Impact of Human Toll-Like Receptor 4 Gene Polymorphism on Infection with Trichomonas vaginalis

Abstract Background: Trichomonas vaginalis ( T. vaginalis ) is an anaerobic protozoan characterized by functional diagnostic flagella which are important motility tools. Trichomonas vaginalis triggers the innate immune system and the corresponding Toll-like receptors (TLRs). Specimens taken from infected women stimulated the TLR4-responsive cells of mice spleens to produce cytokine. Objectives: This genetic study aims to examine the impact of TLR4 single nucleotide polymorphism (SNP, rs4986790) on Iraqi women infected with T. vaginalis . Materials and Methods: Swabs and blood samples were isolated from 186 female patients who were admitted to the gynecology clinic in Al-Sadiq Hospital in Hilla City, Babylon province in Iraq. These samples were obtained for molecular identification of the parasite and sequencing of the TLR4 gene. Results: The polymerase chain reaction (PCR) analysis showed 40 females with positive PCR results (95% CI, 15.85–28.11) of the T. vaginalis β-tubulin gene. The frequency of A allele carriers was slightly higher (33/59) among women infected with trichomoniasis versus that in healthy controls (26/59), while the mutant G allele frequency was greater (7/11) among infected women versus controls (4/11). Moreover, the prevalence of the three genotypes, AA, AG, and GG, among infected women was 75%, 15%, and 10%, respectively ( P < 0.001). Importantly, the homozygous GG genotype in infected women showed two times higher frequency (2/3) than controls (1/3). Conclusion: Although there was no statistically significant impact of TLR4 SNP (rs4986790) on susceptibility to T. vaginalis infection among tested women, GG genotype carriers of this SNP might have more sensitivity for trichomoniasis than other genotypes, and the AA genotype did not show protection against this infection.