The Gene Polymorphisms (-308G/A) and the Tumor Necrosis Factor-alpha Levels in Type 2 Diabetic Patients with and Without Tuberculosis Infection

BACKGROUND: The gene polymorphism (-308G/A) and tumor necrosis factor-alpha (TNF-α) levels influence development of disease in type 2 diabetic patients and tuberculosis patients. AIM: In this study, we analyze the association between the TNF-α polymorphisms (-308G/A) and the levels of TNF-α in type 2 diabetic patients with and without tuberculosis infection. METHODS: This study was an analytic observational with cross sectional approach consisting 40 type 2 diabetic patients with tuberculosis infection, 40 type 2 diabetic patients without tuberculosis infection and 40 healthy control (HC) subjects. The TNF-α gene polymorphism (-308G/A) was analyzed with polymerase chain reaction-restriction fragment lengths polymorphisms (PCR-RFLP) method. The TNF-α levels were measured using an enzyme-linked immunosorbent assay. The association between gene polymorphism (-308G/A) in study groups was analyzed by Fisher’s exact test, tumor necrosis factor-alpha (TNF-α) levels in study groups was carried out using the Kruskal-Wallis test. Hardy-Weinberg Equilibrium also determined genotype deviation and allele frequencies. RESULTS: The GG and GA+AA genotypes frequency in both of patient groups and HC subjects were not differ significantly (95% and 5% vs 95% and 5% vs 92.5% and 7.5%; p > 0.05). The TNF-α levels (pg/ml) of type 2 diabetic without tuberculosis infection were higher than those of type 2 diabetic with tuberculosis infection and HC subjects (7.42 ± 0.78 vs 2.23 ± 0.51 vs 2.57 ± 0.63; p < 0.01). The TNF-α levels in the GA+AA genotypes were higher than the GG wild-type genotype (p > 0.05). There was no significant deviation of genotype frequency and allele from Hardy-Weinberg Equilibrium. CONCLUSION: The gene polymorphism (-308G/A) had no association with type 2 diabetic patients with and without tuberculosis infection and the gene polymorphism (-308G/A) was not influence the TNF-α levels but there was a significant differentiation of TNF-α levels between the groups.