Natural history of recurrent hepatitis C

C4d in acute rejection after liver transplantation--a valuable tool in differential diagnosis to hepatitis C recurrence

Hepatitis C is the most common indication for liver transplantation. Recurrence of HCV is universal leading to graft failure in up to 40% of all patients. The differentiation between acute rejection and recurrent hepatitis C is crucial as rejection treatments are likely to aggravate HCV recurrence. Histological examination of liver biopsy remains the gold standard for diagnosis of acute rejection but has failed in the past to distinguish between acute rejection and recurrent hepatitis C. We have recently reported that C4d as a marker of the activated complement cascade is detectable in hepatic specimen in acute rejection after liver transplantation. In this study, we investigate whether C4d may serve as a specific marker for differential diagnosis in hepatitis C reinfection cases. Immunohistochemical analysis of 97 patients was performed. A total of 67.7% of patients with acute cellular rejection displayed C4d-positive staining in liver biopsy whereas 11.8% of patients with hepatitis C reinfection tested positive for C4d. In the control group, 6.9% showed C4d positivity. For the first time we were able to clearly demonstrate that humoral components, represented by C4d deposition, play a role in acute cellular rejection after LTX. Consequently C4d may be helpful to distinguish between acute rejection and reinfection after LTX for HCV.

Management of hepatitis C-infected liver transplant recipients at large North American centres: changes in recent years

Large (>or=45 transplants per year) North American liver transplant centres were surveyed regarding management of hepatitis C virus (HCV). A total of 25/41 (59%) and 28/48 (58%) of centres responded to the surveys in 1998 and 2003, respectively, with 17 centres participating in both surveys. HCV was the most common indication for transplantation. Use of protocol liver biopsies was higher in 2003 and 60% used them to monitor HCV disease. Fewer centres reported modifying primary immunosuppression (IMS) for HCV-positive (vs. non-HCV) patients in 2003 (26%) vs. 1998 (56%). IMS was most frequently tacrolimus-based, but mycophenolate mofetil use increased in 2003 (52% vs. 23% in 1998). In both years, approximately 40% treated allograft rejection differently in HCV-positive recipients, with less use of OKT3 in 2003. Combination anti-HCV therapy for 12 months or more was the treatment of choice and growth factor use was common (68%). HCV-positive recipients were considered candidates for retransplantation but HCV-specific criteria were used in decision-making. Practice of centres changed over time with an increase in HCV transplantation and use of protocol liver biopsies, and a trend towards lesser modification of IMS in HCV-positive recipients. We conclude that there is considerable variability in the management of HCV among transplant programs and over time.

The Importance of Clinical Parameters When Differentiating Cholestatic Hepatitis C Virus From Allograft Rejection

BACKGROUND

The exact cause and appropriate treatment for cholestasis following liver transplantation in recipients with hepatitis C virus recurrence (RHCV) are difficult to determine. Our objective was to determine the diagnostic accuracy of clinical and histological parameters in liver transplant recipients with RHCV and concurrent cholestasis.

METHODS

A retrospective analysis from June 1996 to May 2003 was performed on adult liver transplant (OLT) recipients with hepatitis C virus. Patients with cholestasis (bilirubin >5 mg/dL, 6 months after OLT) were selected. Demographics, etiology, immune suppression, clinical and histologic outcomes, and virologic features were evaluated. Patients were divided into two groups based on clinical and histological criteria: (1) patients with parameters suggestive of cholestatic HCV; and (2) patients with parameters consistent with acute cellular rejection.

RESULTS

Thirty-seven patients met study criteria (20 males). The average age was 54 years (range = 14-72), and time from transplant to jaundice was 769 days (range = 48-2981). The groups were comparable regarding HCV viral load, age, gender, time from transplant, and United Network of Organ Sharing status at time of transplant. Retransplantation was performed in two patients in group 1, neither of whom survived, and in three patients in group 2, all of whom survived. Clinical parameters correlated well with diagnosis of cholestasis (r = 0.85, P < .001) whereas histological evaluation did not (r = 0.11, P = .53). Mortality in group 1 was 78% (7 of 9) vs. 50% (13 of 26) in group 2. Median duration of survival following liver transplantation in group 1 was 132 days versus 435 days in group 2.

CONCLUSION

Clinical diagnosis parameters for RHCV with cholestasis appear more accurate than histology parameters and should be the primary consideration in directing therapy. Despite timely diagnosis, cholestatic RHCV LTx recipients have a poor prognosis.

Excess body weight, liver steatosis, and early fibrosis progression due to hepatitis C recurrence after liver transplantation

AIM: To investigate how weight gain after OLT affects the speed of fibrosis progression (SFP) during recurrent hepatitis C virus (HCV) infection of the graft.

METHODS: Ninety consecutive patients (63 males, median age 53 years; 55 with HCV-related liver disease), transplanted at a single institution, were studied. All were followed for at least 2 years after OLT and had at least one follow-up graft biopsy, performed not earlier than 1 year after the transplant operation. For each biopsy, a single, experienced pathologist gave an estimate of both the staging according to Ishak and the degree of hepatic steatosis. The SFP was quantified in fibrosis units/month (FU/mo). The lipid metabolism status of patients was summarized by the plasma triglycerides/cholesterol (T/C) ratio. Body mass index (BMI) was measured before OLT, and 1 and 2 years after it.

RESULTS: In the HCV positive group, the highest SFP was observed in the first post-OLT year. At that time point, a SFP ≤0.100 FU/mo was observed more frequently among recipients who had received their graft from a young donor and had a pre-transplant BMI value >26.0 kg/m². At completion of the first post-transplant year, a BMI value >26.5 kg/m² was associated with a T/C ratio ≤1. The proportion of patients with SFP >0.100 FU/mo descended in the following order: female recipients with a high T/C ratio, male recipients with high T/C ratio, and recipients of either gender with low T/C ratio. Hepatic steatosis was observed more frequently in recipients who, in the first post-transplant year, had increased their BMI ≥1.5 kg/m² in comparison to the pre-transplant value. Hepatic steatosis was inversely associated with the staging score.

