The use of cyclosporine for recurrent hepatitis C after liver transplant: a randomized pilot study

Nature-derived hit, lead, and drug-like small molecules: Current status and future aspects against key target proteins of Coronaviruses

BACKGROUND

COVID-19 pandemic, the most unprecedented event of the year 2020, has brought millions of scientists worldwide in a single platform to fight against it. Though several drugs are now in the clinical trial, few vaccines available on the market already but the lack of an effect of those is making the situation worse.

AIM OF THE STUDY

In this review, we demonstrated comprehensive data of natural antiviral products showing activities against different proteins of Human Coronaviruses (HCoV) that are responsible for its pathogenesis. Furthermore, we categorized the compounds into the hit, lead, and drug based on the IC50/EC50 value, drug-likeness, and lead-likeness test to portray their potentiality to be a drug. We also demonstrated the present status of our screened antiviral compounds with respect to clinical trials and reported the lead compounds that can be promoted to clinical trial against COVID-19.

METHODS

A systematic search strategy was employed focusing on Natural Products (NPs) with proven activity (in vitro, in vivo, or in silico) against human coronaviruses, in general, and data were gathered from databases like PubMed, Web of Science, Google Scholar, SciVerse, and Scopus. Information regarding clinical trials retrieved from the Clinical Trial database.

RESULTS

Total "245" natural compounds were identified initially from the literature study. Among them, Glycyrrhizin, Caffeic acid, Curcumin is in phase 3, and Tetrandrine, Cyclosporine, Tacrolimus, Everolimus are in phase 4 clinical trial. Except for Glycyrrhizin, all compounds showed activity against COVID-19.

CONCLUSIONS

In summary, our demonstrated specific small molecules with lead and drug-like capabilities clarified their position in the drug discovery pipeline and proposed their future research against COVID-19.

Immunosuppression in the Management of Presumed Non-infective Uveitis; Are We Sure What We are Treating? Notes on the Antimicrobial Properties of the Systemic Immunosuppressants

PURPOSE

To describe the antimicrobial effects of immunosuppressants used for presumed autoimmune uveitis, and to discuss the potential importance of these effects in the context of increasing knowledge of the human microbiomes and their influence on inflammation.

METHODS

Literature review.

REVIEW OF EVIDENCE

All immunosuppressants have intrinsic antimicrobial effects; these vary considerably between drugs, and include antibacterial, antiviral and antifungal action. Immunosuppression is known to affect the composition of the gut microbiome, and alterations in microbiome composition are known to affect inflammations including uveitis.

CONCLUSIONS

Oral immunosuppressants are assumed to act on presumed autoimmune uveitis by downregulation of, or other interference with, an aberrant immune response. However, their antimicrobial properties are usually forgotten, and in the context of increasing knowledge of the involvement of microbes in the initiation of, and also potentially the perpetuation of, tissue inflammation, these effects may prove to be a fundamental part of their action.

Effect of cyclosporine A versus tacrolimus on the response to antiviral therapy after hepatitis C genotype-4 recurrence post-liver transplantation: A prospective cohort trial

WHAT IS KNOWN AND OBJECTIVE

The influence of immunosuppression on the response to antiviral therapy (AVT) for recurrent hepatitis C virus (HCV) infection in liver transplant (LT) recipients remains controversial, especially for the rarely investigated genotype 4. This study aims to compare the effects of the two widely used calcineurin inhibitors (CNIs) (cyclosporine A (CsA) and tacrolimus (Tac)) on the therapeutic response to different AVT regimens.

METHODS

A prospective, dual-centre, cohort study of 126 Egyptian living donor liver transplant (LDLT) recipients with recurrent HCV genotype 4 infection, who were categorized into three groups according to the AVT used. Group I received pegylated interferon (Peg-IFN-α 2a) plus ribavirin (RBV) (n = 44), group II received the direct antiviral agent (DAA) sofosbuvir plus RBV (n = 52) and group III received daclatasvir and sofosbuvir (also DAAs) plus RBV (n = 30). Each group was further subdivided according to the primary immunosuppression (CsA or Tac). The sustained virological response (SVR) and relapse rates were considered the primary therapeutic outcomes of AVT.

RESULTS

No significant intergroup differences were observed in the achievement of primary and secondary outcomes. SVR rates in the IFN-based regimen were 75% and 66.7% in CsA and Tac users and 81.2% and 83% in DAAs, respectively. Relapse rates in the IFN-based regimen were 10% and 16.7% in CsA and Tac users and 12.5% and 14.9% in DAAs, respectively.

WHAT IS NEW AND CONCLUSION

Within the limitations of a relatively small study, CsA did not offer an advantage over Tac regarding the response to AVT after HCV genotype 4 recurrence in LDLT recipients.

Pre-emptive Treatment of HCV after Living Donor Liver Transplantation with Direct-Acting Antiviral Agents

BACKGROUND

Hepatitis C virus (HCV) universally recurs after liver transplantation (LT). Although the introduction of direct-acting antiviral agents (DAAs) has revolutionized the treatment of HCV infection, no optimal treatment for HCV recurrence after LT has been developed.

METHODS

This study retrospectively evaluated the efficacy of DAAs as a pre-emptive treatment for recurrent HCV infection after living donor liver transplantation (LDLT). From January 2010 to December 2016, 70 patients received pegylated interferon (PegIFN) and 35 patients were treated with DAA-based regimens to treat recurrent HCV after LDLT. All antiviral treatments were pre-emptive.

RESULTS

Genotype 1b was the most common HCV type (61.9%). Twenty-two recipients in the DAA group were treated with ledipasvir/sofosbuvir, nine received daclatasvir plus asunaprevir, three received sofosbuvir, and one received sofosbuvir plus daclatasvir. All 35 patients (100%) in the DAA group achieved a sustained virologic response (SVR), a percentage significantly higher than that (71.4%) in the PegIFN group (p < 0.001). In the PegIFN group, the 1-, 3-, and 5-year graft survival rates were 85.7, 73.9, and 70.7%, respectively, whereas those in the DAA group were 100, 100, and 100%, respectively (p = 0.008).

CONCLUSION

DAA-based regimens are an effective treatment for HCV recurrence after LDLT, resulting in an improved SVR and better graft survival than PegIFN.

Maintenance immunosuppression for adults undergoing liver transplantation: a network meta-analysis

BACKGROUND

As part of liver transplantation, immunosuppression (suppressing the host immunity) is given to prevent graft rejections resulting from the immune response of the body against transplanted organ or tissues from a different person whose tissue antigens are not compatible with those of the recipient. The optimal maintenance immunosuppressive regimen after liver transplantation remains uncertain.

