Association of the TNF-α+489 G/A polymorphism with chronic obstructive pulmonary disease risk in Asians: meta-analysis.

The association between the TNF-α +489 G/A polymorphism and chronic obstructive pulmonary disease (COPD) remains controversial because of small group size and varied design among different studies. In the present study, a meta-analysis was conducted to assess the association between the +489 G/A polymorphism and COPD risk. A comprehensive search was conducted to identify articles that have reported an association between the TNF-α +489 G/A polymorphism and COPD risk. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated under both dominant (AA+GA vs GG genotypes) and allele (A vs G) models. Heterogeneity was assessed, as well as publication bias. Nine articles with ten eligible studies were included in this analysis. Significant association between the +489 G/A polymorphism and COPD was identified in Asians under the allele model (OR = 1.582, 95%CI = 1.035-2.419). However, no significant difference was found in the Caucasian groups. Strong evidence for between-study heterogeneity was identified under both models, and no publication bias was detected. Our results indicated a potential role of the A allele of the TNF-α +489 G/A polymorphism in increasing COPD risk in Asians, but not in Caucasians. Additional studies will be necessary to verify this conclusion.

Association of -238G/A and -863C/A polymorphisms in the TNF-α gene with chronic obstructive pulmonary disease based on a meta-analysis.

Chronic obstructive pulmonary disease (COPD) is a chronic systemic inflammatory disease; increasing evidence indicates that the TNF-α polymorphism is associated with progression of this disease. Few studies have focused upon association between TNF-α -238G/A or -863C/A polymorphism and COPD risk. Reported associations have been controversial because of small sample size and varied study design among the different studies. We performed a meta-analysis to assess the correlation of these two polymorphisms in the TNF-α gene with COPD risk. A comprehensive search was conducted to identify all published articles on the association between TNF-α -238G/A or -863C/A polymorphism and COPD risk from different databases. Pooled odds ratios (ORs) with 95% confidence intervals (CI) were calculated, and the heterogeneity and publication bias were assessed. Eight articles with 10 eligible studies met our inclusion criteria; six studies were of the -238G/A polymorphism and the others involved the -863C/A polymorphism. In the case of the -863C/A polymorphism, significant association was detected only in Asians in the A allele carriers (GA+AA versus GG genotype) and allele (A versus G allele) model (OR = 0.505, 95%CI = 0.321-0.795 and OR = 0.560, 95%CI = 0.368-0.851, respectively). However, no significant association was detected for the -238G/A polymorphism. No evidence of between-study heterogeneity and publication bias was detected. We suggest a potentially protective role of the A allele in the TNF-α -863C/ A polymorphism against developing COPD in Asians. This hypothesis needs further studies for confirmation.

Association of the G403A polymorphism in the RANTES gene with coronary artery disease: a meta-analysis.

The G403A polymorphism in the RANTES (regulated on activation normal T cell expressed and secreted) gene has a key role in the expression of RANTES, which has been detected in a range of cells in atherosclerotic plaque. However, the association of this polymorphism with the risk of coronary artery disease (CAD) remains controversial. A meta-analysis was performed to assess the association of the G403A polymorphism in the RANTES gene with the risk of CAD. A comprehensive search was conducted to identify all studies published on the association of the RANTES gene G403A polymorphism with CAD risk. The fixed or random-effect pooled measure was adopted based on a heterogeneity test among studies, which was evaluated using I(2). Potential sources of between-study heterogeneity were explored using meta-regression analysis. Publication bias was estimated with Begg's rank correlation method. Eight articles were included in this meta-analysis, with 4601 CAD cases and 2522 controls. No significant association of RANTES gene G403A polymorphism with CAD was identified in any of the codominant, dominant, recessive, homozygote, or heterozygote inheritance models. No evidence of publication bias was detected. The meta-analysis suggested that the A allele of the G403A polymorphism in the RANTES gene has no effect on the risk of CAD. This relationship needs to be confirmed by further studies.