Histopathologic efficacy of ribavirin monotherapy in kidney allograft recipients with chronic hepatitis C

Efficacy and safety of glecaprevir/pibrentasvir in renally impaired patients with chronic HCV infection

BACKGROUND AND AIMS

Chronic hepatitis C virus (HCV) infection increases the risk of incident chronic kidney disease (CKD) and progression to end-stage renal disease (ESRD). Previously available direct-acting antiviral regimens are not approved for patients with advanced CKD across all HCV genotypes.

METHODS

EXPEDITION-5 is a phase 3 study to evaluate efficacy and safety of the fixed-dose combination of glecaprevir and pibrentasvir (G/P) for chronic HCV infection (genotype 1 through 6) in adults without cirrhosis or with compensated cirrhosis and with stage 3b, 4 or 5 CKD. Patients received approved duration of G/P according to HCV genotype, cirrhosis status and prior HCV treatment experience. The primary efficacy endpoint was percentage of patients with sustained virologic response at 12 weeks post-treatment (SVR12).

RESULTS

Among the 101 patients enrolled in the study, 24% had predialysis CKD and 76% were on dialysis. Eighty-four patients were treated with G/P for 8 weeks, 13 patients for 12 weeks and four patients for 16 weeks. Fifty-five per cent of patients had genotype 1, 27% had genotype 2, 15% had genotype 3 and 4% had genotype 4, and none had genotype 5 or 6 infection. The SVR12 rate was 97% (98/101, 95% confidence interval, 91.6-99.0). No patients experienced virologic failure. Adverse events (AEs) reported in at least 5% of the patients were pruritus, bronchitis, hypertension and generalized pruritus. Serious AEs were reported in 12% of patients; none related to study drug.

CONCLUSIONS

G/P treatment yielded high SVR12 rates irrespective of the presence of stage 3b, 4 or 5 CKD. No safety signals were detected. CLINICALTRIALS.

GOV IDENTIFIER

This Phase 3 clinical trial was funded by AbbVie and registered with clinicaltrials.gov as NCT03069365 (EXPEDITION-5).

Antiangiogenic therapy for portal hypertension in liver cirrhosis: Current progress and perspectives

Developing medicines for hemodynamic disorders that are characteristic of cirrhosis of the liver is a relevant problem in modern hepatology. The increase in hepatic vascular resistance to portal blood flow and subsequent hyperdynamic circulation underlie portal hypertension (PH) and promote its progression, despite the formation of portosystemic collaterals. Angiogenesis and vascular bed restructurization play an important role in PH pathogenesis as well. In this regard, strategic directions in the therapy for PH in cirrhosis include selectively decreasing hepatic vascular resistance while preserving or increasing portal blood flow, and correcting hyperdynamic circulation and pathological angiogenesis. The aim of this review is to describe the mechanisms of angiogenesis in PH and the methods of antiangiogenic therapy. The PubMed database, the Google Scholar retrieval system, and the reference lists from related articles were used to search for relevant publications. Articles corresponding to the aim of the review were selected for 2000-2017 using the keywords: “liver cirrhosis”, “portal hypertension”, “pathogenesis”, “angiogenesis”, and “antiangiogenic therapy”. Antiangiogenic therapy for PH was the inclusion criterion. In this review, we have described angiogenesis inhibitors and their mechanism of action in relation to PH. Although most of them were studied only in animal experiments, this selective therapy for abnormally growing newly formed vessels is pathogenetically reasonable to treat PH and associated complications.

Direct-acting antiviral therapy for hepatitis C virus infection in the kidney transplant recipient

Hepatitis C virus infection (HCV) is a common comorbidity in patients who have undergone kidney transplantation and is associated with increased morbidity and mortality compared with recipients who do not have chronic HCV infection. Because interferon-α-based therapies can precipitate acute rejection, they are relatively contraindicated after kidney transplantation. Thus, the majority of kidney transplant recipients with HCV remain untreated. There are now all-oral, interferon-free direct-acting antiviral therapies for HCV infection that are extremely effective and well tolerated in the general population. Recent reports in the literature demonstrate that direct-acting antiviral therapies effectively cured HCV in 406 of 418 kidney transplant recipients (97%); the majority were treated with sofosbuvir-based regimens. Smaller numbers of kidney transplant recipients have been treated with paritaprevir-ritonavir, ombitasvir and dasabuvir, elbasvir-grazoprevir, or glecaprevir-pibrentasvir with excellent success. Direct-acting antiviral therapies were well tolerated and did not increase the rate of acute rejection. The latest advances include approval of regimens that can treat patients with advanced allograft dysfunction (eGFR < 30 ml/min per 1.73 m²) and "pan-genotypic" regimens that have activity against all 6 major genotypes of HCV. This review summarizes what is known about the epidemiology of HCV infection in kidney transplant recipients, and presents the landscape of direct-acting antiviral therapies and areas in need of further investigation.

[Management of hepatitis B virus and hepatitis C virus infection in chronic kidney failure]

Chronic infections by hepatitis B (HBV) and C virus (HCV) result in diagnosis and therapeutic issues in dialysis and kidney recipients patients. The exposure to nosocomial, including blood transfusion, risk explains the high prevalence of HBV and HCV infection in this setting. Chronic infection reduces the survival of both patients and allografts, including a specific risk of de novo glomerulonephritis. Cirrhosis was considered as a contra-indication to renal transplantation given the high risk of decompensation and death, questionning the indication of a combined liver and kidney transplantation. Thus, it is mandatory to screen HBV and HCV markers in all dialysis patients, whether or not they are candidates to transplantation. Liver biopsy allows evaluating the severity of the liver disease since the noninvasive markers of fibrosis appear to be less accurate in "renal" patients than in the general population and to better define antiviral therapeutic indications. HCV treatment was mainly based on pegylated interferon α (and low doses of ribavirin), which is contra-indicated in kidney recipients given the risk of graft rejection; HCV treatment is now based on the use of oral direct acting antivirals, which are very potent and well tolerated. HBV replication is now easily suppressed by second-generation nucleos(t)tidic analogues (entecavir and tenofovir), which will be indicated in all the dialysis patients with significant fibrosis (F2,3 or 4 according to the Metavir scoring system) and in any candidate to renal transplantation and to any HBsAg-positive kidney recipients. The best treatment remains preventive by anti-HBV vaccination for HBV and by the respect of universal hygiene rules for HCV.

