Recurrent hepatitis C virus infection after liver transplantation: natural course, therapeutic approach and possible mechanisms of viral control

Norbert Hubert Gruener1,2, Maria-Christina Jung1,2 and Carl Albrecht Schirren1,2,*

1 Department of Medicine II, Klinikum Grosshadern, University of Munich, Marchioninistrasse 15, D-81377 Munich, Germany; 2 Institute for Immunology, University of Munich, Goethestrasse 31, D-80336 Munich, Germany

Received 19 February 2004; returned 26 March 2004; revised 2 April 2004; accepted 23 April 2004


    Abstract
 Top
 Abstract
 Introduction
 Natural history of recurrent...
 Antiviral treatment of recurrent...
 Retransplantation
 Cellular immune response in...
 Conclusions
 Acknowledgements
 References
 
End-stage liver disease associated with hepatitis C virus (HCV) infection has become the leading indication for liver transplantation worldwide. The new transplant liver is infected in nearly all patients, but the disease progression is highly variable. Although short-term survival appears to be similar to that in other causes of liver failure, progression to HCV-related cirrhosis is estimated to reach 20–30% at 5 year follow-up. Identification of factors that influence disease progression is important to optimize results of current treatment. This review summarizes the natural history, therapeutic options and future therapeutic strategies aimed at the induction and reinforcement of an adequate virus-specific CD4+ T cell response.

Keywords: T cells , ELISpot assay , interferon , ribavirin , antiviral therapy


    Introduction
 Top
 Abstract
 Introduction
 Natural history of recurrent...
 Antiviral treatment of recurrent...
 Retransplantation
 Cellular immune response in...
 Conclusions
 Acknowledgements
 References
 
End-stage liver disease associated with hepatitis C virus (HCV) infection has become one of the leading indications for orthotopic liver transplantation (OLTx). Recurrent infection of the allograft occurs in nearly all patients, but the disease progression is highly variable.1 At least 10% of patients who undergo transplantation for hepatitis C cirrhosis will eventually require retransplantation because of hepatitis C-related graft failure.2,3 Antiviral therapy for recurrent hepatitis C has therefore become a major issue facing all adult liver transplantation programmes. Post-transplant prophylaxis, using a combination of interferon-{alpha} and ribavirin, prevents both recurrent viraemia and hepatitis in 15–20% of patients. However, due to intolerance of this therapy drop-out rates approach 50%.4,5 A number of factors, which are likely to be related to the virus, host or environment, may account for the variability of the clinical course. A better understanding of pathophysiological mechanisms leading to disease progression is clearly needed.


    Natural history of recurrent HCV infection following OLTx
 Top
 Abstract
 Introduction
 Natural history of recurrent...
 Antiviral treatment of recurrent...
 Retransplantation
 Cellular immune response in...
 Conclusions
 Acknowledgements
 References
 
Extrahepatic sites, e.g. peripheral blood mononuclear cells (PBMC), capable of supporting HCV replication have been detected by various groups.6,7 These extrahepatic sites harbouring HCV sequences may explain how the new transplant liver is infected by HCV in virtually all patients, with a 10- to 20-fold increase in levels of viraemia after liver transplantation.1 The viral burden plateaus at 1 month post-transplantation and peaks at the time of acute hepatitis (1–4 months). HCV-induced allograft hepatitis is diagnosed in the majority of patients.1,813 Progression to HCV-related cirrhosis is estimated to reach 20–30% at 5 year follow-up.9 Most of these patients will subsequently develop graft failure. An additional 2–5% develop early graft failure because of severe cholestatic hepatitis without cirrhosis. HCV-related disease progression is more aggressive and accelerated in immunocompromised compared with immunocompetent patients: the time period to develop liver cirrhosis is shorter in the transplant setting than in patients with chronic HCV infection; the disease progression of clinically compensated HCV-related graft cirrhosis is accelerated compared with that of immunocompetent patients with HCV-related cirrhosis; once cirrhosis occurs, decompensation is more rapid.11,14 In addition, over the past years, HCV-related disease has advanced more quickly in patients who have undergone transplantation compared with those transplanted in the early 1990s.11 As mentioned earlier, HCV-related disease progression following recurrent infection is highly variable. Factors influencing the course of the disease may be classified chronologically as they develop during the transplantation process: (i) present before transplantation (genotype, viral load and sex); (ii) related to surgery or the donor; (iii) early and late after OLTx (immunosuppression, viral coinfection and histological findings). Although there is robust evidence for the prognostic role of some factors, such as viral load prior to transplantation, the importance of other parameters, such as genotype, are more controversial.

