Role of IFNγ+874 AT gene Polymorphism in the Susceptibility of Pulmonary Tuberculosis in an Iraqi Patients

Abstract

Background:Cellular immune immunity mediates Host immune action against Mycobacterium tuberculosis, which is critical to cytokine and Th1 cells. TNF-alpha appears to be primordial in controlling infection with mycobacteria. This cytokine acts in Synergy with IFN-gamma, stimulates development of intermediate reactive nitrogen (RNI) media that mediate macrophage tuberculostatic function and stimulates immune cell migration to the infection site and helps in the formation of granuloma that regulate the progression of disease. IFN-Gamma is the principal cytokine involved in mycobacterial immune response, and its primary function is to activate macrophages to allow them to perform their microbicidal role. In comparison to TNF-alpha and IFN-gamma, IL-10 is primarily considered an inhibitory cytokine which is essential to the proper balance of inflammatory and immunopathological responses. The increase in IL-10 levels appears to help the host mycobacteria's survival.Methods:Study population included patients with pulmonary or extrapulmonary tuberculosis from Babil province - Iraq. Whole blood samples were collected from 67 TB cases at consultant clinic for respiratory diseases in Hillah - Babil province in the period between October 2020 to June 2021. Out of the (67) TB patients, there were (30) male and (37) female. The patients age range was from 1 to 80 years. The inclusion criteria used in this study was that all the TB cases must meet the clinical diagnosis criteria and confirmed by at least one of the laboratory tests (Smear, PCR and culture). The clinical diagnosis was conducted by the specialists in the consultant clinic for respiratory diseases. While apparently healthy persons included (39) persons equal (24) males and (15) females with age range approximately matched to that of patients. As pathogenesis of TB and associated with IFNγ+874 AT has a hereditary foundation, primer investigation was intended to evaluate the effect on the TB and Healthy people. Genotyping was performed utilizing single stranded polymorphism-polymerase chain response (SSP-PCR).Resultshis study revealed that IFNγ+874 AT genotype was significantly associated with susceptibility to tuberculosis in patients.it increased the risk of TB, in addition, IFNγ+874AT genotype in the control group in this study, had a higher frequency than AA, TT. This indicates that it has a protective effect against tuberculosis.