Antiviral Therapy for Hepatitis C Virus Recurrence Following Liver Transplantation: Long-Term Results From a Single Center Experience

Hepatoprotective effects of the nitric oxide donor isosorbide-5-mononitrate alone and in combination with the natural hepatoprotectant, silymarin, on carbon tetrachloride-induced hepatic injury in rats

The aim of this study was to investigate the effect of the nitric oxide donor isosorbide-5-mononitrate (5-ISMN) alone or in combination with the natural hepatoprotectant with anti-oxidant activity silymarin on the carbon tetrachloride (CCl(4))-induced hepatic injury in rats. 5-ISMN (1.8, 3.6 or 7.2 mg/kg), silymarin (25 mg/kg) or 5-ISMN (1.8, 3.6 or 7.2 mg/kg) combined with silymarin was given once daily orally simultaneously with CCl(4) and for 15 days thereafter. Liver damage was assessed by determining serum enzyme activities and hepatic histopathology. 5-ISMN given at the above doses conferred significant protection against the hepatotoxic actions of CCl(4) in rats, reducing serum alanine aminotransferase (ALT) levels by 31.2, 39.3 and 61.6%, respectively, when compared with controls. Serum aspartate aminotransferase (AST) levels decreased by 19.8, 22.7 and 59.4%, respectively, while alkaline phosphatase (ALP) decreased by 26.1 and 32.6% by the drug at 3.6 and 7.2 mg/kg, respectively. When silymarin was added to 5-ISMN (1.8, 3.6 or 7.2 mg/kg), ALT decreased by 32.8, 59.6, 70.2% and AST by 28.7, 50.3, 60%, when compared with CCl(4) control group levels. Silymarin in combination with 3.6 or 7.2 mg/kg 5-ISMN resulted in 37.5 and 39.2% reductions in ALP when compared with CCl(4) control group. Meanwhile, silymarin alone reduced ALT, AST and ALP levels by 65.9, 52 and 62.3%, respectively. Blood levels of reduced glutathione were markedly decreased in CCl(4)-treated rats. Reduced glutathione levels were increased by the administration of 5-ISMN and restored to near normal values by silymarin treatment. Histopathological alterations by CCl(4) were markedly reduced after treatment with 5-ISMN alone or in combination with silymarin. Histopathologic examination of the livers of CCl(4)-treated rats administered 5-ISMN at 7.2 mg/kg showed marked restoration of the normal architecture of the liver tissue and minimal fibrosis. Silymarin co-administered with 5-ISMN resulted in further improvement of the histologic picture. These results indicates that treatment with 5-ISMN protects against hepatocellular necrosis induced by CCl(4). The study suggests a potential therapeutic use for 5-ISMN in combination with silymarin in liver injury.

Lack of killer immunoglobulin-like receptor 2DS2 (KIR2DS2) and KIR2DL2 is associated with poor responses to therapy of recurrent hepatitis C virus in liver transplant recipients

Killer immunoglobulin-like receptors (KIRs) expressed on natural killer and natural killer T cells are involved in activation of these cells and can influence antiviral immunity in the liver. This study investigated the association between KIR genetic diversity and sustained virologic response (SVR) to Peginterferon and Ribavirin (Peg/RBV) therapy in liver transplant (LT) recipients with hepatitis C virus (HCV) recurrence. We tested KIR genotypes in 44 HCV-infected LT recipients treated with Peg/RBV for 48 weeks. Patients were categorized as having KIR genotypes A/A or B/x and analyzed for association with SVR. Fifteen of 44 (34%) patients had SVR. Only 2 of 18 (11%) who lacked KIR2DS2/KIR2DL2 achieved SVR compared to 13 of 26 (50%) who carried these two genes (odds ratio: 8.0, 95% confidence interval: 1.5-42.0, P = 0.008). The association between lack of KIR2DS2/KIR2DL2 and SVR remained significant after exclusion of 10 patients with non-genotype 1 HCV. No correlation was found with other activating or inhibitory KIR genes. Absence of KIR2DS2 and/or KIR2DL2 is associated with failure of Peg/RBV therapy in patients with recurrent HCV after LT. These findings support the role of natural killer and natural killer T cells in HCV clearance after LT and might be generalizable to treatment of HCV infection outside the setting of LT.