Μanagement of patients with hepatitis B and C before and after liver and kidney transplantation

New nucleos(t)ide analogues (NAs) with high genetic barrier to hepatitis B virus (HBV) resistance (such as entecavir, tenofovir) have improved the prognosis of patients with HBV decompensated cirrhosis and have prevented HBV recurrence after liver transplantation (LT). NAs are considered the most proper approach for HBV infection in patients under renal replacement therapy but their doses should be adjusted according to the patient's creatinine clearance. In addition, physicians should be aware of the potential nephrotoxicity. However, patients with chronic hepatitis C and decompensated cirrhosis can receive only one therapeutic option before LT, as well as for Hepatitis C virus (HCV) recurrence after LT, which is the combination of subcutaneous Peg-IFN and ribavirin. Generally, therapy for HCV after renal transplantation should be avoided. Although the optimal antiviral therapy for HCV infection has not been established, attention has turned to a new, oral direct acting antiviral treatment which marks a promising strategy in prognosis and in amelioration of these diseases.

Hepatitis C virus infection in hemodialysis patients

Hepatitis C virus (HCV) infection is observed in around 20% of dialysis patients and in allograft recipients and results in a significant morbidity and mortality, especially after transplantation. Its prevalence has markedly decreased in patients who are candidates for transplantation since the introduction of screening, hygiene and prevention measures, including systematic screening of blood and organ donations, use of erythropoietin, and compliance with universal hygiene rules. A liver biopsy is preferable to non-invasive biochemical and/or morphological tests of fibrosis to evaluate liver fibrosis before and even after transplantation. In HCV-infected dialyzed patients who are not candidates for renal transplantation, the indication for antiviral therapy is limited to significant fibrosis (fibrosis ≥ 2 on the METAVIR scale). Antiviral treatment should be proposed to any HCV-infected candidate for renal transplantation, whatever the baseline histopathology. The recommendation is to use standard interferon-α as monotherapy, but pegylated interferon can be used, resulting in sustained virological response, while low doses of combined ribavirin may enhance the antiviral efficacy. After transplantation, interferon-α is contra-indicated but may be used in patients for whom the benefits of antiviral treatment clearly outweigh the risks, especially that of allograft rejection. All cirrhotic patients should be screened for hepatocellular carcinoma, whose risk is enhanced by immunosuppressive regimens. Sustained suppression of necro-inflammation may result in the reversal of cirrhosis, which reduces liver-related morbidity and improves patient and allograft survival. Finally, due to the high mortality after renal transplantation, active cirrhosis must be considered to be a contraindication to kidney transplantation, but an indication to combined liver-kidney transplantation; on the contrary, inactive compensated cirrhosis may permit renal transplantation alone.

Liver-kidney recipients with chronic viral hepatitis C treated with interferon-alpha

Antiviral therapy with interferon-alpha (IFN-alpha) and pegylated IFN-alpha (PEG-IFN-alpha) for chronic hepatitis C (HCV)-infected kidney recipients remains controversial. IFN-alpha is not recommended in most cases because it induces severe acute graft rejection. However, IFN-alpha, as PEG-IFN-alpha, is associated with a more pronounced immune response, and is well tolerated in HCV-infected liver recipients without causing graft rejection. In combined liver-kidney transplant (LKT) recipients, IFN-alpha has been occasionally used and appears to be well tolerated. All LKT recipients with a functioning kidney and liver having a HCV replication and who needed IFN-alpha therapy have been included in the study. The occurrence of liver and/or renal acute rejection as well as the HCV replication has been collected. A total of 12 LKT patients treated with PEG-IFN-alpha plus ribavirin have been studied. No acute rejection was observed. Renal function remained stable during and after discontinuing treatment, without any graft dysfunction. Two patients had a partial viral response and four had a sustained viral response. All patients, whatever their viral response, had decreased liver-enzyme levels. Response to PEG-IFN-alpha therapy was correlated with steroid dose and transaminase level when PEG-IFN-alpha was started. These data suggest that the combination therapy of PEG-IFN-alpha plus ribavirin did not have a higher risk of acute kidney-graft rejection after liver-kidney transplantation.

Treatment of recurrent HCV infection following liver transplantation: results of a multicenter, randomized, versus placebo, trial of ribavirin alone as maintenance therapy after one year of PegIFNα-2a plus ribavirin

BACKGROUND & AIMS

We aimed at determining the effect of maintenance therapy with ribavirin alone, after a year of combined peginterferon-alfa 2a (PegIFNα-2a) and ribavirin therapy, on viral response and liver histology after liver transplantation (LT).

METHODS

Hundred and one patients with recurrent HCV and a minimum of stage 1 fibrosis (METAVIR scoring), 1-5years after LT, were enrolled. PegIFNα-2a and ribavirin were initiated at 90 μg/wk and 600 mg/d, respectively, then increased or adjusted as a function of tolerance. At 12 months, combination therapy was discontinued and patients were randomized to ribavirin or placebo for a further 12 months. Growth factor use was permitted.

