**4.1 Current treatment standards**

The aim of antiviral treatment implies the reduction or complete HCV-clearance as responsible noxious agent in the development of HCV-associated graft disease. In spite of low success rates, HCV-infection is treated by subcutaneous administration of 180μg of Peg-IFN-α2a once a week and oral intake of RBV up to three times per day [22, 35, 81]. The cumulative duration of antiviral treatment comprises 12-18 months.

The major advantage of peg-interferon α2a and ribavirin-therapy consists in the summation of the antiviral potency. However, bone marrow toxicity, psychiatric disorders and rejection frequently limit therapy success. Due to high rates of predominantly hematological adverse events (anemia, leucopenia) and a significant risk of graft decompensation, antiviral treatment should be performed under a close patient monitoring. Myelotoxic effect of IFN results in the suppression of granulocytes and thrombocytes, whereas RBV induces anemia [77, 82]. Therapeutical support of hematological and mental disorders may frequently be necessary. Frequently observed anemia may result in the reduction of the RBV-dose or in the administration of erythropoietin. Leucopenia may require a dose reduction of IFN or administration of granulocyte stimulating growth factors. Mood disorders may be handled by antidepressants or social support. While performing a strenuous, expensive and frequently futile effort of virus elimination, 60-70% of transplants with HCV-graft hepatitis are treated without sustained virologic response [72].

#### **4.2 Alternative strategies**

Demonstrating poor treatment results and serious adverse events of IFN-based therapy, reasonable alternative treatment options are needed to complement or to replace the standard therapeutical approach. Silibinin experiences its renaissance in the treatment of chronic liver diseases although it has been known for years as hepatoprotective herbal and used by patients suffering from chronic liver disease of various causes [83-85]. In contrast to unclear antiviral efficacy of oral silibinin treatment, according to the results of published studies, a significant antiviral effect could be observed after intravenous administration of silibinin [84, 86-90]. Next to three other flavonolignan isomers (isosilybin, sylidianin and silychristin) silibinin is the most pharmacologically active component of silybum marianum and has been shown to improve biochemical markers of liver function and symptoms in a range of conditions including acute and chronic viral hepatitis, alcoholic liver disease and drug-related liver injury [83, 91-94]. As a potent free radical scavenger, silibinin has been shown to reduce the initiation of pathogenetically important lipid peroxidation and to lower HCV-RNA-load [92, 95, 96]. The substance exerts a direct antiviral effect on the HCVreplicon system inhibiting RNA-dependant HCV-polymerase. Furthermore, silibinin has been shown to affect the major actors in scar tissue formation suppressing TGF-β1-synthesis and HSC-activity [92, 97, 98].

The evidence of antiviral efficacy of silibinin in patients with HCV-related liver damage is limited due to a paucity of representative clinical trials, in spite of its popularity among patients suffering from various chronic liver diseases [92, 99]. Recent reports have demonstrated significant antiviral properties of intravenously administered silibinin in IFNnon-responders in the natural setting of HCV-infection, convincingly suggesting a dose- and treatment duration-dependent antiviral effect [92]. Several observations based on unfortunately low sample size cohorts, demonstrated that intravenous administration of silibinin after LT may be an effective therapeutic approach in the treatment of HCV-reinfection, even in non-responders to IFN-based therapy [99, 100]. Rapid normalization of aminotransferases and an exponential decline of HCV-load during silibinin treatment have been reported (fig. 6) [100]. Moreover, sustained viral elimination may apparently occur even after treatment with silibinin, only. Interestingly, in patients treated directly after LT, no significant antiviral effect could be observed, probably due to initially high levels of

The major advantage of peg-interferon α2a and ribavirin-therapy consists in the summation of the antiviral potency. However, bone marrow toxicity, psychiatric disorders and rejection frequently limit therapy success. Due to high rates of predominantly hematological adverse events (anemia, leucopenia) and a significant risk of graft decompensation, antiviral treatment should be performed under a close patient monitoring. Myelotoxic effect of IFN results in the suppression of granulocytes and thrombocytes, whereas RBV induces anemia [77, 82]. Therapeutical support of hematological and mental disorders may frequently be necessary. Frequently observed anemia may result in the reduction of the RBV-dose or in the administration of erythropoietin. Leucopenia may require a dose reduction of IFN or administration of granulocyte stimulating growth factors. Mood disorders may be handled by antidepressants or social support. While performing a strenuous, expensive and frequently futile effort of virus elimination, 60-70% of transplants with HCV-graft hepatitis