Donor livers with steatosis are safe to use in hepatitis C virus-positive recipients

Whether donor graft steatosis affects liver function and influences survival after liver transplantation is still open to debate. The aim of this study was to assess the impact of donor graft steatosis on long-term liver histology after liver transplantation. One hundred sixteen consecutive liver transplants were performed in 56 hepatitis C virus-positive (HCV+) patients and 60 HCV- patients who had protocol liver biopsies at 6, 12, 24, and 36 months after liver transplantation. Liver biopsies were obtained from all grafts. No steatosis was seen in 50.9% of the biopsies taken at the back table before implantation, whereas steatosis was mild in 39.6% of the samples and moderate/severe in 9.5% of the samples. In the 56 HCV+ recipients, fibrosis stage 3 was seen in 22.2% and stage 4 was seen in 2.2% of 45 biopsies at 36 months after liver transplantation. There was no correlation between donor graft steatosis and fibrosis after liver transplantation, regardless of the etiology of liver disease. No difference in 36-month survival after liver transplantation was seen, regardless of whether the etiology of the patient's liver disease was HCV-related or non-HCV-related (80.3% versus 75%; P = 0.4) and whether the steatosis in the graft was reportedly absent, mild, or moderate/severe (79.7% versus 73.9% versus 81.1%; P = 0.7). In conclusion, nearly one-quarter of HCV+ recipients have precirrhosis/cirrhosis 3 years after liver transplantation. Steatotic grafts do not seem to exacerbate the progression of fibrosis in HCV+ recipients, nor do they seem to negatively affect 3-year patient survival.

Efficacy of interferon Beta combined with cyclosporine induction and intensified therapy for retreatment of chronic hepatitis C

OBJECTIVE

Hepatitis C virus (HCV) infection is a major burden after liver transplantation. There is no effective treatment for these patients, therefore management is challenging. Cyclophilins are essential host factors for HCV replication. We have reported herein the efficacy of divided administration of interferon (IFN) beta plus cyclosporine for chronic hepatitis C patients who failed pegylated (Peg)-IFN or IFN combined ribavirin treatment.

PATIENTS AND METHODS

We prospectively enrolled 59 patients (median age, 63 years) with genotype 1b who failed to respond to the combinations of IFN plus ribavirin or Peg-IFN plus ribavirin. Our treatment involved induction, intensified, and maintenance therapies. The induction therapy prescribed intravenous 1 MU IFN beta every 4 hours for the first 3 days, 1.5 MU IFN beta every 6 hours for the next 4 days, and then 2 MU IFN beta every 8 hours for 3 weeks. The intensified therapy was the induction therapy shortened to 2 weeks. The maintenance therapy involved Peg-IFN alpha 2b and ribavirin. Cyclosporine was given 4 times daily during the induction and intensified therapies. Ribavirin was given twice daily during the maintenance phase.

RESULTS

The end treatment and sustained virological response rates in the present study were 73% (43/59) and 59% (35/59), respectively. The relapse rate was 19% (8/43). Sixteen percent of patients (3/19) were nonresponders. All adverse effects were reversible. The treatment protocol was well tolerated.

CONCLUSION

Our protocol should be effective for patients who have failed previous combination therapies.

Long-term antiviral therapy for recurrent hepatitis C after liver transplantation in nonresponders: biochemical, virological, and histological impact