RESULTS

At 18 months, a sustained virological response (SVR) was obtained in 47.9% of patients in Per Protocol (PP) analysis, and was higher in patients with genotype 2 or 3 than in patients with genotype 1 or 4, in patients with genotypes 1+4 receiving ciclosporine than in those receiving tacrolimus, in patients with worse renal function, in those having received EPO, in patients with lower weight, and in those with lower viral load at 3 months. Using logistic regression, only the early viral response, recipient weight and renal function were independently associated with better SVR. SVR, viral load, activity, and fibrosis scores were similar, at M18 and M30, in patients randomized to ribavirin, or to placebo.

CONCLUSIONS

A PP SVR was achieved in 47.9% of patients with established recurrent hepatitis C after LT. Maintenance therapy with ribavirin alone does not improve the virological response or the histological parameters.

Randomised clinical trial: pre-dosing with taribavirin before starting pegylated interferon vs. standard combination regimen in treatment-naïve patients with chronic hepatitis C genotype 1

BACKGROUND

Combination therapy with the ribavirin (RBV) prodrug taribavirin (TBV) and pegylated interferon (PIFN) has produced lower rates of anaemia than with RBV and PIFN. Studies have demonstrated that the sharpest decline in viral load during TBV therapy occurs at Weeks 4 through 6, when TBV reaches steady-state blood levels.

AIM

The current proof-of-concept study was conducted to examine whether first-order viral kinetics could be influenced by pre-dosing TBV to steady state before introducing PIFN.

METHODS

Therapy-naïve patients with chronic hepatitis C virus (HCV) genotype 1 (G1) were randomised to receive (i) TBV 600 mg BID monotherapy for 4 weeks followed by combination therapy with PIFN [pre-dosing arm (n = 23)] or (ii) TBV administered concurrently with PIFN [standard dosing arm (n = 19)].

RESULTS

More patients achieved undetectable virus or a ≥2-log(10) reduction of HCV RNA at Week 4 in the pre-dosing vs. the standard dosing arm [33% vs. 22% (P = 0.497)]. There was also a trend towards greater reduction in mean log(10) change in HCV RNA in the pre-dosing vs. the standard dosing arm, which was statistically significant at Day 1 [-0.34 ± 0.46 vs. 0.09 ± 0.32 (P < 0.003)] but not at other time points up to Week 24. No significant difference was observed in the rates of anaemia (haemoglobin <10 g/dL) between study arms (4.5% vs. 5.3%).

CONCLUSIONS

Pre-dosing TBV prior to starting PIFN produces a trend towards improved efficacy although statistical significance was not reached in this small patient population. These results warrant larger clinical trials of TBV pre-dosing.

Efficacy and safety of treatment of hepatitis C virus infection in renal transplant recipients

AIM: To assess the efficacy and safety of combined pegylated interferon and ribavirin therapy in hepatitis C virus (HCV) infection in renal transplant recipients.

METHODS: This is a retrospective chart review of post renal transplant patients who were positive for anti-HCV and HCV-RNA, and who have received treatment with combination of pegylated interferon and ribavirin between October 2003 and December 2008. Only patients with stable graft function and absence of evidence of cirrhosis and who received the therapy for continuous 48 wk were included. Nineteen patients (13 male and 6 female) were identified and included. The patient’s complete blood count, liver and kidney profile, and calculated glomerular filtration rate (GFR) were monitored every 6-8 wk while on treatment. HCV-RNA was tested at 12 wk for early virological response, at 48 wk for end of treatment response (ETR), and then retested at 24, and 48 wk after completion of therapy for sustained virological response (SVR). Liver biopsies were obtained before treatment from all patients and graft kidney biopsies were performed as required.

RESULTS: Of the entire cohort, 9 patients (47.4%) showed an ETR and 8 had SVR (42.1%). Of the 8 patients with abnormal alanine aminotransferase (ALT) levels at baseline, 78.9% had their ALT normalized (including the virological non responders). ALT was normal in all responders at the end of therapy and at 24 wk post therapy (100%). Only one patient (5.3%) developed an increase in creatinine and decline in GFR from baseline towards the end of treatment. This patient’s kidney biopsy revealed borderline rejection. There was no impact on response by HCV-genotype, initial HCV RNA load, age or sex of the patient or duration post transplant before commencement of therapy. All patients tolerated treatment in the same way as non-transplant with no unusual or increased occurrence of side effects.

CONCLUSION: The combination of pegylated interferon and ribavirin is effective in suppressing HCV-RNA, with a low risk of graft rejection or failure in HCV infected renal transplant recipients.

Hepatitis C virus and kidney: a strong association with different clinical aspects

The most frequent kidney disease associated with chronic hepatitis C virus (HCV) infection is membranoproliferative glomerulonephritis in patients with type II mixed cryoglobulinaemia. The principal clinical manifestations of glomerular disease in HCV-infected patients are the presence of proteinuria and haematuria with or without impaired kidney function. Pharmaceutical regimens vary because the main pathogenesis of renal dysfunction often mediated by cryoglobulins has not been fully elucidated. HCV infection remains common in patients on renal replacement therapy and has an adverse impact on their survival. Safe and effective pharmaceutical regimens have not been yet established and nosocomial spread within dialysis units continues to occur. Monotherapy with interferon for HCV infection is probably more effective in dialysis than in non-uraemic patients, while experience with ribavirin is limited because of its adverse haemolytic effect. Based on shortage of cadaver kidneys and the fact that HCV renal transplant recipients have better survival than stay on maintenance haemodialysis or at list for transplantation, health organization proposed the use of cadaver kidneys from anti-HCV-positive donors, bringing up concerns and conflicting views. This present review describes the main renal manifestations of HCV infection, the epidemiological and clinical characteristics of chronic kidney disease population and comments on the limitations and shortcomings of current therapeutical regiments.