Demonstrating poor treatment results and serious adverse events of IFN-based therapy, reasonable alternative treatment options are needed to complement or to replace the standard therapeutical approach. Silibinin experiences its renaissance in the treatment of chronic liver diseases although it has been known for years as hepatoprotective herbal and used by patients suffering from chronic liver disease of various causes [83-85]. In contrast to unclear antiviral efficacy of oral silibinin treatment, according to the results of published studies, a significant antiviral effect could be observed after intravenous administration of silibinin [84, 86-90]. Next to three other flavonolignan isomers (isosilybin, sylidianin and silychristin) silibinin is the most pharmacologically active component of silybum marianum and has been shown to improve biochemical markers of liver function and symptoms in a range of conditions including acute and chronic viral hepatitis, alcoholic liver disease and drug-related liver injury [83, 91-94]. As a potent free radical scavenger, silibinin has been shown to reduce the initiation of pathogenetically important lipid peroxidation and to lower HCV-RNA-load [92, 95, 96]. The substance exerts a direct antiviral effect on the HCVreplicon system inhibiting RNA-dependant HCV-polymerase. Furthermore, silibinin has been shown to affect the major actors in scar tissue formation suppressing TGF-β1-synthesis

The evidence of antiviral efficacy of silibinin in patients with HCV-related liver damage is limited due to a paucity of representative clinical trials, in spite of its popularity among patients suffering from various chronic liver diseases [92, 99]. Recent reports have demonstrated significant antiviral properties of intravenously administered silibinin in IFNnon-responders in the natural setting of HCV-infection, convincingly suggesting a dose- and treatment duration-dependent antiviral effect [92]. Several observations based on unfortunately low sample size cohorts, demonstrated that intravenous administration of silibinin after LT may be an effective therapeutic approach in the treatment of HCV-reinfection, even in non-responders to IFN-based therapy [99, 100]. Rapid normalization of aminotransferases and an exponential decline of HCV-load during silibinin treatment have been reported (fig. 6) [100]. Moreover, sustained viral elimination may apparently occur even after treatment with silibinin, only. Interestingly, in patients treated directly after LT, no significant antiviral effect could be observed, probably due to initially high levels of

are treated without sustained virologic response [72].

**4.2 Alternative strategies** 

and HSC-activity [92, 97, 98].

immunosuppression (unpublished data, Charité, Berlin). Although no large scale studies have been carried out yet, silibinin might be an effective therapeutic approach in the treatment of HCV-re-infection and should be evaluated further. Any kind of antiviral supplementation to current therapy regimen should be welcome in the age of donor organ shortage to strengthen current antiviral therapy regimen and to avoid graft loss with subsequent re-transplantation.

Fig. 6. HCV-load during silibinin treatment after LT

Randomized, placebo-controlled clinical trials with a representative number of graft recipients suffering from HCV-re-infection are needed to definitely answer the question of the efficacy of intravenous silybium marianum solution and its antiviral potential. As long as IFN-α remains the backbone of antiviral therapy, the identification of predictors for therapy outcome is crucial. Regarding potential therapy success, frequent severe adverse events of IFN-RBV-therapy are commonly accepted. An unnecessary exposition to adverse therapy events in non-responders could thus be avoided by an improved predictability.

#### **4.3 Re-transplantation**

Re-transplantation is frequently required (up to 10%) in patients with HCV-related graft cirrhosis as the only option of treatment [12, 15]. Significantly decreased survival rates after re-transplantation compared to first LT are in the center of scientific attention and long-term outcome has been reported to be inferior to other indications [3, 11, 39]. Physical condition, MELD-score, technical obstacles and antiviral therapy response are currently accepted as predictors for graft and patient survival after re-LT [39, 101].