CONCLUSION: Among HCV positive recipients, excess weight gain post-OLT does not represent a factor favoring early liver fibrosis development and might even be protective against it.

Early hepatic stellate cell activation is associated with advanced fibrosis after liver transplantation in recipients with hepatitis C

Recurrent hepatitis C after liver transplantation is a serious problem faced by liver transplant recipients. Activation of hepatic stellate cells is an early step in hepatic fibrogenesis. The aim of this study was to evaluate hepatic stellate cell activation, early after liver transplantation, as a predictor for the subsequent development of advanced fibrosis. Forty-six patients who underwent liver transplantation for hepatitis C and protocol liver biopsies were divided into rapid fibrosers (n = 21), defined as recipients who developed bridging fibrosis or cirrhosis within 2 years of liver transplantation, and slow fibrosers (n = 25). The protocol liver biopsy obtained 4 months after transplantation was stained and quantitated for hepatic stellate cell activation with antibody to alpha smooth muscle actin. Hepatic stellate cell activity was independently associated with rapid fibrosis (odds ratio: 1.6 [95% CI: 1.1,2.2], P = 0.013). The c-statistics for the receiver operating characteristic curve for stellate cell activity and fibrosis were 0.78 and 0.67, respectively, P = 0.36. The receiver operating characteristic curve for a model including stellate cell activity, histology activity index, and alanine aminotransferase. obtained at month 4 had the best c-statistic (0.88). In recipients with stage 0 or 1 fibrosis on the month 4 liver biopsy who subsequently developed advanced fibrosis, the c-statistic for the receiver operating characteristic curves was significantly better for stellate cell activity than for stage of fibrosis (0.77 and 0.51, respectively; P = 0.004). In conclusion, hepatic stellate cell activation early after liver transplantation complements traditional testing for identifying liver transplant recipients with hepatitis C at greatest risk for developing advanced fibrosis.

Hepatitis C and liver transplantation

Liver transplantation is a life-saving therapy to correct liver failure, portal hypertension and hepatocellular carcinoma arising from hepatitis C infection. But despite the successful use of living donors and improvements in immunosuppression and antiviral therapy, organ demand continues to outstrip supply and recurrent hepatitis C with accelerated progression to cirrhosis of the graft is a frequent cause of graft loss and the need for retransplantation. Appropriate selection of candidates and timing of transplantation, coupled with better pre- and post-transplant antiviral therapy, are needed to improve outcomes.

Antithymocyte globulin induction therapy in hepatitis C-positive liver transplant recipients

It is unclear whether antithymocyte globulin (ATG) induction therapy in hepatitis C-positive (HCV-positive) liver transplant recipients influences the risk of developing recurrent HCV disease. Multiple acute rejection episodes and high-dose steroids and/or OKT3 used to treat acute rejection increase the risk of graft loss from HCV. We studied the impact of ATG induction on graft and patient survival in HCV-positive liver transplants performed since 1990. Recipients who died or lost their grafts within 1 month of transplantation were excluded. Second, third, and fourth grafts were excluded, as were patients with stage III or IV hepatocellular carcinoma. There were 443 cadaveric liver transplants in adult recipients, of whom 142 (32%) were HCV positive. The incidence of biopsy-proven acute rejection was less in patients who received ATG induction, 34.2% (ATG induction) versus 66.6% (no ATG induction) (P<or=.01). ATG induction did not influence the risk of graft loss from HCV-related disease (P=.75). When only HCV-related graft loss was considered, 10-year graft survival for HCV-positive recipients was 74% (ATG induction) versus 68.2% (no ATG induction). Whether ATG induction was given or not had no significant impact on either overall graft survival (P=.39) or patient survival (P=.11) in HCV-positive recipients.

The long-term effects of immune suppression on liver transplant recipients with recurrent hepatitis C viral infection

INTRODUCTION

Adequate immune suppression following liver transplantation in recipients with recurrence of hepatitis C virus (HCV) is not standardized. The aim of this study was to evaluate the association between immune suppression protocol and the clinical/histological parameters in HCV transplant recipients with an HCV recurrence.

METHODS

A retrospective analysis was performed on recipients of liver transplants from June 1998 to October 2003 who experienced HCV recurrence. Only patients with liver biopsies at 3 to 5 years following liver transplantation were included in the analysis. The data set included: patient demographics, immune suppression, antiviral therapies, as well as histology to evaluate ductopenia and chronic rejection. Patients divided into groups of high, medium, and low immune suppression were subdivided by treatment with versus without interferon. A control group with similar demographics suffering from cryptogenic cirrhosis was used for comparison.

RESULTS

During this period 45 patients had liver biopsies at 3 to 5 years posttransplantation. Their mean age was 56.5 years and mean time from transplant to biopsy was 1543 days. Their average posttransplant survival was 1964 days. There was no difference among the three groups with respect to HCV RNA levels (log(10) IU/mL), age, gender, time from transplant, donor age, and UNOS status. Median HCV RNA levels within the three groups were comparable at various time periods pre- and posttransplant.

CONCLUSION

The development of chronic allograft damage following transplantation in recipients with recurrent HCV tended to be worse among patients with low levels of immune suppression, suggesting the importance of therapy to maintain allograft function.

Effect of hepatitis C infection on tacrolimus doses and blood levels in liver transplantation recipients

BACKGROUND

In our cohort of patients with hepatitis-C virus, which is the most common indication for liver transplantation, we have noted higher relative blood levels of tacrolimus compared to patients without hepatitis-C virus.

AIM

To verify this observation and determine its clinical significance, we performed a comparison of doses and blood levels of tacrolimus in hepatitis-C virus and non- hepatitis-C virus liver transplantation recipients.

METHODS

Tacrolimus dose and trough level, as well as mean alanine aminotransferase, for all patients transplanted at our center with a deceased donor between 1/1995 and 12/1999 with hepatitis-C virus were recorded at monthly intervals during the first 24 months following transplantation and compared to patients without hepatitis-C virus.

