[Hepatitis C virus and chronic progressive kidney disease]

Abstract

Soon upon its discovery, hepatitis C virus (HCV) was recognized as an important cause and consequence of chronic kidney disease (CKD). HCV is a significant cause of some forms of glomerulonephritis (GN), especially membranoproliferative GN (MPGN). Subsequent population-based studies found an association between HCV positivity and CKD markers such as albuminuria or proteinuria. HCV infection is a frequent sequel of CKD. Blood transfusions (before effective screening of blood donors for HCV was instituted), nosocomial transmission in dialysis units, and transmission by kidney grafts all have contributed to the much higher prevalence of HCV infection in end-stage renal disease (ESRD) and transplant patients as compared to the general population. The current prevalence of HCV in dialysis centers is between 5% and 10% in European Union, and around 8.4% in Croatia. Strict adherence to 'universal precautions', careful attention to hygiene and strict sterilization of dialysis machines is recommended. The prevalence of HCV infection in CKD transplant patients is also high. Consistent risk factors include total time spent on dialysis and a history and/or number of blood transfusions, yet paralleling the prevalence in the general population of the same country or region. Patients with CKD who are considered for treatment should have virologic evidence of chronic HCV infection (i.e. HCV RNA detectable in serum). Treating chronic HCV infection in CKD patients is associated with a number of challenges. As the glomerular filtration rate (GFR) decreases, the half-life of both interferons (IFNs) (standard and pegylated) and ribavirin increases, resulting in a potentially poorer tolerance and the need for dosage adaptations in severe CKD. In kidney graft recipients, the use of IFNs and immunostimulants further entails a substantial risk of rejection. IFN therapy in hemodialysis patients results in good biochemical and virologic response and appears to exert a beneficial effect on the course of liver disease following renal transplantation. IFN-alpha therapy for the treatment of HCV-infected ESRD patients on maintenance dialysis, administered prior to renal transplantation, is associated with high rates of sustained biochemical and virologic response in the post-transplant period. Thus, IFN-alpha therapy seems to be advisable for HCV-infected dialysis patients that are candidates for renal transplantation.