MMF and calcineurin taper in recurrent hepatitis C after liver transplantation: impact on histological course

Interaction of immunosuppressants with HCV antivirals daclatasvir and asunaprevir: combined effects with mycophenolic acid

AIM

To investigate the specific effects of immunosuppressants on the antiviral action of daclatasvir and asunaprevir.

METHODS

The antiviral activity of daclatasvir (DCV) and asunaprevir (ASV) combined with immunosuppressants was tested using two in vitro models for hepatitis C virus (HCV) infection.

RESULTS

Tacrolimus, rapamycin and cyclosporine did not negatively affect the antiviral action of DCV or ASV. Mycophenolic acid (MPA) showed additive antiviral effects combined with these direct acting antivirals (DAAs). MPA induces interferon-stimulated genes (ISGs) and is a potent GTP synthesis inhibitor. DCV or ASV did not induce ISGs expression nor affected ISG induction by MPA. Rather, the combined antiviral effect of MPA with DCV and ASV was partly mediated via inhibition of GTP synthesis.

CONCLUSION

Immunosuppressants do not negatively affect the antiviral activity of DAAs. MPA has additive effect on the antiviral action of DCV and ASV. This combined benefit needs to be confirmed in prospective clinical trials.

Suppression of autophagy by mycophenolic acid contributes to inhibition of HCV replication in human hepatoma cells

Previous studies have shown that mycophenolic acid (MPA) has an anti-HCV activity. However, the mechanism of MPA-mediated inhibition of HCV replication remains to be determined. This study investigated whether MPA has an effect on autophagy, a cellular machinery required for HCV replication, thereby, inhibits HCV replication in Huh7 cells. MPA treatment of Huh7 cells could suppress autophagy, evidenced by decreased LC3B-II level and conversion of LC3B-I to LC3B-II, decreased autophagosome formation, and increased p62 level compared to MPA-untreated cells. Tunicamycin treatment or HCV infection could induce cellular autophagy, however, MPA also exhibited its inhibitory effect on tunicamycin- or HCV infection-induced autophagy. The expression of three autophagy-related genes, Atg3, Atg5, and Atg7 were identified to be inhibited by MPA treatment. Over-expression of these genes could partly recover HCV replication inhibited by MPA; however, silencing their expression by siRNAs could enhance the inhibitory effect of MPA on HCV. Collectively, these results reveal that suppression of autophagy by MPA plays a role in its anti-HCV activity. Down-regulating the expression of three autophagy-related genes by MPA involves in its antiviral mechanism.

Management of immunosuppressant agents following liver transplantation: Less is more

Immunosuppression in organ transplantation was revolutionary for its time, but technological and population changes cast new light on its use. First, metabolic syndrome (MS) is increasing as a public health issue, concomitantly increasing as an issue for post-orthotopic liver transplantation patients; yet the medications regularly used for immunosuppression contribute to dysfunctional metabolism. Current mainstay immunosuppression involves the use of calcineurin inhibitors; these are potent, but nonspecifically disrupt intracellular signaling in such a way as to exacerbate the impact of MS on the liver. Second, the impacts of acute cellular rejection and malignancy are reviewed in terms of their severity and possible interactions with immunosuppressive medications. Finally, immunosuppressive agents must be considered in terms of new developments in hepatitis C virus treatment, which undercut what used to be inevitable viral recurrence. Overall, while traditional immunosuppressive agents remain the most used, the specific side-effect profiles of all immunosuppressants must be weighed in light of the individual patient.

Long-term study of steroid avoidance in renal transplant patients: a single-center experience

OBJECTIVES

Steroids have played a major role in renal transplantation for more than 4 decades. However, chronic use of steroids is associated with many comorbidities. This study aimed to assess the costs and benefits of a steroid-free immunosuppression regimen in a prospective randomized controlled study of living-donor renal transplantation, which was lacking in the literature.

MATERIALS AND METHODS

In our study, 428 patients were enrolled to receive tacrolimus (Tac), mycophenolic acid (MPA), basiliximab (Simulect, Novartis, Basel, Switzerland) induction and steroids only for 3 days (214 patients, study group) and steroid maintenance (214 patients, control group). Median follow-up was 66 ± 41 months.

RESULTS

We found that both groups showed comparable graft and patient survival, rejection episodes, and graft function. Posttransplantation hypertension was detected in 40% of the steroid-free group and 80% of the steroid maintenance group (P = .05), whereas posttransplantation diabetes mellitus was detected in 5% and 15% of these 2 groups, respectively (P = .3).

CONCLUSIONS

Among low-immunological-risk recipients of living-donor renal transplants, steroid avoidance was feasible, safe, and had less morbidity outcome using Simulect induction, then Tac and MPA as maintenance immunosuppression. Steroid avoidance was associated with a lower total cost despite comparable immunosuppression cost, which was attributed to the lower cost of associated morbidities.

Donor-Specific Anti-HLA Antibodies and Endothelial C4d Deposition-Association With Chronic Liver Allograft Failure

BACKGROUND

The significance of humoral immune response for allograft survival after liver transplantation (LT) is still a matter of debate. The aim of this cross-sectional study was to assess immunological and clinical factors associated with advanced fibrosis (F3-F4) and chronic graft failure in LT recipients.

