Pretransplant hepatitis C virus infection: a predictor of proteinuria after renal transplantation

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.

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

Long-term renal allograft survival in kidney transplant recipients infected by hepatitis C virus (HCV) may be influenced by the occurrence of de novo glomerulopathy associated with this virus. Therefore, we studied the evolution of HCV quasispecies in kidney transplant recipients infected by HCV with or without de novo glomerulopathy. The hypervariable region 1 (HVR-1) of the virus envelope was analyzed by cloning and sequencing 20 clones per sample to assess complexity and diversity from six kidney transplant patients who developed de novo glomerulopathy (group I) matched to six kidney transplant recipients without glomerular disease (group II), according to age, time since renal transplantation, and HCV genotype. Two sera were analyzed for each patient: one at the time of renal transplantation and the other at the time of appearance of de novo glomerulopathy, or after a similar duration since transplantation in group II. Overall, there was a significant increase of HCV viremia after the transplantation. This increase did not differ significantly between group I (+0.5 log copies/ml) and group II patients (+1 log copies/ml). The intersample diversity of HCV was similar in the two groups. Complexity and viral diversity were also similar at the time of transplantation. By contrast, complexity, diversity, and the proportion of nonsynonymous substitutions per nonsynonymous site were significantly higher after transplantation in group I patients. Our findings suggest a higher immune response and/or a particular cytokine production in patients developing de novo glomerulopathy rather than a direct effect of HCV on renal cells.

Hepatitis C virus infection and de novo glomerular lesions in renal allografts

In the present study we examine whether hepatitis C virus (HCV) infection status influences glomerular pathologic findings in renal allografts and its effect on graft outcome. Renal allograft biopsies performed between January 1991 and June 1999 were considered. Exclusion criteria were insufficient sample, unknown HCV serological status at time of biopsy and final diagnosis of acute rejection. Light microscopy and immunofluorescence studies were performed on all biopsies. According to a predefined protocol, electron microscopy was carried out. Of 138 eligible renal allograft biopsies, 42 fulfilled at least one exclusion criterion. Of 96 biopsies selected for the study, 44 (45.8%) were from HCV-positive and 52 from HCV-negative recipients. Renal biopsy was performed 74 +/- 55 and 60 +/- 39 months after transplantation in HCV-positive and HCV-negative groups, respectively (p = 0.12). Of 44 HCV-positive biopsies, 20 (45.4%) showed membranoproliferative glomerulonephritis (MPGN) (16 type I and 4 type III). Conversely, in HCV-negative biopsies there were only three cases of MPGN (2 type I and 1 type III). De novo membranous GN (MGN) was diagnosed in 8/44 (18.2%) HCV-positive and in 4/52 (7.7%) HCV-negative cases. The prevalence of chronic transplant glomerulopathy was similar in HCV-positive and HCV-negative groups (11.4% and 11.5%, respectively). The prognosis of de novo GN (either MPGN or MGN) was worse in HCV-positive than in HCV-negative recipients (relative risk 4.89; 95% confidence interval, 1.15-20.69; p = 0.03). By multivariate analysis, HCV-positive serology infection was the only independent predictor of graft loss (relative risk 2.64; 95% confidence interval, 1.35-5.17; p = 0.005). In diagnostic renal allograft biopsies the presence of de novo immune-mediated glomerulonephritis, especially type I MPGN, is strongly associated with HCV infection and results in accelerated loss of the graft.

Hepatitis C virus infection and renal transplantation

With the success of organ transplantation, liver disease has emerged as an important cause of morbidity and mortality of renal transplant (RT) recipients. Numerous studies performed during the 1990s have shown that hepatitis C virus (HCV) infection is the leading cause of chronic liver disease among RT recipients. The transmission of HCV by renal transplantation of a kidney from an HCV-infected organ donor has been shown unequivocally. Liver biopsy is essential in the evaluation of liver disease of RT recipients, and histological studies have shown that HCV-related liver disease after renal transplantation is progressive. The outcome of HCV-related liver disease is probably more aggressive in RT recipients than immunocompetent individuals. Various factors can affect the progression of HCV in the RT population: coinfection with hepatitis B virus, time of HCV acquisition, type of immunosuppressive treatment, and concomitant alcohol abuse. The role of virological features of HCV remains unclear. The natural history of HCV infection after renal transplantation is under evaluation; however, recent surveys with long follow-ups have documented adverse effects of HCV infection on patient and graft survival in RT recipients. Use of renal grafts from HCV-infected donors in recipients with HCV infection does not appear to result in a greater burden of liver disease, at least for a short period. The association between HCV and de novo or recurrent glomerulonephritis after RT has been hypothesized and is an area of avid research. Reported studies do not support interferon (IFN) treatment for RT recipients with chronic hepatitis C because of the frequent occurrence of graft failure, and information on the use of other types of IFN or combined therapy (IFN plus ribavirin or amantadine) is not yet available in the RT population.