Viral hepatitis in solid organ transplantation other than liver

Transplantation is the best treatment for end-stage organ failure. Hepatitis virus infections, mainly hepatitis B virus (HBV) and hepatitis C virus (HCV) infections still constitute a major problem because they are common in allograft recipients and are a significant cause of morbidity and mortality after transplantation. Recently, hepatitis E virus infection has been added as an emergent cause of chronic hepatitis in organ transplantation. The prevalence of HBV and HCV infections has markedly decreased in patients who are candidates for transplantation since the introduction of screening, hygiene and prevention measures, including systematic screening of blood and organ donations, use of erythropoietin, compliance with universal hygiene rules, segregation of HBV-infected patients from non-infected patients and systematic vaccination against HBV. A liver biopsy is preferable to non-invasive biochemical and/or morphological tests of fibrosis to evaluate liver fibrosis before and even after transplantation. Treatment with entecavir or tenofovir is indicated in HBV-infected dialyzed patients who have moderate or severe disease (≥A2 or F2 on the Metavir scale) in preparation for renal transplantation. Due to the risks of severe reactivation, fibrosing cholestatic hepatitis or histological deterioration after transplantation, systematic use of nucleoside or nucleotide analogues shortly before or at the time of transplantation is recommended (tenofovir or entecavir are preferable to lamivudine) in all patients, whatever the baseline histological evaluation. In HCV-infected dialyzed patients who are not candidates for renal transplantation, the indication for antiviral therapy is limited to significant fibrosis (fibrosis ≥2 on the Metavir scale). Treatment must be proposed to all candidates for renal transplantation, whatever their baseline histopathology, and interferon-α should be used as monotherapy. After transplantation, interferon-α is contraindicated but may be used in patients for whom the benefits of antiviral treatment clearly outweigh the risks, especially that of allograft rejection. All cirrhotic patients, notably after solid organ transplantation, should be screened for hepatocellular carcinoma. Sustained suppression of necro-inflammation may result in regression of cirrhosis, which in turn may lead to decreased disease-related morbidity and improved survival. Finally, due to the high mortality after renal transplantation, active (namely without sustained viral suppression) cirrhosis should be considered a contraindication to kidney transplantation, but an indication to combined liver-kidney transplantation; on the contrary, inactive (namely with sustained viral suppression) compensated cirrhosis may permit renal transplantation alone. Organ transplantations other than kidney (cardiac or pulmonary transplantations) involve the same diagnosis and therapeutic issues.

Hepatitis C and kidney transplantation

Hepatitis C virus (HCV) infection is relatively common among patients with end-stage kidney disease (ESKD) on dialysis and kidney transplant recipients. HCV infection in hemodialysis patients is associated with an increased mortality due to liver cirrhosis and hepatocellular carcinoma. The severity of hepatitis C-related liver disease in kidney transplant candidates may predict patient and graft survival after transplant. Liver biopsy remains the gold standard in the assessment of liver fibrosis in this setting. Kidney transplantation, not haemodialysis, seems to be the best treatment for HCV+ve patients with ESKD. Transplantation of kidneys from HCV+ve donors restricted to HCV+ve recipients is safe and associated with a reduction in the waiting time. Simultaneous kidney/liver transplantation (SKL) should be considered for kidney transplant candidates with HCV-related decompensated cirrhosis. Treatment of HCV is more complex in hemodialysis patients, whereas treatment of HCV recurrence in SLK recipients appears effective and safe.

Treatment of hepatitis C virus infection in patients with end-stage renal disease

Hepatitis C virus (HCV) infection is a major health problem in patients with end-stage renal disease (ESRD). The incidence of acute HCV infection during maintenance dialysis is much higher than that in the general population because of the risk of nosocomial transmission. Following acute HCV infection, most patients develop chronic HCV infection, and a significant proportion develop chronic hepatitis, cirrhosis, and even hepatocellular carcinoma. Overall, chronic hepatitis C patients on hemodialysis bear an increased risk of liver-related morbidity and mortality, either during dialysis or after renal transplantation. Interferon (IFN) therapy is modestly effective for the treatment of HCV infection in ESRD patients. Conventional or pegylated IFN monotherapy has been used to treat acute hepatitis C in ESRD patients with excellent safety and efficacy. Regarding chronic hepatitis C, approximately one-third of patients can achieve a sustained virological response (SVR) after conventional or pegylated IFN monotherapy. The combination of low-dose ribavirin and conventional or pegylated IFN has further improved the SVR rate in treatment-naïve or retreated ESRD patients in clinical trials. Similar to the treatment of patients with normal renal function, baseline and on-treatment HCV virokinetics are useful to guide optimized therapy in ESRD patients. Of particular note, IFN-based therapy is not recommended at the post-renal transplantation stage because of the low SVR rate and risk of acute graft rejection. In conclusion, ESRD patients with HCV infection should be encouraged to receive antiviral therapy, and those who achieve an SVR usually have long-term, durable, virological, biochemical, and histological responses.

Chronic viral hepatitis in kidney transplantation

Chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) infection in potential kidney transplant candidates-once considered absolute contraindications to kidney transplantation-no longer creates overt barriers to transplantation. Advances in the medical management of HBV and HCV infection have created opportunities for a substantial number of patients to be effectively treated with antiviral therapy before transplantation. For HBV infection, a number of new drugs enable clearance of the virus with minimal adverse effects and drug resistance. Pretransplantation antiviral therapy is advisable for patients with HCV infection, but adverse effects are common and viral eradication remains challenging. Regardless of viral clearance, pretransplant patients without bridging fibrosis (as confirmed by liver biopsy) or clinical stigmata of cirrhosis should be considered for kidney transplantation as survival is superior when compared to treatment with dialysis, and progression of liver disease is unlikely. For patients with advanced liver disease, simultaneous liver-kidney transplantation is an important consideration. These treatment advances further increase the burden of organ donor shortage; however, organs from deceased donors with chronic HBV or HCV infection could be efficiently allocated to certain individuals with a viral infection of the same type to increase the pool of available transplant organs.

