Cytokine and apoptosis gene polymorphisms influence the outcome of hepatitis C virus infection

BACKGROUND:Hepatitis C virus (HCV) infection is thought to be chronic and the factors leading to viral clearance or persistence are poorly understood.This study was undertaken to investigate the possibility of a significant relationship between the spontaneous clearance or the persistence of hepatitis C virus (HCV) infection and cytokine and apoptosis gene polymorphisms in Tunisian patients on hemodialysis.METHODS:Polymorphisms of the genes IL-1 (-889 IL-1α,-511 and +3954 IL-1β,IL-1Ra),IL-18 (-137 and-607),IL-12 (-1188) and Apo1/Fas (-670) were determined by PCR-RFLP,PCR-SSP and PCR-VNTR in 100 healthy blood donors and 100 patients infected with HCV and undergoing hemodialysis.The patients were classified into two groups:G1 consisted of 76 active chronic hepatitis patients (positive for HCV RNA) and G2 consisted of 24 hemodialysed patients who spontaneously eliminated the virus (negative for HCV RNA).RESULTS:The frequency of genotype association [-137GC/-607CA] IL-18 was higher in G2 (41.7%) than in G1 (15.8%) (P=0.008;OR=0.26;95% CI,0.10-0.73).We also found a higher frequency of the AA genotype of the Apo1/Fas gene in G2 (41.6%) than in G1 (17.5%) (P=0.026;OR=3.49;95% CI,1.13-10.69).Adjustment for known covariate factors (age,gender and genotype) confirmed these univariate findings and revealed that the genotype association GC-CA of the (-137 and-607) IL-18 gene and the AA genotype of the Apo1/Fas gene were associated with the clearance of HCV (P=0.041 and 0.017,respectively).CONCLUSION:The two genotypes GC-CA of the (-137 and-607) IL-18 polymorphism and the AA genotype of the Apo1/Fas gene influence the outcome of HCV infection in Tunisian patients on hemodialysis.

Natural evolution of hepatitis C virus infection in hemodialysis Tunisian patients and CTLA-4 SNP's

AIM: To analyze the polymorphisms of CTLA-4 gene involved in the response against hepatitis C virus(HCV) infection.METHODS: We recruited 500 hemodialysed patients from several hemodialysis centers, all HCV-antibody positive, spread over different regions of Tunisia, as part of a national survey in 2008 conducted in the laboratory of immunology at the Charles Nicolle hospital Tunisia, classified into two groups G1(PCR+) and G2(PCR-) according to the presence or absence of viral RNA. Of these patients, 307 were followed prospectively on a viral molecular level over a period from 2002 to 2008, divided into two groups based on the persistence and viral clearance. PCR-RFLP was performed for the analysis of SNPs(+49) A/G and(+6230) G/A CTLA-4 for these 500 patients and 358 healthy controls.RESULTS: Analysis of clinical and virological charac-teristics of our cohort suggests a nosocomial infection in our hemodialysed patients with transfusion history as a primary risk factor and a predominance of genotype 1b. The haplotype analysis revealed an increase of frequencies of GG(+49)/(CT60) CTLA-4 in the entire patients group compared to controls(P = 0.0036 and OR = 1.42; 95%CI: 1.12-1.79, respectively). This haplotype is therefore associated with susceptibility to HCV infection. CONCLUSION: Our study suggests a possible role of CTLA-4 polymorphisms in the outcome of HCV infection in the Tunisian hemodialysed population.