METHODS

Serum samples from 174 patients prospectively enrolled and followed up for 12 months were tested for anti-HLA antibodies and compared against donor HLA types. Immunohistochemical C4d staining was performed on formalin-fixed, paraffin-embedded liver tissue.

RESULTS

Mean time period from LT to enrollment was 66.9 ± 51.9 months. Independent predictive factors for graft failure included donor-positive cytomegalovirus serostatus (P = 0.02), donor-specific antibodies (DSA) against HLA class II (P = 0.03), donor age (P = 0.01), hepatitis C virus allograft reinfection (P = 0.0008), and biliary complications (P = 0.003). HLA class II DSA and HLA class I antibody positivity, hepatitis C virus reinfection, and mycophenolate mofetil-free regimens were significant risk factors for advanced fibrosis after LT. There was a significant association between C4d deposition on allograft endothelial cells and presence of class II DSA (P < 0.0001). Patients with C4d deposits had a 4.3 times higher risk of graft failure than those with negative staining and a significantly lower median time to graft failure (94.6 months [range, 3.6-158.9 months] vs 176.4 months [range, 9.4-217.8 months], P < 0.0001).

CONCLUSIONS

Screening for HLA DSA might be useful for early identification of LT recipients at increased risk of graft failure who could benefit from closer surveillance and tailored immunosuppressive regimens.

Hepatitis viruses and liver transplantation: evolving trends in antiviral management

Viral hepatitis is both a leading indication for liver transplant (LT) and an important cause of posttransplant graft loss and mortality. Treatment and prevention of hepatitis B virus in LT recipients, with the observed corresponding improvement in post-LT outcomes, is among the great success stories in transplantation. By comparison, treatment of hepatitis C virus with safe and effective regimens is only just becoming a reality. Chronic hepatitis E virus infection in LT recipients represents a newly described phenomenon that can also lead to graft loss; early diagnosis and treatment may be key in the management of these patients.

Hepatitis C recurrence: the Achilles heel of liver transplantation

Hepatitis C virus (HCV) infection is the most common indication for liver transplantation worldwide; however, recurrence post transplant is almost universal and follows an accelerated course. Around 30% of patients develop aggressive HCV recurrence, leading to rapid fibrosis progression (RFP) and culminating in liver failure and either death or retransplantation. Despite many advances in our knowledge of clinical risks for HCV RFP, we are still unable to accurately predict those most at risk of adverse outcomes, and no clear consensus exists on the best approach to management. This review presents a critical overview of clinical factors shown to influence the course of HCV recurrence post transplant, with particular focus on recent data identifying the important role of metabolic factors, such as insulin resistance, in HCV recurrence. Emerging data for genetic markers of HCV recurrence and their usefulness for predicting adverse outcomes will also be explored.

Living-donor 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 decompression. In areas with low deceased-donor organ availability like Japan, living-donor liver transplantation (LDLT) is similarly indicated for HCV cirrhosis as deceased-donor liver transplantation (DDLT) in Western countries and accepted as an established treatment for HCV-cirrhosis, and the results are equivalent to those of DDLT. To prevent graft failure due to recurrent hepatitis C, 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. In contrast to DDLT, many Japanese LDLT centers have reported modified treatment regimens as best efforts to secure first graft, such as aggressive preemptive antiviral treatment, escalation of dosages, and elongation of treatment duration.

Effect of maintenance immunosuppressive drugs on virus pathobiology: evidence and potential mechanisms

Recent evidence suggesting a potential anti-CMV effect of mTORis is of great interest to the transplant community. However, the concept of an immunosuppressant with antiviral properties is not new, with many accounts of the antiviral properties of several agents over the years. Despite these reports, to date, there has been little effort to collate the evidence into a fuller picture. This manuscript was developed to gather the evidence of antiviral activity of the agents that comprise a typical immunosuppressive regimen against viruses that commonly reactivate following transplant (HHV1 and 2, VZV, EBV, CMV and HHV6, 7, and 8, HCV, HBV, BKV, HIV, HPV, and parvovirus). Appropriate immunosuppressive regimens posttransplant that avoid acute rejection while reducing risk of viral reactivation are also reviewed. The existing literature was disparate in nature, although indicating a possible stimulatory effect of tacrolimus on BKV, potentiation of viral reactivation by steroids, and a potential advantage of mammalian target of rapamycin (mTOR) inhibition in several viral infections, including BKV, HPV, and several herpesviruses.

Predisposing factors of diminished survival in simultaneous liver/kidney transplantation

Since the adoption of the Model for End-Stage Liver Disease, simultaneous liver/kidney transplants (SLKT) have substantially increased. Recently, unfavorable outcomes have been reported yet contributing factors remain unclear. We retrospectively reviewed 74 consecutive adult SLKT performed at our center from 2000 to 2010 and compared with kidney transplant alone (KTA, N = 544). In SLKT, patient and death-censored kidney graft survival rates were 64 ± 6% and 81 ± 5% at 5 years, respectively (median follow-up, 47 months). Multivariable analyses revealed three independent risk factors affecting patient survival: hepatitis C virus positive (HCV+, hazard ratio [HR] 2.9, 95% confidence interval [CI] 1.1-7.9), panel reactive antibody (PRA) > 20% (HR 2.8, 95% CI 1.1-7.2) and female donor gender (HR 2.9, 95% CI 1.1-7.9). For death-censored kidney graft survival, delayed graft function was the strongest negative predictor (HR 8.3, 95% CI 2.5-27.9), followed by HCV+ and PRA > 20%. The adjusted risk of death-censored kidney graft loss in HCV+ SLKT patients was 5.8 (95% CI 1.6-21.6) compared with HCV+ KTA (p = 0.008). Recurrent HCV within 1 year after SLKT correlated with early kidney graft failure (p = 0.004). Careful donor/recipient selection and innovative approaches for HCV+ SLKT patients are critical to further improve long-term outcomes.

