Polymorphisms rs3804099 (TLR2) and rs352139 (TLR9) may also be associated with PTB risk in the Moldavian population but their effect is less consistent across different studies.
The GA-genotype of TLR9rs187084 SNP was found to increase the risk of PTB with an OR of 1.68 (1.07-2.65), but was found to decrease the risk of MTB infection with an OR = 0.64 (0.41-0.98).
Genotyping was performed to detect -196 to -174 del polymorphism and G2258A SNP (Arg753Gln, rs5743708) in TLR2 gene and -T1237C (rs5743836) and G2848A (rs352140) SNP in TLR9 gene in patients with pulmonary TB and healthy controls.
The important findings were (1) reduced PBMC secretion of IL-8 in response to all ligands in active TB; (2) normal to increased PBMC secretion of IL-8 in response to all ligands except CpG ODN (TLR 9 ligand) in TB patients who had recovered; (3) absence of difference in mRNA expression for a consortium of inflammatory pathway genes between healthy controls, active pulmonary tuberculosis and treated pulmonary tuberculosis patients.
CONCLUSIONS There was no association between the polymorphisms in TLR4 and 9 and PTB risk overall, but TLR4 rs4986791 and TLR9rs352139 might be associated with increased PTB risk in Africans and Asians, respectively.
We further selected three different tribe populations showing differential susceptibility to PTB and performed genotypic analyses for the TLR9 promoter.
In the present study, we investigated whether variants in the TLR-1 1805T/G (Ile602Ser), TLR-2 2258G/A (Arg753Gln), TLR-4 896A/G (Asp299Gly), TLR-4 1196C/T (Thr399Ile), TLR-6 745C/T (Ser249Pro), TIRAP 975C/T (Ser180Leu) genes and TLR-9 promoter region polymorphisms at positions -1237C/T and -1486C/T are associated with susceptibility or resistance to pulmonary tuberculosis (PTB).