More than 50% of patients with a recurrent posttransplant hepatitis C virus infection fail to respond to antiviral treatment. The aim of this study was to evaluate the interest of a long-term antiviral treatment maintained for more than 48 weeks. Seventy treated patients, with a histological follow-up > 1 year, were enrolled in this observational, retrospective study. The duration of antiviral treatment, tolerance, and occurrence of virological, biochemical, and histological responses were recorded. Thirty-two patients were nonresponders after 48 weeks of treatment. Combined antiviral therapy was maintained for >12 months in 26 and for >18 months in 21. Twelve patients had to discontinue their treatment. At 48 weeks, the rates of virological response and sustained virological response were 37% and 24.3%, respectively; at the end of the follow-up, they were 48.5% and 35.7%. Virological response was significantly associated with a higher incidence of biochemical and histological response, regardless of its time of occurrence (before or after 6 months). Even in the absence of virological response, the rate of progression of fibrosis was significantly slowed in patients treated for more than 6 months. Our results show the feasibility, safety, and efficacy of long-term antiviral therapy in nonresponder patients with a recurrent posttransplant hepatitis C virus infection.

HCV histological recurrence and survival following liver transplantation in patients with and without hepatocellular carcinoma

BACKGROUND AND AIM

Hepatitis C virus (HCV)-related cirrhosis is one of the leading indication for liver transplantation (LT) and a major risk factor for the development of hepatocellular carcinoma (HCC). HCV recurrence after LT is universal. This study evaluated HCV recurrence and survival in patients transplanted for HCV and HCC.

METHODS

We evaluated all adults transplanted for HCV cirrhosis between January 1999 and December 2006, HCC was diagnosed on the explant and HCV recurrence confirmed on protocol liver biopsies performed at 6 months and yearly after LT. The sustained viral response (SVR) was defined as HCV-RNA undetectable at 6 months after therapy discontinuation. The patient survival rates were assessed with Kaplan-Meier curves and the chi-square test was used when appropriate.

RESULTS

Two hundred sixteen patients underwent LT for HCV including 153 men and 63 women of mean age 54 years with a mean follow-up of 35 months. There were 71 (33%) HCC(+) patients. At 1, 3, and 5 years from LT severe fibrosis (Scheuer 3-4) due to the HCV recurrence was reported in 18%, 14%, and 11% for HCC(+) and 14%, 16%, and 28% for HCC(-) patients respectively (P=NS). HCC recurred only in 3 (4%) patients at a mean follow-up of 3 years. Patients who received antiviral treatment after LT were 10% HCC(+) and 12% HCC(-) patients (P=NS). SVR was seen in 3/7 (43%) of HCC(+) and in 10/18 (55%) of HCC(-) patients (P=NS). At 1, 3, and 5 years the patient survivals was 91%, 86%, and 86% for HCC(+) and 94%, 86%, and 83% for HCC(-) patients, respectively (P=NS).

CONCLUSIONS

Severe fibrosis due to HCV recurrence, which increases over time, involves one third of transplanted patients at 5 years after LT. The long-term survival was identical among HCC(+) compared to HCC(-) recipients. The recurrence of HCC was negligible and did not affect patient survival.

Torque Teno Virus: any pathological role in liver transplanted patients?

Few studies have been performed on the prevalence of Torque Teno Virus (TTV) infection in liver transplant (LT) recipients. The aim of this study was to assess the prevalence, viremia and genogroup pattern of TTV among LT patients and to ascertain whether TTV causes liver damage in liver transplanted patients with biochemical and histological changes of unknown origin. Twenty-five patients were evaluated before and after LT; 80 healthy subjects were considered as controls. Serum samples were serially obtained from all the patients before LT and thereafter at 3, 6 and 12 months post-transplant. Serum TTV-DNA and genogroups were assessed by PCR. Patients underwent protocol serial liver biopsies at 6 and 12 months after LT. Results were compared using the Chi-squared tests, McNemar's and Student's t-tests. TTV-DNA was found in 25/25 patients before LT and in 60/80 blood donors (P < 0.01). The TTV-DNA load increased significantly after LT (P < 0.001). TTV-DNA was significantly higher in patients on calcineurin inhibitors (CNI) and azathioprine or mycophenolate mofetil than in patients on CNI alone (P = 0.04) at 3 months after LT. Genogroup analysis showed a significant increase in genogroup 5 positivity after LT. No differences were seen in the viremia of patients compared according to their viral versus other etiologies of their liver disease before transplantation. Viremia and TTV genotype patterns did not correlate with the presence of hypertransaminasemia or histological liver damage of unknown etiology. The prevalence of TTV-DNA was significantly higher in patients with liver cirrhosis than in controls and the viral load was significantly higher after LT than beforehand. On the basis of our data, TTV does not seem to cause liver damage following LT, although larger studies with a long-term follow up are needed to confirm these findings.