OBJECTIVES

To assess the comparative benefits and harms of different maintenance immunosuppressive regimens in adults undergoing liver transplantation through a network meta-analysis and to generate rankings of the different immunosuppressive regimens according to their safety and efficacy.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, Science Citation Index Expanded, World Health Organization International Clinical Trials Registry Platform, and trials registers until October 2016 to identify randomised clinical trials on immunosuppression for liver transplantation.

SELECTION CRITERIA

We included only randomised clinical trials (irrespective of language, blinding, or publication status) in adult participants undergoing liver transplantation (or liver retransplantation) for any reason. We excluded trials in which participants had undergone multivisceral transplantation or participants with established graft rejections. We considered any of the various maintenance immunosuppressive regimens compared with each other.

DATA COLLECTION AND ANALYSIS

We performed a network meta-analysis with OpenBUGS using Bayesian methods and calculated the odds ratio, rate ratio, and hazard ratio (HR) with 95% credible intervals (CrI) based on an available-case analysis, according to National Institute of Health and Care Excellence Decision Support Unit guidance.

MAIN RESULTS

We included a total of 26 trials (3842 participants) in the review, and 23 trials (3693 participants) were included in one or more outcomes in the review. The vast majority of the participants underwent primary liver transplantation. All of the trials were at high risk of bias, and all of the evidence was of low or very low quality. In addition, because of sparse data involving trials at high risk of bias, it is not possible to entirely rely on the results of the network meta-analysis. The trials included mainly participants undergoing primary liver transplantation of varied aetiologies. The follow-up in the trials ranged from 3 to 144 months. The most common maintenance immunosuppression used as a control was tacrolimus. There was no evidence of difference in mortality (21 trials; 3492 participants) or graft loss (15 trials; 2961 participants) at maximal follow-up between the different maintenance immunosuppressive regimens based on the network meta-analysis. In the direct comparison, based on a single trial including 222 participants, tacrolimus plus sirolimus had increased mortality (HR 2.76, 95% CrI 1.30 to 6.69) and graft loss (HR 2.34, 95% CrI 1.28 to 4.61) at maximal follow-up compared with tacrolimus. There was no evidence of differences in the proportion of people with serious adverse events (1 trial; 719 participants), proportion of people with any adverse events (2 trials; 940 participants), renal impairment (8 trials; 2233 participants), chronic kidney disease (1 trial; 100 participants), graft rejections (any) (16 trials; 2726 participants), and graft rejections requiring treatment (5 trials; 1025 participants) between the different immunosuppressive regimens. The network meta-analysis showed that the number of adverse events was lower with cyclosporine A than with many other immunosuppressive regimens (12 trials; 1748 participants), and the risk of retransplantation (13 trials; 1994 participants) was higher with cyclosporine A than with tacrolimus (HR 3.08, 95% CrI 1.13 to 9.90). None of the trials reported number of serious adverse events, health-related quality of life, or costs.

FUNDING

14 trials were funded by pharmaceutical companies who would benefit from the results of the trial; two trials were funded by parties who had no vested interest in the results of the trial; and 10 trials did not report the source of funding.

AUTHORS' CONCLUSIONS

Based on low-quality evidence from a single small trial from direct comparison, tacrolimus plus sirolimus increases mortality and graft loss at maximal follow-up compared with tacrolimus. Based on very low-quality evidence from network meta-analysis, we found no evidence of difference between different immunosuppressive regimens. We found very low-quality evidence from network meta-analysis and low-quality evidence from direct comparison that cyclosporine A causes more retransplantation compared with tacrolimus. Future randomised clinical trials should be adequately powered; performed in people who are generally seen in the clinic rather than in highly selected participants; employ blinding; avoid postrandomisation dropouts or planned cross-overs; and use clinically important outcomes such as mortality, graft loss, renal impairment, chronic kidney disease, and retransplantation. Such trials should use tacrolimus as one of the control groups. Moreover, such trials ought to be designed in such a way as to ensure low risk of bias and low risks of random errors.

Isogarcinol Extracted from Garcinia mangostana L. Ameliorates Imiquimod-Induced Psoriasis-like Skin Lesions in Mice

Isogarcinol (YDIS), a natural compound extracted from Garcinia mangostana L., has a significant immunosuppressive effect on systemic lupus erythematosus and rheumatoid arthritis. This paper reports that it reduced imiquimod-induced psoriasis-like skin lesions in mice. It strongly attenuated the aberrant proliferation and differentiation of keratinocytes. Moreover, the expression of genes involving the interleukin-23 (IL-23)/T-helper 17 (Th17) axis was significantly inhibited in the dorsal skin of the YDIS-treated mice, as was that of the other pro-inflammatory factors TNF-α, IL-2, and even interferon (IFN)-γ. Furthermore, YDIS prevented the abnormal distribution of T cell types and suppressed the differentiation of CD4⁺ T cells into Th17 cells in the spleens of mice exposed to imiquimod. Interestingly, it elevated numbers of regulatory T cells (Tregs) in the spleen and boosted IL-10 expression in the skin. In agreement with the above, YDIS increased serum IL-10 and reduced serum IL-17. It also caused less damage to the liver and, especially, kidneys of mice than cyclosporine A (CsA). In vitro, YDIS caused more death of HaCaT keratinocytes than CsA. It also strongly inhibited inflammatory factor expression in lipopolysaccharide (LPS)-stimulated HaCaT cells. These findings suggest that YDIS is a promising immunosuppressive agent for treating psoriasis.

Post-Transplant Membranous Nephropathy Associated with Chronic Active Antibody-Mediated Rejection and Hepatitis C Infection after Deceased Donor Renal Transplantation

A 53-year-old woman who had undergone deceased donor kidney transplantation twice, at 35 and 43 years of age, presented with renal impairment. She was infected with hepatitis C virus (HCV). The histology of the graft kidney revealed post-transplant membranous nephropathy (MN) with podocytic infolding and antibody-mediated rejection (AMR). IgG subclass staining showed fine granular deposits of IgG1 and IgG3, but not IgG4, in the glomerular capillary walls. Panel reactive antibody scores for human leukocyte antigen class I and class II were 92.67% and 66.68%, respectively. Thus, this case of post-transplanted MN was considered to be associated with AMR and HCV infection.

