The Impact of Toll-Like Receptor 2 Genetic Variations on Susceptibility to Tuberculosis
Keywords: tuberculosis, Mycobacterium, toll-like receptor 2, polymorphism
AbstractBackground: Tuberculosis is a disease of worldwide distribution. This disease is known to caused by Mycobacterium tuberculosis, however several environmental and genetic factors can affect the occurrence and progression of the disease. Toll-like receptor 2 (TLR2) has a particular importance in immune response against this bacteria.
Aims: This study aimed to investigate the association of two single nuclotide polymorphisms(SNPs) in TLR2 gene which are Arg677Trp and Arg753Gln with the incidence of TB in Iraqi patients.
Subject and Methods: A case-control study was conducted which involved 55 patients with confirmed pulmonary TB and other age-matched unrelated 30 healthy individuals as control group. Blood samples were obtained from each subject and DNA was extracted. The gene of TLR2 was amplified with polymerase chain reaction (PCR) using specific sets of primers. Genotyping was achieved by direct sequencing.
Results: Only the SNPArg753Gln appeared in two genotypes which were GG and AG in both TB patients and control groups. In TB patients, these genotypes account for 44 (85.45%) and 11 (14.55%) respectively, compared with 29 (96.7%) and 1 (3.3%) respectively in control group with significant difference (OR =7.251 95% CI=1.008-59.211, P = 0.035). The SNP Arg677Trp had only one genotype which was CC.
Conclusion: The allele A of the SNP Arg753Gln could be considered as a risk factor for TB among Iraqi patients.