Effects of immunosuppression and organ transplantation on the natural history and immunopathogenesis of hepatitis C virus infection

De novo autoimmune hepatitis in liver transplant: State-of-the-art review

In the two past decades, a number of communications, case-control studies, and retrospective reports have appeared in the literature with concerns about the development of a complex set of clinical, laboratory and histological characteristics of a liver graft dysfunction that is compatible with autoimmune hepatitis. The de novo prefix was added to distinguish this entity from a pre-transplant primary autoimmune hepatitis, but the globally accepted criteria for the diagnosis of autoimmune hepatitis have been adopted in the diagnostic algorithm. Indeed, de novo autoimmune hepatitis is characterized by the typical liver necro-inflammation that is rich in plasma cells, the presence of interface hepatitis and the consequent laboratory findings of elevations in liver enzymes, increases in serum gamma globulin and the appearance of non-organ specific auto-antibodies. Still, the overall features of de novo autoimmune hepatitis appear not to be attributable to a univocal patho-physiological pathway because they can develop in the patients who have undergone liver transplantation due to different etiologies. Specifically, in subjects with hepatitis C virus recurrence, an interferon-containing antiviral treatment has been indicated as a potential inception of immune system derangement. Herein, we attempt to review the currently available knowledge about de novo liver autoimmunity and its clinical management.

Immunopathogenesis of Hepatitis C Virus Infection

Despite advances in therapy, hepatitis C virus infection remains a major global health issue with 3 to 4 million incident cases and 170 million prevalent chronic infections. Complex, partially understood, host-virus interactions determine whether an acute infection with hepatitis C resolves, as occurs in approximately 30% of cases, or generates a persistent hepatic infection, as occurs in the remainder. Once chronic infection is established, the velocity of hepatocyte injury and resultant fibrosis is significantly modulated by immunologic as well as environmental factors. Immunomodulation has been the backbone of antiviral therapy despite poor understanding of its mechanism of action.

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.

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.

Hepatitis C virus recurrence after liver transplantation: biomarkers of disease and fibrosis progression

End-stage liver disease due to hepatitis C virus infection (HCV) is the principal indication for liver transplantation. In the USA, over a third of available liver allografts are transplanted into recipients with chronic HCV infection. Reinfection of the graft is universal, but the impact of reinfection on short- and long-term liver function is highly variable. HCV infection in liver transplantation recipients is characterized by an accelerated fibrogenesis, with approximately a third of patients developing cirrhosis within 5 years of follow-up. HCV is associated with decreased patient and graft survival when compared with other indications of orthotopic liver transplantation. The mechanisms responsible for the accelerated liver damage in HCV-infected orthotopic liver transplantation recipients remain largely unknown.

Decrease and dysfunction of dendritic cells correlate with impaired hepatitis C virus-specific CD4+ T-cell proliferation in patients with hepatitis C virus infection

Through the production of stimulatory and suppressive cytokines, dendritic cells (DCs) regulate virus-specific immune responses that are crucial to virus eradication. To explore a possible role of DCs in the persistence of hepatitis C virus (HCV) infection, in this study we analysed peripheral blood DCs (PBDCs) in patients with chronic hepatitis C (CHC) compared with those in both healthy seronegative (HSN) controls and a group of subjects who had spontaneously resolved infection, defined as healthy HCV-seropositive (HSP), and we evaluated the relationships between PBDCs and HCV-specific CD4(+) T-cell reactivity. The number of PBDCs, their immunophenotype and expression of regulatory cytokines were evaluated by flow cytometry on whole-blood samples. HCV-specific CD4(+) T-cell activation, proliferation and cytokine production were evaluated in cultures of peripheral blood mononuclear cells (PBMCs) stimulated in vitro with HCV peptides. We found that PBDCs from CHC subjects were numerically reduced and showed lower interleukin-12 (IL-12) and higher IL-10 expression than those from HSN controls. PBDCs from HSP subjects were similar to those from HSN controls. HCV-specific CD4(+) T-cell proliferation was less frequent and vigorous in CHC than in HSP patients and was directly related to the number of PBDCs and their IL-12 production but inversely related to their IL-10 production. Taken together, these results seem to suggest that cytokines of DC origin contribute to the regulation of HCV-specific immunity in CHC patients and indicate that PBDCs may represent a novel non-invasive tool for immune monitoring of these patients.

