Early detection of hepatitis C allograft reinfection after orthotopic liver transplantation: a molecular and histologic study

The Role of Monocyte/Macrophage and CXCR3 in Differentiation between Recurrent Hepatitis C and Acute Cellular Rejection Postliver Transplantation

Objective

Liver transplantation (LT) is the recommended treatment for patients with advanced liver disease and cirrhosis in all guidelines, mostly as a complication of HCV. The distinction between reinfection of the graft with HCV and acute cellular rejection (ACR) is essential because they are managed differently. Hepatic macrophages, which can either arise from circulating blood-derived monocytes (BDM) or from resident tissue Kupffer cells, are central in the pathogenesis of chronic liver injury. The aim of this work was to evaluate whether the origin of macrophages and the immune mediator CXCR3 could help in differentiating between acute recurrent HCV and ACR after liver transplantation.

Methods

Twenty-nine cases of recurrent hepatitis C and 26 cases of ACR were included in this study. The expression of CD 68 (macrophage marker), CD11b (BDM marker), and CxCR3 in the postliver transplant biopsy using immunohistochemistry was determined.

Results

CD11b expression highlighting macrophages of BDM origin was in favor of recurrent hepatitis C (P < 0.001) than in ACR (P = 0.44), while CXCR3 expression by hepatocytes was in favor of ACR (P = 0.001).

Conclusion

Macrophage infiltrating liver tissue post LT can distinguish between ACR by upregulation of CXCR3 and recurrent hepatitis C by predominant CD11b.

Biopsy Specimens From Allograft Liver Contain Histologic Features of Hepatitis C Virus Infection After Virus Eradication

BACKGROUND & AIMS

Most patients, even those who have received a liver transplant, achieve a sustained virologic response (SVR) to therapy for hepatitis C virus (HCV) infection. Little is known about the histologic features of liver biopsy specimens collected after SVR, particularly in patients who have received a liver transplant. We aimed to better characterize the histologic features of allograft liver biopsy specimens from patients who achieved SVR to anti-HCV therapy after liver transplantation.

METHODS

We performed a retrospective analysis of 170 allograft liver biopsy specimens from 36 patients who received a liver transplant for chronic HCV infection, had recurrent HCV infection after transplantation, and subsequently achieved SVR (collected from 1999 through 2015 at 4 medical centers). SVR was defined as an undetectable serum HCV RNA level 24 weeks after completion of HCV treatment. A total of 65 biopsy specimens were post-SVR (at least 1 post-SVR from each patient; some biopsy specimens were collected at later time points from a subset of patients). We performed polymerase chain reaction analysis for HCV RNA on a subset of the biopsy specimens (28 collected before SVR and 32 after SVR).

RESULTS

Of the 65 post-SVR biopsy specimens, 45 (69%) had histologic features of active HCV infection. Of the initial post-SVR biopsy specimens collected from each of the 36 patients, 32 (89%) showed these changes. For patients with more than 1 post-SVR biopsy specimen, 6 (46%) had no change in fibrosis between biopsies, and fibrosis worsened for 3 patients (23%) based on their most recent biopsy. The HCV RNA level was undetectable in 31 of the 32 biopsy specimens analyzed by polymerase chain reaction.

CONCLUSIONS

In a retrospective analysis of allograft liver biopsy specimens from patients who achieved SVR after a liver transplant for chronic HCV infection, histologic changes associated with active HCV were present in 69% and fibrosis continued to progress in 23%, despite the lack of detection of HCV RNA. Pathologists should be aware of patients' SVR status when analyzing liver biopsy specimens to avoid diagnoses of chronic HCV-associated hepatitis. Because of the persistent inflammatory activity and fibrosis after SVR, clinicians should continue to monitor patients carefully after SVR to anti-HCV therapy.

Impact of new treatment options for hepatitis C virus infection in liver transplantation

Liver transplant candidates and recipients with hepatitis C virus (HCV)-related liver disease greatly benefit from an effective antiviral therapy. The achievement of a sustained virological response before transplantation can prevent the recurrence of post-transplant HCV disease that occurs universally and correlates with enhanced progression to graft cirrhosis. Previous standard-of-care regimens (e.g., pegylated-interferon plus ribavirin with or without first generation protease inhibitors, boceprevir and telaprevir) displayed suboptimal results and poor tolerance in liver transplant recipients. A new class of potent direct-acting antiviral agents (DAA) characterized by all-oral regimens with minimal side effects has been approved and included in the recent guidelines for the treatment of liver transplant recipients with recurrent HCV disease. Association of sofosbuvir with ribavirin and/or ledipasvir is recommended in liver transplant recipients and patients with decompensated cirrhosis. Other regimens include simeprevir, daclatasvir, and combination of other DAA. Possible interactions should be monitored, especially in coinfected human immunodeficiency virus/HCV patients receiving antiretrovirals.

Acute cellular rejection versus recurrent hepatitis C after liver transplantation: Clinical and pathological features driving a rational diagnostic approach

AIM

The aim of our study was develop and validate an algorithm system based on morphological features for finding the differences between recurrent hepatitis C virus (HCV) and acute cellular rejection (ACR) in liver biopsies of HCV-transplanted patients.

METHODS

Two hundred and eighty-eight liver biopsies were analyzed from 121 patients transplanted for HCV. A diagnostic consensus was reached between clinicians and pathologists in 214 biopsies for the diagnosis of recurrent HCV or ACR. A random sample of 114 liver biopsies (derivation cohort) was taken to generate the diagnostic tree and was subsequently evaluated using the validation cohort in 100 liver biopsies by recursive partitioning analysis of morphological variables and time since transplantation.