Recurrent HCV after liver transplantation-mechanisms, assessment and therapy

Chronic HCV infection is the leading indication for liver transplantation. However, as a result of HCV recurrence, patient and graft survival after liver transplantation are inferior compared with other indications for transplantation. HCV recurrence after liver transplantation is associated with considerable mortality and morbidity. The development of HCV-related fibrosis is accelerated after liver transplantation, which is influenced by a combination of factors related to the virus, donor, recipient, surgery and immunosuppression. Successful antiviral therapy is the only treatment that can attenuate fibrosis. The advent of direct-acting antiviral agents (DAAs) has changed the therapeutic landscape for the treatment of patients with HCV. DAAs have improved tolerability, and can potentially be used without PEG-IFN for a shorter time than previous therapies, which should result in better outcomes. In this Review, we describe the important risk factors that influence HCV recurrence after liver transplantation, highlighting the mechanisms of fibrosis and the integral role of hepatic stellate cells. Indirect and direct assessment of fibrosis, in addition to new antiviral therapies, are also discussed.

Management of recurrent hepatitis C virus after liver transplantation

Chronic hepatitis C virus (HCV) infection is the leading cause of death from liver disease and the leading indication for liver transplantation (LT) in the United States and Western Europe. LT represents the best therapeutic alternative for patients with advanced chronic liver disease caused by HCV or those who develop hepatocarcinoma. Reinfection by HCV of the graft is universal and occurs in 95% of transplant patients. This reinfection can compromise graft function and patient survival. In a few cases, the histological recurrence is minimal and non-progressive; however, in most patients it follows a more rapid course than in immunocompetent persons, and frequently evolves into cirrhosis with graft loss. In fact, the five-year and ten-year survival of patients transplanted because of HCV are 75% and 68%, respectively, compared with 85% and 78% in patients transplanted for other reasons. There is also a pattern of recurrence that is very severe, but rare (< 10%), called fibrosing cholestatic hepatitis, which often involves rapid graft loss. Patients who present a negative HCV viremia after antiviral treatment have better survival. Many studies published over recent years have shown that antiviral treatment of post-transplant HCV hepatitis carried out during the late phase is the best option for improving the prognosis of these patients. Until 2011, PEGylated interferon plus ribavirin was the standard of care, resulting in a sustained virological response in around 30% of recipients. The addition of protease inhibitors, such as boceprevir or telaprevir, to the standard of care, or the use of other direct-acting antiviral drugs may involve therapeutic changes in the context of HCV recurrence. This may result a better prognosis for these patients, particularly those with severe recurrence or factors predicting rapid progression of fibrosis. However, the use of these agents in LT still requires clarification in terms of safety and efficacy.

Tacrolimus-based versus cyclosporine-based immunosuppression in hepatitis C virus-infected patients after liver transplantation: a meta-analysis and systematic review

Background

Most liver transplant recipients receive calcineurin inhibitors (CNIs), especially tacrolimus and cyclosporine, as immunosuppressant agents to prevent rejection. A controversy exists as to whether the outcomes of hepatitis C virus (HCV)-infected liver transplant patients differ based on the CNIs used. This meta-analysis compares the clinical outcomes of tacrolimus-based and cyclosporine-based immunosuppression, especially cases of HCV recurrence in liver transplant patients with end-stage liver disease caused by HCV infection.

Methods

Related articles were identified from the Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, Medline, and Embase. Meta-analyses were performed for the results of homogeneous studies.

Results

Nine randomized or quasi-randomized controlled trials were included. The total effect size of mortality (RR = 0.98, 95% CI: 0.77–1.25, P = 0.87) and graft loss (RR = 1.05, 95% CI: 0.83–1.33, P = 0.67) showed no significant difference between the two groups irrespective of duration of immunosuppressant therapy after liver transplantation. In addition, the HCV recurrence-induced mortality (RR = 1.11, 95% CI: 0.66–1.89, P = 0.69), graft loss (RR = 1.62, 95% CI: 0.64–4.07, P  = 0.31) and retransplantation (RR = 1.40, 95% CI: 0.48–4.09, P = 0.54), as well as available biopsies, confirmed that histological HCV recurrences (RR =  0.92, 95% CI: 0.71–1.19, P = 0.51) were similar.

Conclusion

These results suggested no difference in posttransplant HCV recurrence-induced mortality, graft loss and retransplantation, as well as histological HCV recurrence in patients treated with tacrolimus-based and cyclosporine-based immunosuppresion.

A US multicenter study of hepatitis C treatment of liver transplant recipients with protease-inhibitor triple therapy

BACKGROUND & AIMS

NS3/4A protease inhibitors, boceprevir or telaprevir, combined with peginterferon and ribavirin was the standard treatment for HCV genotype 1 and remains the only available direct antiviral drug based therapy in some countries. Efficacy and safety data in liver transplant recipients are limited.

METHODS

This was a retrospective cohort study of 81 patients with genotype 1 HCV treated with boceprevir (10%) or telaprevir (90%) plus peginterferon and ribavirin at 6 US transplant centers (53% stage 3-4/4 fibrosis, 57% treatment experienced). The primary end point was undetectable HCV RNA 12 weeks after treatment completion (SVR12).

RESULTS

The intent-to-treat SVR12 rate was 63% (51/81). Patients with an extended rapid virologic response, (undetectable HCV RNA at 4 and 12 weeks after starting boceprevir or telaprevir), had a higher rate of SVR12 than all other patients (85% vs. 15%, p<0.001). Adverse effects were common; 21% of patients experienced hemoglobin <8g/dl and 57% required blood transfusions during the first 16 weeks. Twenty seven percent were hospitalized and 9% died; all were liver-related.

CONCLUSIONS

The addition of boceprevir or telaprevir to peginterferon and ribavirin yields SVR12 of 63% in liver transplant recipients with genotype 1 recurrent HCV, despite a high prevalence of advanced fibrosis and prior non-response to peginterferon and ribavirin. Rapid virologic response predicted a high likelihood of SVR. Despite a doubling of SVR rates, poor tolerability and high rates of adverse events were frequent and pose barriers to its widespread application.

Recurrent hepatitis C after liver transplant

End stage liver disease from hepatitis C is the most common indication for liver transplantation in many parts of the world accounting for up to 40% of liver transplants. Antiviral therapy either before or after liver transplantation is challenging due to side effects and lower efficacy in patients with cirrhosis and liver transplant recipients, as well as from drug interactions with immunosuppressants. Factors that may affect recurrent hepatitis C include donor age, immunosuppression, IL28B genotype, cytomegalovirus infection, and metabolic syndrome. Older donor age has persistently been shown to have the greatest impact on recurrent hepatitis C. After liver transplantation, distinguishing recurrent hepatitis C from acute cellular rejection may be difficult, although the development of molecular markers may help in making the correct diagnosis. The advent of interferon free regimens with direct acting antiviral agents that include NS3/4A protease inhibitors, NS5B polymerase inhibitors and NS5A inhibitors holds great promise in improving outcomes for liver transplant candidates and recipients.

