Among the subjects, D543NNRAMP1 polymorphism, history of contact with TB patients, and not having a clear BCG scar on the upper arm tended to be significantly association with active TB.
Association studies have revealed that host genetic factors, such as human leukocyte antigen and solute carrier family 11 member A1 (NRAMP1), play roles in susceptibility to TB.
For example, tumour necrosis factor polymorphisms have been associated with susceptibility to malaria and other infections; chemokine receptor polymorphisms with susceptibility to HIV; natural resistance-associated macrophage protein 1 with tuberculosis; and mannose binding lectin polymorphisms with meningococcal disease.
Heterozygosity for a newly studied CAAA insertion/deletion polymorphism in the 3'-untranslated region of solute carrier family 11, member 1 (SLC11A1, formerly NRAMP1) was associated with protection against TB in both HIV-positive (OR = 0.70, 95% CI = 0.49-0.99, P = 0.046) and HIV-negative (OR = 0.65, 95% CI = 0.46-0.92, P = 0.014) TB cases, suggesting that the SLC11A1 protein may have a role in innate TB immune responses that influence susceptibility even in immunocompromised individuals.
Heterozygosity for the -1082 polymorphism of the IL-10 promoter and heterozygosity for 2 linked polymorphic NRAMP1 variants, D543N and 3' untranslated region, were associated with TB susceptibility and resistance, respectively.
Human susceptibility to infectious and inflammatory diseases, including rheumatoid arthritis, inflammatory bowel disease, and tuberculosis, shows allelic association with a highly polymorphic regulatory, Z-DNA-forming microsatellite of (GT/AC)n dinucleotides within the proximal SLC11A1 promoter.
In the homologous human NRAMP1 gene, a total of 11 polymorphisms have been identified, which are being used to test for the linkage of NRAMP1 alleles with human responses to mycobacteria, including susceptibility to tuberculosis and leprosy, as well as BCG immunotherapy in bladder cancer.
In the present study, we scanned the regulatory and coding region of Nuclear LIM Interactor-Interacting Factor gene (NLI-IF), which is physically close to the tuberculosis-associated gene NRAMP1.