Association between tumor necrosis factor--308 Gauss/A polymorphism and risk of silicosis and coal workers pneumoconiosis in Chinese population

Background: Many studies have attempted to clarify the association between TNF-a -308G/A polymorphism and pneumoconiosis, but there has been no definite consensus to date. To further assess the effects of TNF-a -308G/A polymorphism on the risk of pneumoconiosis, a meta-analysis was performed in Chinese population.Methods: We searched the related literature in PubMed and Chinese databases through June 2018. The strength of the associations was assessed used pooled odds ratios (ORs) and 95% confidence intervals (CIs).Results: Nine case-control studies including 730 silicosis cases, 457 coal workers pneumoconiosis cases and 2429 controls were identified according to the inclusion criteria. In the total analyses, a significantly elevated risk was found in allelic model (OR=1.41, 95% CI=1.16-1.71). In the subgroup analyses by geographic area and type of pneumoconiosis, significant results were found both in North China (A versus G, OR=1.33, CI=1.05-1.69) and South China (A versus G, OR=1.56, CI=1.14-2.15); significant results were also found in silicosis (A versus G, OR=1.40, CI=1.11-1.78) and coal worker pneumoconiosis (A versus G, OR=1.42, CI=1.03-1.96).Conclusion: This meta-analysis suggested that TNF-a gene -308G/A polymorphism is associated with increased silicosis and coal workers pneumoconiosis risk in the Chinese population, and further studies in other ethnic groups are required for definite conclusions.