Cytokine--chemokine and apoptotic signatures in patients with hepatitis C

Cytokines and chemokines are proteins that play a critical role in the regulation of immunity and inflammation in patients with chronic Hepatitis C. The aim of our study was to correlate serum cytokines, chemokines and apoptosis in non-treated chronic hepatitis C patients with various degrees of inflammation and fibrosis. We studied 778 patients: 59 had low Knodell fibrosis score and low Knodell histological activity index; 372 had mild fibrosis and low histological activity index; 270 had moderate fibrosis and moderate histological activity index; and, 77 had high fibrosis and high histological activity index on their biopsy. Serum cytokines, chemokines and apoptosis were measured by enzyme-linked-immunosorbent-assay. Multivariate analysis was employed for statistical purposes. A positive correlation was seen between the degree of inflammation and tumor necrosis factor-alpha (TNF-alpha) levels (r = 0.92) in non-cirrhotic patients and between interleukin 2 in all patients (r = 0.85). Interleukin-8 increased significantly at higher histological activity indices and continued to increase in patients with cirrhosis. Transforming growth factor-beta (TGF-beta) levels increased significantly with the severity of fibrosis, but decreased in cirrhotics. In conclusion, cytokines, chemokines and apoptosis levels reflect the progression of inflammation and fibrosis in hepatitis C infected patients, but their signatures differ.

The hepatic transcriptome in human liver disease

The transcriptome is the mRNA transcript pool in a cell, organ or tissue with the liver transcriptome being amongst the most complex of any organ. Functional genomics methodologies are now being widely utilized to study transcriptomes including the hepatic transcriptome. This review outlines commonly used methods of transcriptome analysis, especially gene array analysis, focusing on publications utilizing these methods to understand human liver disease. Additionally, we have outlined the relationship between transcript and protein expressions as well as summarizing what is known about the variability of the transcriptome in non-diseased liver tissue. The approaches covered include gene array analysis, serial analysis of gene expression, subtractive hybridization and differential display. The discussion focuses on primate whole organ studies and in-vitro cell culture systems utilized. It is now clear that there are a vast number research opportunities for transcriptome analysis of human liver disease as we attempt to better understand both non-diseased and disease hepatic mRNA expression. We conclude that hepatic transcriptome analysis has already made significant contributions to the understanding of human liver pathobiology.

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.

HCV Core Protein Augments Cyclosporine Immunosuppression

Hepatitis C viremia occurs universally after liver transplantation. It is speculated that soluble HCV proteins may be immunomodulatory. We measured the effects of HCV core upon human T-cell proliferation, expression of activation markers, and interaction with cyclosporine. Cells were activated with anti-CD3 for 2-6 days. Cultivation with 1, 2, 4, and 8 microg/mL core reduced tritiated thymidine uptake by 7% (P = ns), 63% (P < .001), 69% (P < .001) and 92% (P < .001). Direct cell counting (10(4)) showed proliferative inhibition in treated cultures after 2 days (84%, P < .05), 4 days (93%, P < .05), and 6 days (88%, P < .05). Viability remained greater than 90%. Expression of activation markers was reduced with core treatment. Treatment with 4 microg/mL core for 2, 4, and 6 days reduced CD2+CD25+ by 67% (P < .05), 67% (P < .05), and 51% (P < .05) and CD2+DR+ expression by 54% (P < .05), 46% (P < .05), and 54% (P < .05). Interaction between core and cyclosporine was determined by isobologram analysis which determines whether interactions are synergistic, additive or antagonistic. Combining core with cyclosporine resulted in an additive effect upon proliferative suppression. Linear regression confirmed an additive interaction with an r2 value of 0.98. The data shows that soluble core causes dose dependent suppression of T-cell proliferation and may potentiate suppression by cyclosporine.

Biomedicines to reduce inflammation but not viral load in chronic HCV--what's the sense?

