IMPACT OF HEPATITIS-C VIRUS-INFECTION ON PATIENTS WITH CHRONIC-RENAL-FAILURE

Hepatitis C virus (HCV) is a small single-stranded RNA virus that caus es non-A, non-B hepatitis in over 90% of cases. Diagnosis of HCV infec tion relies on detection of specific antibodies or the presence of vir al nucleic acid, HCV is encountered worldwide and is transmitted by pa renteral routes. The acute clinical presentation is usually symptomles s but infection persists in more than 80% of infected patients leading to cirrhosis in 20-30% of cases after 20 years from infection. Alpha interferon is the only effective treatment for HCV chronic hepatitis, inducing clearance of the virus in 10-20% of patients; however, there have been no controlled trials of prevention of cirrhosis or hepatocel lular carcinoma by therapy with interferon or other antiviral agents. Patients with end-stage renal failure are at risk for HCV infection, A complete screening for the detection of HCV in dialysis and kidney-tr ansplanted patients should include the detection of anti-HCV antibodie s by ELISA and of HCVR-NA in serum by PCR. The prevalence of anti-HCV antibodies in hemodialysis and kidney-transplanted patients reflects t hat observed in the general population, with a definite North to South gradient. ALT increases are usually of low grade and intermittent in dialyzed patients with HCV infection and GGT seems to be a more stable and useful sign of liver disfunction. Prevalence of HCV infection is significantly higher in hemodialysis than in peritoneal dialysis patie nts; moreover, patient to patient infection for HCV has been proved in hemodialysis units but not in peritoneal dialysis or home hemodialysi s: blood transfusions and manipulation of blood-contaminated material are the main reasons for these differences. The liver lesions observed in dialysis patients were comparable to those in anti-HCV-positive bl ood donors, Cirrhosis induced by HCV seems to cause death in less than 1% of dialyzed patients, but these figures could be very different in patients who acquired HCV in their youth. Preliminary results from pi lot studies have shown the effectiveness of interferon in dialyzed pat ients with HCV infection. However the cost-benefit ratio and efficacy of interferon therapy should be evaluated in randomized controlled tri als with an adequate sample size. HCV infection in kidney transplant r ecipients is acquired before or at the moment of transplantation becau se of HCV infection in the donor. The question about transplanting HCV -infected organs even in HCV-infected recipients is still unanswered. HCV infection is usually clinically silent during the first years afte r transplantation and does not seem to affect either patient or graft survival in the first 10-15 years. Treatment with interferon should be avoided in kidney transplant recipients because of the high frequency of rejection.