The association of polymorphisms in TNF and ankylosing spondylitis in common population: a meta-analysis

Studies investigating the association between the polymorphisms in TNF and ankylosing spondylitis have been reported the conflicting results. Here we performed a meta-analysis based on the evidence available from the literature up-to-date to further clarify this relationship.

Our systematic search was done in the PubMed, Embase and Cochrane databases (up to March 2020). The pooled and individual odds ratios (ORs) with 95% confidence intervals (CIs) of the minor allele of each locus were presented to assess the associations between TNF polymorphisms and AS in different ethnicities in common population.

Seventeen studies, consisting of seven European studies, eight East Asian studies and two Latin-American studies, were included in this meta-analysis. In the total population, the A allele in TNF-238 (OR = 0.702, 95%CI = 0.506-0.973, p = 0.034) and TNF-308 (OR = 0.638, 95%CI = 0.507-0.804, p = 0.000), the C allele in TNF-1031 (OR = 0.594, 95%CI = 0.446-0.791, p = 0.000), the T allele in TNF-850 (OR = 3.462, 95%CI = 1.764-6.798, p = 0.000) and rs769178 (OR = 2.593, 95%CI = 2.175-3.091, p = 0.000) were significantly associated with AS susceptibility. There were no significant association between the minor alleles of TNF-376, TNF-857, TNF-863 and AS susceptibility. There are inconsistent results in the Latin-American population and East Asian population with those in the total population.

Our meta-analysis suggests that TNF-α polymorphisms at positions - 238, - 308, - 850, - 1031 and rs769178 could have an influence on ankylosing spondylitis susceptibility in the total population. But there is no association of the TNF-376, TNF-857, TNF-863 polymorphisms with ankylosing spondylitis. Some results in the subgroups are not consistent with those in the total population.