The Association Between the Tumor Necrosis Factor-Alpha Gene −308A/G Polymorphism and Chronic Pancreatitis: A Meta-Analysis

Background: Tumor necrosis factor-alpha (TNF-α) is a major proinflammatory cytokine that has been posited to be involved in the development of chronic pancreatitis (CP). Several studies have been carried out that explored the association between the TNF-α -308A/G polymorphism and CP; however, conflicting results have emerged. The aim of this study was to perform a meta-analysis to provide a more precise assessment of the relationship between the TNF-α -308A/G polymorphism and CP risk. Methods: Case-control studies were identified using PubMed, Embase, Web of Science, Cochrane Library, and Chinese National Knowledge Infrastructure through January 2019 from which seven were identified that met all inclusion criteria. Results: This meta-analysis included 695 CP cases and 742 controls. A positive association was found between the A allele and the risk of CP using the additive model (OR [odds ratio] = 1.83, 95% CI [confidence interval] = 1.08-3.10). We also found, after excluding the Hardy-Weinberg equilibrium-violating studies, that the AA genotype was significantly associated with CP in both the additive and recessive models (OR = 2.28, 95% CI = 1.27-4.07; OR = 2.19, 95% CI = 1.26-3.81). Conclusion: This meta-analysis indicates that the A allele of the TNF-α -308A/G polymorphism increases the risk of CP.