Association of the TNF-α gene promoter polymorphisms at nucleotide -238 and -308 with acne susceptibility: a meta-analysis.

BACKGROUND: The tumour necrosis factor (TNF)-α -238 and -308 polymorphisms are potential candidate genes that may serve as modulators in susceptibility to acne. AIM: We performed a meta-analysis of case-control studies to assess the association of the TNF-α -238 and -308 polymorphisms with acne susceptibility. METHODS: The PubMed, EMBASE, Scopus, SinoMed and China National Knowledge Infrastructure databases were systematically searched to identify eligible studies. OR and 95% CI were calculated to evaluate the association. RESULTS: We identified seven independent case-control studies up to September 2017. The results revealed an association between the A allele of the TNF-α -238 polymorphism and increased susceptibility to acne in Asian (OR = 1.61, 95% CI 1.08-2.40) but not in European (OR = 1.10, 95% CI 0.63-1.93) populations. For the TNF-α -308 polymorphism, the minor A allele was associated with increased acne susceptibility in Asian (OR = 1.93, 95% CI 1.15-3.24) and Turkish (OR = 4.14, 95% CI 2.25-7.61) populations, but not in European (OR = 1.17, 95% CI 0.66-2.06) or Arab (OR = 0.88, 95% CI 0.64-1.22) populations. Egger test found no evidence of publication bias. CONCLUSION: Our findings suggest that the TNF-α -238 A allele is associated with increased susceptibility to acne in Asian but not in European populations, while the TNF-α -308 A allele is associated with increased susceptibility to acne in Asian and Turkish populations but not in European or Arab populations.