#### **5. Summary and future prospective**

As long as HCV-recurrence exists as currently inevitable phenomenon, HCV will continue to endanger the success of LT. While performing a strenuous, expensive and frequently futile effort of interferon-based virus elimination, 60-70% of graft recipients are still treated without achieving SVR, thus leaving overall poor results. The natural course of HCV-

recurrence is not uniform and is influenced by a whole variety of factors. Therefore, the identification of non-invasive inflammation and fibrosis markers might help to differentiate re-infected patients with stable graft function without significant inflammation or fibrosis progression from patients at risk for short-term graft damage and define the indication for antiviral treatment. Moreover, it is indispensable to identify patients who are likely to respond to IFN-based antiviral treatment. The individual variability of disease development may be divided roughly into three different patient groups (A: no fibrosis progression, B: treatable progression and C: untreatable progression of graft dysfunction). The indication for antiviral therapy in group B seems to be more urgent in contrast to group A, which may stay stable for several years regarding their graft function, thus avoiding possibly unnecessary exposition to pharmaceutical side effects. Group-C- patients, as high risk patients may require treatment adjustment regarding its intensity, duration and mode including alternative therapeutical strategies.

Although HCV-recurrence represents an inevitable post-transplant phenomenon, the development of advanced fibrosis stages is highly variable or even individual. Furthermore, the outcome of antiviral treatment seems to depend on multiple factors, too. In spite of recent advances in HCV-graft-hepatitis treatment, prediction of therapy response and risk stratification in graft fibrosis progression, a further extensive investigation is still required. Improvement in prevention, prediction of disease course, individualized antiviral treatment and alternative antiviral medication may help to increase survival rates after LT for an HCVassociated graft disease.

#### **6. References**


recurrence is not uniform and is influenced by a whole variety of factors. Therefore, the identification of non-invasive inflammation and fibrosis markers might help to differentiate re-infected patients with stable graft function without significant inflammation or fibrosis progression from patients at risk for short-term graft damage and define the indication for antiviral treatment. Moreover, it is indispensable to identify patients who are likely to respond to IFN-based antiviral treatment. The individual variability of disease development may be divided roughly into three different patient groups (A: no fibrosis progression, B: treatable progression and C: untreatable progression of graft dysfunction). The indication for antiviral therapy in group B seems to be more urgent in contrast to group A, which may stay stable for several years regarding their graft function, thus avoiding possibly unnecessary exposition to pharmaceutical side effects. Group-C- patients, as high risk patients may require treatment adjustment regarding its intensity, duration and mode

Although HCV-recurrence represents an inevitable post-transplant phenomenon, the development of advanced fibrosis stages is highly variable or even individual. Furthermore, the outcome of antiviral treatment seems to depend on multiple factors, too. In spite of recent advances in HCV-graft-hepatitis treatment, prediction of therapy response and risk stratification in graft fibrosis progression, a further extensive investigation is still required. Improvement in prevention, prediction of disease course, individualized antiviral treatment and alternative antiviral medication may help to increase survival rates after LT for an HCV-

[1] Schuppan D, Krebs A, Bauer M *et al.* Hepatitis C and liver fibrosis. Cell Death Differ 2003

[2] Rossol S. [Chronic HCV infections. A model disease for therapy, economics and social

[4] Thomas DL, Astemborski J, Rai RM et al. The natural history of hepatitis C

[5] Friedman SL. Mechanisms of disease: Mechanisms of hepatic fibrosis and therapeutic implications. Nat Clin Pract Gastroenterol Hepatol 2004 Dec;1(2):98-105. [6] Friedman SL. Molecular regulation of hepatic fibrosis, an integrated cellular response to

[7] Svirtlih N, Jevtovic D, Simonovic J *et al.* Older age at the time of liver biopsy is the

[8] Sterling RK, Stravitz RT, Luketic VA *et al.* A comparison of the spectrum of chronic

[9] Gitto S, Micco L, Conti F *et al.* Alcohol and viral hepatitis: a mini-review. Dig Liver Dis

[10] Powell EE, Edwards-Smith CJ, Hay JL *et al.* Host genetic factors influence disease progression in chronic hepatitis C. Hepatology 2000 Apr;31(4):828-833.

virusinfection: host, viral, and environmental factors. JAMA 2000 Jul 26;284(4):450-

important risk factor for advanced fibrosis in patients with chronic hepatitis C.

hepatitis C virus between Caucasians and African Americans. Clin Gastroenterol

medical aspects]. Gesundheitswesen 2007 Mar;69(3):146-150.

tissue injury. J Biol Chem 2000 Jan 28;275(4):2247-2250.