RESULTS

The presence of endotheliitis together with a time of less than 6 weeks since LT definitely excluded recurrent HCV. After obtaining the regression tree, diagnostic accuracy was 96% and 93% in the derivation and validation cohort, respectively. Both cases surpassed the pathologist's original diagnosis, which had a diagnostic accuracy of 91% (P < 0.05, for both comparisons).

CONCLUSION

A recursive partitioning analysis of the morphological features in liver biopsies from HCV-transplanted patients may be useful for easily distinguishing between recurrent HCV and ACR.

Hepatitis C virus reinfection after liver transplantation: Is there a role for direct antiviral agents?

Recurrence of hepatitis C virus (HCV) infection following liver transplantation (LT) is almost universal and can accelerate graft cirrhosis in up to 30% of patients. The development of effective strategies to treat or prevent HCV recurrence after LT remains a major challenge, considering the shortage of donor organs and the accelerated progression of HCV in LT recipients. Standard antiviral therapy with pegylated-interferon plus ribavirin is the current treatment of choice for HCV LT recipients, even though the combination is not as effective as it is in immunocompetent patients. A sustained virological response in the setting of LT improves patient and graft survival, but this is only achieved in 30%-45% of patients and the treatment is poorly tolerated. To improve the efficacy of pre- and post-transplant antiviral therapy, a new class of potent direct-acting antiviral agents (DAAs) has been developed. The aim of this review is to summarize the use of DAAs in LT HCV patients. PubMed, Cochrane Library, MEDLINE, EMBASE, Web of Science and clinical trial databases were searched for this purpose. To date, only three clinical studies on the topic have been published and most of the available data are in abstract form. Although a moderately successful early virological response has been reported, DAA treatment regimens were associated with severe toxicity mitigating their potential usefulness. Moreover, the ongoing nature of data, the lack of randomized studies, the small number of enrolled patients and the heterogeneity of these studies make the results largely anecdotal and questionable. In conclusion, large well-designed clinical studies on DAAs in HCV LT patients are required before these drugs can be recommended after transplantation.

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.

The meaning of tissue and serum HCV RNA quantitation in hepatitis C recurrence after liver transplantation: a retrospective study

BACKGROUND

While the role of serum HCV RNA quantitation in hepatitis C virus recurrence after liver transplantation is well established, the meaning of HCV RNA tissue quantitation is largely unclear, and no correlations with recipient outcome have been investigated yet.

AIMS

To assess the predictive value, and a possible prognostic role, of tissue and serum HCV RNA in first post-transplant biopsies.

METHODS

We retrospectively reviewed the first post-transplant biopsies of 83 recipients. Tissue and serum HCV RNA was quantitated by RT-PCR, and compared with serum, clinical and histological data.

RESULTS

HCV RNA quantitation allowed us to categorise recipients into three different risk groups: (1) tissue HCV RNA ≤ 1.5 IU/ng with any serum HCV RNA; (2) tissue HCV RNA>1.5 IU/ng and serum HCV RNA < 40 × 10(6)copies/mL; (3) tissue HCV RNA>1.5 IU/ng and serum HCV RNA ≥ 40 × 10(6)copies/mL. Hepatitis C virus recurrence rates in the three groups were 68%, 91% and 100% (P=0.004); hepatitis C virus-related mortality was 0%, 14% and 45% respectively (P<0.001).

CONCLUSIONS

This preliminary study on serum and tissue HCV RNA quantitation allows recipient "stratification" in prognostic groups, which could be applicable in the future for timely antiviral treatment and/or immunosuppression modulation.

New insights in recurrent HCV infection after liver transplantation

Hepatitis C virus (HCV) is a small-enveloped RNA virus belonging to the Flaviviridae family. Since first identified in 1989, HCV has been estimated to infect 170 million people worldwide. Mostly chronic hepatitis C virus has a uniform natural history, from liver cirrhosis to the development of hepatocellular carcinoma. The current therapy for HCV infection consists of a combination of Pegylated interferon and ribavirin. On the other hand, HCV-related liver disease is also the leading indication for liver transplantation. However, posttransplant HCV re-infection of the graft has been reported to be universal. Furthermore, the graft after HCV re-infection often results in accelerated progression to liver failure. In addition, treatment of recurrent HCV infection after liver transplantation is often compromised by enhanced adverse effects and limited efficacy of interferon-based therapies. Taken together, poor outcome after HCV re-infection, regardless of grafts or recipients, poses a major issue for the hepatologists and transplant surgeons. The aim of this paper is to review several specific aspects regarding HCV re-infection after transplant: risk factors, current therapeutics for HCV in different stages of liver transplantation, cellular function of HCV proteins, and molecular mechanisms of HCV entry. Hopefully, this paper will inspire new strategies and novel inhibitors against recurrent HCV infection after liver transplantation and greatly improve its overall outcome.

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.