Management of Hepatitis C Before and After Liver Transplantation in the Era of Rapidly Evolving Therapeutic Advances

Management of hepatitis C (HCV) in liver transplantation (LT) population presents unique challenges. Suboptimal graft survival in HCV+ LT recipients is attributable to universal HCV recurrence following LT. Although eradication of HCV prior to LT is ideal for the prevention of HCV recurrence it is often limited by adverse events, particularly in patients with advanced cirrhosis. Antiviral therapy in LT candidates needs careful monitoring, and prophylaxis with HCV antibodies is ineffective. Early antiviral therapy after LT has been investigated, but no clear benefit has been demonstrated. Protocol liver biopsy is generally recommended in HCV+ LT recipients, and antiviral therapy can be considered in those with severe/progressive HCV recurrence. Sustained virological response (SVR) can be achieved in approximately 30% of LT recipients with pegylated interferon/ribavirin (PEG-IFN/RBV) with survival benefit, but adverse effects are common. Favorable patient characteristics for response to therapy include non-1 genotype, previously untreated, low baseline HCV-RNA, and donor IL28B genotype CC. Direct acting antiviral (DAA)-based triple therapy is associated with higher rates of SVR, but with similar or slightly higher rates of side effects, and immunosuppressive regimens need to be closely monitored and adjusted during the treatment period. Notably, the safety and efficacy of HCV treatment are very likely to improve with newer generation DAA. The benefit of immunosuppressive strategy on the natural history HCV recurrence has not been well elucidated. Based upon available evidence, cyclosporine A (CSA), mycophenolate mofetil (MMF), and sirolimus appear to have a neutral or small beneficial impact on HCV recurrence. Donor interleukin 28 B (IL28B) polymorphisms appear to impact the course and treatment outcomes in recurrent HCV. Retransplantation should be considered for patients with reasonable survival probability.

Directly acting antivirals (DAAs) for the treatment of chronic hepatitis C virus infection in liver transplant patients: "a flood of opportunity"

Chronic hepatitis C virus (HCV) is the leading cause of liver transplantation (LT) in adults. However, infection of the allograft is universal and associated with reduced graft and patient survival. Although successful eradication improves posttransplant outcome, current antiviral therapies have poor efficacy and tolerability. Direct acting antiviral agents (DAAs) provide new opportunities for treatment of HCV recurrence. The addition of a first-generation NS3/4A protease inhibitor (PI) has increased the efficacy of pegylated interferon and ribavirin in patients with chronic HCV genotype 1 infection. Preliminary efficacy results from open-labeled studies of PI-based triple therapy in LT recipients are encouraging. However, the tolerability of triple therapy is reduced following LT, because of increased anemia and drug-drug interactions. The use of PI-based triple therapy in LT recipients seems best suited to larger centers, experienced with management of PI toxicity. Fortunately, other classes of DAAs targeting different steps of HCV replication are in clinical trials, including nucleotide polymerase (NUC-NS5B) inhibitors, nonnucleotide polymerase (non-NUC-NS5B) inhibitors and NS5A inhibitors. Several dual and triple DAA regimens are in clinical development. Phase II studies conducted in patients before and after LT suggest that these regimens will dramatically reduce the impact of recurrent HCV. There is a tide in the affairs of men. Which, taken at the flood, leads on to fortune (Shakespeare: J Caesar Act 4, scene 3).

Challenges of recurrent hepatitis C in the liver transplant patient

Cirrhosis secondary to hepatitis C virus (HCV) is a very common indication for liver transplant. Unfortunately recurrence of HCV is almost universal in patients who are viremic at the time of transplant. The progression of fibrosis has been shown to be more rapid in the post-transplant patients than in the transplant naïve, hence treatment of recurrent HCV needs to be considered for all patients with documented recurrent HCV. Management of recurrent HCV is a challenging situation both for patients and physicians due to multiple reasons as discussed in this review. The standard HCV treatment with pegylated interferon and Ribavarin can be considered in these patients but it leads to a lower rate of sustained virologic clearance than in the non-transplanted population. Some of the main challenges associated with treating recurrent HCV in post-transplant patients include the presence of cytopenias; need to monitor drug-drug interactions and the increased incidence of renal compromise. In spite of these obstacles all patients with recurrent HCV should be considered for treatment since it is associated with improvement in survival and a delay in fibrosis progression. With the arrival of direct acting antiviral drugs there is renewed hope for better outcomes in the treatment of post-transplant HCV recurrence. This review evaluates current literature on this topic and identifies challenges associated with the management of post-transplant HCV recurrence.

Interaction between calcineurin inhibitors and IL-28B rs12979860 C>T polymorphism and response to treatment for post-transplant recurrent hepatitis C

BACKGROUND

The impact of calcineurin inhibitors on achievement of sustained virological response to antiviral therapy for post-transplant recurrent hepatitis C is controversial. This study aimed at investigating the interactions between calcineurin inhibitors and interleukin-28B (IL-28B) gene polymorphisms and sustained virological response.

METHODS

Retrospective study of 147 liver transplant recipients with recurrent hepatitis C, who received 48 weeks of peg-interferon-α (N=113) or standard interferon (N=34), in association with ribavirin. Cyclosporine and tacrolimus were administered in 68 and 79 patients, respectively. IL-28B rs12979860 allele frequency was assessed in both donors and recipients.

RESULTS

Overall, 57 patients (38.8%) obtained sustained virological response; no difference was found between cyclosporine and tacrolimus-treated patients (42.6% vs. 35.4%, p=0.371). Recipient and donor IL-28B genotypic frequencies were C/C=30.6%, C/T=51.7%, T/T=17.7% and C/C=44.9%, C/T=50.3%, T/T=4.8%, respectively. Combining donor and recipient alleles, response rates decreased from cyclosporine-treated patients carrying ≤ 1 T allele (56.1%) to tacrolimus-treated patients carrying ≤ 1 T allele (44.7%) to patients carrying ≥ 2 T alleles (25.0%, p=0.0009).

CONCLUSIONS

Donor and recipient rs12979860 alleles synergistically influence sustained virological response rate to antiviral treatment for recurrent hepatitis C. In patients carrying <2 T alleles cyclosporine favours a better response than tacrolimus, while no difference was found in the presence of ≥ 2 T alleles.

Corticosteroids do not reverse the inhibitory effect of cyclosporine on regulatory T-cell activity in contrast to mycophenolate mofetil

BACKGROUND

Inevitable hepatitis C virus recurrence after liver transplantation, a major barrier to survival of the transplanted liver may be promoted by immunosuppression and by CD4(+)CD25(+) regulatory T cells (Treg). Treg cells are essential for the induction and maintenance of immunologic self-tolerance as well as transplant tolerance. Moreover, we have previously described low doses of cyclosporine (CsA) to inhibit Treg activity by inducing interleukin-2 and interfron-γ. We investigated here in, the effect of mycophenolate mofetil (MMF) and corticosteroids, usually used in combination with a calcineurin inhibitor on human CD4(+)CD25(+) Treg cells.

