Genetic Association of Interferon Gamma Induced Protein-10 (IP-10), CXCL- 10 Gene Polymorphisms with TB Pleurisy Susceptibility in South Indian Population

Abstract

CXCL-10 known as Interferon gamma-induced protein 10 (IP-10) or small-inducible cytokine 10 is a 8.7 kDa protein, which is secreted in response to IFN-γ by monocytes, endothelial cells and fi-broblasts. It has chemo-attraction for monocytes/macrophages, T cells, NK cells and dendritic cells in promotion of T cell adhesion to endothelial cells. In the present study, we investigated whether polymorphisms in CXCL-10 gene have any role in the manifestation of Tuberculous (TB) pleurisy. Two SNPs in CXCL-10 promoter region (﹣1447A > G and ﹣135G > A) were genotyped in patients with TB Pleurisy (n = 186), Pulmonary TB patients (n = 159) and healthy controls (n = 205) by PCR-RFLP. Disease associations were statistically analyzed by Fisher exact test. At the ﹣135G > A position, the frequencies of genotype GA and allele G were significantly high in TB pleurisy patients compared to healthy controls. While the frequencies of genotype AA and allele A were significantly low in TB pleurisy patients compared to healthy controls. The frequency of haplotype A-G with the combination of 1447A > G and ﹣135G > A was significantly high in TB pleurisy. Our results reveal that genotype GA and allele G at ﹣135G > A position were strongly associated with susceptibility to tuberculous pleurisy. The GA genotype may be a useful genetic marker for early detection of the disease in high risk individuals.