RESULTS

The tacrolimus levels for hepatitis-C virus and non-hepatitis-C virus patients were not significantly different at any of the monthly intervals, except month 9. In addition, the overall mean tacrolimus levels for hepatitis-C virus and non-hepatitis-C virus patients were not significantly different (P = ns). However, the mean tacrolimus dose (mg/kg) was significantly higher for hepatitis-C virus patients at 12, 15, 18, 21 and 24 months, P < 0.01. The total mean tacrolimus dose in hepatitis-C virus patients was lower during year one by 39% (P = 0.018) and by 73% (P = 0.001) during year two. The total difference in cost of tacrolimus (for year one and two) administered to hepatitis-C virus patients was $4920, P = 0.03. The serum alanine aminotransferase was significantly higher in hepatitis-C virus patients at each monthly interval except month 1, P < or = 0.01.

CONCLUSIONS

Liver transplant recipients with hepatitis-C virus require significantly lower oral doses of tacrolimus to achieve the same blood levels compared to non-hepatitis-C virus patients. This difference may result in a significant reduction in the cost of tacrolimus in hepatitis-C virus patients. The most likely explanation for these findings is decreased hepatic clearance of tacrolimus caused by mild hepatic injury from recurrent hepatitis-C virus.

Tools enabling the elucidation of molecular pathways active in human disease: application to Hepatitis C virus infection

BACKGROUND

The extraction of biological knowledge from genome-scale data sets requires its analysis in the context of additional biological information. The importance of integrating experimental data sets with molecular interaction networks has been recognized and applied to the study of model organisms, but its systematic application to the study of human disease has lagged behind due to the lack of tools for performing such integration.

RESULTS

We have developed techniques and software tools for simplifying and streamlining the process of integration of diverse experimental data types in molecular networks, as well as for the analysis of these networks. We applied these techniques to extract, from genomic expression data from Hepatitis C virus-infected liver tissue, potentially useful hypotheses related to the onset of this disease. Our integration of the expression data with large-scale molecular interaction networks and subsequent analyses identified molecular pathways that appear to be induced or repressed in the response to Hepatitis C viral infection.

CONCLUSION

The methods and tools we have implemented allow for the efficient dynamic integration and analysis of diverse data in a major human disease system. This integrated data set in turn enabled simple analyses to yield hypotheses related to the response to Hepatitis C viral infection.

Management of hepatitis C virus infection in the setting of liver transplantation

1. Posttransplantation recurrence of hepatitis C virus infection is a universal phenomenon with a highly variable natural history. 2. Approximately 10% to 25% of hepatitis C virus- infected recipients of liver allografts will develop cirrhosis within 5 years' after transplantation. 3. The 1-year actuarial risk of hepatic decompensation after recurrence of cirrhosis approximates 42%. 4. Some of the factors associated with aggressive recurrence include donor and recipient age, recent year of transplantation, recipient gender and race, the use of antithymocyte globulin, and high dose of corticosteroids. 5. Highly aggressive recurrent hepatitis C virus infection leading to cirrhosis fares poorly after retransplantation in the presence of hyperbilirubinemia and renal failure, with a 1-year survival of approximately 40%. 6. Elevated serum aminotransferases are a poor indicator or recurrent disease. 7. Current sustained virological response after combination pegylated alpha interferon and ribavirin treatment is approximately 25%. 8. There is no consensus on initiation time point, duration of treatment, or dosage. Given immunosuppression, at least 48 weeks of therapy is a reasonable approach. 9. Treatment for 48 weeks is cost effective. Incremental cost-effectiveness ratio for men aged 55 years is $29,100 per life-year saved.

Prediction of fibrosis in HCV-infected liver transplant recipients with a simple noninvasive index

Recurrent hepatitis C is a frequent event in liver transplantation (LT). Serial liver biopsies remain the best way of monitoring disease progression. Due to the limitations of a liver biopsy, there is an interest in developing noninvasive markers of liver fibrosis. While several models for predicting fibrosis have been constructed in patients who have not undergone transplantation, these are lacking in the transplant population. The aim of this study was to construct one simple model based on routine laboratory data to predict fibrosis in hepatitis C virus (HCV)-infected LT patients. A total of 510 yearly protocol liver biopsies performed in 188 LT patients (67% male; median age 54 years) were divided into 2 groups: training set (n = 414) and validation set (n = 96). Laboratory variables at time of biopsies were recorded. Multivariate analysis identified 4 variables as independent predictors of fibrosis: prothrombin time (PT), albumin/total protein ratio, aspartate aminotransferase (AST), and time since LT. The area under the receiver operating characteristic (ROC) curves (AUCs) were 0.80 and 0.84 for the training and the validation set, respectively. In the training set, using a cutoff of 0.2, the model had a sensitivity, specificity, positive predictive value, and negative predictive value of 74%, 69%, 42%, and 90%, respectively, to differentiate significant (bridging fibrosis and cirrhosis) from mild fibrosis (none or portal). In the validation cohort, these values increased to 87%, 71%, 49%, and 95%, respectively. In conclusion, in the LT setting, a simple fibrosis index is useful to select HCV-infected patients with a very low risk of significant fibrosis in whom protocol liver biopsies may be avoided.

