Association Between TNF- Promoter-308 A/G Polymorphism and Systemic Lupus Erythematosus Susceptibility: A Case-Control Study and Meta-Analysis

The tumour necrosis factor- (TNF-) promoter -308 A/G polymorphism plays an important role in the aetiology of systemic lupus erythematosus (SLE). Several studies have estimated the association between TNF- -308 A/G and SLE risk. However, results were inconsistent. A case-control study was carried out to explore the association between TNF- -308 A/G and the SLE risk in a Chinese Han population. Meta-analysis combining present with previous studies was conducted to further explore the association. Our case-control study included 556 patients with SLE along with 570 matched healthy controls. TNF- -308 A allele was significantly increased in patients with SLE compared with controls (OR=2.184, 95% CI: 1.718-2.778, P<0.001). Genotypes AA and AG were associated with the susceptibility to SLE as compared with the GG genotype, as well as the dominant model (AA+AG versus GG), respectively. The meta-analysis included 41 comparative studies involving 4799 patients and 6635 controls. An association between SLE and allele A was found in the overall populations (OR=1.70, 95% CI: 1.46-1.98, P<0.001). In addition, we discussed the correlation between this polymorphism and lupus nephritis (LN) risk, showing that allele A was significantly related to LN in the overall populations (OR=1.80, 95% CI: 1.21-2.68, P=0.004). The results from our case-control study and the meta-analysis indicate that the TNF- -308 A allele is significantly associated with an increased risk of SLE/LN.