Although cytokines and cytotoxic T lymphocytes (CTL) are among the predominant mechanisms of host defense against viral pathogens, they can induce an inflammatory response that often leads to tissue injury. Hepatitis C virus (HCV) infection, a major cause of liver-related disease, results in the induction of proinflammatory cytokines, such as tumor necrosis factor-alpha (TNF-alpha), and CTL activity, followed by liver injury. Although inflammation facilitates the wound healing process, chronic persistence over several decades results in scar accumulation, fibrosis and often cirrhosis. This review summarizes biological data implicating a cause-and-effect relationship between TNF-alpha levels and the progression of fibrosis in chronic HCV infections, in contrast to the role of TNF-alpha in hepatitis B virus infections. Furthermore, an overview of therapeutic approaches to halting the inflammatory cascade in individuals with chronic HCV, including the use of agents to reduce the level of TNF-alpha, is presented.

Outcome after orthotopic liver transplantation in five HIV-infected patients with virus hepatitis-induced cirrhosis

BACKGROUND

We report on our experiences with orthotopic liver transplantation (OLT) in HIV-infected patients. Between July 1998 and October 2001, five HIV-infected patients underwent OLT because of virus-induced liver cirrhosis. One patient suffered from hepatitis B virus (HBV)-, three patients from hepatitis C virus (HCV)- and one patient from HCV/HBV/HDV-related cirrhosis (HDV, hepatitis D virus). The mean duration of HIV infection was 15 years. Patients were prospectively followed up with a mean duration of 25.6 months.

RESULTS

Three patients died 3, 10 and 31 months after OLT, respectively, due to graft failure. The causes of graft failure were: recurrent thrombosis of the hepatic artery, HCV-associated cholestatic hepatitis and chemotherapy-induced liver damage due to Hodgkin's disease, which was diagnosed 17 months after OLT, in addition to chronic HCV disease. The two survivors show a stable liver function and non-progredient HIV infection under antiretroviral therapy 61 and 23 months after OLT, respectively.

CONCLUSIONS

A medium- or even long-term survival after OLT can be achieved in HIV-infected patients without progression of HIV disease under antiretroviral therapy. However, in our study three out of five patients died due to graft failure. Therefore, prognostic criteria have to be defined for the selection of HIV-infected patients, who may benefit from OLT.

Rapid steroid withdrawal in hepatitis C virus-positive kidney transplant recipients

The effects of rapid steroid withdrawal (SW) on kidney transplantation (KT) outcome were investigated in 12 HCV+ patients in a prospective cohort study. These results were compared with 17 HCV+ patients who received KT in the prior 2 yr and treated with a standard prednisone taper protocol. SW patients received only 6 d of steroid treatment after transplantation. Eleven received Thymoglobulin and one Basiliximab induction treatment along with a calcineurin inhibitor and mycophenolate mofetil. Patient and graft survival was 92% in SW group (median follow-up 12 months, range 6-17), and 92 and 82% in the historic control group respectively (median follow-up 21 months, range 11-27). In the SW and control group, acute rejection rates were 9 and 18%, and mean creatinine levels at last follow-up 1.30 +/- 0.36 and 1.68 +/- 0.58 mg/dL respectively. Only two SW patients had an increase in liver function tests during follow-up (18%), compared with six patients in the control group (43%). This study demonstrates that rapid SW is safe for HCV+ KT recipients, without an increase in acute rejection episodes or liver function abnormalities in the short term.

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.

Effect of tumour necrosis factor alpha antagonists on serum transaminases and viraemia in patients with rheumatoid arthritis and chronic hepatitis C infection

BACKGROUND

Tumour necrosis factor alpha (TNF alpha) antagonists are effective for the treatment of rheumatoid arthritis (RA), but concerns remain about the safety of these agents in the presence of chronic infections, including hepatitis C virus (HCV) infection.

OBJECTIVE

To examine the influence of treatment with TNF alpha antagonists on levels of HCV viraemia and serum transaminases in patients with RA and HCV.

METHODS

In a retrospective survey the course of 16 HCV infected patients with RA who had received the TNF alpha antagonists etanercept or infliximab was analysed. Eight additional patients with RA and HCV were also enrolled into a three month prospective trial of etanercept. Serum concentrations of albumin, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, and HCV were followed.