Hepatogastroenterology 2007 Dec;54(80):2324-2327.

Hepatol 2004 Jun;2(6):469-473.

2009 Jan;41(1):67-70.

[3] Burra P. Hepatitis C. Semin Liver Dis 2009 Feb;29(1):53-65.

including alternative therapeutical strategies.

Jan;10 Suppl 1:S59-67.

associated graft disease.

456.

**6. References** 


[30] Lake JR, Shorr JS, Steffen BJ *et al.* Differential effects of donor age in liver transplant

[31] Bahra M, Jacob D, Neumann UP *et al.* Influence of donor histology on outcome in

[32] Barrett S, Collins M, Kenny C *et al.* Polymorphisms in tumour necrosis factor-alpha,

[34] Ben-Ari Z, Mor E, Papo O *et al.* Cytokine gene polymorphisms in patients infected with

[35] Shackel NA, Jamias J, Rahman W *et al.* Early high peak hepatitis C viral load levels

[36] Gayowski T, Singh N, Marino IR *et al.* Hepatitis C virus genotypes in liver transplant

[38] Lake JR. The role of immunosuppression in recurrence of hepatitis C. Liver Transpl

[39] Bahra M, Neumann UP, Jacob D *et al.* Outcome after liver re-transplantation in patients with recurrent chronic hepatitis C. Transpl Int 2007 Sep;20(9):771-778. [40] Marcello T, Grakoui A, Barba-Spaeth G et al. Interferons alpha and lambda inhibit

[41] Zervos XA, Weppler D, Fragulidis GP *et al.* Comparison of tacrolimus with neoral

[42] Bahra M, Neumann UI, Jacob D et al. MMF and calcineurin taper in recurrent hepatitis

[43] Kniepeiss D, Iberer F, Grasser B et al. Sirolimus and mycophenolate mofetil after liver

[44] Asthana S, Toso C, Meeberg G et al. The impact of sirolimus on hepatitis C recurrence

[45] Fiore CE, Pennisi P, Tamborino C. YKL-40 and graft rejection. Am J Med 2000 Jun

[46] Eurich D, Boas-Knoop S, Morawietz L et al. Association of mannose-binding lectin-2

gene polymorphism with the development of hepatitis C-induced hepatocellular

after liver transplantation. Can J Gastroenterol Jan;25(1):28-34.

alpha therapy and outcome. Transplantation 1997 Aug 15;64(3):422-426. [37] Prieto M, Berenguer M, Rayon JM *et al.* High incidence of allograft cirrhosis in hepatitis

transplantation. Liver Transpl 2006 Nov;12(11):1723-1724.

hepatitis B virus. Am J Gastroenterol 2003 Jan;98(1):144-150.

Transplant 2005 Mar;5(3):549- 557.

Liver Transpl 2009 Jul;15(7):709- 718.

2003 Nov;9(11):S63-66.

Feb;5(2):406-411.

1;108(8):688- 689.

episodes. Hepatology 1999 Jan;29(1):250-256.

Transplant Proc 1998 Jun;30(4):1405-1406.

carcinoma. Liver Int Aug;31(7):1006-1012.

kinetics. Gastroenterology 2006 Dec;131(6):1887-1898.

transplantation. Transpl Int 2003 Jul;16(7):504-509.

27;84(2):144-148.

recipients infected with hepatitis B, hepatitis C and without viral hepatitis. Am J

patients undergoing transplantation for hepatitis C. Transplantation 2007 Jul

transforming growth factor-beta, interleukin-10, interleukin-6, interferon gamma, and outcome of hepatitis C virus infection. J Med Virol 2003 Oct;71(2):212-218. [33] Ben-Ari Z. Role of cytokine gene polymorphism in recurrent HCV infection after liver

independently predict hepatitis C-related liver failure post-liver transplantation.

recipients: impact on posttransplant recurrence, infections, response to interferon

C virus genotype 1b infection following transplantation: relationship with rejection

hepatitis C virus replication with distinct signal transduction and gene regulation

asprimary immunosuppression in hepatitis C patients after liver transplantation.