Recurrent hepatitis C after liver transplantation: on-treatment prediction of response to peginterferon/ribavirin therapy

Sustained virologic response (SVR) in the treatment of recurrent hepatitis C virus (HCV) infection after liver transplantation (LT) remains suboptimal. We evaluated efficacy of pegylated interferon alfa (PEG) and ribavirin (RBV) (PEG/RBV) combination therapy in LT recipients with recurrent HCV and predictive values of rapid virological response (RVR) and early virologic response (EVR). Between January 2001 and October 2005, LT recipients with recurrent HCV were intended to be treated for 48 weeks with PEG/RBV combination therapy independent of genotype or virologic response [53 patients (79% genotype 1)]. On-treatment predictor of response at week 4 (RVR) was defined as undetectable HCV RNA, and at week 12 (EVR) as undetectable HCV RNA or a >2 log(10) drop from pretreatment viral load. SVR was seen in 19 (35%) patients. Patients with genotype 2/3 were more likely to achieve SVR than those with genotype 1 (87% versus 23%; P = 0.001). The highest rate of SVR was seen in patients with RVR [specificity and positive predictive value (PPV) = 100%] while the highest rate of treatment failure was seen in those who did not have EVR [sensitivity and negative predictive value (NPV) = 100%]. The NPV of RVR to identify those who will not achieve SVR was also very high (88%). EVR had low PPV (63%) to identify those with SVR. In conclusion, PEG/RBV combination therapy is effective in the treatment of post-LT recurrent HCV. On-treatment virologic monitoring is highly predictive of SVR and may optimize the virologic response and minimize toxicity. Given its high PPV and NPV, RVR appears to be the most appropriate decision time point for continuation of therapy.

Ribavirin with either standard or pegylated interferon to treat recurrent hepatitis C after liver transplantation

AIM

To investigate the efficacy of two anti-viral protocols in hepatitis C virus-reinfected liver transplant recipients.

METHODS

In this prospective study, 26 liver transplant patients were treated with standard interferon-alpha2b for 12 months or standard interferon-alpha2b for 3 months followed by pegylated interferon-alpha2b for 9 months. Interferon was combined with ribavirin in all patients. The histological course of the study population was compared with an untreated historic control group (n = 38) with similar baseline characteristics.

RESULTS

The sustained virological response rates in the standard interferon group and in the pegylated interferon group were 27.3% and 26.7%, respectively. Only 29% of patients with sustained virological response had end of treatment histological response, whereas 47% of viral non-responders showed end of treatment histological response. The percentage of patients with histological improvement was significantly higher in the study population when compared to the controls. Univariate analysis indicated that hepatitis C virus genotype non-1, high baseline alanine aminotransferase, the time interval between liver transplant and interferon therapy and the body mass index predicted sustained virological response. In the multivariate model, baseline alanine aminotransferase and the body mass index remained a significant predictor of sustained virological response.

CONCLUSIONS

Both treatment regimens offer similar efficacy profiles. Failure to eradicate hepatitis C virus should not lead to treatment discontinuation if serial liver biopsies demonstrate histological response.

