BACKGROUND
Host immunity is essential for efficient recognition and clearance of M. tuberculosis infection. Polymorphisms in genes that regulate immune response have been reported to influence the susceptibility/resistance to pulmonary tuberculosis (TB). Here we evaluated associations between 14 polymorphisms in 12 core genes involved in immune responses and pulmonary TB in Moldavian population, and investigated whether interactions between these and previously analyzed polymorphisms could exist and modulate the risk of pulmonary TB.
METHODS
Polymorphisms VDR rs7975232, VDR rs1544410, VDR rs2228570, MR1 rs1052632, TLR1 rs5743618, TLR2 rs111200466, TLR10 rs11096957, SLC11A1 rs2276631, IL1B rs1143643, IL10 rs1800896, IFNG rs2430561, TNF rs1800629, IRAK1 rs1059703, and FOXP3 rs2232365 were genotyped in 271 Moldavian pulmonary TB cases and 251 community-matched healthy controls. Associations were tested using Fisher test and logistic regression. Complemented with the data from our previous study (PMID: 30529560), investigation of gene-gene interactions was performed for a total of 43 loci. Significance level was adjusted by the Bonferroni correction.
RESULTS
Single polymorphism analysis revealed a nominal association between TNF rs1800629 and pulmonary TB (Fisher exact test p-value = 0.01843). Marginal differences between cases and controls were observed for haplotypes in the gene cluster TLR1-TLR6-TLR10 and gene TLR2. In the pairwise interaction analysis, the combination of genotypes TLR6 rs5743810 GA and TLR10 rs11096957 GT was significantly associated with an increased genetic risk of pulmonary TB (OR = 2.48, 95% CI = 1.62–3.85; Fisher exact test p-value = 1.5 × 10− 5, significant after Bonferroni correction).
CONCLUSION
The TLR6 rs5743810 and TLR10 rs11096957 two-locus interaction confers a significantly higher risk for pulmonary TB and has potential as a novel biomarker for predicting TB susceptibility.