Hepatitis C virus recurrence and immunosuppression-free state after liver transplantation

HCV-related disease is the most common indication for liver transplantation (LT). HCV recurrence, which is almost universal, has a significant impact on patient and graft survival after LT and still represents a great unsolved issue for the liver transplant community. Several treatment strategies have been proposed. Since antiviral therapy has limited efficacy and can be administrated only in selected transplant recipients and additionally that immunosuppressive drugs have a negative impact on HCV re-infection, the achievement of an immunosuppression-free state after LT could play a central role in the avoidance of rapid HCV recurrence.

Prevention of hepatitis C recurrence after liver transplantation: An update

Hepatitis C related liver failure and hepatocarcinoma are the most common indications for liver transplantation in Western countries. Recurrent hepatitis C infection of the allograft is universal and immediate following liver transplantation, being associated with accelerated progression to cirrhosis, graft loss and death. Graft and patient survival is reduced in liver transplant recipients with recurrent Hepatitis C virus (HCV) infection compared to HCV-negative recipients. Many variables may impact on recurrent HCV liver disease. Overall, excess immunosuppression is believed to be a key factor; however, no immunosuppressive regimen has been identified to be more beneficial or less harmful. Donor age limitations, exclusion of moderately to severely steatotic livers and minimization of ischemic times could be a potential strategy to minimize the severity of HCV disease in transplanted subjects. After transplantation, antiviral therapy based on pegylated IFN alpha with or without ribavirin is associated with far less results than that reported for immunocompetent HCV-infected patients. New findings in the field of immunotherapy and genomic medicine applied to this context are promising.

Mycophenolate mofetil inhibits hepatitis C virus replication in human hepatic cells

Hepatitis C virus (HCV) infection is the most common indication for liver transplantation and the major cause of graft failure. A widely used immunosuppressant, cyclosporine A (CsA), for people who receive organ transplantation, has been recognized to have the ability to inhibit HCV replication both in vivo and in vitro. In this study, we investigated the effects of several other immunosuppressants, including mycophenolate mofetil (MMF), rapamycin and FK506, on HCV replication in human hepatic cells. MMF treatment of hepatic cells before or during HCV infection significantly suppressed full cycle viral replication, as evidenced by decreased expression of HCV RNA, protein and production of infectious virus. In contrast, rapamycin and FK506 had little effect on HCV replication. Investigation of the mechanism(s) disclosed that the inhibition of HCV replication by MMF was mainly due to its depletion of guanosine, a purine nucleoside crucial for synthesis of guanosine triphosphate, which is required for HCV RNA replication. The supplement of exogenous guanosine could reverse most of anti-HCV effect of mycophenolate mofetil. These data indicate that MMF, through the depletion of guanosine, inhibits full cycle HCV JFH-1 replication in human hepatic cells. It is of interest to further determine whether MMF is indeed beneficial for HCV-infected transplant recipients in future clinical studies.

Mycophenolic acid augments interferon-stimulated gene expression and inhibits hepatitis C Virus infection in vitro and in vivo

Mycophenolic acid (MPA) is a highly effective immunosuppressant that has broad antiviral activity against different viruses and can act in synergy with interferon-α (IFN-α) on hepatitis C virus (HCV) replication. MPA is a potent inosine monophosphate dehydrogenase (IMPDH) inhibitor but the antiviral mechanisms are less understood. The aim of this study was to investigate the inhibition of HCV infection by MPA and the molecular basis for its synergy with IFN-α. The role of IMPDH and interferon-stimulated genes (ISGs) was investigated in two HCV models using gain- or loss-of-function approaches. The in vivo effect of MPA treatment was studied in NOD/SCID mice engrafted with HCV replicon cells. Potent antiviral effects of MPA at clinically relevant concentrations were observed with both the subgenomic and JFH1-derived infectious HCV models. MPA treatment in mice resulted in a specific and robust inhibition of HCV replication. Ectopic expression of an MPA-resistant IMPDH2 mutant in HCV host cells completely reversed the antiproliferative effect of MPA but only partially affected the antiviral potency. However, similar to ribavirin, MPA induced expression of multiple antiviral ISGs, including interferon regulatory factor 1 (IRF1). Cotreatment of MPA with IFN-α resulted in additive effects on ISG expression and enhanced IFN-induced luciferase reporter activity. Knockdown of IRF1, but not IFITM3, significantly attenuated the inhibition of HCV replication by MPA.

