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

Acute and Chronic Rejection After Liver Transplantation: What A Clinician Needs to Know

While antibody mediated hyper-acute vasculitic rejection is rare in liver transplant recipients, acute and chronic rejection have clinical significance. The liver allograft behaves differently to other solid organ transplants as acute rejection generally does not impair graft survival and chronic rejection (CR) is uncommon. The incidence of acute and chronic rejection has declined in current era due to improved immunosuppressive regimens. Acute rejection generally improves with steroid boluses and steroid resistant rejection is uncommon. CR may improve with escalation of immunosuppression or may result in irreversible loss of graft function leading to retransplantation or death. The current review discusses diagnosis and management of acute and chronic liver allograft rejection.

Diagnostic and vaccine strategies to prevent infections in patients with inflammatory bowel disease

OBJECTIVES

The treatment of inflammatory bowel disease (IBD) has been revolutionized by the use of immunomodulatory agents. Although these potent drugs are effective in controlling disease activity, they also cause an increased risk of new infections or reactivation of latent infections. On these premises, we aimed to provide guidance on the definitions of immunocompromised patients, opportunistic infections and the risk factors associated with their occurrence in an IBD context, and to suggest the proper screening tests for infectious diseases and the vaccination schedules to perform before and/or during therapy with immunomodulators.

METHODS

All the most recent evidences - filtered by the combined work of gastroenterologists and infectious disease experts - were summarized with the aim to provide a practical standpoint for the physician.

RESULTS

A systematic screening of all infections which may arise during therapy with immunomodulator drugs is necessary in all patients with IBD.

CONCLUSIONS

The ideal timing to perform screening tests and vaccinations is at the diagnosis of the disease, regardless of its severity at onset, because the course of IBD and its treatment may vary over time, and an immunocompromised status may hamper efficacy and/or possibility to perform all necessary vaccines.

Role of mTOR inhibitors for the control of viral infection in solid organ transplant recipients

Appropriate post-transplant immunosuppressive regimens that avoid acute rejection, while reducing risk of viral reactivation, have been sought, but remain a chimera. Recent evidence suggesting potential regulatory and antiviral effects of mammalian target of rapamycin inhibitors (mTORi) is of great interest. Although the concept of an immunosuppressive drug with antiviral properties is not new, little effort has been made to put the evidence together to assess the management of immunosuppressive therapy in the presence of a viral infection. This review was developed to gather the evidence on antiviral activity of the mTORi against the viruses that most commonly reactivate in adult solid organ recipients: cytomegalovirus (CMV), polyomavirus, Epstein-Barr virus (EBV), human herpesvirus 8 (HHV8), and hepatitis C virus (HCV). A rapid review methodology and evaluation of quality and consistency of evidence based on the GRADE system was used. The existing literature was variable in nature, although indicating a potential advantage of mTORi in CMV, polyomavirus, and HHV8 infection, and a most doubtful relation with EBV and HCV infection. Several recommendations about the management of these infections are presented that can change certain current patterns of immunosuppression and help to improve the prognosis of the direct and indirect effects of viral infection in solid organ recipients.

Curing Hepatitis C in Liver Transplant Recipients Is Associated with Changes in Immunosuppressant Use

BACKGROUND AND AIMS

All-oral interferon-free antivirals are highly effective in treating recurrent hepatitis C (HCV) infection in liver transplant (LT) recipients. The aim of the study was to assess immunosuppression needs after achieving a sustained viral response (SVR).

METHODS

We compared immunosuppression needs before and after achieving a SVR in adult LT recipients treated for recurrent HCV infection with all-oral direct acting agents.

RESULTS

We identified 52 liver LT treated recipients who achieved a SVR. The median (25th and 75th percentile interquartile range [IQR]) age was 62 years (57.75, 65). Most recipients received tacrolimus (TAC) for their immunosuppressant regimen. After achieving SVR, there was no statistically significant difference in daily dose of TAC unadjusted per weight (p > 0.05). However, there was a statistically significant decrease in daily dose of TAC adjusted per weight, serum levels of TAC, and the product of glomerular filtration rate and TAC. No statistically significant differences in cyclosporine unadjusted/adjusted per weight daily dose or serum levels were noted.

CONCLUSIONS

Immunosuppression needs were increased for those patients treated with TAC but not cyclosporine. LT recipients prescribed TAC require close monitoring after treatment completion to avoid potential risk of acute rejection.

Impact of immunosuppression minimization and withdrawal in long-term hepatitis C virus liver transplant recipients

AIM: To investigate the effects of different immunosuppressive regimens and avoidance on fibrosis progression in hepatitis C virus (HCV) liver transplant (LT) recipients.

METHODS: We retrospectively compared the liver biopsies of well-matched HCV LT recipients under calcineurin inhibitors (CNI group, n = 21) and mycophenolate (MMF group, n = 15) monotherapy, with those patients who successfully withdrawn immunosuppression (IS) therapy from at least 3 years (TOL group, n = 10). To perform the well-matched analysis, all HCV transplanted patients from December 1993 were screened. Only those HCV patients who reached the following criteria were considered for the analysis: (1) at least 3 years of post-operative follow-up; (2) patients with normal liver graft function under low dose CNI monotherapy (CNI group); (3) patients with normal liver graft function under antimetabolite (Micophenolate Mofetil or coated mycophenolate sodium) monotherapy (MMF group); and (4) recipients with normal liver function without any IS. We excluded from the analysis recipients who were IS free or under monotherapy for < 36 mo, recipients with cirrhosis or with unstable liver function tests.