Renal transplantation in HIV-infected patients: 2010 update

The prognosis of human immunodeficiency virus (HIV) infection has improved in recent years with the introduction of antiretroviral treatment. While the frequency of AIDS-defining events has decreased as a cause of death, mortality from non-AIDS-related events including end-stage renal diseases has increased. The etiology of chronic kidney disease is multifactorial: immune-mediated glomerulonephritis, HIV-associated nephropathy, thrombotic microangiopathies, and so on. HIV infection is no longer a contraindication to transplantation and is becoming standard therapy in most developed countries. The HIV criteria used to select patients for renal transplantation are similar in Europe and North America. Current criteria state that prior opportunistic infections are not a strict exclusion criterion, but patients must have a CD4+ count above 200 cells/mm(3) and a HIV-1 RNA viral load suppressible with treatment. In recent years, more than 200 renal transplants have been performed in HIV-infected patients worldwide, and mid-term patient and graft survival rates have been similar to that of HIV-negative patients. The main issues in post-transplant period are pharmacokinetic interactions between antiretrovirals and immunosuppressants, a high rate of acute rejection, the management of hepatitis C virus coinfection, and the high cardiovascular risk after transplantation. More studies are needed to determine the most appropriate antiretroviral and immunosuppressive regimens and the long-term outcome of HIV infection and kidney graft.

Pegylated interferon-alpha-based treatment for chronic hepatitis C in renal transplant recipients: an open pilot study

Treatment of hepatitis C in renal transplant recipients remains a controversial issue, as interferon therapy has been associated with a high risk of rejection and poor efficacy. We report here the use of pegylated interferon-alpha, alone or in combination with ribavirin, in renal transplant recipients with chronic hepatitis C. Eight renal transplant recipients with chronic hepatitis C were recruited. The mean delay between renal transplantation and antiviral therapy was 198.8 months. Sustained virological response was observed in four of out eight patients. Three patients with sustained virological response were genotype 2, one was genotype 1; fibrosis stages were F1 for one patient, F2 for 2, F3 for one. At baseline, renal dysfunction was moderate in seven patients and severe in one patient. No patient experienced rejection episodes during or after pegylated interferon-alpha therapy. One patient developed haemolytic uraemic syndrome, which eventually resulted in graft loss and return to dialysis. In conclusion, for renal transplant recipients treated with pegylated interferon-alpha-based therapy, we observed a low risk of renal dysfunction, acceptable tolerance and significant virological efficacy. This is therefore the first study to suggest that pegylated interferon-alpha could be proposed late after transplantation to renal transplant recipients.

Hepatitis C infection and chronic renal diseases

More than 170 million people worldwide are chronically infected with the hepatitis C virus (HCV), which is responsible for over 1 million deaths resulting from cirrhosis and liver cancers. Extrahepatic manifestations are also relevant and include mixed cryoglobulinemia, lymphoproliferative disorders, and kidney disease. HCV infection is both a cause and a complication of chronic kidney disease, occurring largely in the context of mixed cryoglobulinemia. This infection also represents a major medical and epidemiologic challenge in patients with end-stage renal disease on renal replacement therapy with dialysis or transplantation. In these settings the presence of HCV correlates with higher rates of patient mortality than in HCV-negative subjects on dialysis or undergoing kidney transplant. The major concern is the lack of safe and effective drugs to treat HCV-infected patients with chronic kidney disease. Unfortunately, there are no large-scale clinical trials in this population, especially those receiving renal replacement therapy, so that strong evidence for treatment recommendations is scant. This review article provides the readers with the most recent insights on HCV infection both as cause and complication of chronic kidney disease, discusses pitfalls and limitations of current therapies, and reports on preliminary experience with novel therapeutic agents, as well as directions for future research.

Hepatitis C and renal transplantation: a review on historical aspects and current issues

Chronic liver disease has a significant impact on the survival of renal transplant recipients with an incidence rate of 4-38%. Approximately, 8-28% of renal transplant recipients die due to chronic liver disease. Hepatitis C seems to be the leading cause of chronic liver disease in kidney recipients. Hepatitis C virus (HCV) infection has a wide range of prevalence (2.6-66%) among renal transplant recipients living in different countries with great genotype diversity in different parts of the world. Nowadays, antiviral drugs are used for the management of hepatitis C. Because of graft-threatening effects of some antiviral drugs used in HCV-infected renal transplant recipients, we specifically focused on HCV treatment after renal transplantation. Treatment of post-renal transplantation chronic liver disease with INF and ribavirin remains controversial. Anecdotal reports on post-renal transplantation hepatitis C demonstrate encouraging findings. This review summarises the most current information on diagnosis, treatment, prognosis, complications as well as the new aspects of treatment in HCV-infected renal transplant recipients. HCV belongs to the family of Flaviviridae, genus Hepacivirus.

Treatment of chronic hepatitis C in hemodialysis patients

Hepatitis C virus (HCV) infection is especially problematic in patients with end-stage renal disease (ESRD) who are undergoing hemodialysis. Rates of HCV infection are higher among hemodialysis patients than in the general population, and several routes of transmission are thought to stem from the dialysis unit. Management of chronic hepatitis C is also more complicated in hemodialysis patients because of altered pharmacokinetics and a predisposition for drug-related toxicity, particularly ribavirin-induced anemia. Clinical trials of patients with chronic hepatitis C and healthy, functioning kidney grafts are rare because of the inherent dangers of graft rejection. As a result, most studies in patients with ESRD have focused on patients waiting for a kidney transplant. Additionally, because ribavirin is contraindicated in this patient population, many studies have examined monotherapy treatments. According to meta-analyses, conventional interferon alfa treatment yields a sustained virological response (SVR) rate of 37%, whereas studies of pegylated interferon alfa monotherapy have yielded SVR rates between 13% and 75%. Several small studies have also used the monitoring of ribavirin plasma concentrations or hemoglobin levels to facilitate the use of combination therapy. In light of the results from these clinical trials, we herein review treatment guidelines and recommend strategies to help optimize the treatment of patients with ESRD.

