Monocyte chemoattractant protein-1 in spinal tuberculosis: -362G/C genetic variant and protein levels in Chinese patients

The objective of the study is to explore the possible association of the monocyte chemoattractant protein (MCP)-1-362G/C genetic polymorphism and plasma levels of MCP-1 in patients with spinal tuberculosis (TB). The MCP-1-362G/C (rs2857656) polymorphism and blood levels of MCP-1 in patients with spinal TB and healthy subjects were evaluated and compared. Three hundred thirty-two patients and 336 healthy subjects were genotyped using polymerase chain reaction and Sanger DNA sequencing technology. MCP-1 plasma levels were measured by a solid-phase enzyme-linked immunosorbent assay. When comparisons were made between patients and controls, the frequency of the MCP-1-362*C minor allele (55.4% versus 47.5%, P = 0.004, odds ratio [OR] = 1.376, 95% confidence interval [CI]: 1.109–1.706) and the carriers of the MCP-1-362*C allele (80.7% versus 71.4%, P = 0.005, OR = 1. 657, 95% CI: 1.167–2.403) were over-represented in patients. The mean MCP-1 plasma level in spinal TB patients was significantly higher than in controls (154.44 ± 68.81 pg/mL versus 36.69 ± 21.71 pg/mL, t = –5.85, P < 0.001). The patients with the CC genotype had the highest MCP-1 level (150.63 ± 73.89 pg/mL), followed by those with the GC genotype (108.63 ± 52.09 pg/mL, t = 2.351, P = 0.022) and GG (91.29 ± 54.31 pg/mL, t = 3.091, P = 0.003) homozygotes. We report the association of the -362G/C genetic polymorphism and increased plasma levels of MCP-1 in patients with spinal TB and nominate the -362*C minor allele as a risk factor for spinal TB in the Chinese population.