RESULTS: Thirty six recipients were enrolled in the study. Demographics, clinical data, time after LT and baseline liver biopsies were comparable in the three groups. After six years of follow-up, there was no worsening of hepatic fibrosis in the MMF group (2.5 ± 1.5 Ishak Units vs 2.9 ± 1.7 Ishak Units, P = 0.5) and TOL group (2.7 ± 10.7 vs 2.5 ± 1.2, P = 0.2). In contrast, a significant increase in the fibrosis score was observed in the CNI group (2.2 ± 1.7 vs 3.9 ± 1.6, P = 0.008). The yearly fibrosis progression rate was significantly worse in the CNI group (0.32 ± 0.35) vs MMF group (0.03 ± 0.31, P = 0.03), and TOL group (-0.02 ± 0.27, P = 0.02). No differences have been reported in grading scores for CNI group (2.79 ± 1.9, P = 0.7), MMF group (3.2 ± 1.5, P = 0.9) and TOL group (3.1 ± 1.4, P = 0.2). Twenty four patients were treated with low dose ribavirin (8 TOL, 7 MMF, 9 CNI). The hepatitis C titers were comparable in the three groups. No episodes of rejection have been reported despite differences of liver function test in the three groups during the observational period.

CONCLUSION: IS withdrawal and MMF monotherapy is safe and seems to be associated with the slowest fibrosis progression in HCV LT recipients.

REFINE: a randomized trial comparing cyclosporine A and tacrolimus on fibrosis after liver transplantation for hepatitis C

REFINE was a 12-month, prospective, open-label study in 356 patients receiving de novo liver transplantation for hepatitis C virus (HCV) cirrhosis, randomized to cyclosporine A (CsA) or tacrolimus with (i) no steroids, IL-2 receptor antibody induction and mycophenolic acid, or (ii) slow steroid tapering. The primary analysis population based on availability of liver biopsies comprised 165 patients (88 CsA, 77 tacrolimus). There was no difference in the primary endpoint, fibrosis stage ≥2 at 12 months, which occurred in 63/88 CsA-treated patients (71.6%) and 52/77 tacrolimus-treated patients (67.5%) (odds ratio [OR] 1.11; 95% CI 0.56, 2.21; p = 0.759). Similarly, no significant between-group difference occurred at month 24 (OR 1.15; 95% CI 0.47, 2.80; p = 0.767). Among steroid-free patients, fibrosis score ≥2 was significantly less frequent with CsA versus tacrolimus at month 12 (7/37 [18.9%] vs. 16/38 [42.1%]; p = 0.029). HCV viral load was similar in both the tacrolimus- and CsA-treated cohorts. Mean blood glucose was significantly higher with tacrolimus from day 15 onward. Biopsy-proven acute rejection, graft loss and death were similar. These results showed no differences in posttransplant HCV-induced liver fibrosis between patients treated with CsA or tacrolimus in steroid-containing regimens, whereas CsA in steroid-free protocols was associated with reduced severity of fibrosis progression at 1 year posttransplant.

Immunosuppression minimization vs. complete drug withdrawal in liver transplantation

Despite the increase in long-term survival, liver transplant recipients still exhibit higher morbidity and mortality than the general population. This is in part attributed to the lifelong administration of immunosuppression and its associated side effects. Several studies reported in the last decades have evaluated the impact of immunosuppression minimization in liver transplant recipients, but results have been inconsistent due to the heterogeneity of study designs and insufficient sample sizes. On the other hand, complete immunosuppression withdrawal has proven to be feasible in approximately 20% of carefully selected liver transplant recipients, especially in older patients and those with longer duration after transplantation. The long-term risks and clinical benefits of this strategy, however, also need to be clarified. As a consequence, and despite the general perception that a large proportion of liver recipients are over-immunosuppressed, it is currently not possible to derive evidence-based guidelines on how to manage long-term immunosuppression to improve clinical outcomes. Large clinical trials of drug minimization and/or withdrawal focused on clinically-relevant long-term outcomes are required. Development of personalized medicine tools and a deeper understanding of the pathogenesis of idiopathic inflammatory graft lesions will be pre-requisites to achieve these goals.

Current status of immunosuppression in liver transplantation

With advancements in immunosuppressive strategies and availability of better immunosuppressive agents, survival rate following liver transplantation has improved significantly in the recent times. Besides improvements in surgical techniques, the most important factor that has contributed to this better outcome is the progress made in the field of immunosuppression. Over the last several years, the trend has changed to tailored immunosuppression with the aim of achieving optimal graft function while avoiding its undesirable side effects. Induction agents are no longer used routinely and the aim is to provide minimal immunosuppression in the maintenance phase. The present review discusses the various types of immunosuppressive agents, their mechanism of action, clinical utility, advantages and disadvantages, and their side effects in short and long-term. It also discusses about tailoring immunosuppression in presence of various situations such as renal dysfunction, metabolic syndrome, hepatitis C recurrence, cytomegalovirus infections and so on. The issue of chronic kidney disease and the available renal sparing immunosuppressive strategies has been particularly stressed upon. Finally, it discusses about the practical aspects of various immunosuppression regimens including drug monitoring.

