<p class="MDPI12title"><span style="color: black; mso-themecolor: text1;">Genetic Polymorphisms of <em>IL6</em>-174G/C <em>TNFα</em>-308G/A and <em>TNFα</em>-238G/A and Risk to Pleural Tuberculosis in Venezuelan Patients

Tuberculosis (TB) has various clinical presentations; pulmonary TB (PTB) affects only the lungs, while extra-pulmonary TB is defined as the disease involving any other or-gans, including pleural TB (PLTB). Immunological studies of patients with ex-tra-pulmonary TB mainly focus on the cellular Th1 response, which produce key cyto-kines like IFN-γ, TNF-α, IL-12, and IL-6. The TNF-α, and IL-6, which play functional roles in host resistance to Mycobacterium tuberculosis (Mtb) infection. Findings suggest that TNF-α facilitates macrophage containment of Mtb; while that IL-6 increases the apoptosis of macrophages induced by Mtb. Studies involving the human genome have helped identify single nucleotide polymorphisms (SNPs) in genes encoding cytokines associated with TB susceptibility. This study aimed to determine the potential of the IL6-174G/C (rs1800795), TNFα-308G/A (rs1800629) and TNFα -238G/A (rs361525) SNPs as genetic biomarkers of susceptibility to PLTB in the Venezuelan mestizo popu-lation. A total of 269 individuals were included: 69 patients with PLTB and 200 healthy individuals. The IL6-174G/C, TNFα-308G/A and TNFα-238G/A polymorphisms were determined by sequence-specific primer polymerase chain reaction (SSP-PCR). Results showed significantly increased frequencies of the G/C, G/A and G/A genotypes in pa-tients with PLTB (94.0%, 94.2% and 83.3%) compared to controls (40.0%, 19.0% and 13.4%) for the IL6-174G/C, TNFα-308G/A and TNFα-238G/A polymorphisms, respec-tively. Logistic regression analysis showed significant associations of G/C, G/A and G/A genotypes and susceptibility to PLTB. The IL6-174G/C TNFα-308G/A and TNFα-238G/A gene polymorphisms could represent potential genetic biomarkers of susceptibility to PLTB in the Venezuelan mestizo population.