CONCLUSION

MPA exerts a potent anti-HCV effect in vitro and in mice and acts in synergy with IFN-α. MPA's antiviral activity partially depends on IMPDH but also involves stimulation of ISGs, providing a molecular basis for its synergy with IFN-α.

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.

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.

Long-term, maintenance MMF monotherapy improves the fibrosis progression in liver transplant recipients with recurrent hepatitis C

Hepatitis C virus (HCV) recurrence after orthotopic liver transplantation (LT) is universal. We designed a retrospective case-control study to evaluate the effect of mycophenolate mofetil (MMF) monotherapy in patients with recurrent hepatitis C. Fifteen patients with histologically proven hepatitis C recurrence after LT were switched from calcineurin inhibitors (CNIs) to MMF monotherapy because of impairment of kidney function and/or metabolic side effects, and treated for 48 months (MMF group). Fifteen well-matched LT recipients who continued to receive CNIs therapy over the same period served as control group. Demographics, clinical data, time after LT, and baseline liver biopsies were similar in the two groups. There was no worsening of hepatic fibrosis during the study in the MMF group [2.6 ± 1.5 (baseline) Ishak Units vs. 2.7 ± 1.8 (after 48 months of MMF treatment), P = 0.6]. In contrast, a significant increase in the fibrosis score [2 ± 1.1 (baseline) vs. 3.2 ± 1.7 (after 48 months of CNI treatment), P = 0.0002] was observed in the control group. The yearly fibrosis progression rate was of 0.05 ± 0.44 in the MMF group and 0.33 ± 0.24 in the CNI group (P = 0.04). MMF monotherapy is associated with a favourable effect on hepatic fibrosis progression in HCV liver transplant recipients.

[Human papillomavirus-associated warts in organ transplant recipients. Incidence, risk factors, management]

Human papillomaviruses infect the squamous epithelia of the skin and cause warts, and are occasionally found in squamous cell carcinomas. Since cell-mediated immunity plays a crucial role in the control of HPV-infections, organ transplant recipients, unable to mount an adequate T-helper 1 cell-mediated immune surveillance, frequently develop widespread and resistant induced warts. Skin tumors, especially squamous cell carcinomas, are the most common post-transplantation neoplasm. Warts, actinic keratoses and invasive squamous cell carcinomas are known to develop at the same time in the areas. The role of HPV in the development of invasive squamous cell carcinoma under immunosuppression, remains to be elucidated in respect to common risk factors and increased numbers of warts potentially identifying patients at increased risk for carcinoma. We prospectively studied 1690 organ transplant recipients in the dermatology clinic at the Charité University Hospital in Berlin, to evaluate risk factors being involved in the development of HPV-induced warts and to assess a potential association of with the development of non-melanoma skin cancers in this population. The cumulative incidence of warts steadily increased throughout the post-transplant years. The presence of more than 10 verrucae was associated with the development of actinic keratoses, invasive squamous cell carcinoma and basal cell carcinoma. This study shows clear evidence that certain risk factors of skin carcinogenesis in organ transplant recipient such as increased age at transplantation, a high dose of immunosuppression related to a specific type of graft and use of azathioprine or cyclosporine are strongly associated with an increased incidence of warts. Furthermore, HPV-induced verrucae vulgares could be used as a potential predictor for the development of coincidental non melanoma skin cancer in organ transplant recipients and therefore could serve as an early identification marker of skin cancer high-risk patients. The challenging management of warts in organ transplantation patients is reviewed.

Outcome of recurrent hepatitis C virus after liver transplantation in a randomized trial of tacrolimus monotherapy versus triple therapy

Less potent immunosuppression is considered to reduce the severity of hepatitis C virus (HCV) recurrence after liver transplantation. An optimal regimen is unknown. We evaluated tacrolimus monotherapy versus triple therapy in a randomized trial of 103 first transplants for HCV cirrhosis. One hundred three patients who underwent transplantation for HCV were randomized to tacrolimus monotherapy (n = 54) or triple therapy with tacrolimus, azathioprine, and steroids (n = 49), which were tapered to zero by 3 to 6 months. Both groups had serial transjugular biopsies with hepatic venous pressure gradient (HVPG) measurement. The time to reach Ishak stage 4 was the predetermined endpoint. All factors documented in the literature as being associated with HCV recurrence and the allocated treatment were evaluated for reaching stage 4 and HVPG >or= 10 mm Hg. No significant preoperative, perioperative, or postoperative differences, including the frequency of biopsies between groups, were found. During a mean follow-up of 53.5 months, 9 monotherapy patients and 6 triple therapy patients died, and 5 monotherapy patients and 4 triple therapy patients underwent retransplantation. Stage 4 fibrosis was reached in 17 monotherapy patients and 10 triple therapy patients (P = 0.04), with slower fibrosis progression in the triple therapy patients (P = 0.048). Allocated therapy and histological acute hepatitis were independently associated with stage 4 fibrosis. HVPG increased to >or=10 mm Hg more rapidly in monotherapy patients versus triple therapy patients (P = 0.038). In conclusion, long-term maintenance immunosuppression with azathioprine and shorter term prednisolone with tacrolimus in HCV cirrhosis recipients resulted in a slower onset of histologically proven severe fibrosis and portal hypertension in comparison with tacrolimus alone, and this was independent of known factors affecting fibrosis.