C after liver transplantation: impact on histological course. Am J Transplant 2005


[63] Eurich D, Bahra M, Boas-Knoop S et al. Transforming growth factor beta1

hepatitis C virus--induced liver disease. Liver Transpl Mar;17(3):279-288. [64] Eurich D, Boas-Knoop S, Ruehl M et al. Relationship between the interleukin-28b gene

[65] Rauch A, Kutalik Z, Descombes P et al. Genetic variation in IL28B is associated with

[66] Robek MD, Boyd BS, Chisari FV. Lambda interferon inhibits hepatitis B and C virus

[67] O'Brien TR. Interferon-alfa, interferon-lambda and hepatitis C. Nat Genet 2009

[68] Sheppard P, Kindsvogel W, Xu W et al. IL-28, IL-29 and their class II cytokine receptor

[69] Cescon M, Grazi GL, Cucchetti A *et al.* Predictors of sustained virological response after

[70] Brady DE, Torres DM, An JW *et al.* Induction pegylated interferon alfa-2b in

[71] Burra P, Targhetta S, Pevere S et al. Antiviral therapy for hepatitis C virus recurrence

[72] Everson GT, Kulig CC. Antiviral therapy for hepatitis C in the setting of liver transplantation. Curr Treat Options Gastroenterol 2006 Dec;9(6):520-529. [73] Neumann U, Puhl G, Bahra M *et al.* Treatment of patients with recurrent hepatitis C

[74] Rodriguez-Luna H, Khatib A, Sharma P *et al.* Treatment of recurrent hepatitis C

[75] Schmitz V, Kiessling A, Bahra M *et al.* Peginterferon alfa-2b plus ribavirin for the

[76] Terrault NA, Berenguer M. Treating hepatitis C infection in liver transplant

[77] Bahra M, Neumann UP, Jacob D *et al.* Fibrosis progression in hepatitis C positive liver

(interferon-ribavirin therapy). Transplantation 2007 Feb 15;83(3):351-353. [78] Ge D, Fellay J, Thompson AJ et al. Genetic variation in IL28B predicts hepatitis C treatment- induced viral clearance. Nature 2009 Sep 17;461(7262):399-401.

antiviral treatment for hepatitis C recurrence following liver transplantation. Liver

combination with ribavirin in patients with genotypes 1 and 4 chronic hepatitis C: a prospective, randomized, multicenter, open-label study. Clin Gastroenterol

following liver transplantation: long-term results from a single center experience.

after liver transplantation with peginterferon alfa-2B plus ribavirin.

infection after liver transplantation with combination of pegylated interferon alpha2b and ribavirin: an open-label series. Transplantation 2004 Jan 27;77(2):190-

treatment of hepatitis C recurrence following combined liver and kidney

recipients after sustained virologic response to antiviral combination therapy

Gastroenterology Apr;138(4):1338-1345, 1345 e1331-1337.

replication. J Virol 2005 Mar;79(6):3851-3854.

IL-28R. Nat Immunol 2003 Jan;4(1):63-68.

Transplant Proc 2006 May;38(4):1127-1130.

Transplantation 2006 Jul 15;82(1):43-47.

transplantation. Ann Transplant 2007;12(3):22-27.

recipients.Liver Transpl 2006 Aug;12(8):1192-1204.

Transpl 2009 Jul;15(7):782-789.

Hepatol Jan;8(1):66-71 e61.

194.

Transpl Mar;17(3):289-298.

Oct;41(10):1048-1050.

polymorphisms and progression of graft fibrosis after liver transplantation for

polymorphism and the histological severity of hepatitis C virus-induced graft inflammation and the response to antiviral therapy after liver transplantation. Liver

chronic hepatitis C and treatment failure: a genome-wide association study.

