Association of the IFNG rs2430561 (+874T/A) Variant with Pleural Tuberculosis in a Venezuelan Mestizo Population

Background

Tuberculosis (TB) has various clinical presentations. Pulmonary TB (PTB) affects only the lungs. In contrast, miliary TB (MTB) is a disseminated form of the disease, while pleural TB (PLTB) is a localized disease that affects the pleura. Immunological studies of patients with extra-pulmonary TB mainly focus on the cellular Th1 response, which produces key cytokines like IFN-γ (IFNG), TNF-α (TNFA), IL-12, and IL-6. Findings suggest that IFNG plays a functional role in host resistance to Mycobacterium tuberculosis (Mtb) infection because it facilitates macrophage containment of Mtb, prevents bacterial replication within cells, increases macrophage phagocytic activity, and allows macrophages to eliminate (or contain) the bacteria. Studies of the human genome have identified single-nucleotide polymorphisms (SNPs) in genes encoding cytokines associated with TB susceptibility. This study aimed to investigate the potential of the IFNG (rs2430561) polymorphism as a biomarker for susceptibility or non-susceptibility to PLTB in the Venezuelan mestizo population.