Azathioprine in liver transplantation: a reevaluation of its use and a comparison with mycophenolate mofetil

Calcineurin inhibitors (CNIs) combined with steroids with or without azathioprine (AZA), have been a standard immunosuppression regimen after liver transplantation (LT). Since 2000 many centers have substituted AZA by mycophenolate mofetil (MMF). However, in LT the superiority of MMF over AZA is not clearly demonstrated. Therefore, we questioned the benefit of MMF versus AZA in LT with regard to rejection, renal dysfunction and hepatitis C virus (HCV) recurrence and survival. Using a literature search, relevant randomized controlled trials (RCT) and cohort studies were identified: two RCTs compared MMF to AZA only for acute rejection. Treated rejection was less with MMF in only one RCT (38.5% vs. 47.7%; p = 0.025), with no difference in patient and graft survival. No RCTs compared MMF and AZA in patients with CNI-related chronic renal dysfunction. Among two studies evaluating MMF, with substitution of AZA, one was stopped due to severe rejection. Recurrent HCV was less severe in 5/9 studies with AZA compared with 2/17 using MMF, six of which documented worse recurrence. Published data in LT show little, if any, clinical benefit of MMF versus AZA. RCTs should reevaluate AZA in LT. Evaluation of HCV replication and recurrence will be particularly important as AZA may have advantages over MMF.

Hepatitis C and liver transplantation: enhancing outcomes and should patients be retransplanted

Hepatitis C (HCV)-related end-stage liver disease is the most common indication for liver transplantation. Safe expansion of the donor pool with improved rates of deceased donation and more widespread use of living and extended criteria donation are likely to decrease wait list mortality. In addition, improved antiviral treatments and a better understanding of the delicate balance between under- and over-immunosuppression in this population are needed. Finally, when recurrent advanced fibrosis occurs, the criteria for patient selection for retransplantation remain widely debated. This article reviews the literature on these topics and the work being done in each area to maximize outcomes in patients receiving transplants for HCV-related cirrhosis.

Conversion to mycophenolate mofetil for modulating recurrent hepatitis C in liver transplant recipients

BACKGROUND

The aim of this study was to analyze the influence of cyclosporine A (CsA) taper in conjunction with mycophenolate mofetil (MMF) therapy on recurrent hepatitis C virus (HCV) in liver transplant patients.

PATIENTS AND METHODS

Nineteen liver recipients with serologically and morphologically confirmed recurrent HCV were included in this study. After MMF introduction up to a maximum dose of 2000 mg/day, CsA dose was significantly tapered. In the control group immunosuppression remained unchanged. Allograft function and morphology, viral loads, and renal function were analyzed continuously.

RESULTS

MMF treatment was well tolerated without risk of rejection. Allograft fibrosis progressed in 6 patients of the MMF group (66.6%) and none (0%) of the controls at 12-month biopsy (P=0.005). Moreover, aminotransferases and viral loads increased slightly in the MMF-treated patients. Renal function improved significantly (serum creatinine: 239.3+/-90.2 micromol/L vs. 175.8+/-46.0 micromol/L; P=0.008) in the treatment group, while deteriorating (serum creatinine: 156.8+/-44.6 micromol/L vs. 214.8+/-120.1 micromol/L; P=0.06) in the controls.

CONCLUSION

MMF introduction allows a safe CsA taper in HCV-positive liver transplant patients and results in significant improvement of renal function. However, there seems to be a risk of marked progression of HCV-induced allograft injury.

Randomized trial of steroid-free induction versus corticosteroid maintenance among orthotopic liver transplant recipients with hepatitis C virus: impact on hepatic fibrosis progression at one year

BACKGROUND

Due to the known high recurrence rate of hepatitis C virus (HCV) among orthotopic liver transplant (OLT) recipients who receive tacrolimus+corticosteroid maintenance, use of steroid-free induction was considered.

METHODS

OLT recipients with HCV were randomized to receive tacrolimus+daclizumab (steroid-free) vs. tacrolimus+corticosteroids during 1999-2001 and then tacrolimus+mycophenolate mofetil (MMF)+daclizumab (steroid-free) vs. tacrolimus+MMF+corticosteroids during 2002-2005. Patients in the steroid-free arm of both periods received no steroids except for treating biopsy-proven rejection. Primary objective was to compare mean fibrosis stage at the 1-year protocol biopsy, between the steroid-free and corticosteroid arms, stratifying by period.

RESULTS

No noticeable differences in mean fibrosis stage between the two treatment arms, either averaging across periods (P=0.99) or during either period (P>0.35) were found. Occurrence of acute rejection during the first year was the only factor associated with a significantly increased fibrosis stage at 1 year (P=0.0003); stage > or =2 was seen in 63% (17 of 27) vs. 19% (8 of 43) of those with vs. without rejection. In addition, MMF use was associated with significantly fewer patients experiencing acute rejection during the first 6 and 12 months posttransplant (P=0.006 and 0.046). Regarding steroid-related side effects, posttransplant diabetes mellitus occurred in 10% vs. 45%, and wound infection in 6% vs. 31% of steroid-free vs. corticosteroid patients (P=0.003 and 0.01).

