Association of the MCP-1 promoter polymorphism with tuberculosis in the Hong Kong Chinese population

Abstract

Hong Kong is a place of intermediate burden of tuberculosis (TB). The TB notification rate in Hong Kong was 108 per 100,000 persons in 2001. MCP-1 is a chemokines recruiting activated T cells to form granuloma in mouse M. tuberculosis (MTB) infection, suggesting MCP-1 involved in the immunopathogensis of TB. A functional polymorphism (A-2518G) in the promoter region of MCP-1 was shown to influence the transcriptional level of the gene. We hypothesize that MCP-1 polymorphisms may contribute to human susceptibility to TB. Genomic DNA was extracted from frozen EDTA-treated whole blood samples of TB patients and blood donors. A 930 base pair segment of the MCP-1 were amplified by polymerase chain reaction (PCR) and the genomic variants were detected by restriction fragment length polymorphism (RFLP) using restriction enzyme, PvuII. We performed a population case-control study to test if the -2518 A/G polymorphism of the MCP-1 gene contributes to the susceptibility to tuberculosis. A total of 941 individuals, including 447 controls and 494 TB patients, was genotyped. The GG genotype and the G allele of the MCP-1 gene polymorphism were significantly more common in the TB patients than in the controls (P = 0.01). This finding indicates that the -2518 A/G polymorphism of the MCP-1 gene is associated with TB in Hong Kong Chinese population.