A Pilot Study of Genetic Polymorphism of Interleukin-10 and Interferon-γ Genes as Potential Susceptibility Factors in Tuberculous Egyptian Children

Background: Tuberculosis (TB) is a world number one killer infectious disease. It has been estimated that 3.1 million children under 15 years of age are infected with TB worldwide. The risk of acquiring infection and developing severe complications are related to genetic variability at cytokines loci. Single nucleotide polymorphisms (SNPs) located at these genes could influence cytokine levels and regulate resistance and susceptibility to TB. Interferon-gamma (IFN-y) is crucial to control intracellular growth of Mycobacterium tuberculosis while interleukin-10 (IL-10) has an antagonistic role. The aim of this study: was to assess the functional significance of single base change polymorphic variant identified in the promoter region of IL10 (G-1082A) and the first interon of interferon gamma (T+874A) genes and its relationship to TB susceptibility. Subject & methods: Forty Egyptian tuberculous children and 40 healthy controls were genotyped using Allelic discrimination assay of IL10 (G-1082A) and IFN-g (T+874A) genes polymorphisms in a pilot study. Results: IL10 - 1082 G and IFNy + 874 A alleles frequency were higher in TB patient as compared to healthy control (67.5%vs 7.5% and 50%vs 15% respectively) with a significant association between TB and those alleles (p =0.000). Regarding relapse, and microscopy positive TB There was a statistically significant difference between IL-10 (A-1082G) genotypes (p=0.023 & p=0.009) meanwhile there was no statistically significant difference as regards INF-g +874 genotypes. Conclusion: IL-10 (A-1082G) and IFNy (T+874A) genes polymorphism might be crucial for protective immune responses and may serve as biomarker of protection or susceptibility