Prevalence of HCV antibodies in a uraemic population undergoing maintenance dialysis therapy and in the staff members of the dialysis unit

Routine serologic testing for hepatitis C virus infection should be instituted among dialysis patients

Since the cloning of hepatitis C virus (HCV), a number of serologic and virologic tests for detecting infections with this virus have been made available for clinical practice. This led to the recognition of HCV as a major health hazard in hemodialysis (HD) centers. Yet the nephrology community has not been offered explicit recommendations about routine serologic testing for HCV of dialysis patients and consequently has remained unclear and divided about the utility of this testing. This review presents evidence in support of instituting routine serologic testing for HCV among dialysis patients. It concludes that because of the peculiar features of HCV infection in HD patients, serologic testing for HCV is the only means for unequivocal diagnosis of hepatitis C and an irreplaceable instrument for monitoring the incidence and the prevalence of the infection in this population. Serologic surveillance for HCV infection is crucial for identifying the association of new cases of HCV infection with potential risk factors for HCV transmission, particularly nosocomial, that can be modified in a way to prevent further dissemination of the virus. Data collected from routine serologic testing for HCV will undoubtedly improve our understanding of the epidemiology of HCV in the dialysis population and will provide a strong foundation for developing preventive measures and infection control strategies that are highly effective in controlling HCV infection. Routine serologic testing for HCV is also of direct benefit to the individual patient since establishing the HCV serologic status of each patient is important for optimizing patient care.

Hepatitis C in dialysis patients

Patients on hemodialysis have a higher prevalence of hepatitis C (HCV) infection compared with the general population. Several factors have been associated with an increased risk of HCV infection in hemodialysis patients, including number of blood transfusions, duration of hemodialysis, previous transplantation, intravenous drug abuse, male gender, and in-center hemodialysis. In addition, there is mounting evidence to suggest nosocomial transmission within hemodialysis units. Although the precise modes of transmission have not been identified, breakdown in standard infection control practices, physical proximity to an infected patient, and sharing of dialysis machines are possible causes. Nonetheless, at the present time, the Centers for disease Control and Prevention (CDC) does not recommend dedicated machines, patient isolation, or a ban on re-use in hemodialysis patients with HCV infection. Consequently, strict adherence to universal precautions and careful attention to hygiene are recommended to reduce the transmission of HCV in dialysis units.

Hepatitis C virus: the nephrologist's view

The last 4 years have been a period of rapid expansion in our understanding of both the molecular biology and clinical significance of hepatitis C virus (HCV) infection. Initial studies using first-generation enzyme-linked immunosorbent assays suggested that the end-stage renal disease population had an exceptionally high prevalence of anti-HCV compared with asymptomatic healthy blood donors. Subsequent analyses with second-generation assays and polymerase chain reaction techniques to detect viremia confirmed these earlier studies. Considering the prevalence of HCV within the dialysis population, it comes as no surprise that several studies confirmed HCV as the leading cause of non-A, non-B hepatitis among renal allograft recipients. Furthermore, transmission of HCV by transplantation of a kidney from an HCV-infected organ donor has been unequivocally demonstrated. The natural history of HCV infection in the immunosuppressed allograft recipient and its impact on long-term patient outcome are still being analyzed. Finally, HCV has been associated with essential mixed cryoglobulinemia and several histologic patterns of immune complex glomerulonephritis, including membranous and membrano-proliferative glomerulonephritis. Although HCV antigen-antibody complexes have not been demonstrated in the kidney, the marked decrease in proteinuria following clearance of HCV RNA with interferon alpha-2b therapy suggests an etiologic role for HCV in these glomerular diseases. Furthermore, the demonstration of HCV RNA in the cryoprecipitate of patients with essential mixed cryoglobulinemia and a beneficial response to treatment with interferon alpha-2b also suggest a role for HCV in the pathogenesis of these clinical syndromes.

Management of chronic hepatitis in special populations

Over the last several years, much progress has been made in the treatment of adult patients with chronic viral hepatitis and compensated liver disease in the absence of significant other illnesses. However, the treatment of chronic viral hepatitis in other patient populations is still experimental. These groups include children, patients immunocompromised by human immunodeficiency virus infection or immunosuppression following organ transplantation, those with end-stage renal disease, and patients with extrahepatic manifestations of hepatitis viral infection. Data on the treatment of chronic hepatitis in these special populations are reviewed.