Taking all risk factors into account, immune status appears to be the main variable influencing disease progression in recurrent HCV infection.15,16 Risk factors for aggressive recurrence, graft loss, and death are methylprednisolone pulse therapy, treated acute cellular rejection, cytomegalovirus (CMV) infection and use of OKT3.1719 However, the benefit of steroid withdrawal, although commonly practised in transplant recipients with hepatitis C, has not been proved.20

There appears to be no consistent difference between cyclosporin and tacrolimus in their effects on hepatitis C.10 Mycophenolate mofetil may show synergic antiviral properties when used with interferon; however, post-transplantation use has not been associated with consistent beneficial or deleterious effects.21 Global immunosuppression level, not a single immunosuppressive agent, dominates the effect on recurrence of HCV; the management of immunosuppression is therefore controversial and further clinical studies are required.


    Antiviral treatment of recurrent HCV infection following OLTx
 Top
 Abstract
 Introduction
 Natural history of recurrent...
 Antiviral treatment of recurrent...
 Retransplantation
 Cellular immune response in...
 Conclusions
 Acknowledgements
 References
 
Treatment of HCV recurrence after OLTx is currently being investigated in several centres around the world. The efficacy and tolerability of antiviral regimens are significantly reduced in transplant recipients compared with immunocompetent patients. A liver transplant recipient with recurrent HCV infection frequently presents with multiple baseline negative predictors for sustained virological responses to interferon: high pre-treatment viraemia level; high prevalence of HCV genotype 1 infection; need for lifelong immunosuppression and previous non-response to interferon-{alpha} therapy before transplantation. In addition, the doses of antiviral agents that can be tolerated will be limited by reduced haemoglobin, platelet and neutrophil counts during the early post-transplantation period. Interferon-{alpha} monotherapy is ineffective as either treatment or prophylaxis.22,23 The most promising therapy is pegylated interferon-{alpha}/ribavirin combination therapy. The addition of ribavirin may improve the sustained virological response rate to almost 20%; however, ribavirin-induced haemolysis may be severe.4,5 So far, post-transplant immunoprophylaxis with polyclonal hepatitis C immunoglobulin has had no effect on recurrent viraemia or hepatitis.

There are scant data concerning the optimal timing of the antiviral therapy; a prospective trial directly comparing antiviral therapy initiated prophylactically compared with initiation at histological recurrence has not been performed. From the studies available there is no compelling evidence that the immunostimulatory effects of interferon-{alpha} induce acute cellular rejection or are associated with a significantly increased frequency or severity of rejection in liver transplant recipients.22,2426 Optimal timing and duration of treatment still have to be defined in further trials. Future therapeutic approaches may include molecular therapies that directly inhibit HCV protein processing and RNA replication. This may allow safe and effective pre-transplantation suppression and post-transplantation prophylaxis.


    Retransplantation
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 Introduction
 Natural history of recurrent...
 Antiviral treatment of recurrent...
 Retransplantation
 Cellular immune response in...
 Conclusions
 Acknowledgements
 References
 
Based on the progression of recurrent disease it is expected that increasing numbers of patients will require re-OLTx with long-term follow-up. The prevalence of HCV infection in patients undergoing liver retransplantation has increased significantly from 6.5% in 1990 to 38.4% in 1995.27 If patients with poor prognostic factors, such as raised bilirubin (>10 mg/dL) and creatinine (>2.0 mg/dL), are excluded, the results of re-OLTx for recurrent disease in HCV-infected transplant recipients are equivalent to those for other causes of graft failure.28,29 Re-transplantation for recurrent HCV disease is debated vigorously in the context of limited organ supply and long waiting lists for transplant surgery.


