Previous studies have investigated the potential relationship between promoter polymorphism (-308, G/ A) of tumor necrosis factor (TNF)-α and various autoimmune diseases. However, results from published data were inconclusive. To verify relationship between TNF-α polymorphism (-308, G/A) and susceptibility to autoimmune diseases such as vitiligo, celiac disease, and rheumatoid arthritis, we have performed a metaanalysis with all relevant articles before October 2016. The electronic search of PubMed, google, and Embase databases was performed to identify eligible studies investigating the relationship of TNF-α polymorphism with autoimmune diseases including vitiligo, celiac disease, and rheumatoid arthritis. Genotype frequency data of TNF-α polymorphism (-308, G/A) were extracted and the meta analysis was performed by Comprehensive meta-analysis program with odds ratio (OR) and 95% confidence intervals (95% CI). Genotype models were applied with dominant and recessive models and allele model analyzed. The final analysis included 37 publication papers with a total of 6,102 autoimmune disease patients and 6,987 control subjects. In result, a statistical significant correlation between TNF-α polymorphism (-308, G/A) and susceptibility to autoimmune disease was not detected in our meta-analysis (p>0.05 in all models). Our results suggest that the TNF-α polymorphism might not be related to the development of autoimmune disease. If further results in larger studies would be accumulated in the future, this relationship would be clarified.

Introduction
 Materials and Methods
  Literature search strategy
  Inclusion and exclusion criteria
  Statistical analysis
 Results
 Discussion
 References

• Young Ock Kim(Herbal Crop Utilization Research Team, Department of Medicinal Crop Research Institute, Republic of Korea)
• Kyu Bong Cho(Department of Biomedical Laboratory Science, College of Health Sciences, Shinhan University, Uijeongbu 11644, Korea) Corresponding author