Hepatitis C is a risk factor for death after liver retransplantation

Retransplantation for liver allograft failure associated with hepatitis C virus (HCV) has been increasing due to nearly universal posttransplant HCV recurrence and has been demonstrated to be associated with poor outcomes. We report on the risk factors for death after retransplantation among liver recipients with HCV. A retrospective cohort of liver transplant recipients who underwent retransplantation between January 1997 and December 2002 was identified in the Scientific Registry of Transplant Recipients database. Cox regression was used to assess the relative effect of HCV diagnosis on mortality risk after retransplantation and was adjusted for multiple covariates. Of 1,718 liver retransplantations during the study period, 464 (27%) were associated with a diagnosis of HCV infection. Based on Cox regression, retransplant recipients with HCV had a 30% higher covariate-adjusted mortality risk than those without HCV diagnosis (hazard ratio [HR], 1.30; 95% confidence interval [CI], 1.10-1.54; P = 0.002). Other covariates associated with significant relative risk of death after retransplantation included older recipient age, presence in an intensive care unit (ICU), serum creatinine, and donor age. Additional regression analysis revealed that the increase in mortality risk associated with HCV was concentrated between 3 and 24 months postretransplantation, among patients age 18 to 39 at retransplant, and in patients retransplanted during the years 2000 to 2002. In conclusion, HCV liver recipients account for a considerable proportion of all retransplantations performed. Surprisingly, younger age predicted a higher mortality for recipients with HCV undergoing liver retransplantation. This may reflect a willingness to retransplant younger patients with an increased severity of illness or a more virulent HCV infection in this population. Although HCV was predictive of an increased risk of death, consideration of other characteristics of HCV patients, including donor and recipient age and need for preoperative ICU care may identify those at significantly higher risk.

Should patients with chronic hepatitis C infection be transplanted?

Chronic hepatitis C (HCV) infection affects more than 170 million people throughout the world and 2 to 3 million Americans. End-stage liver disease secondary to chronic HCV infection is the most frequent indication for liver transplantation in this country. Currently, the gold standard for treatment for immunocompetent patients is a combination of peginterferon (PEG-IFN) and ribavirin for 6 to 12 months depending on the genotype. This treatment achieves a sustained virological response (SVR) in 54% to 61% of patients overall. Almost 50% of patients do not respond or have recurrences posttreatment and progress in over 10 to 20 years into chronic liver disease and its complications. Liver transplantation is the only therapeutic modality that impacts on quality of life and survival of these patients. However, recurrence of HCV in the new allograft is universal with accelerated progression to cirrhosis in 5 to 10 years. Response to treatment is usually low (20% to 30%), and associated with significant side effects and depression. A significant percentage of patients with recurrent HCV after transplantation require retransplantation to control the complications of end-stage liver disease. Other solid organ transplants recipients already HCV-positive, or infected at the time of transplantation from blood transfusions or an infected graft, develop accelerated, progressive liver disease facilitated by the adverse effects of immunosuppression in addition to HCV replication. To prevent morbidity, mortality, and high costs related to the consequences of HCV infection, all solid organ transplant candidates should be tested for HCV infection and treated appropriately with PEG-IFN and ribavirin prior to transplantation.

Hepatitis B and hepatitis C viruses in liver transplantation

Liver transplantation (LT) for end-stage liver disease (ESLD) secondary to hepatitis viruses has evolved rapidly during the last two decades. ESLD secondary to hepatitis C virus (HCV) accounts for approximately 50% of LT in the United States and Europe. Despite the decrease in the number of new HCV infections, the prevalence of advanced HCV-related liver disease is steadily increasing. In light of the near universal recurrence of posttransplantation HCV infection and our limited ability to treat recurrent disease, transplantation is in danger of being overrun by viral hepatitis, unless effective strategies can be used to treat disease, expand the donor pool of available organs, and prevent disease recurrence. In the early 1980s, results of LT for chronic hepatitis B virus infection were hampered by recurrent infection and subsequent allograft failure. However, with the introduction of passive immunoprophylaxis with hepatitis B immunoglobulin and treatment with potent nucleoside analogs, there has been a resurgence of LT for hepatitis B virus-related ESLD. Despite the wide acceptance of LT as a therapy for ESLD, there is little consensus on the appropriate immunosuppressive regimens, and prophylactic and therapeutic treatments vary widely from one center to another. This review summarizes available data and highlights appropriate strategies to improve outcomes.

Hepatitis C virus antiviral therapy in patients with cirrhosis

Chronic hepatitis C virus (HCV) infection is generally a slowly progressive disease. A minority of infected patients, however, eventually will develop cirrhosis and its life-threatening complications.Recent development of combination interferon (IFN) and ribavirin(RBV) antiviral therapy has changed the approach to patients infected with the virus. Once cirrhosis develops, treatment is a difficult task and should be done with close monitoring because of numerous adverse effects. In patients with compensated cirrhosis,combination therapy is the most efficient approach and offers the highest sustained virological response. Although data are limited,no significant differences have been reported between the use of pegylated interferon (PEG-IFN) and standard IFN in combination with RBV. Moreover, PEG-IFN has a higher risk of hematological complications, and this should be considered when using in advanced disease. Antiviral therapy for patients with decompensated cirrhosis should be used only in a clinical trial setting because of reported severe adverse effects. After liver transplantation, combination therapy may be an alternative for a limited number of patients. Although definitive recommendations cannot be made because of limited studies, there is a group of very well compensated patients with HCV and cirrhosis who benefited from treatment by clinicians well versed in the use of combination therapy.

Pilot study of pegylated interferon alfa-2b and ribavirin for recurrent hepatitis C after liver transplantation

Recurrent hepatitis C is often treated with an interferon and ribavirin combination therapy, but the results have been disappointing. Given the promising results reported with pegylated interferon and ribavirin for hepatitis C, we were interested in evaluating the effectiveness of this treatment in liver transplant recipients with recurrent hepatitis C (HCV).

METHODS

Between November 2001 and September 2002, patients with recurrent HCV were screened to determine if they were eligible for treatment. Liver function tests, HCV-RNA, and liver biopsies were performed on all patients prior to treatment. HCV-RNA was repeated at 3 months, the end of treatment (EOT), and 6 months after EOT for patients who were HCV-RNA negative at EOT. Patients were prospectively followed after starting weekly pegylated interferon alfa-2b 1.5 mcg/kg per week and ribavirin 800 mg per day (Schering-Plough, Kenilworth, NJ, USA) with folic acid 1 mg per day.

RESULTS

Thirty-nine patients eligible for treatment displayed a median age of 50.4 years. Eighteen patients completed treatment, 4 remain on treatment, and 17 were intolerant. Sustained HCV-RNA eradication occurred in 66.7% of patients who completed treatment. Side effects led to treatment withdrawal in 17 patients (43.6%) In an intention-to treat analysis, sustained HCV-RNA eradication occurred in 30.8% of patients.

