Evolution of hepatitis C virus quasispecies in renal transplant patients with de novo glomerulonephritis

Hepatitis C infection in hemodialysis patients: A review

Hepatitis C virus (HCV)-related liver disease is a significant cause of morbidity and mortality in patients with end-stage renal disease (ESRD) who is treated with dialysis or kidney transplantation (KT). The survival rate for HCV-infected renal transplant recipients is better than that for HCV-infected hemodialysis patients on transplant waiting lists. Early diagnosis and treatment HCV infection prior to KT prevents complications post-transplantation and reduces mortality. In addition to screening for anti-HCV antibodies and detecting HCV RNA, percutaneous liver biopsy is particularly valuable for assessing the stage of liver damage in HCV-infected patients, because the stage of fibrosis is important determining optimal treatment for HCV. Studies have been demonstrated that with conventional interferon (IFN) monotherapy or pegylated IFN monotherapy are similar efficacy and safety in HCV-infected hemodialysis patients. Sustained viral responses (SVRs) with these monotherapies have ranged approximately 30% to 40%. Limited reports support the use of IFN and ribavirin combination therapy as antiviral treatment for ESRD patients or patients on hemodialysis. Ribavirin can be started at low dose and careful monitoring for side effects. Patients that show SVR after treatment are strong candidates for KT. It is also generally accepted that ESRD patients with decompensated cirrhosis and portal hypertension should be referred to the liver transplant team for consideration of combined liver-KT.

Hepatitis C virus and kidney disease

Hepatitis C virus (HCV) is the most frequently observed viral infection in patients with kidney disease. HCV can cause glomerular disease, which can lead to end-stage renal disease that requires dialysis and/or kidney transplantation. It is recommended to test HCV patients once a year for proteinuria, microscopic hematuria and estimated glomerular filtration rate. Membranoproliferative glomerulonephritis is the most common glomerular disease induced by HCV. Over the past few decades, the prevalence of HCV infection has decreased among dialysis and kidney transplant patients. However, survival is significantly lower in HCV-positive than in HCV-negative dialysis patients whereas survival is significantly better in HCV-positive kidney transplant patients compared with HCV-positive dialysis patients. Thus, dialysis patients without a sustained virological response after anti-HCV therapy should be proposed for kidney transplantation. Recurrence or de novo occurrence of glomerular disease is responsible for the lower kidney allograft survival in HCV-positive compared with HCV-negative kidney transplant patients. Dialysis and kidney transplantation do not appear to negatively affect progression of liver fibrosis in the majority of patients. The available data also suggest that occult HCV infection does not exist in dialysis and kidney transplant patients.

Management of the kidney transplant patient with chronic hepatitis C infection

Chronic Hepatitis C (HCV) infection is an important cause of morbidity and mortality in patients with end-stage renal disease. Renal transplantation confers a survival advantage in HCV-infected patients. Renal transplant candidates with serologic evidence of HCV infection should undergo a liver biopsy to assess for fibrosis and cirrhosis. Patients with Metavir fibrosis score ≤3 and compensated cirrhosis should be evaluated for interferon-based therapy. Achievement of sustained virological response (SVR) may reduce the risks for both posttransplantation hepatic and extrahepatic complications such as de novo or recurrent glomerulonephritis associated with HCV. Patients who cannot achieve SVR and have no live kidney donor may be considered for HCV-positive kidneys. Interferon should be avoided after kidney transplant except for treatment of life-threatening liver injury, such as fibrosing cholestatic hepatitis. Early detection, prevention, and treatment of complications due to chronic HCV infection may improve the outcomes of kidney transplant recipients with chronic HCV infection.

Hepatitis C virus infection and renal disease after renal transplantation

Hepatitis C virus (HCV) infection is the main cause of chronic liver disease after renal transplantation (RT). It is considered in some series to be a risk factor for graft loss and patient death. Also, HCV has been implicated in the pathogenesis of glomerular diseases in native and transplanted kidneys. The presence of membranoproliferative (MP) or membranous (M) glomerulonephritis (GN) in HCV-positive patients has been well documented after RT, but there is no clear data concerning the real prevalence of HCV-induced glomerulonephritis. MPGN with or without cryoglobulinemia and MGN have been described in HCV RNA-positive patients in general without severe liver disease. Also, there is a possible association between HCV infection and acute/chronic transplant glomerulopathy. Renal thrombotic microangiopathy has been described in HCV-positive patients with positive anti-cardolipin antibodies. The pathogenesis of MPGN and MGN in HCV patients after RT seems to be similar to that which occurs in native kidneys: the deposition of immune complexes containing HCV proteins in the glomeruli. Renal biopsy, using light microscopy, immunofluorescence techniques, and electron microscopy, is useful to achieve a correct diagnosis. Unfortunately, interferon is not recommended due to the significant risk of rejection. The possibility of pegylated interferon needs to be tested. Ribavirin can improve proteinuria but HCV RNA remains positive. Finally, recent data suggest that the use of interferon in HCV patients on dialysis can negate HCV RNA and prevent associated glomerulonephritis after RT.

Long-term ribavirin therapy in hepatitis C virus-positive renal transplant patients: effects on renal function and liver histology

BACKGROUND

Long-term renal transplant (RT) recipient mortality and graft loss increase significantly in hepatitis C virus positive (HCV-[+]ve) patients. Treatment with alpha-interferon in this population is associated with a high rate of acute rejection. The aims of this study were the evaluation of the efficacy and the safety of ribavirin monotherapy in 16 HCV-(+) RT patients (group A) matched to 32 HCV-(+) RT patients (group B) who did not receive ribavirin.

METHODS

Ribavirin was started at a daily dose of 1,000 mg and then adapted to hemoglobin level. The study was scheduled for 1 year.

RESULTS

Ribavirin monotherapy was associated with a decrease in liver enzymes and serum creatinine levels. When proteinuria was present, this decreased or disappeared. There were no significant changes in HCV viremia. There was a significant progression in liver fibrosis with no improvement in inflammation scores. Hemoglobin levels fall dramatically, despite an important support by recombinant erythropoeitin (median, 20,000 IU/wk). In 3 cases, ribavirin therapy had to be stopped. In the control group, after 1 year of follow-up, there was a significant increase in serum alanine aminotransferase and creatinine values. Proteinuria decreased in only 2 of 12 patients (P = 0.03 as compared with group A).

CONCLUSION

One year of ribavirin monotherapy seems to have, at best, no beneficial effect on liver histology, although it improves liver enzyme levels. Despite its efficiency to dramatically decrease proteinuria, its impact on renal function remains unknown.