CONCLUSION

There remains a lack of clarity surrounding the most effective treatment options for patients with chronic hepatitis C and ESRD. Treatment can be effective with many patients attaining SVR; however, unfavorable tolerability with interferon alfa-based therapy remains a concern and thus close supportive care should be aggressively pursued to help maintain adherence.

Hepatitis C virus and kidney disease

Hepatitis C virus (HCV) infection remains frequent in patients on renal replacement therapy and has an adverse impact on survival in infected patients on chronic hemodialysis as well as renal transplant (RT) recipients. Nosocomial spread of HCV within dialysis units continues to occur. HCV is also implicated in the pathogenesis of renal dysfunction often mediated by cryoglobulins leading to chronic kidney disease as well as impairing renal allograft function. The role of antiviral therapy for hepatitis C in patients with renal failure remains unclear. Monotherapy with conventional interferon (IFN) for chronic hepatitis C is probably more effective in dialysis than in non-uraemic patients but tolerance is lower. Limited data only are available about monotherapy with pegylated interferon and combination therapy (pegylated IFN plus ribavirin) for chronic HCV in the dialysis population. Clinical experience with antiviral therapy for acute HCV in dialysis population is encouraging. Interferon remains contraindicated post-RT because of concerns about precipitating graft dysfunction. Sustained viral responses obtained by antiviral therapy in renal transplant candidates are durable after renal transplantation and may reduce HCV-related complications after RT (post-transplant diabetes mellitus, HCV-related glomerulonephritis, and chronic allograft nephropathy).

Hepatitis C virus infection in haemodialysis and kidney transplant patients

Chronic infection with hepatitis C virus (HCV) is an important global health problem. The prevalence of HCV is significantly higher in haemodialysis and kidney transplant patients, as compared to the general population. In spite of the relatively milder liver disease activity reported in HCV-infected haemodialysis patients, HCV infection adversely affects survival. Likewise, HCV has a detrimental effect on both patient and graft survival after kidney transplantation. However, patient survival is significantly better with kidney transplantation compared to remaining on dialysis; therefore, HCV infection alone should not be a contraindication to transplantation. Combination antiviral therapy with pegylated interferon-alpha and low-dose ribavirin is currently evolving in haemodialysis patients. Interferon-alpha (standard/pegylated) is relatively contraindicated after kidney transplantation because of an increased risk of allograft rejection. Therefore, antiviral treatment of transplant candidates while on dialysis remains the best option and may avoid the risk of HCV-associated liver and renal disease after transplantation. Large multi-centre clinical trials are required in HCV-infected haemodialysis and kidney transplant patients in order to define optimal therapeutic strategies before and after transplantation.

Hepatitis C infection in patients with chronic kidney disease

The management of hepatitis C virus (HCV)-infected patients with chronic kidney disease (CKD) is complex and represents a particular concern since numerous issues, such as antiviral therapy in dialysis patients and post renal transplant, and prevention of HCV spread within dialysis units, remain unresolved. An enormous body of literature has been published on HCV in the CKD population; however, clinical evidence on important issues is mostly based on uncontrolled clinical trials or retrospective surveys. The aim of this paper is to provide a systematic review of the literature. Responses to the critical issues have been developed by a consensus of experts, endorsed by the Italian Association for the Study of the Liver (AISF) and some clinical recommendations have been added.

Viral infection after renal transplantation: surveillance and management

Viral infections remain a significant cause of morbidity and mortality following renal transplantation. Although cytomegalovirus is the most common opportunistic pathogen seen in transplant recipients, numerous other viruses have also affected outcomes. In some cases, preventive measures such as pretransplant screening, prophylactic antiviral therapy, or post transplant viral monitoring may limit the impact of these infections. Recent advances in laboratory monitoring and antiviral therapy have improved outcomes. This review will summarize the major viral infections seen following transplant and discuss strategies for prevention and management of these potential pathogens.

Treatment of HCV in patients with renal failure

There continues to be a high prevalence of hepatitis C virus infection in patients with chronic kidney disease (CKD) on maintenance hemodialysis, despite screening of blood products and precautions to prevent the transmission of viral hepatitis within dialysis units. In addition, an increased rate of mortality from liver disease has been observed in infected patients on long-term dialysis, despite the frequent absence of biochemical dysfunction. Hepatitis C-infected renal transplant recipients have diminished patient and graft survivals compared to uninfected controls. Treatment with interferon in renal transplant candidates has resulted in sustained viral responses that have been long lasting even after subsequent renal transplant. A major concern limiting the use of interferon following renal transplant is graft dysfunction due to rejection. Ribavirin's induction of hemolytic anemia is the major reason why it is avoided in patients with CKD. Cautious use of reduced-dose ribavirin in small studies has been promising in these patients with close monitoring of hematocrit and additional measures to enhance compensatory erythropoiesis.

Combination therapy with ribavirin and amantadine in renal transplant patients with chronic hepatitis C virus infection is not superior to ribavirin alone

BACKGROUND

Standard treatment of chronic hepatitis C virus (HCV) infection based on interferon is not an option in renal transplant recipients due to the high risk of acute allograft rejection.

OBJECTIVES

To assess efficacy and tolerability of combined treatment with ribavirin and amantadine regarding viral clearance, normalization of liver enzymes, and improvement of HCV-related hepatopathy and graft nephropathy in HCV-RNA-positive renal transplant patients.