CONCLUSION

Side effects are an important limiting factor in the treatment of recurrent HCV with pegylated interferon and ribavirin. However, these results are encouraging as sustained HCV eradication occurred in at least 66.7% of patients who completed treatment. Prospective randomized trials are required to assess the effectiveness of this treatment and its impact on quality of life and histology.

Factors differentially correlated with the outcome of liver transplantation in hcv+ and HCV- recipients

BACKGROUND

Survival following liver transplantation for hepatitis C virus (HCV) is significantly poorer than for liver transplants performed for other causes of chronic liver disease. The factors responsible for the inferior outcome in HCV+ recipients, and whether they differ from factors associated with survival in HCV- recipients, are unknown.

METHODS

The UNOS database was analyzed to identify factors associated with outcome in HCV+ and HCV- recipients. Kaplan-Meier graft and patient survival and Cox proportional hazards analysis were conducted on 13,026 liver transplants to identify the variables that were differentially associated with outcome survival in HCV- and HCV+ recipients.

RESULTS

Of the 13,026 recipients, 7386 (56.7%) were HCV- and 5640 were HCV+. In HCV- and HCV+ recipient populations, five-year patient survival rates were 83.5% vs. 74.6% (P<0.00001) and five-year graft survival rates 80.6% vs. 69.9% (P<0.00001), respectively. In a multivariate regression model, donor age and recipient creatinine were observed to be significant covariates in both groups, while donor race, cold ischemia time (CIT), female to male transplants, and recipient albumin were independent predictors of survival of HCV- recipients. In the HCV+ cohort, recipient race, warm ischemia time (WIT), and diabetes also independently predicted graft survival.

CONCLUSIONS

A number of parameters are differentially correlated with outcome in HCV- and HCV+ recipients of orthotopic liver transplantation. These findings may not only have practical implications in the selection and management of liver transplant patients, but also may shed new insight into the biology of HCV infection posttransplant.

Recurrent Hepatitis C in Liver Allografts

RATIONALE AND DESIGN

The accuracy of a prospective histopathologic diagnosis of rejection and recurrent hepatitis C (HCV) was determined in 48 HCV RNA-positive liver allograft recipients enrolled in an "immunosuppression minimization protocol" between July 29, 2001 and January 24, 2003. Prospective entry of all pertinent treatment, laboratory, and histopathology results into an electronic database enabled a retrospective analysis of the accuracy of histopathologic diagnoses and the pathophysiologic relationship between recurrent HCV and rejection.

RESULTS

Time to first onset of acute rejection (AR) (mean, 107 days; median, 83 days; range, 7-329 days) overlapped with the time to first onset of recurrent HCV (mean, 115 days; median, 123 days; range, 22-315 days), making distinction between the two difficult. AR and chronic rejection (CR) with and without co-existent HCV showed overlapping but significantly different liver injury test profiles. One major and two minor errors occurred (positive predictive values for AR = 91%; recurrent HCV = 100%); all involved an overdiagnosis of AR in the context of recurrent HCV. Retrospective analysis of the mistakes showed that major errors can be avoided altogether and the impact of unavoidable minor errors can be minimized by strict adherence to specific histopathologic criteria, close clinicopathologic correlation including examination of HCV RNA levels, and a conservative approach to the use of additional immunosuppression. In addition, histopathologic diagnoses of moderate and severe AR and CR were associated with relatively low HCV RNA levels, whereas relatively high HCV RNA levels were associated with a histopathologic diagnosis of hepatitis alone, particularly the cholestatic variant of HCV.

CONCLUSIONS

Liver allograft biopsy interpretation can rapidly and accurately distinguish between recurrent HCV and AR/CR. In addition, the histopathologic observations suggest that the immune mechanism responsible for HCV clearance overlap with those leading to significant rejection.

Treatment of recurrent hepatitis C after liver transplantation: a pilot study of peginterferon alfa-2b and ribavirin combination

BACKGROUND/AIMS

After liver transplantation (LT) for HCV-related cirrhosis, recurrence of HCV infection is universal and the risk of progression to cirrhosis is high. The modalities and efficacy of antiviral therapy in this indication are still controversial. We present here the results of a pilot study of a 12-month combination therapy by pegylated alfa 2b-interferon (PEG-IFN) and ribavirin in 20 patients.

METHODS

Twenty patients entered the study (13 male and 7 female, median age 53.8 years). In 80% of patients, HCV infection was of genotype 1. The delay between LT and antiviral therapy was 28 months. The doses were progressively increased from 0.5 to 1 micro g/kg/week for PEG-IFN and from 400 to 1000-1200 mg/d for ribavirin. Follow-up was based on biochemical (ALT), virological (HCV-RNA) and histological (liver biopsy) examinations.

RESULTS

Four patients (20%) were withdrawn due to adverse effects. In 6 patients the dose of PEG-IFN had to be reduced to 0.5 micro g/kg/week. A reduction in the dose of ribavirin in 13/16 cases was due to the onset of anemia. Histological evidence of mild acute rejection increased the immunosuppressive regimen in 5/20 patients. At the end of the treatment, 75% of the patients had a biochemical response and 55% a virological response. The mean METAVIR score, according to activity and fibrosis, was A1.8 F2.2 before treatment and A0.3 F1.6 at the end of treatment. In 9/20 patients, virological response persisted 6 months after the end of the treatment.

CONCLUSIONS

Our results suggest that combination therapy by PEG-IFN and ribavirin may be well tolerated and beneficial during recurrent hepatitis C in liver transplant recipients.

Donor age affects fibrosis progression and graft survival after liver transplantation for hepatitis C

BACKGROUND

The use of liver allografts from an older donor (OD) (age>50 years) is a widespread strategy to manage the disparity between supply and demand of organs for liver transplantation. This study determines the effect of OD allografts on fibrosis progression and graft survival after liver transplantation in patients with and without infection caused by hepatitis C virus (HCV).