Management of hepatitis C infection after liver transplantation

Recurrent hepatitis C virus (HCV) infection after orthotopic liver transplantation (OLT) has been associated with progression to cirrhosis in approximately 20% of patients, 5 years postoperatively. Accelerated decompensation has also been noted when compared with cirrhosis in non-transplant patients. Different treatment strategies are available for recurrent HCV infection post-OLT, but efforts are hindered by the modest response rates, poor tolerability and the risk of rejection as well as graft loss. Anti-HCV immunoglobulin therapy to prevent graft infection with HCV has no established role at present but studies are ongoing. Treatment prior to transplantation in patients with decompensated cirrhosis has been evaluated but the results are too preliminary to make firm recommendations. Prophylactic interferon-based antiviral therapy in the early postoperative period to prevent graft infection was shown to have low response rates and high rates of adverse effects. Treatment of established recurrent HCV infection with combination peginterferon (pegylated interferon) and ribavirin is associated with 10-59% sustained virological response and the predictive value of a positive early virological response has been validated in the post-transplant setting. Improvement in inflammatory activity after viral eradication is well established, but fibrosis regression or stabilisation is less predictable and factors such as rejection and biliary complications may still contribute to graft loss. Most studies have initiated therapy at least 6 months postoperatively in order to optimise patient tolerance and enable the addition of ribavirin. The use of adjuvant agents to treat drug-induced neutropenia and anaemia in this population is evolving and becoming a crucial part of therapy. Determination of optimal doses of both pegylated interferon and ribavirin, and guidance on when to stop treatment, as well as improving tolerability are important steps in achieving higher response rates and minimising drug toxicity.

Therapeutic management of recurrent hepatitis C after liver transplantation

Recurrent hepatitis C ranges from minimal damage to cirrhosis developing in a few months or years in a substantial proportion of transplant recipients. Different virus, host and donor factors are involved in the pathogenesis of recurrence, but many are poorly understood. Therapeutic strategies can be utilized in the pre-, peri- or posttransplantation setting. Antiviral therapy using interferon and ribavirin and modifying immunosuppression are the main strategies to prevent progression disease. The efficacy of interferon and ribavirin is limited and side effects, reduction/withdrawal are frequent. Current sustained virological response rates are approximately 28%. An optimal immunosuppression regimen has not been established. The choice of calcineurin inhibitors has not clearly been shown to affect histological hepatitis C virus (HCV) but higher cumulative exposure to corticosteroids to treat acute rejection is associated with more severe recurrence. The manner in which the doses of immunosuppression are modified has more influence on HCV recurrence than the use of a specific drug per se. Debate about the influence of immunosuppressive regimens on HCV recurrence is ongoing. Potential antifibrotic therapy and new agents targeting HCV infection and replication are emerging and are anticipated to be added to our armentarium in battling recurrent HCV post-LT.

Antiviral therapy for hepatitis C in the setting of liver transplantation

Hepatitis C viremia after liver transplantation for hepatitis C virus (HCV) liver disease is universal. Progressive HCV disease after transplantation is the leading cause of death, graft failure, and retransplantation. Whether to treat, with which agents, and timing of therapy are unanswered questions. Timing options include pretransplantation, prophylactic, post-transplantation preemptive, and post-transplantation recurrence-based therapy. The latter is most commonly utilized. There are little data for each of these, much less comparisons. Pegylated interferon-alpha has supplanted standard interferon-alpha due to increased efficacy and is generally used in combination with ribavirin (RBV). Efficacy is less than in nontransplant settings due to immunosuppression, an increased prevalence of genotype 1 HCV, patient comorbidities, and decreased functional status. Administration of HCV therapy to cirrhotic patients prior to transplantation may eradicate or suppress HCV and prevent or reduce severity of recurrence. Sustained virological response (SVR) as high as 50% was attained in genotypes 2 or 3 HCV. Comparison of preemptive and histology-based post-transplantation HCV therapy should be done, and more data will be available on pretransplantation therapy. Post-transplant patients are less tolerant of therapy, particularly RBV. SVR, the primary goal of therapy, likely halts disease progression, but only 20% to 30% of treated patients achieve SVR. Preemptive therapy early after transplantation may have advantages due to the potential to delay or blunt severity of graft infection and recurrent hepatitis. In post-transplant therapy, RBV toxicity is attenuated in relation to decreased renal function, and side effects of interferon are more prominent. An ongoing trial will assess preemptive therapy with treatment after histologic recurrence. Novel anti-HCV therapies such as protease and polymerase inhibitors are emerging. These must be tested with urgency in the transplant setting. Retransplantation for progressive HCV disease is more controversial due to poor outcomes, graft shortage, and disease recurrence.