ASSOCIATION BETWEEN TUMOR NECROSIS FACTOR-α (G-308A) POLYMORPHISM AND CHRONIC PERIODONTITIS, AGGRESSIVE PERIODONTITIS, AND PERI-IMPLANTITIS: A META-ANALYSIS

Objective Chronic periodontitis (CP), aggressive periodontitis (AP), and peri-implantitis (PI) are chronic inflammatory diseases. Tumor necrosis factor -a (TNF-a) is an effective immune inflammatory mediator. Several studies have been conducted to explore the association between the TNF-alpha (G-308A) polymorphism and susceptibility to CP, AP, and PI. Our objective was to examine whether the TNF-alpha (G-308A) polymorphism is related to these diseases. Methods We conducted a meta-analysis to investigate the association between the TNF-alpha (G-308A) polymorphism and CP, AP, and PI. The PubMed, Embase, CNKI, and Web of Science electronic databases were searched for studies published from inception to August 11, 2020; the reference lists of included studies were also searched. The included studies were assessed in the following genetic models: dominant model, recessive model, allelic model, heterozygous model, and homozygous model. Results Forty articles (50 comparisons) with 2243 CP, 824 AP, 615 PI, 795 healthy periimplant, and 3575 healthy controls were considered for the TNF-alpha (G-308A) polymorphism in this meta-analysis. Variant A of TNF-alpha (G-308A) was associated with increased AP risk in the general population, especially in Asians, and this polymorphism was significantly associated with elevated risk of CP in Asians and Caucasians. There was no association between the A allele and PI risk. None of the contrasts of the genetic model yielded a significant finding in Latin Americans. Different genotyping methods may affect the association between the TNF-alpha (G-308A) polymorphism and these diseases. Conclusion These findings supported that variant A of the TNF-alpha (G-308A) polymorphism may contribute to CP and AP susceptibility, particularly in Asians and Caucasians. More efforts and further studies with larger sample sizes will be required to validate the risk of CP, AP, and PI.