Molecular detection of monocyte chemotactic protein-1 polymorphism in spontaneous bacterial peritonitis patients

AIM: To investigate the association of the functional monocyte chemotactic protein-1(MCP-1) promoter polymorphism(A-2518G) with spontaneous bacterial peritonitis(SBP).METHODS: Fifty patients with post-hepatitis C liver cirrhosis and ascites were categorized into two groups; group Ⅰ included 25 patients with SBP and group Ⅱ included 25 patients free from SBP. In addition, a group of 20 healthy volunteers were included. We assessed the MCP-1 gene polymorphism and gene expression as well as interleukin(IL)-10 levels in both blood and ascitic fluid. RESULTS: A significant MCP-1 gene polymorphism was detected in groups Ⅰ and Ⅱ(P = 0.001 and 0.02 respectively). Group Ⅰ was associated with a significantly higher frequency of AG genotype [control 8(40%) vs SBP 19(76.0%), P < 0.001], and group Ⅱ was associated with a significantly higher frequency of GG genotype when compared to healthy volunteers [control 1(5%) vs cirrhotic 16(64%), P < 0.001]. Accordingly, the frequency of G allele was significantly higher in both groups(Ⅰ and Ⅱ) [control 10(25%) vs SBP 27(54%), P < 0.001 and vs cirrhotic 37(74.0%), P < 0.001, respectively]. The total blood and ascetic fluid levels of IL-10 and MCP-1 gene expression were significantly higher in group Ⅰ than in group Ⅱ. Group Ⅰ showed significant reductions in the levels of MCP-1 gene expression and IL-10 in the whole blood and ascetic fluid after therapy. CONCLUSION: MCP-1 GG genotype and G allele may predispose HCV infected patients to a more progressive disease course, while AG genotype may increase the susceptibility to SBP. Patients carrying these genotypes should be under supervision to prevent or restrict further complications.