HCV in liver transplantation

HCV-related cirrhosis represents the leading indication for liver transplantation in the Western countries. HCV reinfection after liver transplantation occurs in virtually all patients transplanted for HCV-related liver disease Histological evidence of chronic HCV infection develops in 50 to 90 % of patients by 12 months after liver transplantation, and cirrhosis occurs in about 20 % of patients within 5 years after transplant. Several studies have evaluated host, viral, and transplant-related factors that might be associated with the severity of HCV recurrence. Among host factors, immunosuppression is one of the major factors that accounts for accelerated HCV recurrence and it has been an area of extensive research and controversy. Donor age, steatosis, and immunogenetic factors are also relevant in determining the outcome in patients transplanted for HCV-related cirrhosis. A major step to prevent complications of HCV recurrence related to the rapid fibrosis is the posttransplant antiviral treatment. Two strategies have been tried: pre-emptive or other strategies as soon as possible after liver transplantation or elective therapy once there is histological evidence of recurrent hepatitis C. Retransplantation due to graft failure from recurrent hepatitis C is rarely an option in the era of organ shortage as it is associated with poor outcome, but many case needs to be considered early in the evolution of disease. New antivirals may change the outcome dramatically of patients transplanted for HCV cirrhosis.

Clinicopathological features of hepatitis C virus disease after living donor liver transplantation: relationship with in situ hybridisation data

AIMS

Recurrent hepatitis is a significant complication after liver transplantation for hepatitis C virus (HCV) disease. To evaluate responsiveness to treatment of HCV disease after liver transplantation, in situ hybridisation (ISH) was employed.

METHODS

Sense and anti-sense probes for HCV were synthesised, and ISH studies were performed on 19 liver biopsy specimens from 19 recipients who had undergone living donor liver transplantation for HCV disease. ISH positive cells and total hepatocytes were counted, and the percentage of positive cells was calculated. Other clinical findings were compared retrospectively with the ISH results.

RESULTS

The subjects were divided into three groups: recurrent HCV hepatitis (RHC, n = 11), acute cellular rejection (ACR, n = 5), and recurrent HCV hepatitis with ACR (MIX, n = 3). The percentage of ISH positive cells was almost the same degree (10-20%) in the three groups. The RHC group was subdivided into two sets of patients in whom serum HCV titres decreased (group D, n = 7) or did not decrease (group ND, n = 3) after 1 month of IFN therapy. The percentage of ISH positive cells in group D was significantly lower than that in group ND (p < 0.05)

CONCLUSIONS

ISH for the recipients with HCV may be useful for predicting the response to interferon therapy.

What is expected from the pathologist in the diagnosis of viral hepatitis?

The clinician expects from the pathologist a clinically relevant diagnosis on the basis of liver biopsy interpretation. Today, a liver biopsy, as invasive procedure, is only justified when a significant benefit for the patient can be expected particularly with respect to the clinical management. Consequently, liver biopsy is usually not required in uncomplicated acute viral hepatitis. It is, however, an important diagnostic tool in chronic hepatitis and in transplanted liver to confirm the clinical diagnosis and to assess stage and grade of necroinflammation, treatment efficiency, and concurrent diseases. The diagnosis of liver disease is based on teamwork between clinician and pathologist. Evaluation of the biopsy in the clinical context requires clinical information and appropriate size and handling of the biopsy specimen. Aim of this review is the discussion of morphologic features of acute and chronic viral hepatitis with regard to their clinical relevance.

Molecular and cellular aspects of hepatitis C virus reinfection after liver transplantation: how the early phase impacts on outcomes

Hepatitis C virus (HCV)-related liver disease postliver transplantation is associated with an accelerated course in comparison with that observed in the nonimmunosuppressed individual. Outcomes in transplantation for this indication have, therefore, been a major area of clinical interest in the field of liver transplantation. The factors underlying the rapid progression of HCV-related liver disease posttransplantation are complex and multifactorial. Nevertheless, recent data indicate a range of parameters assessable early posttransplantation that may be useful in the prediction of outcome of transplantation for this condition. This overview, therefore, concentrates on the early events occurring postliver transplantation in the HCV-infected patient, and the implications of these recent observations for the pathogenesis of the various forms of HCV-related allograft injury.

Treatment of hepatitis C in liver transplant recipients

Recurrent hepatitis C after liver transplantation is a universal phenomenon. Graft reinfection occurs rapidly; once it is established, allograft cirrhosis and decompensation rapidly ensue in many patients. Treatment with pegylated interferon plus ribavirin is the standard of care among nontransplant patients with hepatitis C; however, the applicability of these therapies in liver transplant patients is severely limited. Before transplantation, many patients are simply too ill to endure the long treatment duration necessary to achieve viral eradication; thus, treatment-related toxicity is a frequent barrier to success. Clinical trials in the pretransplantation population have yielded poor outcomes, with sustained virologic response rates only as high as 25%. Early after transplantation, treatment may be initiated prophylactically, or it may be initiated therapeutically in patients with evidence of recurrent disease. In small studies, prophylactic therapy has been associated with sustained virologic response rates lower than 20%, whereas in therapeutic intervention studies, sustained virologic response rates have ranged from 20% to 37%. In the setting of therapeutic intervention, preliminary indications suggest that rapid and early virologic response may become important clinical tools enabling the early identification of patients likely to respond to treatment. Two important clinical trials, PHOENIX (Pegasys and Copegus Administered After Liver Transplantation for Hepatitis C) in the prophylactic setting and PROTECT (Pegylated Interferon Alpha-2b and Ribavirin After Orthotopic Liver Transplantation: Efficacy and Safety in Hepatitis C Recurrence Therapy) in the therapeutic setting, are under way and should further advance our understanding of the management of hepatitis C in patients undergoing liver transplantation.