METHODS

Human CD4(+)CD25(+) cells isolated from healthy donors were cultured in the presence of CsA +/- corticoids or MMF. Suppressive activity of regulatory T cells was assessed in mixed leukocyte reactions including CD25(+) solvents with autologous activated peripheral blood mononuclear cells (PBMC).

RESULTS

MMF and dexamethasone inhibited PBMC and Treg proliferation in dose-dependent fashing, maintaining the suppressive activity of Treg cells. However, the association of corticoids with CsA could not reverse the inhibitory effects of CsA on Treg activity, unlike the MMF and CsA combination.

CONCLUSION

We have previously shown CsA to significantly impair the function of CD4(+)CD25(+) Treg cells. Herein we reports that corticoids were not able to reverse this effect, whereas MMF couterbalanced it, suggesting that the combination of MMF with CsA maintains regulatory T cells activity promoting tolerance.

Strategies to reduce hepatitis C virus recurrence after liver transplantation

Hepatitis C virus (HCV) is a major health problem that leads to chronic hepatitis, cirrhosis and hepatocellular carcinoma, being the most frequent indication for liver transplantation in several countries. Unfortunately, HCV re-infects the liver graft almost invariably following reperfusion, with an accelerated history of recurrence, leading to 10%-30% of patients progressing to cirrhosis within 5 years of transplantation. In this sense, some groups have even advocated for not re-transplanting this patients, as lower patient and graft outcomes have been reported. However, the management of HCV recurrence is being optimized and several strategies to reduce post-transplant recurrence could improve outcomes, decrease the rate of re-transplantation and optimize the use of available grafts. Three moments may be the focus of potential actions in order to decrease the impact of viral recurrence: the pre-transplant moment, the transplant environment and the post-transplant management. In the pre-transplant setting, it is not well established if reducing the pre transplant viral load affects the risk for HCV progression after transplant. Obviously, antiviral treatment can render the patient HCV RNA negative post transplant but the long-term benefit has not yet been fully established to justify the cost and clinical risk. In the transplant moment, factors as donor age, cold ischemia time, graft steatosis and ischemia/reperfusion injury may lead to a higher and more aggressive viral recurrence. After the transplant, discussion about immunosuppression and the moment to start the treatment (prophylactic, pre-emptive or once-confirmed) together with new antiviral drugs are of interest. This review aims to help clinicians have a global overview of post-transplant HCV recurrence and strategies to reduce its impact on our patients.

Review article: the treatment of genotype 1 chronic hepatitis C virus infection in liver transplant candidates and recipients

BACKGROUND

Recently, the therapeutic landscape with regard to anti-HCV therapy has changed dramatically. The new directly acting anti-virals (DAAs) have demonstrated improved sustained virological response (SVR) compared with pegylated-interferon and ribavirin.

AIM

To examine and present the latest data with regard to anti-viral therapy in genotype 1 HCV-positive transplant candidates and recipients.

METHODS

An electronic search using Medline was performed. Search terms included 'HCV, DAA and protease inhibitor' in combination with 'treatment pre-transplantation' and 'treatment post-transplantation'.

RESULTS

Patients with advanced fibrosis and cirrhosis have inferior SVR rates compared with patients with minimal fibrosis. A low accelerating dose regimen (LADR) of pegylated interferon and ribavirin (PR) appears to be a safe therapeutic option. Side effects also appear to be more pronounced in patients with advanced disease. Data from the large registration studies with triple therapy (boceprevir or telaprevir plus PR) demonstrated improved SVR rates even in patients with advanced disease, although virological relapse rates were highest amongst these patients. In transplant recipients, initial data are being reported on the use of triple therapy, and although no SVR data are available, promising results are accruing. The drug-drug interactions appear to be manageable. Side effects in particular anaemia appear to be markedly increased in the posttransplant setting.

CONCLUSIONS

The use of the new DAAs in patients with advanced fibrosis/cirrhosis pretransplant and posttransplant appears possible, with manageable side effects and drug-drug interactions, and improved early virological response rates. We recommend that these patients are managed in centres with the appropriate expertise.

Recurrent hepatitis C virus infection post liver transplantation: impact of choice of calcineurin inhibitor

Recurrence of hepatitis C virus infection following liver transplantation (LT) for hepatitis C is universal. After LT, hepatitis C is associated with accelerated fibrosis progression and reduced graft and patient survival. Furthermore, responses to antiviral therapy in patients with recurrent hepatitis C virus post-transplant are consistently sub-optimal. Calcineurin inhibitors (CNIs) like cyclosporine A (CsA) and tacrolimus continue to dominate immunosuppressive regimens in this population; however, there is still uncertainty as to whether either offers an advantage in terms of patient outcomes. Although tacrolimus demonstrates improved efficacy in the general LT population, differences have begun to emerge between these agents regarding diabetogenic potential, antiviral activity, and fibrosis progression in patients with hepatitis C. This review critically evaluates the existing literature, providing an overview of the reported differences, concluding that despite conflicting evidence, a potential benefit of CsA in patients with hepatitis C is supported by the data and warrants further investigation. Future studies examining the role of CNIs in hepatitis C virus-positive LT recipients are required to accurately examine the effects of CNIs on outcomes such as fibrosis progression, survival, and effects on response to antiviral therapy, to provide robust information that allows clinicians to make an informed choice concerning which CNI is best for their patients.

Efficacy of antiviral therapy for hepatitis C after liver transplantation with cyclosporine and tacrolimus: a systematic review and meta-analysis

Cyclosporine A (CSA), but not tacrolimus (TAC), inhibits hepatitis C virus (HCV) replication in vitro. Clinical reports on the efficacy of interferon-α (IFNα)-based antiviral therapy (AVT) for recurrent HCV after liver transplantation (LT) with CSA and TAC are conflicting. Our aim was to assess whether AVT for recurrent HCV after LT is more effective with CSA or TAC. We performed an electronic database search (1995-2012) and a manual abstract search (2005-2012). The a priori defined eligibility criteria included the use of AVT for recurrent HCV with IFN (standard or pegylated) and ribavirin and the reporting of sustained virological response (SVR) rates with CSA and TAC (the primary outcome). Two authors identified and extracted data independently. Dichotomous data were expressed as relative risks (RRs) and 95% confidence intervals (CIs) with a random effects model. In all, 5058 references were retrieved, and 1 randomized controlled trial (RCT) and 17 observational studies (13 full-text articles) met the eligibility criteria; the meta-analysis was based on the latter studies. The pooled SVR rates were 42% (395/945) with CSA and 35% (471/1364) with TAC (RR = 1.18, 95% CI = 1.00-1.39, P = 0.05). Although the pooled data contained significant heterogeneity (I(2) = 45%, P = 0.02), the SVR rates in the RCT were comparable (39% with CSA and 35% with TAC). Limiting the analysis to the 7 studies reporting on 40 or more patients in each group (with 1634 patients in all) favored CSA (RR = 1.23, 95% CI = 1.09-1.38, P < 0.001), and heterogeneity disappeared (I(2) = 0%, P = 0.62). In conclusion, IFN-based AVT for recurrent HCV after LT seems marginally more effective with CSA versus TAC; the study heterogeneity, however, limits firm conclusions.