METHODS

All patients undergoing liver transplantation at our center from March 1998 to December 2001 were analyzed. Protocol liver biopsies were performed at 1, 16, and 52 weeks after transplantation and yearly thereafter. One liver pathologist scored all biopsy specimens for modified hepatic activity index (0-18) and fibrosis (0-6).

RESULTS

A total of 402 patients (167 with HCV and 235 without HCV) underwent liver transplantation during the study period. Among patients with HCV, baseline characteristics of OD recipients were similar to younger donor (YD) (age<50 years) recipients. In patients with HCV, graft survival was shorter in OD graft recipients than in YD recipients (P<0.001). In patients without HCV, graft survival was independent of donor age. In patients with HCV, a fibrosis score of 3 or greater was present in 17% of OD recipients at 4 months and in 26% at 12 months after transplantation, compared with 8% of YD recipients at 4 months and 13% at 12 months (P<0.001).

CONCLUSIONS

Liver transplantation with OD grafts is associated with rapid progression of fibrosis and decreased graft survival in patients with HCV, but not in patients without HCV. OD grafts should be considered preferentially for patients without HCV.

EFFECT OF ANTIMETABOLITE IMMUNOSUPPRESSANTS ON FLAVIVIRIDAE, INCLUDING HEPATITIS C VIRUS

BACKGROUND

Recurrence of hepatitis C virus (HCV) after liver transplantation is almost universal and decreases both graft and patient survival. Medications that alter nucleic acid metabolism, including some common immunosuppressants used in HCV-infected patients, may affect viral replication.

METHODS

Bovine viral diarrhea virus (BVDV) is in the Flaviviridae family and is closely related to HCV. We measured the effect of two immunosuppressants, azathioprine (AZA) and mycophenolate acid (MPA), on both BVDV replication by plaque assay and host-cell replication by flow cytometry. We also compared the effect of ribavirin and AZA on the level of HCV replicon RNA by real-time reverse-transcriptase polymerase chain reaction.

RESULTS

At doses that achieved similar cytotoxicity, AZA decreased BVDV replication 10 times more than MPA. The inhibition of BVDV by AZA occurred at lower doses than the cellular cytotoxicity and did not depend on cytotoxicity. A two-log reduction in viral titers occurred despite blocking the cytotoxicity of AZA by inhibiting ribonucleotide reductase with high concentrations of thymidine. A metabolite of AZA, 6-mercaptopurine, still possessed this antiviral effect, but a metabolite further downstream, 6-thioguanine, did not, even though 6-thioguanine is the metabolite responsible for cellular toxicity. The effect of AZA on a HCV replicon was at least as large as that of ribavirin.

CONCLUSIONS

This report suggests that AZA is a more potent antiviral than MPA for Flaviviridae and may exert a specific antiviral effect on HCV. Additional clinical studies to investigate this previously unanticipated antiviral effect of AZA on HCV in the posttransplant setting are indicated.

Sustained viral response to interferon and ribavirin in liver transplant recipients with recurrent hepatitis C

Recurrent hepatitis C infection is an important cause of progressive fibrosis, cirrhosis, and graft loss following orthotopic liver transplantation. Treatment for posttransplant recurrence of hepatitis C with interferon-based therapy is difficult but results in loss of detectable virus in up to 30% of patients. However, the durability of viral clearance and the associated histologic response in this setting is unknown. The aim of this study was to determine whether viral loss in response to antiviral therapy is durable and associated with improvement in liver histology. All liver transplant recipients who received interferon-based treatment for recurrent hepatitis C virus (HCV) at the University of Florida from 1991 to 2002 were included in this study. Patients who lost detectable HCV after treatment with interferon alone or in combination with ribavirin were followed to assess the durability of viral response and its impact on liver histology. One hundred nineteen transplant recipients were treated with interferon or combination therapy. Twenty-nine (20 men, 9 women; mean age, 54 yrs [range, 42-74 yrs]) lost detectable HCV RNA and remained virus negative for at least 6 months after discontinuing therapy (sustained viral response[SVR]). The mean follow-up after discontinuing therapy was 24.7 months (range, 6-70 mos). Our study cohort included one patient with SVR following interferon monotherapy and 28 patients with SVR following combination therapy with interferon plus ribavirin. All patients remained HCV RNA negative (assessed by polymerase chain reaction or branched-DNA assay) during follow-up of up to 5 years. Liver histology assessed 2 years after treatment showed less inflammation compared with before treatment in 50% and showed no change in 38%. By 3 to 5 years post-treatment (n = 15 recipients), inflammation was reduced in 60% and remained unchanged in 33%. Fibrosis stage at 2 years improved by > or = 1 stage in 27 %, remained unchanged in 38 %, and worsened in 35% despite viral clearance. At 3 to 5 years, the fibrosis stage had improved in 67%, remained unchanged in 13%, and worsened in 20%. Both grade of inflammation and fibrosis stage improved by 3 to 5 years posttreatment compared with baseline histology (p < 0.05). In conclusion, loss of HCV after treatment of recurrent chronic hepatitis C with interferon and ribavirin is durable, and the durability of the SVR is associated with improvement in hepatic inflammation and regression of fibrosis.

