Association of tumor necrosis factor α − 308G/A and interleukin-6 − 174G/C gene polymorphism with pneumonia-induced sepsis

Abstract

PurposeSepsis is a lethal outcome of the inflammation and coagulation process. Human interleukin (IL)-6 and tumor necrosis factor (TNF) α are well-known inflammation factors closely associated with sepsis. In the present study, we aim to investigate the association of promoter-region polymorphisms IL-6 (−174G/C) rs1800795 and TNF-α (−308G/A) rs1800629 with pneumonia-induced sepsis. Materials and MethodsA total of 277 Chinese patients with severe pneumonia-induced sepsis were recruited into this study. All study participants were admitted to the intensive care unit until discharge or death in the First Affiliated Hospital of Zhengzhou University from July 2010 to July 2014. The patients were classified as severely septic, septic shock, and mortality. Clinical data and demographic information were recorded. TaqMan genotyping was performed to detect single nucleotide polymorphism distribution. ResultsThe genotype results demonstrated that carriers of the TNF-α rs1800629 A allele had a 4.28-fold higher risk for septic shock (adjusted odds ratio [OR], 4.28; 95% confidence interval [CI], 2.24-8.18; P < .01) compared with severe sepsis, and carriers of the IL-6 rs1800795 C allele had a 2.42-fold higher risk for septic shock (OR, 2.42; 95% CI, 1.08-5.45; P < .01) compared with severe sepsis. No significant difference of SNP distribution was found between the survivors and the nonsurvivors. After the results were adjusted for age and the outcomes of blood cultures, a multivariate logistic regression analysis showed similar results. Individuals with the TNF-α 308 rs1800629 A allele (adjusted OR, 2.96; 95% CI, 1.30-7.87) or the IL-6 rs1800795 C allele (adjusted OR, 1.87; 95% CI, 1.03-3.61) had a higher prevalence of septic shock. However, these SNP distribution differences were not associated with mortality. ConclusionsIn intensive care unit patients, the TNF-α −308A allele and the IL-6 rs1800795 allele variants were susceptibility risk factors for septic shock induced by pneumonia.