CONCLUSIONS

OLT recipients with HCV tolerated the steroid-free protocol with fewer side effects; however, its use had no apparent impact on hepatic fibrosis progression. Occurrence of acute rejection was strongly associated with increased hepatic fibrosis at 1 year, and MMF use appears to have significantly reduced the rejection rate.

Risk factors for hepatitis C recurrence after liver transplantation

Hepatitis C virus (HCV)-related end-stage liver disease is the main indication for liver transplantation performed in Europe and the United States. Recurrence of hepatitis C in the graft is universal and may lead to chronic hepatitis in most patients and to cirrhosis in 20-30% of patients within 5-10 years of transplantation. The natural history of HCV recurrence is highly variable but leads to a lower survival rate than other recurrent liver diseases. The immunosuppressed status and several other factors have been linked with the pattern and severity of recurrence. What remains controversial are those factors associated with fibrosis progression and how these could be modified to improve outcome of recurrent hepatitis C. No single factor but a combination of several factors is associated with fibrosis progression on the graft. The major factors associated with accelerated disease recurrence include: high viral load pre- (>10(6) IU / mL) and / or early post-transplantation (>10(7) IU / mL at 4 months), donor older than 40-50 years, prolonged ischaemic time, cytomegalovirus coinfection, over immunosuppression and / or abrupt changes in immunosuppression, HIV coinfection, infection by genotype 1b. Cautious follow-up of the pathology of the graft is mandatory including routine biopsies and / or noninvasive monitoring of fibrosis.

Clinical trial: switch to combined mycophenolate mofetil and minimal dose calcineurin inhibitor in stable liver transplant patients--assessment of renal and allograft function, cardiovascular risk factors and immune monitoring

BACKGROUND

Calcineurin inhibitor (CNI)-related nephrotoxicity significantly contributes to chronic renal failure after liver transplantation.

METHODS

In this prospective study, liver transplantation patients with renal dysfunction were randomized either to receive mycophenolate mofetil (MMF) followed by stepwise reduction of CNI with defined minimal CNI-trough levels (MMF group), or to continue their maintenance CNI dose (control group). Immune monitoring was performed in a subgroup of the patients.

RESULTS

In the MMF group (n = 50), renal function assessed by serum creatinine improved >10% in 62% of patients, was stable in 36% and deteriorated >10% in 2% after 12 months compared with baseline values. Mean serum creatinine levels (+/- s.d.) significantly decreased from 1.90 +/- 0.44 mg/dL to 1.61 +/- 0.39 mg/dL and the corresponding calculated glomerular filtration rate significantly increased from 38.8 +/- 9.6 mL/min/1.73 m(2) to 47.0 +/- 11.8 mL/min/1.73 m(2) over a 12-month follow-up period. Blood pressure and levels of liver enzymes significantly decreased. In the control group (n = 25), there were no significant changes with respect to the investigated parameters. The MMF group had significantly lower numbers of circulating cytotoxic T cells compared with the controls; whereas regulatory T cells significantly increased.

CONCLUSION

Combined MMF and minimal dose CNI therapy after liver transplantation is nephroprotective and may promote allograft tolerance.

Recurrent viral liver disease (hepatitis B and C) after liver transplantation

Hepatitis C represents more than 35% of liver transplant candidates worldwide. Meanwhile, hepatitis B continues to be an important cause of end-stage liver disease and hepatocellular carcinoma in Asia and Africa. Recurrent viral liver disease is a significant event after liver transplantation and continues to be one of the main causes of graft dysfunction and loss in the middle and long-term follow-up. Mechanisms of liver reinfection and disease recurrence vary between these two viruses and pre-emptive as well as the therapeutic approaches are different. Hepatitis B patients can be managed with immune globulin immediately after liver transplant and various agents such as nucleotide and nucleoside analogues can be associated. As a result, disease recurrence has been delayed or prevented in these patients. Individuals transplanted for hepatitis C are known to have universal reinfection and a high rate of disease recurrence has been reported in the literature. Strategies to treat hepatitis C recurrence are limited to the use of pegylated interferon and ribavirin when disease is demonstrated histologically and biochemically, although other strategies have been described with limited or no success. We herein review the mechanisms of disease recurrence and the current as well as the future therapeutic approaches to prevent and to treat these diseases.

Predictors of graft and patient survival in hepatitis C virus (HCV) recipients: model to predict HCV cirrhosis after liver transplantation

BACKGROUND

Hepatitis C virus (HCV) recurrence after liver transplantation (LT) is almost universal, but the natural history of recurrent HCV in the allograft is highly variable. Our study had two aims: 1) to assess the impact of different pre- and postLT factors on graft and patient survival in HCV transplant recipients and 2) to create a model which may predict the patients at risk for HCV-related graft cirrhosis at 5 years postLT.

METHODS

A total of 168 LTs were considered for this study. Univariate and multivariate Cox proportional hazards regression model was used, as well as logistic regression analysis to create a model of prediction of HCV cirrhosis within 5 years after LT.

