Associations between tumor necrosis factor-alpha polymorphisms and susceptibility to pulmonary tuberculosis: meta-analysis

Abstract

The aim of this study was to determine whether tumor necrosis factor-alpha (TNF-alpha) polymorphisms are associated with susceptibility to pulmonary tuberculosis (PTB) in different ethnic populations. MEDLINE and Embase databases and manual searches were employed to identify articles in which TNF-alpha polymorphisms were determined in patients with PTB and controls. A meta-analysis was conducted on the associations of the TNF-alpha -308A/G, -238A/G, and -857T/C polymorphisms with PTB susceptibility. A total of 13 studies met the inclusion criteria, including 12, 6, and 4 studies on TNF-alpha -308A/G, -238A/G, and -857T/C polymorphisms, respectively. Meta-analysis showed no association between the TNF-alpha -308A allele and PTB susceptibility in all study subjects (odds ratio, OR = 1.182, 95%CI = 0.989-1.411, P = 0.066). After stratification by ethnicity, TNF-alpha -308A was not found to be associated with PTB in the European, Asian, or Middle East populations. No association was identified between PTB susceptibility and the TNF-alpha -238A allele in all study subjects (OR = 1.031, 95%CI = 0.741-1.436, P = 0.855), or in the European and Asian populations. However, TNF-alpha -857T was significantly associated with PTB susceptibility specifically in Asians (OR = 0.682, 95%CI = 0.550-0.846, P = 4.8 x 10(-5)). Meta-analysis using the dominant model, recessive model, or homozygote contrast showed the same pattern of results as for the TNF-alpha -857T allele. Overall, no correlation was noted between the TNF-alpha -308A/G and -238A/G polymorphisms and PTB susceptibility. However, the TNF-alpha -857T/C polymorphism was found to be associated with PTB susceptibility in the Asian population.