Current status of liver transplantation in children

There are two critical issues on opposite ends of the timeline for patients who are eligible for liver transplantation. On the one hand, the crisis in the cadaveric organ supply makes surviving to transplant ever more risky. On the other hand, patients who receive successful transplants face the consequences of long-term immunosuppression and its potentially life-threatening complications. The donor shortage is forcing difficult decisions that affect all patients who await liver transplantation. It is important to scrutinize carefully the results of all policies that govern allocation and the ethics of the solutions we advocate to ensure that no patient subgroup is being at a disadvantage. Current immunosuppression practices are being challenged by an increasing understanding of the immunologic events triggered by the allograft and the goal to free patients from consequences of a lifetime of immunosuppression. Clinicians can expect, and perhaps require, that new immunosuppressive protocols will address how the planned intervention might be expected to advance the understanding of tolerance mechanisms. As knowledge increases, clinicians can anticipate innovative new immunosuppressive proposals. Calcineurin and steroid-free induction, the use of donor-derived bone marrow infusion, recipient pretreatment, costimulatory blockade, and new antibody induction approaches are all being proposed--often in combination--for clinical trials. Researchers face additional challenges in defining endpoints if the goal is not just the short-term reduction in rejection but the minimization, and eventual discontinuation, of immunosuppressive drugs while maintaining excellent long-term graft function. How much "failure" will be accepted and how will it be defined? How will clinicians interpret liver biopsies if they begin to accept that some lymphocytic infiltrates may be beneficial mediators of the ongoing immune activation necessary for the maintenance of tolerance? How will they adjust immunosuppression practices to the dynamic processes in the immune response that maintain tolerance? Remarkable short-term successes in providing transplants for thousands of children with liver failure have brought these challenges into sharp focus. Clinicians must seek to move the life-giving science of transplantation toward a new goal: providing long lifetimes of excellent graft function with minimal toxicity from immunosuppressive drugs and the hope of freedom from immunosuppression altogether. Pediatric liver recipients, whose grafts have inherent tolerogenic potential and for whom we can anticipate decades of life after transplant, may prove to be an ideal study population to further these goals.

Treatment of patients with hepatitis C virus on the waiting list

1. Over 90% of patients with hepatitis C on the waiting list might be candidates for therapy with interferon plus ribavirin. 2. One must exercise caution in the treatment of these patients. Those with Child-Turcotte-Pugh score >11 or Model for End-Stage Liver Disease score >25 should be excluded from treatment. 3. Sustained virologic response (hepatitis C virus RNA-negative) is mainly dependent on viral genotype, with 50% of genotype 2 and 3 patients achieving sustained virologic response. 4. The ability to achieve sustained virologic response in genotype 1 patients is dependent on dose and duration of treatment. 5. Patients rendered hepatitis C virus RNA-negative pretransplantation may not experience posttransplantation recurrence.

The clinical and immunologic impact of using interferon and ribavirin in the immunosuppressed host

1. Allograft infection with hepatitis C virus (HCV) in immunosuppressed adults results in decreased allograft and patient survival. 2. Risk factors for accelerated progression of hepatitis C related to immunosuppression include treated episodes of acute cellular rejection (ACR), pulse therapy with methylprednisolone, and use of OKT3. 3. Both interferon alfa (IFN-alpha) and ribavirin (RVN) show antiviral actions against HCV and stimulate innate and adaptive immunity to increase cytolysis and polarize T helper subtype 1 (T(H)1) responses. In addition, IFN-alpha inhibits fibrogenesis in the liver. 4. Both IFN-alpha and RVN have been studied in immunosuppressed liver transplant recipients as prophylaxis or treatment of established hepatitis C to reduce allograft failure and patient mortality. Reported protocols include monotherapies with RVN, standard IFN-alpha, and pegylated IFN-alpha and combination therapies using RVN and either standard IFN-alpha or pegylated IFN-alpha. 5. The clinical impact of using IFN-alpha and RVN in highly selected immunosuppressed patients varied among studies. Combination therapy with standard IFN-alpha and RVN resulted in the greatest sustained biochemical and virological responses. However, no therapy prevented progression of acute cholestatic hepatitis C despite evidence of virological responses. Substantial proportions of patients developed adverse events requiring dose reduction or discontinuation that compromised efficacy. RVN monotherapy was not only virologically ineffective, but may have stimulated hepatic fibrosis. Current data regarding monotherapy or combination therapy with pegylated IFN-alpha are limited, but encouraging. 6. Despite potent immunostimulatory actions of both IFN-alpha and RVN that enhance natural killer, T(H)1, their use did not significantly increase the incidence of ACR. 7. Additional studies are needed to resolve the controversy over prophylaxis versus treatment of established disease and the potential utility of low-dose maintenance IFN-alpha therapy to retard fibrogenesis without clearing HCV. 8. After new, less toxic, and more potent antiviral agents become available, they should be tested immediately in patients with hepatitis C post-liver transplantation.

Host and donor risk factors before and after liver transplantation that impact HCV recurrence

1. The natural history of hepatitis C after liver transplantation is variable. Several factors, including those related to the virus, the host, the environment and the donor, are probably implicated in the outcome. 2. The immune status per se likely represents the main significant variable in influencing disease severity in hepatitis C virus-infected patients. Findings that support this statement include the higher aggressivity of hepatitis C in immunocompromised liver transplant recipients as compared with that observed in immunocompetent patients, both before and after the development of compensated cirrhosis, and the significant association described between the degree of immunosuppression and disease severity. 3. Similar to that observed in the immunocompetent population, the age at the time of infection (age of the donor) strongly affects posttransplantation hepatitis C virus-related disease progression. 4. Hepatitis C-related disease progression is faster in patients who underwent transplantation in recent years as compared with those who underwent transplantation in earlier cohorts. The increasing age of the donor and the use of stronger immunosuppression may, in part, explain the worse outcomes seen in recent years. 5. Additional host-related variables predictive of outcome include the immunogenetic background, the timing of recurrence, and the early histologic findings.

Controversies in the management of hepatitis C virus infection after liver transplantation

Recurrence of hepatitis C virus infection after liver transplantation is universal. A significant percentage of these patients develop progressive graft injury and cirrhosis. Those factors that modulate disease progression in liver transplant recipients with recurrent hepatitis C virus infection remain controversial and are poorly understood. Treatment of recurrent hepatitis C virus after liver transplantation with either interferon or interferon and ribavirin has yielded only limited success. Regardless of this, treatment is instituted. Peginterferon is more effective than standard interferon for treatment of chronic hepatitis C virus infection in the nontransplantation setting when used either alone or with ribavirin. The effectiveness of peginterferon, both with and without ribavirin in the posttransplantation setting, is currently being explored. In this review those factors thought to affect disease progression in patients with recurrent hepatitis C virus will be discussed, strategies that have been used to treat recurrent hepatitis C virus will be reviewed, and the impact that peginterferon may have on hepatitis C virus infection in the pretransplantation and posttransplantation setting will be explored.