Effect of pretransplant hepatitis C virus RNA status on posttransplant outcome

Undetectable hepatitis C virus (HCV) RNA [RNA(-)] before liver transplantation (OLT) has been shown to decrease the rates of disease recurrence. We sought to determine whether RNA(-) subjects differ in post-OLT recurrence (virological/VR, histological/HR), graft failure (GF), or patient survival from RNA(+) patients using a retrospective review. From 1995 to 2004, a total of 49 patients were RNA(-) at OLT as a result of interferon-based therapy: 22 SVR and 27 with end-of-treatment response (ETR) transplanted when RNA(-) within 6 months of ET. Forty-eight RNA(+) patients were analyzed as controls. Virological recurrence (VR) was seen in 55% of RNA(-) subjects with no difference in HR between RNA(-) vs (+) groups, namely 36.7% versus 56.3% (P = .068), respectively. The RNA(+) subjects showed a lower time to HR (5.6 vs 11 months; P = .027). The SVR subjects displayed lower VR (36.4%) and histological recurrence (HR) (13.6%) compared to ETR (VR 70.4%, P = .023; HR 55.6%, P = .003) or RNA(+) (HR 56%, P = .0008). The SVR subjects, who were identified with a sensitive assay (SVR(S), lower limit <600 IU/mL) showed no VR, HR, or GF. The 1- and 5-year survivals were 87.8%/75.6% and 89.6%/77.8% for RNA(-) and (+) groups, respectively (P = .77). In conclusion, RNA(-)-transplanted patients displayed lower VR and longer time to HR. The SVR patients showed lower VR and HR compared to ETR and RNA(+) patients.

Review article: the treatment of hepatitis C virus recurrence after liver transplantation

BACKGROUND

Recurrent hepatitis C represents a major challenge for the liver transplant community. Given the potentially significant impact that hepatitis C recurrence has on graft and patient survival, several treatment strategies have been utilized to prevent/slow the progression to hepatitis C-related graft failure.

AIM

To review the efficacy and applicability of treatment strategies for managing recurrent hepatitis C.

METHODS

Search of MEDLINE (1990 to December 2006) and national meeting abstracts. Search terms included hepatitis C, liver transplantation, treatment, sustained virological response (SVR), and end of treatment virological response. An emphasis was placed on randomized trials.

RESULTS

The largest study of treatment prior to liver transplantation (n = 124) achieved SVR in 24%. Eight randomized trials (n = 383) examined the efficacy of preemptive therapy with SVR ranging from 0-33%. Eligibility for treatment was low and dose reduction common. Four randomized trials (n = 245; all abstracts) have reported SVR from 33-42% for treating those with histological evidence of recurrent disease.

CONCLUSIONS

Therapies for treating hepatitis C recurrence have limited applicability and tolerability, and they have a low SVR. Based on available results, preemptive therapy is not recommended. Pegylated interferon and ribavirin is currently the preferred choice for treating established recurrence. There is an urgent need for safer and more effective anti-viral therapy in this situation.

Rapidly progressive recurrent hepatitis C virus infection starting 9 days after liver transplantation

Early histological recurrence of hepatitis C after liver transplantation (LT) has a negative impact on patient and graft survival. We report a case of histological recurrence of HCV occurring in the second week after LT. A 75-year-old woman with chronic HCV and hepatocellular carcinoma underwent LT with an organ from a 75-year-old HCV-negative deceased donor. After an uneventful early postoperative period, an increase in the transaminases was observed, and on postoperative day 9 day, the alanine aminotransferase (ALT) was 673 IU/mL and aspartate aminotransferase (AST) 300 IU/mL, with normal alkaline phosphatase and bilirubin. Analysis of liver biopsy samples showed diffuse necroinflammatory changes with acidophilic bodies and concomitant mild acute cellular rejection. Subsequently there was a further increase in the transaminases, and on postoperative day 13, the AST rose to 445 IU/mL and ALT to 992 IU/mL. Repeat biopsy was performed, and analysis of the samples revealed lymphocytic portal inflammation with lymphoid aggregates and mild interface hepatitis, parenchymal necrosis, activation of sinusoidal lining cells, and mild steatosis. The biopsy sample was characteristic for HCV recurrence. The HCV RNA level was 84,000,000 copies/mL, and markers for other viral causes were not present. The patient became jaundiced and her course progressively worsened. She died on day 87 after transplantation. To our knowledge, this is the earliest reported case of histological recurrence of HCV after LT. It illustrates the importance of older donor and recipient age in the same patient as cofactors for early HCV recurrence and poor outcome.

Approach to recurrent hepatitis C following liver transplantation

Hepatitis C-associated liver failure is the most common indication for liver transplantation. Histologic evidence of recurrence is apparent in approximately 50% of hepatitis C virus (HCV)-infected recipients in the first postoperative year. Approximately 10% of HCV-infected recipients will die or lose their allograft due to hepatitis C-associated allograft failure. HCV-infected recipients who undergo retransplantation have 5-year patient and graft survival rates that are broadly similar to those for transplant recipients who are not HCV infected. Although the choice of calcineurin inhibitor, mycophenolate mofetil, or both has not been clearly shown to affect histologic recurrence of hepatitis C, higher cumulative exposure to corticosteroids is associated with increased mortality and more severe histologic recurrence. In contrast to treatment of non-HCV-infected recipients, treatment of HCV-infected transplant recipients for acute cellular rejection is associated with attenuated patient survival. Steroid-resistant rejection with or without the use of T-cell-depleting therapies is associated with a greater than fivefold increased risk of mortality in HCV-infected liver transplant recipients. Pegylated interferon with or without ribavirin should be considered for treatment of recipients with histologically apparent recurrence of hepatitis C before total bilirubin exceeds 3 mg/dL. The role of hepatitis C immunoglobulin and new immunosuppressive agents in the management of hepatitis C after transplant continues to evolve.

