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. 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- -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 Gl (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 ) 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.