Is hepatitis C virus recurrence a risk factor for chronic liver allograft rejection?

Immune-mediated complications of the graft in interferon-treated hepatitis C positive liver transplant recipients

Hepatitis C virus (HCV) re-infection of the graft is universal and interferon based antiviral therapy remains at present the treatment of choice in HCV liver transplant recipients. Apart from the antiviral effects, interferon and ribavirin have both potent immunomodulatory properties resulting in a broad range of immune-related disorders including acute cellular rejection and chronic ductopenic rejection as well as de novo autoimmune hepatitis. Further complicating the picture, HCV infection per se is associated with a variety of autoimmune phenomena. We discuss here the immune-mediated complications and their relationship to chronic HCV and interferon based antiviral therapy.

Evolution of hepatitis C virus in liver allografts

1. Hepatitis C virus (HCV) RNA+ liver allograft recipients invariably reinfect the liver allograft within hours after transplantation, and the majority (>70%) develop chronic hepatitis. The rate at which these patients experience progression to cirrhosis and the overall percentage are significantly increased in comparison with HCV infection in the nontransplant setting. 2. Core needle biopsy evaluation is used to establish the diagnosis of recurrent HCV, which can be difficult to distinguish from acute cellular rejection and other causes of allograft dysfunction. In the vast majority of cases, however, distinguishing recurrent HCV from other posttransplant syndromes is reliably achieved by a careful examination of hematoxylin and eosin-stained sections and correlation with clinical and serological data. 3. Recurrent HCV often coexists with other causes of liver allograft dysfunction, and the determination of the most important cause of injury and whether other causes of injury are present is important. Included are residual changes of preservation/reperfusion injury, biliary sludging/structuring, acute cellular and chronic rejection, and autoimmune hepatitis. 4. The complex interplay between immunosuppression management, viral replication, and the recipient immune system results in distinct patterns of recurrent chronic HCV in the liver allograft: (1) conventional or usual acute and chronic HCV, which resembles that seen in the general population with HCV; (2) fibrosing cholestatic hepatitis; and (3) plasma cell-rich HCV, which might represent a variant of, or overlap with, autoimmune hepatitis and rejection. 5. The variable but usually hastened histopathological progression toward cirrhosis in HCV+ allografts is similar to that seen in the nontransplant setting, but in allografts, the overall severity of lymphocytic inflammation is less, and ductular reactions, stellate cell activation, and subsinusoidal fibrosis are accentuated. Hepatic stressors and causes of an impaired ability of hepatocytes to replicate include persistently high levels of viral replication, HCV-specific CD4+ T responses, advanced donor age, high levels or rapid withdrawal of immunosuppression, and coexistent liver damage from preservation/reperfusion injury, biliary structuring, or coexistent cytomegalovirus or herpes 6 viral infection. 6. Immunological effector mechanisms involved in the rejection and control of HCV replication/HCV elimination show significant overlap. Patients with very high levels of HCV RNA rarely show significant clinically significant acute or chronic rejection, whereas their occurrence is frequently associated with very low levels or clearance of HCV RNA. Studying the evolution from recurrent HCV to acute rejection in patients treated with interferon and/or weaned from immunosuppression might provide valuable insights into the relationship between these 2 processes as well as liver allograft acceptance.

Post-transplant reactivation of hepatitis C virus: lymphocyte infiltration and the expression of adhesion molecules and their ligands in liver allografts

Hepatitis C virus (HCV) recurrence after liver transplantation has been associated with chronic rejection. Biopsies from 10 patients with post-transplant HCV were examined for expression of adhesion molecules ICAM-1, VCAM-1, and ELAM-1, number of lymphocytes positive for their ligands LFA-1, VLA-4, and SLeX, and activation markers MHC class II antigens and IL2-R by immunohistochemistry. The phenotypes of the graft-infiltrating lymphocytes were determined. Results were compared to those for patients with normal graft function or rejection. Five recipients with HCV reactivation and one with de novo HCV had a biopsy available showing induction of ICAM-1 in sinusoidal endothelium (p<0.05) and hepatocytes (p<0.01), and Class II antigens in hepatocytes (p<0.01), compared to normal controls. Lymphocytes in the graft infiltrate expressed LFA-1, VLA-4, and Class II antigens, but IL2-R was not significantly expressed. CD3+, CD4+, and CD8+ cells were observed. In our study, HCV recurrence was not associated with acute or chronic rejection, and the inflammation was due to the viral infection.