Hepatitis C: a challenge to hepatologists and to the liver transplantation team

Hepatitis C is the main cause of cirrhosis and hepatocellular carcinoma and the leading indication of liver transplantation. The aim of this article was to review specific epidemiological, clinical and therapeutic aspects of hepatitis C and their implication for the hepatologists belonging to liver transplantation services. These specific aspects were reviewed in the literature mainly using Medline. Data regarding the epidemiological, clinical and therapeutic aspects of hepatitis C are discussed, with emphasis on their consequences for the liver transplantation team. Hepatitis C is a challenge for hepatologists and for the liver transplantation team. The burden we observe today is the late consequence of infection that occurred in the past. Measures for early recognition of complications of liver disease are recommended. HCV treatment should always be performed before liver transplantation if possible, but if not, HCV recurrence should be recognized and treated early after transplantation.

Challenges and Controversies in the Management of Hepatitis C Virus Infection (Part 2)

Patients with HCV-related cirrhosis are frequently seen in clinical practice when the diagnosis is established either clini-cally when signs of chronic liver disease are evident, or histo-logically when liver biopsy is performed as part of the assess-ment of patients with HCV infection. It continues to be debat-able whether cirrhotic patients should receive antiviral therapy. Those who propose treatment state that eradication of HCV is the main goal of antiviral therapy thus limiting the spread of HCV infection and stress that cirrhosis is not a permanent in-jury that cannot be reversed. Opponents of antiviral therapy in patients with cirrhosis state that such treatment produces very low virological response rates in the face of a reportedly high incidence of side effects.

Kinetics of hepatitis C virus reinfection after liver transplantation

Improved understanding of hepatitis C virus (HCV) dynamics during and after liver transplantation can be useful in optimizing antiviral therapy in transplant recipients. We analyzed serum HCV ribonucleic acid (RNA) levels during and after cadaveric liver transplantation in 6 HCV patients. After removal of the liver and before the new liver started producing virions, HCV RNA levels dropped with an average half-life (t(1/2)) of 0.8 hours. Viral loads then continued to drop up to 23 hours postimplantation (t(1/2) = 3.4 hours), and began to rise (doubling-time = 2.0 days) as soon as 15 hours after the anhepatic phase. In 3 patients the viral load reached a plateau before rising, suggesting that a nonhepatic source supplied virions and balanced their intrinsic clearance. However, from the decline in viral load over the first 24 hours of the postanhepatic phase, we estimate that nonhepatic sources can at most correspond to 4% of total viral production, 96% of which occurs in the liver, even after we corrected for fluid exchanges during surgery. As the new liver was reinfected, production increased and viral load rose to a new steady state. Using nonlinear regression, we were able to fit the patients' HCV RNA data to a viral dynamic model and estimate the de novo infection rate (mean 1.5 x 10(-6) mL/virion/day), as well as the average percentage of hepatocytes infected at the posttransplantation steady state (19%). In conclusion, we have quantified liver reinfection dynamics in the absence of posttransplantation antiviral therapy. Our findings support the notion that early antiviral therapy may delay or prevent reinfection.

Early hepatic stellate cell activation predicts severe hepatitis C recurrence after liver transplantation

Only a subset of hepatitis C virus (HCV)-infected patients develop progressive hepatic fibrosis after liver transplantation (LT). Hepatic stellate cell (HSC) activation is a pivotal step in hepatic fibrosis and precedes clinically apparent fibrosis. We determined whether early HSC activation, measured in 4-month protocol post-LT biopsies, is predictive of subsequent development of more histologically severe recurrence of HCV. Early (4 month) post-LT HSC activation, as measured by alpha-smooth muscle actin (alpha-SMA) staining, was determined in liver biopsies from recipients with severe (fibrosis score > or = 2, n = 13) and with mild (fibrosis score of 0, n = 13) recurrence of HCV at one-year post-LT. Immunohistochemical staining for alpha-smooth muscle actin (alpha-SMA) was used to generate HSC activation scores (regional and total). Total HSC activation scores at 4 months were similar in patients with severe and mild HCV recurrence (3.9 +/- 2.0 vs. 2.7 +/- 2.2, P = 0.2). Regional HSC activation, assessed as parenchymal (zones 1, 2, and 3) or mesenchymal (portal tracts and fibrous septa), was different between the study groups, with higher mesenchymal scores predictive of progression. No patients in the mild recurrence group had detectable mesenchymal alpha-SMA staining vs. 46% (6/13) of patients with severe recurrence (P < 0.01). Mesenchymal activation of HSC had a specificity and positive predictive value of 100% for development of progressive fibrosis in liver allografts of patients with hepatitis C. In conclusion, early activation of mesenchymal HSCs is a marker for progressive fibrosis in patients with hepatitis C post-LT and may help select patients who would benefit from HCV or HSC-targeted therapy.

