TLR8 gene polymorphism and association in bacterial load in southern Punjab of Pakistan: an association study with pulmonary tuberculosis

Only 5-10% of people infected with Mycobacterium tuberculosis develop active tuberculosis which suggests a role of genetic variation in host immunity. Genetic variants in TLRs are potential indicator for host susceptibility and outcome of several diseases. We explored the association of nonsynonymous genetic variants (Met1Val) with Toll-like receptor 8 in Pakistani population. Genotypic and allelic distribution of TLR8 polymorphism (rs3764880) in patients with TB and healthy donors from different areas of southern Punjab, Pakistan, was determined. Results provide that our population is highly influenced by TLR8 Met1Val SNP for TB, and G allele appeared to increase TB susceptibility. Mutant genotype GG or G/- and G allele was significantly higher among all the categories of cases than in controls. Among different levels of bacillary load and genotypes, GG or G/- and G allele significantly supports the incidence of 2 + class for bacterial load.