    Cellular immune response in patients with recurrent HCV infection after OLTx
 Top
 Abstract
 Introduction
 Natural history of recurrent...
 Antiviral treatment of recurrent...
 Retransplantation
 Cellular immune response in...
 Conclusions
 Acknowledgements
 References
 
HCV-specific CD4+ T cell response during the natural course of recurrent infection

The mechanisms of viral control in HCV infection are poorly understood. There are several lines of direct and indirect evidence that suggest that deficient cell-mediated immunity plays a key role in the development of chronic HCV infection. Vigorous and multispecific T cell responses associated with viral clearance in acute hepatitis C have been found by several groups whereas in chronic infection T cell responses are attenuated and difficult to detect ex vivo.3032 In the transplant setting treatment with OKT3 or coinfection with CMV, which has been shown to induce cell-mediated immune defects, has been associated with a higher risk of HCV-related allograft cirrhosis.18,19

Up to now only very few studies have investigated the role of the specific cellular immune responses in the pathogenesis of HCV-induced allograft injury. Concerning the CD8+ T cell response no studies are available. Among other things, e.g. HLA class I mismatch, this is due to the fact that there are several technical limitations concerning the analysis of HCV-specific CD8+ T cells. In contrast the CD4+ T cell response has been studied by Rosen et al. and our group.

In one of our studies we analysed liver- and blood-derived T cell lines of 34 patients with recurrent HCV infection. Virus-specific interferon-{gamma} production in response to various HCV proteins (structural as well as non-structural parts of the virus) was determined by ELISpot assay. As antigens we used the structural core protein (amino acids 1–120) and the non-structural (NS)3/4 (amino acids 1192–1931) and NS5 (amino acids 2014–3010) proteins. In up to 60% of these patients we found an HCV-specific CD4+ T cell response characterized by production of {gamma}-interferon. The HCV-specific CD4+ T cell response was preferentially localized on liver as opposed to peripheral blood cells. HCV-specific CD4+ T cells were more often detected early (≤6 months) than late (>6 months) after OLTx. During the early phase after OLTx NS3/4 was more often recognized than structural protein core or NS5. This is reminiscent of patients with acute self-limited hepatitis C infection whose multispecific CD4+ T cell response is also mainly directed at NS protein; however, the HCV-specific T cell response in the transplant setting seems to be less efficient, compared with patients with acute hepatitis C infection who spontaneously clear the virus and have a self-limited disease in up to 50% of cases.33 The reasons for this observation are a matter of debate. Chimerism of dendritic cells and other immunocompetent cells as well as HLA mismatch may account for this lower efficiency or lower strength of the HCV-specific CD4+ T cell response. During the late phase after OLTx a virus-specific CD4+ T cell response was less frequently detectable and was directed equally against structural protein core and NS proteins. This is similar to the chronic course of hepatitis C.3436

Rosen et al.37 investigated the HCV-specific CD4+ T cell response in peripheral blood in patients with minimal or no histological recurrence and found a significant T cell proliferation to more than one HCV antigen in 40% of these patients; however, in patients with severe recurrence of HCV or HCV-related cirrhosis of the allograft they did not find such a response. In contrast to these observations we found no correlation between HCV-specific CD4+ T cells and histology, histological activity index (HAI), liver enzymes or viral load. The majority of our patients with rejection or non-specific histology had detectable amounts of HCV-specific CD4+ T cells.35 Different read-out systems used in the study by Rosen et al. (proliferation assay) and our group (ELISpot assay) may explain the contradictory results of the two studies. In addition we investigated liver tissue and PBMC whereas Rosen et al. focused on PBMC. CD4+ T cells able to proliferate may be unable to produce interferon-{gamma}

HCV-specific CD4+ T cell response during and after antiviral therapy

More recently we showed in another study of 20 patients with recurrent infection, that despite immunosuppression, a sustained antiviral response is associated with a strong, multispecific CD4+ T cell response which is mainly directed at NS proteins. This response was maintained in PBMC over a long period, and it was significantly stronger in sustained responders than in transient responders or non-responders.

