differences in the incidences of the SNPs studied were found, nor for the degree of tubal pathology. In conclusion, the mutant NLRP3 A allele is a risk factor for the development of symptoms, specifically lower abdominal pain, after a C. trachomatis infection in women attending an STD clinic.