Genetic variation and up-regulation of IL-12 enhance susceptibility to recurrent vulvovaginal candidiasis

Abstract

Objective(s)Approximately up to 9% of women may experience more than three episodes per year of vulvovaginal candidiasis (VVC) that is named as recurrent vulvovaginal candidiasis (RVVC). Genetic factors play an important role in the susceptibility to RVVC. This study was aimed to find the effect of genetic variants of interleukin (IL)-12 genes as well as mRNA expression level for on susceptibility to RVVC caused by Candida albicans. MethodsIn this case-control study, 95 patients with RVVC and 101 healthy controls were enrolled. The expression level and prevalence of polymorphisms in IL-12 was assayed using real-time PCR and ARMS-PCR, respectively. Single nucleotide polymorphisms (SNPs) in IL-12 (rs568408) are associated with the susceptibility to RVVC. ResultsAnalysis of IL-12A gene alleles at rs568408 position showed that 38.94% and 61.06% of the patients had allele A and G, respectively. However, in the healthy control 43.57% and 56.43% had alleles A and G, respectively. This difference in frequency of A and G alleles between the control and patients group was statistically significant. In the present study the highest ratio of IL-12A (rs568408) genotypes for patients with RVVC was belonged to AG (63.15%), followed by GG 29.47%, and AA (7.38%). While, the highest ratio of IL-12A (rs568408) genotypes for the control individuals was belonged to AG (73.26%) followed by AA (19.80%), and GG (6.94%) that was significantly different with the patients. In the patients with RVVC, the mRNA level of IL-12 was significantly up-regulated compared to the control group. ConclusionThe results of this case-control study suggest that the IL-12 rs568408 polymorphism might play a role in the recurrent Candida infections. Genetic variation in IL-12 may significantly enhance susceptibility to RVVC by up-regulation of IL-12 expression. The genotype frequency and A/G alleles at position IL-12 rs568408 in patients with RVVC caused by C. albicans and healthy individuals were significantly different.