We found, with one exception, that the HCV-specific CD4+ T cell response during viral elimination was preferentially localized in the PBMC; this indicates that there is no attraction of virus-specific T cells in the liver after viral elimination.38

From the available data we conclude that the CD4+ T cell response plays an important role in viral clearance in recurrent HCV infection after OLTx.


    Conclusions
 Top
 Abstract
 Introduction
 Natural history of recurrent...
 Antiviral treatment of recurrent...
 Retransplantation
 Cellular immune response in...
 Conclusions
 Acknowledgements
 References
 
Considering the large number of hepatitis C-infected patients on the waiting list for transplantation, and the numbers predicted to be added in the future, the liver transplant community requires a better understanding of the natural history and pathogenesis of HCV recurrence. HCV-specific CD4+ T cells may play an important role, and future therapeutic strategies should be aimed at the induction and reinforcement of an adequate virus-specific CD4+ T cell response.


    Acknowledgements
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 Abstract
 Introduction
 Natural history of recurrent...
 Antiviral treatment of recurrent...
 Retransplantation
 Cellular immune response in...
 Conclusions
 Acknowledgements
 References
 
We thank Johann Harten, MD, for critically reading the manuscript and gratefully acknowledge the Wilhelm Sander-Stiftung for continuous support.


    Footnotes
 
* Corresponding author. Tel: + 49-89-7095-0; Fax: + 49-89-7000-9540; Email: carl.albrecht.schirren{at}med.uni-muenchen.de


    References
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 Introduction
 Natural history of recurrent...
 Antiviral treatment of recurrent...
 Retransplantation
 Cellular immune response in...
 Conclusions
 Acknowledgements
 References
 
1 . Berenguer, M., Lopez-Labrador, F. X. & Wright, T. L. (2001). Hepatitis C, and liver transplantation. Journal of Hepatology 35, 666–78.[CrossRef][ISI][Medline]

2 . Pruthi, J., Medkiff, K. A., Esrason, K. T. et al. (2001). Analysis of causes of death in liver transplant recipients who survived more than 3 years. Liver Transplantation 7, 811–5.[CrossRef][ISI][Medline]

3 . Feray, C., Gigou, M., Samuel, D. et al. (1994). The course of hepatitis C virus infection after liver transplantation. Hepatology 20, 1137–43.[ISI][Medline]

4 . Bizollon, T., Palazzo, U., Ducerf, C. et al. (1997). Pilot study of the combination of interferon alfa and ribavirin as therapy of recurrent hepatitis C after liver transplantation. Hepatology 26, 500–4.[ISI][Medline]

5 . De Vera, M. E., Smallwood, G. A., Rosado, K. et al. (2001). Interferon-alpha and ribavirin for the treatment of recurrent hepatitis C after liver transplantation. Transplantation 71, 678–86.[CrossRef][ISI][Medline]

6 . Nishiguchi, S., Fukuda, K., Shiomi, S. et al. (2003). Peripheral blood mononuclear cells are possible extrahepatic replication sites for hepatitis C virus. Hepatogastroenterology 50, 1301–4.[ISI][Medline]

7 . Basaras, M., de las Heras, B., Garcia Bengoechea, M. et al. (1996). Detection of hepatitis C virus RNA in serum and peripheral blood mononuclear cells in patients with chronic hepatitis C treated with interferon alpha. European Journal of Clinical Microbiology and Infectious Diseases 15, 887–90.[ISI][Medline]