Management of hepatitis C virus infection in the setting of liver transplantation

1. Posttransplantation recurrence of hepatitis C virus infection is a universal phenomenon with a highly variable natural history. 2. Approximately 10% to 25% of hepatitis C virus- infected recipients of liver allografts will develop cirrhosis within 5 years' after transplantation. 3. The 1-year actuarial risk of hepatic decompensation after recurrence of cirrhosis approximates 42%. 4. Some of the factors associated with aggressive recurrence include donor and recipient age, recent year of transplantation, recipient gender and race, the use of antithymocyte globulin, and high dose of corticosteroids. 5. Highly aggressive recurrent hepatitis C virus infection leading to cirrhosis fares poorly after retransplantation in the presence of hyperbilirubinemia and renal failure, with a 1-year survival of approximately 40%. 6. Elevated serum aminotransferases are a poor indicator or recurrent disease. 7. Current sustained virological response after combination pegylated alpha interferon and ribavirin treatment is approximately 25%. 8. There is no consensus on initiation time point, duration of treatment, or dosage. Given immunosuppression, at least 48 weeks of therapy is a reasonable approach. 9. Treatment for 48 weeks is cost effective. Incremental cost-effectiveness ratio for men aged 55 years is $29,100 per life-year saved.

Detection of hepatitis C virus RNA in formalin-fixed paraffin-embedded sections with digoxigenin-labeled cRNA probes

Although recent studies have analyzed Hepatitis C (HCV) infections in liver tissue by in situ hybridization (ISH), many of these studies have been of limited diagnostic utility because of the low copy numbers of HCV in formalin-fixed paraffin-embedded (FFPE) tissue and failure to correlate the ISH analysis with other methods of detecting HCV. Thirty six cases of liver biopsies from patients with known HCV antibody status including 20 cases of serum HCV positive and 16 cases of serum HCV negative were analyzed. All cases showed histologic features suggestion of HCV infection. Analyses of all 36 cases were done by RT-PCR combined with Southern hybridization (RT-PCR-SH) and in situ hybridization (ISH). A prolactin riboprobe was used as a negative control. Immunohistochemistry (IHC) with an antibody against HCV (Rb 246) was also used to analyze HCV viral protein in the tissues. Of the 20 serum antibody-positive cases, RT-PCR-SH detected 18 positive cases, while ISH and IHC detected 19 and 16 positive cases, respectively. Of the 16 serum antibody-negative cases, RT-PCR-SH detected 8 positive cases while ISH and IHC detected 8 and 11 positive cases, respectively. A positive ISH signal for HCV was also detected in some lymphocytes and bile ducts in the liver. These results show that ISH with a highly specific riboprobe is comparable to RT-PCR-SH for detection of HCV infection in liver tissue.

Natural history of hepatitis C following liver transplantation

PURPOSE OF REVIEW

Currently, chronic hepatitis C virus-infection-related cirrhosis is the most common indication for liver transplantation in the USA and most parts of the world. While the incidence of new hepatitis C virus cases has decreased, the prevalence of infection will not peak until the year 2040. In addition, as the duration of infection increases, the proportion of new patients with cirrhosis will double by 2020 in an untreated patient population. If this model is correct, the projected increase in the need for liver transplantation secondary to chronic hepatitis C virus infection will place an impossible burden on an already limited supply of organs. In this article we present a comprehensive review of post-transplant hepatitis C virus infection and address the major challenges that face the transplant community.

RECENT FINDINGS

Hepatitis C virus infection recurs virtually in every post-transplant patient. Typically, serum levels of hepatitis C virus RNA increase rapidly from week 2 post-liver transplant, achieving 1-year post-liver transplant levels that are 10-20-fold greater than the mean pre-liver transplant levels. Progression of chronic hepatitis C virus is more aggressive after liver transplantation with a cumulative probability of developing graft cirrhosis estimated to reach 30% at 5 years. Approximately 10% of the patients with recurrent disease will die or require re-transplantation within 5 years post-transplantation. Interventions to prevent, improve, or halt the recurrence of hepatitis C virus infection have been evaluated by multiple small studies worldwide with similar overall rates of virological clearance of approximately 9-30%. Current consensus recommends combination therapy with pegylated interferon and ribavirin for those patients with histological recurrence of hepatitis C virus infection and fibrosis of >/= 2/4. Therapy is adjusted to tolerance and rescued with granulocyte colony-stimulating factor and erythropoietin for bone marrow suppression.

SUMMARY

The major challenges that face the transplant community in the coming years include new strategies to meet the growing demand for limited organ donor supplies and improvement of treatment for those patients in whom recurrence of viral disease has occurred. Only with improved antiviral treatments and strategies will we make a significant impact on this problem.

Detection of West Nile virus using formalin fixed paraffin embedded tissues in crows and horses: quantification of viral transcripts by real-time RT-PCR

West Nile virus (WNV) RNA was quantified in WNV infected crows and horses with the help of a real-time reverse transcriptase-PCR assay. A 5' nuclease assay, based on NS5 gene detection with a fluorescent probe was used for quantifying WNV RNA using formalin fixed paraffin embedded tissue specimens. Quantitative detection of WNV RNA showed the presence of a higher amount of the viral RNA in crow tissues compared to equine tissues and these results correlated well with the detection of WNV antigen by immunostaining. In crows, the highest amount of virus was seen in the intestine and in horses in the brain.