RESULTS

Predictive factors for both decreased graft and patient survival included patients recently transplanted (2000-2004), induction without azathioprine, short-term therapy with mycophenolate mofetil and prednisone (< or =6 months), presence of early cholestasis, histologically proven early recurrence of hepatitis C. Recipient human leukocyte antigen DR3 positivity, presence of early cholestasis, and donor age >50 years were identified as independent predictors of graft cirrhosis within 5 years. A predictive model was established in order to calculate at 6 months a risk score for graft HCV cirrhosis within 5 years postLT using a formula that included the identified independent predictors. The area under receiver operating characteristic curve was 0.83, indicating a good ability to predict medium-term HCV allograft cirrhosis.

CONCLUSION

This model may be a useful tool for better identifying high-risk HCV patients who should be selected for early initiation of antiviral therapy.

Switch to 1.5 grams MMF monotherapy for CNI-related toxicity in liver transplantation is safe and improves renal function, dyslipidemia, and hypertension

Although mycophenolate mofetil (MMF) monotherapy has been successfully used in liver transplant recipients suffering from calcineurin-inhibitor (CNI)-related chronic toxicity, still no consensus has been reached on its safety, efficacy and tolerability. We attempted the complete weaning off CNI in 42 individuals presenting chronic renal dysfunction and/or dyslipidemia and/or arterial hypertension and simultaneously introduced 1.5 gm/day MMF. CNI could be completely withdrawn in 41 cases. A total of 32 (75%) patients are currently on <or=1.5 gm/day of MMF. Mean follow-up from the introduction of MMF is 31.5 months and mean length of follow-up from the beginning of MMF monotherapy is 27.3 months. Renal function improved in 31/36 (89%) cases. Blood levels of cholesterol and triglycerides decreased in 13 of 17 (76%) and 15 of 17 (89%) patients, respectively. Arterial hypertension improved in 4 of 5 (80%) cases. A total of 8 patients showed a single episode of fluctuation of liver function tests during tapering off CNI. This feature was interpreted as an acute rejection (AR), based on the resolution of the clinical setting after escalation of MMF daily dose to 2 gm. A further patient developed a biopsy-proven AR insensitive to MMF adjustment, requiring reinstitution of the CNI dose. No deaths or major toxicity requiring MMF discontinuation occurred. In conclusion, low dose MMF monotherapy is safe, effective, and well tolerated.

Mycophenolate mofetil in liver transplantation ? is monotherapy safe?

Liver transplantation (LTX) today has become a routine procedure granting curative treatment for various hepatic diseases with excellent survival rates. Constant improvement of immuno-suppressive regimens has led to significant reduction of rejection frequency and increased safety in long-term management. Calcineurin-inhibitors play the key role in most immunosuppressive protocols providing strong T-cell suppression yet often associated with numerous side-effects. Increasing renal insufficiency as well as hypertension, hyperglycaemia, hyperuricaemia, and increased risk of secondary malignancy account for the major problems in short- and long-term follow-up of LTX patients. Mycophenolate mofetil (MMF) as a purine-synthesis inhibitor has proved to be a potent immunosuppressive agent largely free of the CI-associated side-effects. MMF therefore has been used to modulate immunosuppressive protocols in order to both increase efficacy and to reduce CI-related side-effects such as nephrotoxicity. In recent years, MMF-monotherapy protocols have been suggested for LTX patients with renal insufficiency. This review provides an overview on the current role of MMF in immunosuppressive protocols after LTX and evaluates innovative therapeutic concepts.

Mycophenolic acid inhibits hepatitis C virus replication and acts in synergy with cyclosporin A and interferon-alpha

BACKGROUND & AIMS

Chronic hepatitis C virus (HCV) infection is the leading indication for liver transplantation. Clinical evidence suggests that particular immunosuppressive agents can have an influence on HCV recurrence. Cyclosporine A (CsA) specifically inhibits HCV replication through blocking the viral RNA polymerase enzyme NS5B. In this study, we investigated the effect of mycophenolic acid (MPA) and other immunosuppressants on HCV replication.

METHODS

MPA and other compounds were tested in vitro using an HCV-replication model containing a luciferase reporter gene.

RESULTS

At clinically relevant concentrations (1.0-6.0 microg/mL), MPA inhibited HCV replication to approximately 75%. CsA and interferon (IFN)-alpha also showed inhibition in a dose-dependent manner. In these short-term (18 hours) experiments, MPA did not inhibit cell proliferation or induce cell death, which could have accounted for the antiviral effect. In contrast to the antiviral activity of MPA against West Nile virus, the effect of MPA on HCV replication was guanosine independent. When combined, MPA and CsA showed significant synergistic inhibition of replication, reaching maximum inhibition of approximately 90% at the highest doses. Synergistic effects were observed with suboptimal concentrations of IFN-alpha with MPA or CsA. The kinetics of HCV inhibition by MPA, CsA, and IFN-alpha were clearly distinct, with earliest effects seen with IFN-alpha. No specific inhibitory effects were observed with tacrolimus or rapamycin.

CONCLUSIONS

The immunosuppressive drug MPA is as potent as CsA as an inhibitor of HCV replication. MPA was shown to have a distinct anti-HCV mechanism of action, independent of cell proliferation and guanosine depletion.

Liver transplantation: an update

PURPOSE OF REVIEW

Recent attention in liver transplantation has focused on equity in organ allocation and management of post-transplant complications.