Poor survival after liver retransplantation: is hepatitis C to blame?

Data from 1990 to 1996 suggest that the prevalence of hepatitis C virus (HCV) infection in repeated orthotopic liver transplantation (re-OLT) is increasing, and patient survival may be worse. Aims of the study are to: (1) assess the prevalence of HCV in re-OLT, (2) compare survival between primary OLT and re-OLT for HCV versus non-HCV diseases, and (3) evaluate Model for End-Stage Liver Disease (MELD) scores in re-OLT. The United Network for Organ Sharing database for adult patients undergoing primary OLT or re-OLT from January 1996 to June 2002 was analyzed. Patients with malignancy or those who underwent re-OLT within 30 days of primary OLT were excluded. A total of 22,120 primary OLTs and 2,129 re-OLTs were performed. HCV was noted in 9,564 primary OLTs (43.2%) and 899 re-OLTs (42.2%). Overall 1, 3, and 5-year patient survival rates were 86%, 79%, and 73% for primary OLT, but 67%, 56%, and 52% for re-OLT (P <.001). Survival rates of patients with HCV at 1, 3, and 5 years were 86%, 76%, and 68% for primary OLT and 61%, 50%, and 45% for re-OLT (P <.001). Survival was less for patients with HCV compared with those with autoimmune hepatitis (AIH) and hepatitis B for re-OLT (P <.01). However, survival after re-OLT was no different for those with HCV than for those with all other causes. MELD scores between 11 and 20 were the most common for re-OLT. A marked decreased in survival was noted in all patients who underwent re-OLT with MELD scores greater than 25. HCV prevalence in OLT has reached a plateau in recent years. Survival after re-OLT is inferior to that for primary OLT, but re-OLT survival appears to have improved. Survival after re-OLT is lower in patients with HCV compared with those with AIH and hepatitis B, but no different than for those with most other liver diseases. Survival appeared worse in patients who underwent re-OLT with a MELD score greater than 25.

Sequence variation in the hypervariable region 1 of hepatitis C virus and posttransplantation recurrent hepatitis

Hepatitis C virus (HCV) shows remarkable genetic variation in both populations and individuals, in whom it circulates as quasispecies (QS). Sequence variation within an infected host has adaptive significance and reflects the modes and intensity of selection mechanisms operating on the virus. We investigated the sequence diversity of hypervariable region 1 of HCV in liver transplant recipients and correlated it with the recurrence of hepatitis. Twenty-six patients were considered during a 2-year period; all had graft reinfection, and 14 patients developed hepatitis recurrence. Cloned sequences were obtained from sera collected before or within 1 month after orthotopic liver transplantation (OLT) and at 3 and 24 months thereafter. Sequence diversity within single sera and over consecutive samples was analyzed quantitatively by matrix comparison and phylogenetic analysis. Propagation of viral QS in the graft was markedly dependent on individual factors. Viral QS in post-OLT sera were less complex and evolved slower compared with immunocompetent subjects with chronic hepatitis. Sequence variation was greater during the first 3 months post-OLT than during the remaining period. Genetic diversity within single samples was not related to hepatitis recurrence or other clinical features. Conversely, sequence diversity over consecutive samples was reduced in patients who experienced hepatitis recurrence, in particular, in those infected with genotype 1b and with an HLA-DR mismatched graft. Selection of viral sequences was markedly impaired in liver transplant recipients and tended to be greater early after OLT. Reduced sequence turnover correlated negatively with the outcome of graft reinfection.

Sympathetic nervous system inhibition increases hepatic progenitors and reduces liver injury

Recovery from liver damage might be enhanced by encouraging repopulation of the liver by endogenous hepatic progenitor cells. Oval cells are resident hepatic stem cells that promote liver regeneration and repair. Little is known about the mediators that regulate the accumulation of these cells in the liver. Parasympathetic nervous system inhibition reduces the number of oval cells in injured livers. The effect of sympathetic nervous system (SNS) inhibition on oval cell number is not known. Adrenergic inhibition mobilizes hematopoietic precursors into the circulation and has also been shown to promote liver regeneration. Thus, we hypothesized that SNS inhibition would promote hepatic accumulation of oval cells and reduce liver damage in mice fed antioxidant-depleted diets to induce liver injury. Our results confirm this hypothesis. Compared with control mice that were fed only the antioxidant-depleted diets, mice fed the same diets with prazosin (PRZ, an alpha-1 adrenoceptor antagonist) or 6-hydroxydopamine (6-OHDA, an agent that induces chemical sympathectomy) had significantly increased numbers of oval cells. Increased oval cell accumulation was accompanied by less hepatic necrosis and steatosis, lower serum aminotransferases, and greater liver and whole body weights. Neither PRZ nor 6-OHDA affected the expression of cytokines, growth factors, or growth factor receptors that are known to regulate progenitor cells. In conclusion, stress-related sympathetic activity modulates progenitor cell accumulation in damaged livers and SNS blockade with alpha-adrenoceptor antagonists enhances hepatic progenitor cell accumulation.

Impact of current transplantation practices on the changing epidemiology of infections in transplant recipients

The spectrum of infections in transplant recipients has been substantially affected by novel immunosuppressive regimens and the use of antimicrobial agents. Epidemiology and presentation of traditional opportunistic pathogens has changed. Invasive aspergillosis and cytomegalovirus occur later in the post-transplant period. The incidence of infections that were previously encountered rarely--eg, BK virus nephropathy--has increased, the clinical course of hepatitis C virus recurrence has become more aggressive, the risk factors for invasive aspergillosis have changed, and non-aspergillus moulds are occurring more commonly in transplant recipients. Recognition of these trends as they unfold has significant implications for the clinical care of the transplant recipients, for providing insights into the pathogenesis, and for continually improving the approaches to the management of infections.