8 . Gane, E. J., Portmann, B. C., Naoumov, N. V. et al. (1996). Long-term outcome of hepatitis C infection after liver transplantation. New England Journal of Medicine 334, 815–20.[Abstract/Free Full Text]

9 . Prieto, M., Berenguer, M., Rayon, J. M. et al. (1999). High incidence of allograft cirrhosis in hepatitis C virus genotype 1b infection following transplantation: relationship with rejection episodes. Hepatology 29, 250–6.[ISI][Medline]

10 . Charlton, M., Seaberg, E., Wiesner, R. et al. (1998). Predictors of patient and graft survival following liver transplantation for hepatitis C. Hepatology 28, 823–30.[ISI][Medline]

11 . Berenguer, M., Ferrell, L., Watson, J. et al. (2000). HCV-related fibrosis progression following liver transplantation: increase in recent years. Journal of Hepatology 32, 673–84.[CrossRef][ISI][Medline]

12 . Testa, G., Crippin, J. S., Netto, G. J. et al. (2000). Liver transplantation for hepatitis C: recurrence and disease progression in 300 patients. Liver Transplantation 6, 553–61.[CrossRef][ISI][Medline]

13 . Sanchez-Fueyo, A., Restrepo, J. C., Quinto, L. et al. (2002). Impact of the recurrence of hepatitis C virus infection after liver transplantation on the long-term viability of the graft. Transplantation 73, 56–63.[CrossRef][ISI][Medline]

14 . Berenguer, M., Prieto, M., Rayon, J. M. et al. (2000). Natural history of clinically compensated hepatitis C virus-related graft cirrhosis after liver transplantation. Hepatology 32, 852–8.[ISI][Medline]

15 . Keeffe, E. B. (2001). Liver transplantation: current status and novel approaches to liver replacement. Gastroenterology 120, 749–62.[ISI][Medline]

16 . Collier, J. & Heathcote, J. (1998). Hepatitis C viral infection in the immunosuppressed patient. Hepatology 27, 2–6.[ISI][Medline]

17 . Sheiner, P. A., Schwartz, M. E., Mor, E. et al. (1995). Severe or multiple rejection episodes are associated with early recurrence of hepatitis C after orthotopic liver transplantation. Hepatology 21, 30–4.[ISI][Medline]

18 . Rosen, H. R., Chou, S., Corless, C. L. et al. (1997). Cytomegalovirus viremia: risk factor for allograft cirrhosis after liver transplantation for hepatitis C. Transplantation 64, 721–6.[ISI][Medline]

19 . Rosen, H. R., Shackleton, C. R., Higa, L. et al. (1997). Use of OKT3 is associated with early and severe recurrence of hepatitis C after liver transplantation. American Journal of Gastroenterology 92, 1453–7.[ISI][Medline]

20 . Belli, L. S., de Carlis, L., Rondinara, G. et al. (1998). Early cyclosporine monotherapy in liver transplantation: a 5-year follow-up of a prospective, randomized trial. Hepatology 27, 1524–9.[ISI][Medline]

21 . Di Bisceglie, A. M., McHutchison, J. & Rice, C. M. (2002). New therapeutic strategies for hepatitis C. Hepatology 35, 224–31.[CrossRef][ISI][Medline]

22 . Wright, T. L., Combs, C., Kim, M. et al. (1994). Interferon-alpha therapy for hepatitis C virus infection after liver transplantation. Hepatology 20, 773–9.[ISI][Medline]

23 . Feray, C., Samuel, D., Gigou, M. et al. (1995). An open trial of interferon alfa recombinant for hepatitis C after liver transplantation: antiviral effects and risk of rejection. Hepatology 22, 1084–9.[ISI][Medline]

24 . Gane, E. J., Lo, S. K., Riordan, S. M. et al. (1998). A randomized study comparing ribavirin and interferon alfa monotherapy for hepatitis C recurrence after liver transplantation. Hepatology 27, 1403–7.[ISI][Medline]