Management of recurrent hepatitis C in orthotopic liver transplant recipients

End-stage liver disease and hepatocellular carcinoma from chronic hepatitis C are the most common indications for orthotopic liver transplantation and the incidence of both are projected to increase over the next decade. Recurrent hepatitis C virus infection of the allograft is associated with an accelerated progression to cirrhosis, graft loss, and death. This article presents an overview of the natural history of hepatitis C virus recurrence in liver transplant recipients and guidance on optimal management strategies.

MicroRNA signature at the time of clinical HCV recurrence associates with aggressive fibrosis progression post-liver transplantation

Diagnosis and prediction of the severity of hepatitis C virus recurrence (HCVrec) after liver transplantation (LT) remain a challenge. MicroRNAs have been recently recognized as potential disease biomarkers. Archival liver biopsy samples from 43 HCV+ LT recipients were collected at clinical HCVrec time and at 3 years post-LT. Patients were classified as progressors (P = F0/F1) or nonprogressors (NP = F3/F4) according to the severity of fibrosis on the 3-year biopsy. Training (n = 27) and validation (n = 16) sets were defined. RNA was isolated from all biopsies at clinical HCVrec time, labeled and hybridized to miRNA-arrays. Progressors versus nonprogressors were compared using the two-sample t-test. A p-value ≤0.01 was considered significant. The ingenuity pathway analysis tool was used for microRNA and miRNA:mRNA ontology data integration. Nine microRNAs were differentially expressed between groups. A supervised cluster analysis separated samples in two well-defined groups (progressors vs. nonprogressors). Pathway analysis associated those microRNAs with hepatitis, steatosis, fibrosis, cirrhosis and T cell-related immune response. Data integration identified 17 genes from a previous genomic study as 9-microRNAs signature targets. Seven microRNAs were successfully validated in the validation set using QPCR. We have identified a 9-microRNA signature able to identify early post-LT patients at high risk of severe HCVrec during long-term follow-up.

Immunomodulating options for liver transplant patients

Much has changed since the early years of liver transplantation. Improvements in post-transplant survival are largely due to more selective and less toxic immunosuppression regimens and advances in operative and perioperative care. This has allowed liver transplantation to become an extremely successful treatment option for patients with endstage liver disease. Beginning with cyclosporine, a cyclic endecapeptide of fungal origin and the first of the calcineurin inhibitors to find widespread use, immunosuppressive regimens have evolved to include additional calcineurin inhibitors, steroids, mTOR inhibitors, antimetabolites and antibodies, mostly targeting T-cell activation. This review will present currently available immunosuppressive agents used in the perioperative period of liver transplantation, as well as maintenance treatments, tailoring therapeutic strategies for specific populations, and advances in immune monitoring and tolerance.

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.

Hepatitis C virus infection in the immunocompromised host: a complex scenario with variable clinical impact

The relationship between Hepatitis C Virus (HCV) infection and immunosuppression is complex and multifaceted. Although HCV-related hepatocytolysis is classically interpreted as secondary to the attack by cytotoxic T lymphocytes against infected cells, the liver disease is usually exacerbated and more rapidly evolutive in immunosuppressed patients. This generally occurs during the immunosuppression state, and not at the reconstitution of the host response after immunosuppressive therapy discontinuation. The field of immunosuppression and HCV infection is complicated both by the different outcome observed in different situations and/or by contrasting data obtained in the same conditions, with several still unanswered questions, such as the opportunity to modify treatment schedules in the setting of post-transplant follow-up. The complexity of this field is further complicated by the intrinsic tendency of HCV infection in itself to lead to disorders of the immune system. This review will briefly outline the current knowledge about the pathogenesis of both hepatic and extrahepatic HCV-related disorders and the principal available data concerning HCV infection in a condition of impairment of the immune system. Attention will be especially focused on some conditions - liver or kidney transplantation, the use of biologic drugs and cancer chemotherapy - for which more abundant and interesting data exist.

Viral hepatitis in liver transplantation

Liver transplantation is the only alternative for patients with end-stage liver disease. Viral hepatitis B and C are among the most common causes of cirrhosis and hepatocellular carcinoma and a frequent indication for liver transplantation. Hepatitis B virus immunoglobulin and nucleot(s)ide analogues have facilitated the management of patients with hepatitis B who have received liver transplants and resulted in excellent long-term outcomes. On the contrary, recurrence of hepatitis C is the main cause of graft loss in most transplant programs. Current therapeutic approaches are far from optimal, because sustained virologic responses are only achieved in one-third of treated patients, and adverse effects are common and severe. However, the rapid development of direct-acting antivirals against hepatitis C virus will change the management of this disease and in a few years prevent graft infection with this virus.