Virological response for recurrent hepatitis C improves long-term survival in liver transplant recipients

Recurrent hepatitis C virus (HCV) infection occurs universally and is regarded as a major cause of mortality after liver transplantation (LT) for HCV-related end-stage liver disease. We conducted this large, single-center, retrospective study to ascertain the long-term impact of virological response to treatment of recurrent hepatitis C on survival of LT recipients. From August 1987 to October 2011, 285 patients have received interferon-based antiviral therapy for recurrent hepatitis C. Of these 285, 245 patients were enrolled in this study. One hundred and twenty-six patients (51.4%) achieved sustained virological response (SVR). Relapsers (undetectable HCV-RNA at end of treatment, becoming positive afterward) comprised 9.0% (22/245), and nonresponse (NR; never achieving undetectable HCV-RNA) 39.6% (97/245). The median follow-up after completion of antiviral treatment was 2081 days. Using Kaplan-Meier method, patients who achieved SVR were shown to have significantly better 5-year patient survival (95.2%) than the NR group (49.9%) (P < 0.001), and a trend toward better 5-year survival than relapsers (87.5%) (P = 0.14); relapsers had a significantly longer survival than NR group (P = 0.005). When compared with NR, SVR and relapse appeared to be significant predictors of better survival, independent of underlying characteristics. In conclusion, virological response, especially SVR, translates into markedly improved long-term patient outcomes in patients transplanted for hepatitis C.

In vitro effects of cyclosporine A and tacrolimus on regulatory T-cell proliferation and function

BACKGROUND

Liver transplantation is the treatment of end-stage liver diseases, including hepatitis C. Immunosuppression prevents graft rejection but seems to accelerate the recurrence of hepatitis C. Regulatory T cells (Tregs) may be beneficial in tolerance but deleterious in recurrent hepatitis C. We evaluated the effects of cyclosporine or tacrolimus, the principal immunosuppressive drugs, on Treg proliferation and function.

METHODS

Human Tregs were isolated from healthy donors and cultured with cyclosporine, tacrolimus, or NIM811, a cyclosporine analog devoid of calcineurin-inhibiting activity. Treg proliferation and suppressive activity were assessed. The phenotype, cytokine production, and phosphorylation profile of nuclear factor of activated T cell of Tregs were also analyzed.

RESULTS

Cyclosporine and tacrolimus both decreased Treg proliferation, but only low doses of cyclosporine reduced Treg activity, by inducing the production of interleukin 2 proinflammatory cytokines in these cells. Moreover, NIM811 also inhibited Treg activity. The phosphorylation of nuclear factor of activated T cell in Tregs was not altered by cyclosporine, suggesting that the effects of this drug are independent of the calcineurin pathway.

CONCLUSION

In summary, low doses of cyclosporine inhibit Treg activity, a finding that might explain the beneficial effect of this drug on hepatitis C recurrence. In contrast, by maintaining Treg activity, tacrolimus could be more helpful than cyclosporine in controlling rejection.

Peginterferon-α-2b and ribavirin for hepatitis C recurrence postorthotopic liver transplantation

GOALS

To evaluate the safety and efficacy of peginterferon-α-2b plus ribavirin in patients with recurrent hepatitis C after orthotopic liver transplant.

BACKGROUND

Reinfection of liver allografts in hepatitis C virus -infected transplant recipients begins immediately after transplantation. Treatment of these patients is challenging because of poor tolerability.

STUDY

A multicenter, open-label study enrolling patients with persistent viremia after primary orthotopic liver transplant for cirrhosis related to hepatitis C virus infection. Patients received peginterferon-α-2b (1.5 µg/kg/wk) plus ribavirin (400 to 1200 mg/d administered using a dose-escalating regimen and according to body weight) for 48 weeks. The primary endpoint was sustained virologic response (SVR).

RESULTS

In total, 125 patients started treatment and 58.4% completed 48 weeks. SVR rate was 28.8% (G1, 23.8%; G2/3, 55.0%), end-of-treatment response rate was 40.8%, and relapse rate was 18.2%. SVR was 55% among patients who completed treatment. Genotype 2/3 infection, male sex, baseline hemoglobin>14 g/dL, 80:80:80 compliance, rapid virologic response (RVR), and complete early virologic response (cEVR) were predictors of SVR. SVR was higher among patients with RVR compared with those without RVR (83.3% vs. 25.7%; P=0.0098), and among patients with cEVR compared with those without EVR (66.7% vs. 1.8%; P<0.0001). Thirty-eight patients discontinued because of an adverse event and 69 required dose reduction or interruption. Anemia (74%) and neutropenia (30%) were common, and rejection was low (3.2%).

CONCLUSIONS

SVR was low in this study. Anemia was a particular challenge in achieving maximal ribavirin therapeutic exposure and may account in part for the lower SVR.

The adverse pharmacology of calcineurin inhibitors and their impact on hepatitis C recurrence after liver transplantation: implications for clinical practice

Calcineurin inhibitors are widely used as maintenance immunosuppressants in solid-organ transplantation to minimize the risk of allograft rejection. Although the use of these agents has transformed the outcomes for patient and graft survival, this has come at a cost, notably the well-known adverse events of nephrotoxicity and metabolic abnormalities, to name a few. Over the last decade, tremendous interest has also focused on the impact of these medications on the replication of hepatitis C virus (HCV), with cyclosporine in particular having a negative effect on viral replication in vitro. Although small retrospective studies suggested that there may be a beneficial effect with cyclosporine on the progression of recurrent HCV and response to interferon, these findings have not been validated in several well-designed randomized controlled trial studies. The authors will review the pharmacology and pharmacokinetics of these well-known drugs and discuss the impact of these medications on the natural history of HCV recurrence after liver transplantation.

