Polymorphisms in RNA sensing toll like receptor genes and its association with clinical outcomes of dengue virus infection

Functional polymorphisms in RNA recognizing toll like receptors (TLR) 3, 7, 8 and toll-interleukin-1 receptor domain containing adapter protein adapter (TIRAP) coding genes were investigated in 120 dengue cases [87 dengue fever (DF) cases and 33 dengue hemorrhagic fever (DHF) cases] and 109 healthy controls (HC) to identify their association with clinical outcomes of dengue virus infection. Results revealed significantly lower frequency of TLR3 rs3775291 T allele [DHF vs. DF P = 0.015 odds ratio (OR) with 95% confidence interval (CI) 0.390 (0.160-0.880); DHF vs. HC P = 0.018 OR with 95% CI 0.410 (0.170-0.900)] and 'T' allele carriers [DHF vs. DF P = 0.008 OR with 95% CI 0.288 (0.115-0.722); DHF vs. HC P = 0.040 OR with 95% CI 0.393 (0.162-0.956)] and higher frequency of TIRAP rs8177374 'C/T' genotype [DHF vs. HC P = 0.020 OR with 95% CI 2.643 (1.167-5.986)] in DHF. Higher frequency of TLR8 rs3764879-rs3764880 haplotype C-A was observed in male DF cases compared to male HC [P = 0.025 OR with 95% CI 2.185 (1.101-4.336)]. The results suggest that TLR3 and TIRAP gene variants influence the risk for DHF.