Morphologic Features of Hepatitis C Recurrence in Patients After Orthotopic Liver Transplantation-Preliminary Analysis of our Case Observations

INTRODUCTION

Hepatitis C virus (HCV) recurrence is almost universal in patients after liver transplantation. The diagnosis of reinfection is more difficult than that of a primary process, as shown by our pathomorphologic analysis of cases of HCV recurrence.

MATERIAL

During 5.5 years, 240 liver biopsies included 54 obtained from liver transplant recipients with primary HCV infections, among whom 26 (56.5%) had clinical signs and symptoms of hepatitis. Nineteen patients from this population underwent 30 liver biopsies. In addition, seven biopsies were performed in five patients without clinical signs of reinfection.

RESULTS

In 44.2% of patients with HCV recurrence and 15% without reinfection, the intensity of the primary process in the native livers was assessed as high. Reinfection was found in all patients with liver carcinoma and 67% with hepatocyte dysplasia. Histologic signs of infection were estimated as minimal (n = 4), mild (n = 19), or moderate (n = 4). In five patients with reinfections and one without recurrence, histologic manifestations of acute rejection were also observed. In conclusion, HCV was the indication for liver transplantation in 22.4% cases. Clinical manifestation of recurrence was found in 56.5% of the patients, who tended to be older than those without disease recurrence. Upon microscopy, lobular lesions predominated over the portal changes. Factors predisposing to HCV recurrence were coexistence of other liver disorders, a high intensity of the inflammatory process, hepatocyte dysplasia, and/or hepatocellular carcinoma in the native liver and acute rejection episodes.

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.

Recurrent hepatitis C after liver transplantation: clinical and therapeutical issues

Hepatitis C virus (HCV) reinfection after liver transplantation is almost constant, assessed by the persistence of HCV RNA in 90% of cases. Acute hepatitis appeared in 75% of patients at a median of 4 months' post-transplantation. The 5-year actuarial rate of acute and chronic hepatitis on the graft is 75% and 60%, respectively. The rate of HCV cirrhosis on the graft is variable from 8 to 25% at 5 years. After transplantation, HCV viraemia is dramatically increased and correlates with the occurrence of acute hepatitis on the graft. Intrahepatic levels of HCV are high at the time of acute hepatitis, and decrease with constitution of chronic graft hepatitis lesions, implying an immunological response to the viral infection. A relationship between genotype 1b and the prevalence of HCV hepatitis on the graft has been suggested in European but not American series. The influence of the age of the recipient, quasispecies, viral compartmentalization, immunosuppressive treatment, and of HLA matching is being evaluated. The 5-year patient survival is around 65-80%. However, the occurrence of cirrhosis with a risk of graft failure may decrease the 10 and 15-year patient survival. Attempts to give prophylactic post-transplant antiviral treatment are under evaluation. Antiviral treatment of post-transplant graft lesions with combination therapy interferon-ribavirin gave promising results but indications and duration of treatment should be evaluated. In conclusion, HCV reinfection is frequent, but medium-term survival is good. However, the long-term graft and patient survival remains unknown, and efficient prevention and treatment of HCV graft is mandatory.

Recurrence of hepatitis C virus infection after liver transplantation

In patients transplanted for HCV cirrhosis, reinfection by the virus is constant. Medium-term survival is good but long-term occurrence of cirrhosis is likely to impair the long-term prognosis of these patients. Patients should be informed before transplantation of the spontaneous risk of HCV recurrence and of its consequences. As for hepatitis B in the last decade, new antiviral therapies and immunosuppressive approaches will certainly change the course of HCV after transplantation.