RECENT FINDINGS

Adoption of the model for end-stage liver disease (MELD) for liver allocation has been successful in implementing a system based on medical urgency rather than waiting time. Refinements are being studied in reducing geographic disparities and improving transplant benefit by balancing pre-transplant mortality and post-transplant survival. With hepatocellular carcinoma becoming a bigger proportion of liver transplants since MELD, emerging literature is examining expansion of the current criteria for transplantation of hepatocellular carcinoma. Hepatitis C virus infection is associated with worse patient and graft survival post-transplantation than other liver diseases. The optimal timing and delivery of current antiviral therapy and immunosuppressive strategies in reducing the severity of hepatitis C virus recurrence post-transplantation are discussed. Chronic renal dysfunction after liver transplantation is a source of considerable morbidity. Nephron-sparing immunosuppression regimens are emerging with encouraging results.

SUMMARY

Organ allocation tends to evolve under MELD with a focus on reducing geographic disparities and maximizing transplant benefit. Hepatitis C virus, hepatocellular carcinoma and chronic renal dysfunction are a major challenge and continued research in these areas will undoubtedly lead to better outcomes for transplant recipients.

Management of Recurrent Hepatitis C in Liver Transplant Recipients

Recurrent HCV infection is universal in liver transplant recipients who are viremic pretransplant. The rate of histologic disease progression after transplantation is more rapid, and the risk of cirrhosis by 5 to 10 years is about 30%. Several donor, recipient, and viral factors have been associated with worse post-transplant outcomes in recipients with recurrent hepatitis C. Whether or not HCV-infected recipients of live donor grafts have worse out-comes compared with deceased donor graft recipients is controversial. To maximize the long-term survival of recipients with HCV infection, eradication of infection is the ultimate goal. Treatment of recurrent HCV after liver transplantation can be undertaken at several different time points: (1) prophylactically, at the time of transplantation; (2) pre-emptively, in the early post-transplant period; and (3) after established recurrent histologic disease is present. Prophylactic therapy for HCV infection has no established role at present, but studies are ongoing. Preemptive therapy using IFN and RBV has resulted in variable SVR rates (9%-43%) and is generally poorly tolerated, especially if the patient has advanced liver disease pretransplantation. Treatment of established recurrent HCV disease with combination PEGIFN and RBV is associated with a SVR in about 30% to 35% of patients overall but is limited by high rates of dose reduction or drug discontinuation. In conclusion, successful HCV eradication in the post-transplant setting is difficult with current treatment options, but it is possible. Determination of the optimal doses of antiviral drugs in transplant patients and improvements in drug tolerability may be important first steps in achieving enhanced response rates. There is a need for new drugs in this population that have greater efficacy and a better safety profile.

Management of hepatitis C in liver transplant recipients

Recurrent hepatitis C virus (HCV) disease is the leading cause of graft loss in liver transplant recipients with pre-transplant HCV infection. While natural history is variable, median time to recurrent cirrhosis is less than a decade. Factors contributing to risk of recurrence and rate of fibrosis progression are only partially known. Older donor age, treatment of acute rejection, cytomegalovirus infection and high pre-transplant viral load are most consistently linked with worse outcomes. Whether these factors can be modified to positively impact on HCV disease progression is unknown. The main therapeutic approach for patients with recurrent HCV disease has been the treatment with interferon and ribavirin (RBV) once recurrent disease is documented or progressive. Efficacy is lower than in nontransplant patients and tolerability, especially of RBV, is a major limitation. Stable or improved fibrosis scores are seen in the majority of sustained responders. Optimal dose, duration and timing of treatment have not been determined. Alternative strategies under study include pre-transplant treatment of decompensated cirrhotics, preemptive antiviral therapy started within weeks of transplantation and prophylactic therapy using HCV antibodies. Ongoing studies may establish a future role for alternative treatment approaches. Additionally, limited overall efficacy of interferon-based therapy in the transplant setting highlights the urgent need for new drug therapies.

Liver transplantation for hepatitis C virus related liver disease

Liver transplantation is a useful treatment for end stage liver disease of all aetiologies but recurrent disease presents an ongoing challenge, particularly for hepatitis C virus (HCV) where recurrence is almost universal. Immunosuppression is needed for all patients after transplantation and should be tailored to the individual patient, with particular problems being noted for those with HCV. The longer term effects of immunosuppression, particularly renal failure and the adverse effects of certain treatments on the liver graft, have become more important as survival improves and results are studied for longer periods after transplantation.

Treatment of recurrent hepatitis C after liver transplantation

Chronic hepatitis C virus (HCV) infection is the most common indication for liver transplantation in the United States and Europe, and more than 20,000 patients worldwide have undergone transplantation for complications of chronic hepatitis C. In North America, HCV accounts for 15% to 50% of the liver transplants performed in United States transplant programs. To maximize the long-term survival of liver transplant recipients who have HCV infection, eradication of infection is the ultimate goal. Pretransplant antiviral therapy with the goal of achieving viral eradication before transplantation is a consideration in some patients, especially those who have mildly decompensated liver disease. This article focuses on the management of liver transplant recipients who have HCV infection at the time of transplantation. Prophylactic and preemptive therapies, as well as treatment of established recurrent disease, are the strategies reviewed.