25 . Jain, A., Demetris, A. J., Manez, R. et al. (1998). Incidence and severity of acute allograft rejection in liver transplant recipients treated with alfa interferon. Liver Transplantation and Surgery 4, 197–203.[ISI][Medline]

26 . Singh, N., Gayowski, T., Wannstedt, C. F. et al. (1998). Interferon-alpha for prophylaxis of recurrent viral hepatitis C in liver transplant recipients: a prospective, randomized, controlled trial. Transplantation 65, 82–6.[ISI][Medline]

27 . Rosen, H. R. & Martin, P. (1998). Hepatitis C infection in patients undergoing liver retransplantation. Transplantation 66, 1612–6.[CrossRef][ISI][Medline]

28 . Ghobrial, R. M., Farmer, D. G., Baquerizo, A. et al. (1999). Orthotopic liver transplantation for hepatitis C: outcome, effect of immunosuppression, and causes of retransplantation during an 8-year single-center experience. Annals of Surgery 229, 824–33.[CrossRef][ISI][Medline]

29 . Markmann, J. F., Markowitz, J. S., Yersiz, H. et al. (1997). Long-term survival after retransplantation of the liver. Annals of Surgery 226, 408–20.[CrossRef][ISI][Medline]

30 . Lechner, F., Wong, D. K., Dunbar, P. R. et al. (2000). Analysis of successful immune responses in persons infected with hepatitis C virus. Journal of Experimental Medicine 191, 1499–512.[Abstract/Free Full Text]

31 . Gerlach, J. T., Diepolder, H. M., Jung, M. C. et al. (1999). Recurrence of hepatitis C virus after loss of virus-specific CD4(+ ) T-cell response in acute hepatitis C. Gastroenterology 117, 933–41.[ISI][Medline]

32 . Gruener, N. H., Gerlach, J. T., Jung, M. C. et al. (2000). Association of hepatitis C virus-specific CD8+ T cells with viral clearance in acute hepatitis C. Journal of Infectious Diseases 181, 1528–36.[CrossRef][ISI][Medline]

33 . Gerlach, J. T., Diepolder, H. M., Zachoval, R. et al. (2003). Acute hepatitis C: high rate of both spontaneous and treatment-induced viral clearance. Gastroenterology 125, 80–8.[CrossRef][ISI][Medline]

34 . Schirren, C. A., Jung, M. C., Gerlach, J. T. et al. (2000). Liver-derived hepatitis C virus (HCV)-specific CD4+ T cells recognize multiple HCV-epitopes and produce interferon gamma. Hepatology 32, 597–603.[CrossRef][ISI][Medline]

35 . Schirren, C. A., Jung, M. C., Worzfeld, T. et al. (2001). Hepatitis C virus-specific CD4+ T cell response after liver transplantation occurs early, is multispecific, compartmentalizes to the liver, and does not correlate with recurrent disease. Journal of Infectious Diseases 183, 1187–94.[CrossRef][ISI][Medline]

36 . Schirren, C. A., Jung, M., Worzfeld, T. et al. (2000). Cytokine profile of liver- and blood-derived nonspecific T cells after liver transplantation: T helper cells type 1/0 lymphokines dominate in recurrent hepatitis C virus infection and rejection. Liver Transplantation 6, 222–8.[ISI][Medline]

37 . Rosen, H. R., Hinrichs, D. J., Gretch, D. R. et al. (1999). Association of multispecific CD4(+ ) response to hepatitis C and severity of recurrence after liver transplantation. Gastroenterology 117, 926–32.[ISI][Medline]

38 . Schirren, C. A., Zachoval, R., Gerlach, J. T. et al. (2003). Antiviral treatment of recurrent hepatitis C virus (HCV) infection after liver transplantation: association of a strong, multispecific, and long-lasting CD4+ T cell response with HCV-elimination. Journal of Hepatology 39, 397–404.[CrossRef][ISI][Medline]