New targets for treatment against HCV infection

Owing to the tremendous effort from both academia and industry, drug development for hepatitis C virus (HCV) infection has been flourishing, with a range of pipeline compounds at various stages of development. Although combination of the recently launched serine protease inhibitors will further improve the response rate of current interferon-based therapy, some intrinsic limitations of these compounds and the tendency of resistance development by the virus, urge the development of alternative or additional therapeutic strategies. In this article we provide an overview of different host and viral factors which have emerged as new potential targets for therapeutic intervention using state-of-the-art technologies.

A plant-derived flavonoid inhibits entry of all HCV genotypes into human hepatocytes

BACKGROUND & AIMS

Interferon-based therapies for hepatitis C virus (HCV) infection are limited by side effects and incomplete response rates, particularly among transplant recipients. We screened a library of plant-derived small molecules to identify HCV inhibitors with novel mechanisms.

METHODS

We isolated phenolic compounds from Marrubium peregrinum L (Lamiaceae). Replication of HCV RNA, virus production, and cell entry were monitored using replicons and infectious HCV. Inhibition of HCV was measured in hepatoma cells and primary human hepatocytes using luciferase reporter gene assays, core enzyme-linked immunosorbent assays, or infectivity titration. We tested the bioavailability of the compound in mice.

RESULTS

We identified a flavonoid, ladanein (BJ486K), with unreported antiviral activity and established its oral bioavailability in mice. Natural and synthetic BJ486K inhibited a post-attachment entry step, but not RNA replication or assembly; its inhibitory concentration 50% was 2.5 μm. BJ486K was effective against all major HCV genotypes, including a variant that is resistant to an entry inhibitor; it prevented infection of primary human hepatocytes. Combined administration of BJ486K and cyclosporine A had a synergistic effect in inhibition of HCV infection.

CONCLUSIONS

BJ486K has oral bioavailability and interferes with entry of HCV into cultured human hepatocytes. It synergizes with cyclosporine A to inhibit HCV infection. Its inhibitory effects are independent of HCV genotype, including a variant that is resistant to an entry inhibitor against scavenger receptor class B type I. Flavonoid derivatives therefore might be developed as components of combination therapies because they are potent, broadly active inhibitors of HCV entry that could prevent graft reinfection after liver transplantation.

[Liver transplantation: personalized immunosuppression in patients with hepatitis C virus infection and hepatocellular carcinoma]

Transplantation has become the treatment of choice in end-stage liver disease, with 5-year survival rates of around 68-74% in European and North-American registries (www.unos.org, www.eltr.org, www.ont.es). These results are largely due to the development of powerful immunosuppressive agents, mainly calcineurin inhibitors. However, these immunosuppressive drugs are not free of adverse effects, especially nephrotoxicity. Moreover, two of the most frequent indications for transplantation, cirrhosis due to hepatitis C virus and hepatocellular carcinoma, can recur in the transplanted graft. Whether specific immunosuppression could be less harmful in these conditions is the subject of debate. With the greater use of suboptimal donors and of expanded criteria for liver transplantation in patients with hepatocellular carcinoma, aggressive recurrences can be expected to increase. The present review attempts to elucidate whether there is an immunosuppression strategy that could minimize the risk of aggressive tumoral recurrence or recurrence of hepatitis C.

Spanish society of liver transplantation (SETH) consensus recommendations on hepatitis C virus and liver transplantation

In November 2010, the Spanish Society of Liver Transplantation (Sociedad Española de Trasplante Hepático, SETH) held a consensus conference. One of the topics of debate was liver transplantation in patients with hepatitis C. This document reviews (i) the natural history of post-transplant hepatitis C, (ii) factors associated with post-transplant prognosis in patients with hepatitis C, (iii) the role of immunosuppression in the evolution of recurrent hepatitis C and response to antiviral therapy, (iv) antiviral therapy, both before and after transplantation, (v) follow-up of patients with recurrent hepatitis C and (vi) the role of retransplantation.

Virus-drug interactions--molecular insight into immunosuppression and HCV

Liver transplantation is an effective treatment for end-stage liver disease that is attributable to chronic HCV infection. However, long-term outcomes are compromised by universal virological recurrence in the graft. Reinfection that occurs after transplantation has increased resistance to current interferon-based antiviral therapy and often leads to accelerated development of cirrhosis. Important risk factors for severe HCV recurrence are linked to immunosuppression. Owing to the lack of good randomized, controlled trials, the optimal choice of immunosuppressants is still debated. By contrast, much progress has been made in the understanding of HCV biology and the antiviral action of interferons. These new insights have greatly expanded our knowledge of the molecular interplay between HCV and immunosuppressive drugs. In this article, we explore the effect of different immunosuppressants on the complex cellular events involved in HCV infection and interferon signalling. Potential implications for clinical practice and future drug development are discussed.

Immunosuppression and HCV recurrence after liver transplantation

HCV related liver disease is the most common indication for liver transplantation. Recurrence of HCV infection is universal and has a substantial impact on patient and graft survival. Immunosuppression is a major factor responsible for the accelerated recurrence and compressed natural history of recurrent HCV infection. Accumulating experience has provided data to support certain strategies for immunosuppressive regimens. From the available evidence, more severe recurrence results from repeated bolus corticosteroid therapy and anti-lymphocyte antibodies used to treat rejection. Low dose and slow tapering of steroids are better than high dose maintenance and/or rapid tapering. Recent meta-analyses favour steroid-free regimens but these are complicated to interpret as the absence of steroids may simply represent less immunopotency. There is no difference in HCV recurrence between tacrolimus and cyclosporine regimens, but tacrolimus increases graft and patient survival in HCV transplanted patients. There may be a beneficial effect of maintenance azathioprine given for 6 months or longer. There is no conclusive evidence for benefit of mycophenolate and interleukin-2 receptor blockers. Few data are available for mTOR inhibitors. Better evidence is needed to establish the optimal immunosuppressive regimen for HCV recipients and more randomized trials should be performed.

Diabetes mellitus following liver transplantation in patients with hepatitis C virus: risks and consequences

Recurrent hepatitis C virus (HCV) infection of the allograft occurs universally following liver transplantation. Longitudinal natural history studies have identified several pre- and posttransplant factors associated with more rapid fibrosis progression, including baseline host and viral factors, donor factors and posttransplant immunosuppression effects, such as metabolic syndrome. Evidence accumulated over the past two decades indicates that HCV has metabolic associations, in particular insulin resistance and diabetes mellitus. Approximately half of HCV-positive liver transplant recipients develop posttransplant diabetes mellitus (PTDM), which is associated with accelerated fibrosis progression and poorer graft and patient survival outcomes. This review summarizes the risks and consequences of insulin resistance and PTDM in HCV-positive liver transplant recipients. Risk for developing PTDM is one factor that should be considered when choosing the primary immunosuppressive regimen following liver transplantation. Comparative studies suggest that cyclosporine A-based immunosuppression may provide improved responses to antiviral therapy and reduced incidence of PTDM compared with tacrolimus-based immunosuppression. Addressing insulin resistance and PTDM in HCV-positive liver transplant recipients may have the potential to slow HCV complications and improve survival outcomes.