Infections in recipients of kidney transplants

A review of infections in kidney transplant recipients is presented in this article, beginning with a discussion of the pretransplant infectious diseases evaluation and an overview of the timing of infectious posttransplant, and then focusing on individual types of infection.

Chronic hepatitis C infection in patients with end stage renal disease: characterization of liver histology and viral load in patients awaiting renal transplantation

OBJECTIVES

Hepatitis C virus (HCV) is common in patients with end stage renal disease (ESRD) awaiting renal transplantation (RT). However, few data are available on the liver histology and viral titer in these patients relative to patients with HCV and normal renal function. The aims of this study were to assess liver histology, quantitative HCV-RNA titer, and alanine aminotransferase (ALT) levels in patients with ESRD awaiting RT, and to identify clinical predictors of histological progression to advanced bridging fibrosis and/or cirrhosis.

METHODS

A total of 50 consecutive patients (mean age 42 yr, 62% male) with ESRD and HCV, who were awaiting RT, underwent liver biopsy. Two HCV populations, one with persistently normal ALT and another with elevated ALT, both with normal renal function, served as controls. HCV-RNA titer was assessed by quantitative PCR.

RESULTS

Of the patients with ESRD, 94% had normal ALT. Log HCV RNA titer was significantly higher in patients with ESRD (5.8+/-0.3) than in either normal ALT (5.4+/-0.1) or elevated ALT (5.3+/-0.1) controls (p < 0.05). Knodell Histological Activity Index (HAI) in patients with ESRD was similar to that observed in control patients with normal ALT (4.8+/-0.4 vs 4.9+/-0.4) but significantly less (p < 0.05) than that observed in control patients with elevated ALT (8.4+/-0.5). The percentage of patients with bridging fibrosis or cirrhosis was similar in patients with ESRD and controls with persistently normal ALT (22% vs 13%) but significantly less (p < 0.001) than that observed in control patients with elevated ALT (48%). No significant differences in ALT, HCV-RNA titer, duration on hemodialysis, or time from first possible exposure was observed between ESRD patients with advance fibrosis (n = 11) and those with mild disease (n = 39).

CONCLUSIONS

Our data suggest that liver biopsy is necessary to exclude significant liver pathology in patients with HCV and ESRD, and to help define those patients in whom interferon treatment might be helpful.

Impaired kidney transplant survival in patients with antibodies to hepatitis C virus

BACKGROUND

With a few exceptions, most published studies do not show an influence of antibodies to the hepatitis C virus (HCV) on the success of a kidney transplant.

METHODS

We studied all our renal transplant recipients who had received kidneys from cadaver donors (n = 335) and had been treated with quadruple immunosuppression (steroids, azathioprine, and antilymphocyte antibodies, followed by cyclosporin). We had information on the status of the hepatitis C antibodies before and/or after the transplant in 320 cases (95.5%; in 300, pre-transplant). Patients with HCV antibodies before and/or after the transplant were considered to be HCV positive (HCV+).

RESULTS

The HCV+ patients had more time in dialysis and a greater number of transfusions, hyperimmunized cases, and re-transplants. The evolution in the first post-transplant year was similar in both groups, but afterwards, the HCV+ patients had proteinuria more often as well as worse kidney function. The survival rate of the graft was significantly less in the HCV+ cases: 90.6, 68.3 and 51.0% at respectively 1, 5 and 10 years, compared with 91.5, 84.7 and 66.5% in HCV-patients (P<0.01). The patient survival rate was: 96.4, 87.0, and 71.9% in the HCV+ patients at 1, 5, and 10 years, compared with 98.2, 96.0 and 90.0% in the HCV- cases respectively (P<0.01). The differences remained the same in stratified studies according to time spent in dialysis or pre/post-transplant evolution of HCV antibodies, even when immunologically high-risk patients were excluded. In multivariant analysis, the presence of HCV antibodies acted as a independent prognostic factor for the survival of the kidney and the patient: 3.0 (1.8-5.0) and 3.1 (1.2-7.8) odds-ratio (95% of the confidence interval), respectively. The main cause of death among HCV+ patients was cardiovascular; there was no apparent increase in mortality rate due to infections or chronic liver disease. The loss of organs was mainly due to chronic nephropathy or death with a functioning kidney.

CONCLUSION

The presence of hepatitis C antibodies, before or after transplantation, is associated with a worse long-term survival rate for both the patient and the transplanted kidney in our patients treated with quadruple therapy.