Association of MCP-1 -2518A/G and -362G/C variants and tuberculosis susceptibility: a meta-analysis

A number of studies have found that the -2518A/G and -362G/C polymorphisms in the monocyte chemoattractant protein-1 (MCP-1) gene are implicated in the susceptibility to tuberculosis. However, the results are inconsistent. To investigate the relationship between -2518A/G and -362G/C polymorphisms in MCP-1 gene and the susceptibility of tuberculosis, a systematic literature search for relevant articles published up to January, 2013 was conducted in the databases of PubMed, Elsevier, Web of Science, Wanfang and CNKI. A total number of twenty-two case-control studies that included 9365 cases and 10149 controls on two single-nucleotide polymorphisms (SNPs): -2518A/G and -362G/C, were identified. The results indicated that the G allele of -2518A/G polymorphism was associated with increased risk of tuberculosis (GG vs. AA+AG: OR 1.455, 95% CI 1.092-1.937, P = 0.01). In the subgroup analysis by ethnicity, significant elevated risks were found in Asians and Americans, but not in Africans. The C allele of -362G/C polymorphism was associated with resistance to tuberculosis (CC vs. GG+GC: OR 0.837, 95% CI 0.772-0.987, P = 0.03). This meta-analysis suggests that the G allele of -2518A/G polymorphism is a risk factor for tuberculosis in Asians and Americans, while not in Africans. It further indicates that C allele of -362G/C polymorphism is a protective factor for tuberculosis.