Impact of immunosuppression on immunopathogenesis of liver damage in hepatitis C virus-infected recipients following liver transplantation

1. Hepatitis C virus (HCV) infection in the allograft occurs in the setting of greater viral burdens than in patients pretransplantation. 2. Viral burden is increased by such immunosuppressive therapies as corticosteroids and interleukin-2 receptor antibodies. 3. Cholestatic HCV infection occurs in the setting of very high viral load and is almost certainly induced by overimmunosuppression. It is managed best by rapid reduction in levels of immunosuppression. 4. The more common chronic hepatitic HCV disease seems to behave at the molecular/cellular level in a fashion similar to the nontransplantation setting with activation of T helper subtype 1 inflammatory, profibrotic, and proapoptotic pathways. The role of immunosuppression in the acceleration of this disease is unclear, and rapid reduction in immunosuppressive doses may be detrimental. 5. Changes to definitions of types of HCV disease recurrence, disease severity, and acute allograft rejection in the presence of HCV infection are required to improve understanding of the pathogenesis.

Effect of coadministered lopinavir and ritonavir (Kaletra) on tacrolimus blood concentration in liver transplantation patients

With the advent of highly active antiretroviral therapy (HAART), HIV positivity is no longer a contraindication for liver transplantation. Some of the antiretroviral agents, particularly protease inhibitors (e.g., ritonavir, indinavir, and nelfinavir) have been described as potent inhibitors of the metabolism of certain immunosuppressive drugs. In this article we describe a profound interaction between tacrolimus and Kaletra (Abbott Laboratories, Chicago, IL) (a combination of lopinavir and ritonavir) in 3 liver transplantation patients. Patient 1, who was maintained on a 5 mg twice daily dose of tacrolimus with a trough blood concentration around 10.6 ng/mL, required only 0.5 mg of tacrolimus per week after addition of Kaletra to achieve similar tacrolimus blood concentrations, with a half-life of 10.6 days. In patient 2, the area under the blood concentration versus time curve for tacrolimus increased from 31 ng/mL/h to 301 ng/mL/h after addition of Kaletra, with a corresponding half-life of 20 days. When the patient was subsequently switched to nelfinavir, the half-life decreased to 10.3 days. Patient 3, who was maintained with 4 to 8 mg/d of tacrolimus and a corresponding blood concentration of 10 ng/mL before Kaletra, required a tacrolimus dose of 1 mg/wk and tacrolimus concentrations of 5 ng/mL with Kaletra. In conclusion, a combination of lopinavir and ritonavir led to a much more profound increase in tacrolimus blood concentrations than use of single protease inhibitor, nelfinavir. A tacrolimus dose of less than 1 mg/wk may be sufficient to maintain adequate blood tacrolimus concentrations in patients on Kaletra. Patients may not need a further dose of tacrolimus for 3 to 5 weeks depending on liver function when therapy with Kaletra is initiated. Great caution is required in the management of tacrolimus dosage when Kaletra is introduced or withdrawn in HIV-positive patients after liver transplantation, particularly in the presence of hepatic dysfunction.

Natural history of hepatitis C and outcomes following liver transplantation

Hepatitis C-associated liver failure is the most common indication for liver transplantation and the infection recurs nearly universally following transplantation. Histologic evidence of recurrence is apparent in approximately 50% of HCV-infected recipients in the first postoperative year. Approximately 10% of HCV-infected recipients will die or lose their allograft secondary to hepatitis C-associated allograft failure in the medium term. HCV-infected recipients who undergo retransplantation experience 5-year patient and graft survival rates that are similar to recipients undergoing retransplantation who are not HCV-infected. While the choice of calcineurin inhibitor or the use of azathioprine have not been clearly shown to affect histologic recurrence of hepatitis C or the frequency of rejection in HCV-infected recipients, cumulative exposure to corticosteroids is associated with increased mortality, higher levels of HCV viremia, and more severe histologic recurrence. In contrast to non-HCV-infected recipients, treatment for acute cellular rejection is associated with attenuated patient survival among recipients with hepatitis C. The development of steroid-resistant rejection is associated with a greater than 5-fold increased risk of mortality in HCV-infected liver transplant recipients. In lieu of large studies in a posttransplant population, therapy with pegylated IFN (+/- ribavirin) should be considered in recipients with histologically apparent recurrence of hepatitis C before total bilirubin exceeds 3 mg/dl. The role of hepatitis C immunoglobulin and new immunosuppression agents in the management of posttransplant hepatitis C infection is still evolving.

Pathogenesis of hepatitis C virus recurrence in the liver allograft

1. Hepatitis C virus (HCV) infection in the allograft occurs in the setting of greater viral burden than in nontransplantation patients. 2. Infection of the allograft occurs early (within days and possibly during the intraoperative reperfusion phase). 3. Viral burden plateaus at 1 month posttransplantation and (in the absence of cholestatic HCV) peaks at the time of acute hepatitis (1 to 4 months). 4. Acute hepatitis is associated with immune cell infiltration and hepatocyte apoptosis. 5. Cholestatic HCV seems to be a disease of direct HCV cytopathic injury in the setting of extreme virus levels, an intrahepatic T helper subtype 2 cell (T(H)2)-like response, and lack of a specific HCV-directed response. 6. Chronic hepatitic HCV seems to behave at the molecular and/or cellular level in a similar fashion to the nontransplantation setting, with activation of T(H)1 inflammatory, profibrotic, and proapoptotic pathways. This process operates at a greater viral burden than pretransplantation and leads to more progressive disease. 7. More studies are required to examine and distinguish allograft rejection in the setting of HCV infection from HCV infection alone.