Liver transplantation and hepatitis C

Hepatitis-C-virus- (HCV-) related end-stage cirrhosis is the primary indication for liver transplantation in many countries. Unfortunately, however, HCV is not eliminated by transplantation and graft reinfection is universal, resulting in fibrosis, cirrhosis, and finally graft decompensation. The use of poor quality organs, particularly from older donors, has a highly negative impact on the severity of recurrence and patient/graft survival. Although immunosuppressive regimens have a considerable impact on the outcome, the optimal regimen after liver transplantation for HCV-infected patients remains unclear. Disease progression monitoring with protocol biopsy and new noninvasive methods is essential for predicting patient/graft outcome and starting antiviral treatment with the appropriate timing. Antiviral treatment with pegylated interferon and ribavirin is currently considered the most promising regimen with a sustained viral response rate of around 30% to 35%, although the survival benefit of this regimen remains to be investigated. Living-donor liver transplantation is now widely accepted as an established treatment for HCV cirrhosis and the results are equivalent to those of deceased donor liver transplantation.

Impact of calcineurin inhibitors with or without interferon on hepatitis C virus titers in a chimeric mouse model of hepatitis C virus infection

Cyclosporine A (CSA) has potent effects against hepatitis C virus (HCV) in vitro, but its clinical efficacy after liver transplantation (LT) is uncertain. We evaluated the impact of CSA and tacrolimus (TAC) with or without concomitant interferon (IFN) therapy on serum HCV titers in a chimeric mouse model of HCV infection. Six groups of HCV-infected mice received only the vehicle, IFN, CSA, CSA and IFN, TAC, or TAC and IFN for 4 weeks. The quantitative HCV polymerase chain reaction levels were determined after 1, 2, and 4 weeks of drug administration. There were no significant differences in the HCV titers after 4 weeks of treatment between the non-IFN-treated groups (log HCV titers: 3.5 ± 0.3 for the vehicle group, 4.4 ± 0.6 for the CSA group, and 4.3 ± 0.4 for the TAC group, P = 0.3). Although IFN had a consistent effect of reducing HCV titers across the groups, there was no significant impact of CSA on HCV levels when it was used alone or in combination with IFN at any time point. The 4-week HCV titers were as follows: 3.2 ± 0.3 for the IFN group, 4.7 ± 0.4 for the CSA/IFN group, and 4.0 ± 0.5 for the TAC/IFN group (P = 0.07). The CSA/IFN and TAC/IFN groups did not differ significantly (P = 0.6). Six of the 7 animals in the IFN group (85.7%) had an HCV titer decline ≥ 1 log, whereas in the test groups (CSA/IFN and TAC/IFN), 6 of 9 animals (66.7%) achieved a 1-log decline in the HCV titer (P = 1). Using this animal model, we could find no evidence supporting the routine use of CSA after LT in HCV-infected patients.

Liver transplantation and hepatitis C

Hepatitis C virus (HCV)-related end-stage cirrhosis with/without hepatocellular carcinoma is the primary indication for liver transplantation in many countries. Unfortunately, HCV is not eliminated by transplantation and graft re-infection is the rule, resulting in HCV-related graft disease. The natural history of recurrent hepatitis is variable; overall, progression to cirrhosis occurs in 20-30% and allograft failure in 10% after 5-10 years from transplantation. The use of poor quality organs, particularly from old donors, has a significant negative impact on disease severity and transplant outcome. In contrast, antiviral therapy, particularly if it results in permanent eradication of the virus, is associated with improved histology, reduced rate of graft decompensation and enhanced outcome. Disease monitoring, through protocol liver biopsies and new non-invasive tools, is essential to select patients at need of antiviral therapy. Peginterferon with ribavirin, used similarly to what is done in the non-transplant setting, is currently the treatment of choice; sustained viral response is achieved in about 35% of cases. Side effects, particularly anemia, are extremely frequent and sometimes severe (rejection, de novo autoimmune hepatitis). Retransplantation (RT) is the last option for the small subset of patients with allograft failure due to HCV recurrence who fulfil minimum criteria based on RT survival models.

Hot topic in hepatitis C virus research: the type of immunosuppression does not matter

1. The natural history of recurrent hepatitis C virus (HCV) is highly variable. Old donor age is a factor that has consistently been shown to affect disease progression. 2. Overall, immunosuppression determines the progression of HCV-related disease; however, the type of immunosuppressive agent used for induction or maintenance is not a key factor. 3. Steroid boluses should be avoided; they are associated with increased viremia, fibrosis progression, and reduced survival. 4. Antiviral therapy, particularly if it is successful, is associated with improved outcomes for liver transplant recipients with HCV. 5. There are no convincing data for modifying the type of immunosuppression before antiviral therapy is started.

Management of recurrent hepatitis C infection after liver transplantation

Recurrence of hepatitis C virus remains a near-universal phenomenon after liver transplantation (LT) and is responsible for the high morbidity and low survival seen in these patients. The severity of recurrent disease varies depending on multiple factors, only some of which are modifiable. Antiviral therapy is associated with improved outcomes, but viral clearance is only attainable in a small percentage of this patient population. This patient population is in need of new therapeutic options, and it remains to be seen whether direct-acting antiviral agents will be the answer to this ongoing therapeutic question.

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.

Cyclophilin inhibitors as a novel HCV therapy

A critical role of Cyclophilins, mostly Cyclophilin A (CyPA), in the replication of HCV is supported by a growing body of in vitro and in vivo evidence. CyPA probably interacts directly with nonstructural protein 5A to exert its effect, through its peptidyl-prolyl isomerase activity, on maintaining the proper structure and function of the HCV replicase. The major proline substrates are located in domain II of NS5A, centered around a “DY” dipeptide motif that regulates CyPA dependence and CsA resistance. Importantly, Cyclosporine A derivatives that lack immunosuppressive function efficiently block the CyPA-NS5A interaction and inhibit HCV in cell culture, an animal model, and human trials. Given the high genetic barrier to development of resistance and the distinctness of their mechanism from that of either the current standard of care or any specifically targeted antiviral therapy for HCV (STAT-C), CyP inhibitors hold promise as a novel class of anti-HCV therapy.