STUDY DESIGN

Prospective randomized controlled study comparing ribavirin, 1000 mg daily (n=7), versus ribavirin, 1000 mg, in combination with amantadine, 200 mg daily (n=8), for 12 months, versus no therapy (controls, n=26). Results were evaluated by intention-to-treat analysis.

RESULTS

No relevant differences among treatment groups were found regarding liver enzymes, HCV viremia, liver histology and renal parameters. However, antiviral treatment was limited by anemia, resulting in premature withdrawal from therapy and requiring substitution with recombinant erythropoietin in most patients. The best predictor for tolerability of active treatment was a creatinine clearance rate>50 ml/min.

CONCLUSIONS

Addition of amantadine to ribavirin seems not to be superior to ribavirin monotherapy in renal transplant patients with chronic replicating HCV infection. However, this may be explained in part by the poor tolerability of both ribavirin and amantadine in patients with impaired renal function, resulting in drop-outs and subtherapeutic drug dosage.

The kidney transplant recipient with hepatitis C infection: pre- and posttransplantation treatment

Liver disease secondary to chronic hepatitis C virus (HCV) infection is an important cause of morbidity and mortality in dialysis patients and kidney transplant recipients. Evaluation of patients with chronic HCV infection is warranted to determine stage of disease and the need for HCV therapy. Although combination therapy with interferon (IFN) plus ribavirin is the standard of care for chronic HCV infection, IFN monotherapy is recommended in dialysis patients because ribavirin is contraindicated in the presence of renal failure. The goals of pretransplantation HCV therapy are to decrease the risk for progression of HCV-associated liver disease, stabilize renal function in patients with HCV-related glomerulopathy, and prevent development of HCV-associated renal disease after transplantation. Posttransplantation HCV therapy is generally not recommended because of concerns regarding risk for precipitating acute rejection; however, antiviral therapy may be indicated to treat HCV-related glomerulopathy or prevent progression of chronic hepatitis C in patients with more advanced stages of fibrosis. When treatment is required, restored renal function allows use of combination therapy with IFN and ribavirin. Limitations of current HCV therapy include lack of tolerability and suboptimal response rates. New antiviral agents that can be used in dialysis patients (e.g., ribavirin alternatives) and in the posttransplantation setting (e.g., IFN alternatives) are needed to improve outcomes in these populations.

Ribavirin inhibits angiogenesis by tetrahydrobiopterin depletion

Ribavirin is a broad-spectrum antiviral drug that is used to treat hepatitis C virus (HCV)-infected patients. The virological response after ribavirin treatment appears to be insufficient to fully explain ribavirin-induced beneficial effects. Angiogenesis plays a pathogenic role in HCV-induced liver damage. Here, we investigated the influence of therapeutic ribavirin concentrations on angiogenesis. Ribavirin inhibited endothelial cell tube formation in vitro and vessel formation in the chick chorioallantoic membrane assay in vivo. Ribavirin inhibits inosine monophosphate dehydrogenase, which causes depletion of cellular GTP and in turn reduction of cellular tetrahydrobiopterin levels. The availability of tetrahydrobiopterin limits NO production by endothelial NO synthase. Ribavirin reduced levels of tetrahydrobiopterin (as revealed by HPLC), NO (as revealed by electron spin resonance spectroscopy), and cGMP (as revealed by RIA) in endothelial cells. Addition of tetrahydrobiopterin or NO prevented ribavirin-induced tube formation inhibition. In conclusion, angiogenesis inhibition by ribavirin has not been described before. This inhibition may contribute to ribavirin-induced pharmacological effects including adverse events.

Treatment of hepatitis C virus infection (HCV) after renal transplantation: implications for HCV-positive dialysis patients awaiting a kidney transplant

Patient survival is significantly lower in hepatitis C virus (HCV)-positive compared to HCV-negative dialysis patients. After renal transplantation, immunosuppressive therapy can result in an increased burden of HCV viremia. Both patient and graft survivals are lower in HCV-positive compared to matched HCV-negative renal-transplant patients. Therefore, it is important to treat HCV infection. At present, after renal transplantation, there is no current safe and efficient therapy. Alpha-interferon (alpha-IFN) does not give a sustained virological response, and is associated with a high rate of renal failure. Ribavirin and amantadine monotherapies are associated with a significant improvement in liver enzymes, but have no impact upon HCV viremia. Ribavirin, however, may be indicated in cases of HCV-related glomerulopathy because it can significantly decrease proteinuria. The combined use of alpha-IFN and ribavirin should only be given to those patients who have developed posttransplant fibrosing cholestatic hepatitis. Therefore, HCV infection needs to be treated pretransplant. In dialysis patients, the only recommended therapy, as yet, is alpha-IFN monotherapy. Pegylated alpha-IFN is under evaluation and ribavirin is contraindicated because it results in severe hemolytic anemia. Twelve months of alpha-IFN therapy results in sustained virological clearance in approximately 40% of patients, regardless of their genotype. HCV RNA, after three months of alpha-IFN therapy, is a predictive factor for a long-term sustained response. Finally, when HCV-positive dialysis patients with a sustained virological response undergo successful renal transplantation, very few suffer a virological relapse, thus emphasizing that these patients were cured.

Meta-analysis: anti-viral therapy of hepatitis C virus-related liver disease in renal transplant patients

BACKGROUND

The efficacy and safety of interferon-based therapy in renal transplant recipients with hepatitis C remains unclear, although a number of small clinical trials have been published addressing this issue.

AIM

To evaluate efficacy and safety of antiviral therapy with interferon (interferon alone or interferon plus ribavirin) in renal transplant patients with hepatitis C by performing a systematic review of the literature with a meta-analysis of clinical trials.

METHODS

The primary outcomes were sustained virological response (as a measure of efficacy) and/or drop-out rate (as a measure of tolerability). We used the random-effects model of DerSimonian and Laird, with heterogeneity and sensitivity analysis.