Diagnostic issues in liver transplantation pathology

Liver biopsy is used to determine the pathogenesis of liver dysfunction after liver transplantation. One or more causative factors may be identified on biopsy. The pathologist must be familiar with the histopathology of acute rejection to differentiate it from other potential complications, including biliary obstruction, intercurrent cytomegalovirus hepatitis, or recurrent disease. Consensus documents from the Banff international panel provide useful guidelines for the appropriate grading of acute and chronic rejection.

A prospective randomized trial of mycophenolate mofetil in liver transplant recipients with hepatitis C

Hepatitis C is the most common indication for liver transplantation (LT) in the United States. Recurrence of hepatitis C virus (HCV) infection post-LT remains a problem for which there is no completely satisfactory treatment. The aim of the present study is to evaluate mycophenolate mofetil (MMF), which has both immunosuppressive and antiviral properties, to determine whether it is associated with a difference in the rate of HCV recurrence and also examine its impact on patient and graft survival. Between August 1995 and May 1998, a total of 106 patients who were HCV positive before LT were randomized to tacrolimus (TAC) and prednisone versus TAC, prednisone, and MMF therapy. The rate of recurrence of HCV, patient and graft survival, incidences of rejection, and histological findings were examined. Fifty six patients were randomized to TAC and steroid therapy (double [D] drug; group D), and 50 patients were randomized to TAC, steroid, and MMF therapy (triple [T] drug; group T). Liver biopsies were performed when liver function was abnormal; protocol liver biopsies were not performed. Mean follow-up was 4.3 +/- 0.8 years. Actuarial patient survivals at 4 years were 72.6% in group D and 73.8% in group T (P = not significant). Actuarial graft survivals at 4 years were 65.6% in group D and 65.4% in group T. One patient in group D and 2 patients in group T underwent a second LT for recurrent HCV. One patient in each group died of recurrent HCV without re-LT. Twenty-six patients in group D (46.4%) and 23 patients in group T (46.0%) showed signs of recurrent HCV. Mean hepatitis activity index (HAI) scores were 7.4 +/- 2.7 in group D and 7.0 +/- 3.4 in group T, and mean fibrosis scores were 2.9 +/- 1.7 in group D and 2.6 +/- 1.1 in group T. The rate of rejection was 0.57/patient in each group for the entire follow-up period. None of these values reached statistical significance. Rates of HCV recurrence, graft loss or death from recurrent HCV, and 4-year actuarial patient and graft survival were not different between the groups. In liver transplant recipients with HCV, MMF has no impact on patient survival, graft survival, rejection, or rate of HCV recurrence based on biochemical changes and histological findings. In addition, there was no difference in HAI or fibrosis score between the two groups. Either MMF has no anti-HCV effect or its immunosuppressive properties overwhelm its antiviral effect in the clinical setting.

Hepatitis C virus and liver transplantation

Advances in immunosuppressive therapy, operative techniques, and perioperative management have resulted in long-term patient survival rates approaching 90% following liver transplantation for chronic viral hepatitis. The increasing number of referrals for liver transplantation reflects the impact of chronic HCV infection as a cause of end-stage liver disease. Unlike hepatitis B, there is still no effective treatment in preventing recurrent hepatitis C after liver transplantation. The spectrum of allograft injury related to universal HCV infection recurrence ranges from no evidence of histologic injury to mild inflammation to severe disease with allograft failure in small proportion of patients. Various factors may explain these differing outcomes, including degree of pretransplantation viremia, HLA compatibility, presence of more pathogenic HCV genotypes, integrity of cellular immune response, and type of immunosuppression. Fortunately, patient survival does not seem to be affected short-term; the long-term outcome of liver transplantation for chronic hepatitis C is unclear but is likely to be decreased. Combination therapy with interferon plus ribavirin seems to be a promising treatment strategy for posttransplantation recurrent hepatitis C, and the use of pegylated interferon plus ribavirin may improve these results. Patients with moderate to severe allograft hepatitis are appropriate candidates for combination antiviral therapy. Histopathologically documented recurrent hepatitis C in liver transplant recipients is associated with impaired quality of life, inferior physical condition, and a higher incidence of depression compared with patients who did not have HCV and in those without HCV recurrence. In conclusion, it is possible that the continued improvements in antiviral therapy against HCV infection may ultimately decrease the number of patients needing liver transplantation. Suitable candidates with chronic HCV infection thus warrant treatment with pegylated interferon plus ribavirin combination therapy in the hope of decreasing disease progression. Recent studies, which require confirmation, suggest that nonresponders to standard antiviral therapy may benefit from maintenance therapy. The donor pool for patients with chronic hepatitis C and decompensated cirrhosis can be improved by using HCV-positive donors and by increasing utilization of newer surgical techniques, including adult-to-adult living-donor liver transplantation and split-liver transplantation.

Pathology of the liver

Traditional anatomic pathology studies and molecular investigations both contributed to the breadth of current information in the field of liver pathology this year. Techniques such as reverse transcription polymerase chain reaction can identify recurrence of hepatitis C virus infection in the liver as early as 5 days after transplantation. Chronic rejection after transplantation may be characterized not only by ductopenia but also by loss of portal tract hepatic artery branches. There are many diseases of small bile ducts in adults, and idiopathic adulthood ductopenia has been identified in extended family members. Adverse reactions to drugs may precipitate their removal from the pharmacopoeia, such as the many cases reported of severe bridging and submassive necrosis due to troglitazone (a thiazolidinedione antidiabetic agent). Several publications highlighted the association of hepatitis C virus infection with lymphoproliferative diseases and, newly, with cholangiocarcinoma.