RESULTS

We identified 12 clinical trials (102 unique patients); there was one controlled study. The summary estimate for sustained virological response and drop-out rate was 18.0% (95% CI 7.0-29.0%) and 35.0% (95% CI 20-50%), respectively. The most frequent side-effect requiring interruption of treatment was graft dysfunction (n = 28; 71.7%). Meta-regression analysis showed an inverse and significant association between reference year and drop-out logit rate (P = 0.012); an inverse link between sustained virological response logit rate and frequency of hepatitis C virus genotype 1 (P = 0.067) and cirrhosis (P = 0.08) was found, even if no statistical significance was reached. No publication bias was observed.

CONCLUSIONS

Interferon-based therapy of hepatitis C has poor tolerance and safety after renal transplant. The optimal treatment of hepatitis C after renal transplant requires additional agents or alternative therapeutic approaches.

Chronic hepatitis C virus infection in renal transplant: treatment and outcome

BACKGROUND

Chronic hepatitis C virus (HCV) infection is a common cause of liver disease in post-renal transplant period and causes poor patient and graft survival. We analyzed the effects of antiviral therapy using ribavirin monotherapy or ribavirin in combination with interferon (IFN)-alpha in our kidney transplant recipients with chronic hepatitis C.

METHODS

Total of 14 patients received antiviral therapy, all of whom had stable graft function, raised aminotransferases and positive HCV viremia at the start of treatment. Eight patients received ribavirin alone for a period of six months to two yr, in doses of 400-800 mg daily. Five patients received IFN-alpha therapy for a period of two months to 1.5 yr, in doses of 1.5 million units daily or three million units thrice weekly with ribavirin. One patient received pegylated IFN 50 microg once weekly in combination with ribavirin. The response was seen in terms of biochemical and virological improvement at the end of study period.

RESULTS

In patients treated with ribavirin alone (n = 8), mean alanine aminotransferase (ALT) levels before and after treatment were significantly different (198.4 +/- 147.6 and 104.8 +/- 66.5 IU/L respectively; p < 0.05). ALT levels normalized completely in three patients at the end of treatment, improved in three patients and deteriorated in two. Only in one of eight patients on ribavirin alone, HCV-RNA became negative after six months of treatment while in the rest (n = 7) HCV-RNA continued to be positive. In subjects on IFN plus ribavirin (n = 6), the mean ALT levels decreased significantly (from 280.2 +/- 114.9 IU/L at baseline to 71 +/- 49 IU/L at end of therapy; p < 0.05). Two patients had sustained remission (33.3%) on IFN plus ribavirin (persistently negative HCV-RNA), two patients relapsed after initial remission and in two patients treatment was stopped after two months because of graft dysfunction. Totally four patients developed graft dysfunction at some time during the course of IFN therapy (66.6%), but it was discontinued in only two (33.3%). All patients regained normal creatinine levels after discontinuation of IFN, although one patient developed chronic allograft nephropathy as shown by kidney biopsy. Four patients in IFN group developed leucopenia. Two patients developed severe anemia one of whom required blood transfusion and one developed severe flu-like syndrome requiring stoppage of therapy.

CONCLUSION

Ribavirin monotherapy in renal transplant recipients with chronic hepatitis C infection results in good biochemical response but is not associated with virological clearance. IFN in combination with ribavirin is effective in two-thirds of patients after a minimum therapy of six months, but it is poorly tolerated, results in graft dysfunction in significant number of patients, and relapse can occur after stopping treatment.

Hepatitis C in transplant recipients of solid organs, other than liver

Hepatitis C virus (HCV) infection is prevalent in candidates for, and recipients of, solid organ transplants. HCV infection can lead to diminished patient and allograft survival in the long-term in recipients of kidney transplants. Outcomes in recipients of other solid organ transplants (lung, heart, small bowel, pancreas, pancreas-kidney) are not well established. Large, well-designed, prospective studies are needed to answer these questions. Interferon therapy for HCV before transplantation can lead to improved outcomes. Therefore, transplant candidates should be considered for and offered interferon therapy before embarking on organ transplantation. Posttransplant interferon therapy can be complicated by acute allograft rejection and is not recommended, except with advanced liver disease.

Diagnostic Accuracy of the Fibrotest in Hemodialysis and Renal Transplant Patients with Chronic Hepatitis C Virus

BACKGROUND

An accurate diagnosis of hepatitis C virus (HCV)-related liver lesions is mandatory in dialysis patients and kidney recipients to better define the treatment of and contraindications to kidney transplantation. The aim of this study was to assess the diagnostic accuracy of the fibrotest (a noninvasive method to assess liver fibrosis in HCV on a scale from 0 to 1) in hemodialysis and renal transplant patients infected by chronic HCV.

METHODS

In all, 110 patients with biopsy-proven HCV (60 renal transplant recipients and 50 hemodialysis patients), determined using the METAVIR scoring system, were studied.

RESULTS

Forty-six percent of patients had fibrosis > or =F2. A positive predictive value of a score >0.6 for the presence of significant fibrosis by comparison with liver biopsy was 71%, and an negative predictive value of < 0.2 for excluding significant fibrosis was 77%, respectively. The areas under the ROC curves for the diagnosis of significant fibrosis were 0.66, 0.47, and 0.71 in the global population, hemodialysis patients, and renal transplant patients, respectively. In all, 75% of patients were correctly classified using the fibrotest. If biopsy was restricted to scores in the intermediate range (< 0.6 and >0.2), the index could reduce the indication for biopsy by 47%. The results did not differ significantly in hemodialysis and renal transplant patients.

CONCLUSION

The fibrotest has a diagnostic value in hemodialysis and renal transplant patients which is similar to that reported in the general population (75%) and its use could avoid 32% of liver biopsies if it were interpreted in detail in nephrology patients.