RESULTS

Viraemia was measured in 22 patients receiving a TNF alpha antagonist at the start of treatment and after 1-34 months (median 9 months follow up). Twenty four patients had serial tests of liver related enzymes and albumin. None of the differences between liver related tests at baseline and at follow up achieved significance (p>0.05). Similarly, the mean HCV measurement at 1-3, 4-6, 7-12, and 13-34 months did not differ significantly from baseline (p>0.05).

CONCLUSION

In this study, liver related blood tests and HCV viral load measurements did not change substantially. These findings suggest that TNF alpha antagonists merit further study for the treatment of RA in HCV infected patients. Larger and longer term studies are still needed.

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.

Increased risk of cholestatic hepatitis C in recipients of grafts from living versus cadaveric liver donors

Histologic injury caused by recurrent hepatitis C virus (HCV) has been reported in up to 90% of HCV-infected patients who undergo liver transplantation with a cadaveric graft. However, the natural history of HCV after living donor liver transplantation (LDLT) is not well described. We performed a retrospective analysis of 68 consecutive HCV-infected adult patients: 45 recipients of cadaveric grafts (CAD) were compared with 23 LDLT patients. Elevated serum transaminases, positive HCV RNA, and liver biopsy consistent with histologic evidence of HCV defined recurrence. When comparing CAD with LDLT, both the incidence of HCV recurrence and time to recurrence were not different. The overall incidence of severe sequelae of HCV recurrence, either cholestatic hepatitis, grade III-IV inflammation, and/or HCV-induced graft failure requiring retransplantation, was also not different when comparing CAD with LDLT. However, when comparing CAD versus LDLT, no CAD patient developed cholestatic hepatitis C, compared with 17% of LDLT who developed this complication (P =.001). Thus, in this patient population, the timing and incidence of HCV recurrence were not different when comparing CAD versus LDLT, but the incidence of cholestatic hepatitis was significantly greater in patients with HCV who underwent LDLT.

Hepatitis C virus dynamics and pathology: the role of CTL and antibody responses

This paper investigates the role of CTL and antibody responses in hepatitis C virus (HCV) dynamics and pathology. Mathematical models suggest that a strong CTL response is required for resolution of HCV infection and that a weak CTL response can result in persistent infection. According to the model, establishment of persistent infection is accompanied mainly by an ongoing antibody response, while CTLs are not maintained at high levels. In the model, this outcome correlates with absence of pathology. Persistent infection in the face of an ongoing antibody response can result in evolution of antigenic escape. According to the model, evolution towards escape from antibodies can shift the balance of immune responses so that the weak CTL levels become increasingly more dominant relative to antibodies. This shift results in onset of liver pathology as the virus evolves towards increased levels of antigenic escape. Therefore, the relative balance of the immune response can be a decisive factor that determines whether patients are asymptomatic or whether pathology is observed. Virus evolution can shift this balance towards pathology over time. Theoretical results are discussed in the context of published data.

[Role of interferons in the treatment of hepatitis B and hepatitis C virus infections]

BACKGROUND

Since the discovery of hepatitis C (HCV), the efficacy of treatment has significantly progressed using standard mono-therapy: with Interferon alpha (IFN) during six months we obtained approximately 10% sustained response and currently with the association of pegylated IFN and Ribavirin a 55% sustained response was achieved.

CURRENT POSITION AND MAJOR POINTS

HCV infection continues to present therapeutic problems which have not entirely been solved, mainly related to clinical and biological tolerance, and non-responders. Moreover, the care of patients with extra-hepatic localization, cirrhotic patients, as well as therapeutic problems of co-infected HIV-HCV patients. As regards hepatitis B (HBV) new effective treatments against this virus have appeared, IFN then nucleoside analogs, some of which are available in France (i.e. lamivudine, adefovir, dipovoxil). The main objective of chronic hepatitis B treatment is to obtain the complete inhibition of the HBV virus by Hbe-antigen antibody seroconversion which would therefore significantly increase patient survival. In this article the advantages and disadvantages of the different treatments are assessed.

FUTURE PERSPECTIVES

Despite the considerable and rapid progress obtained in the therapeutic treatment of infection due to HCV and HBV a number of unknown factors remain, which warrants further trials, in particular to evaluate the efficacy as well as the tolerance of the antiviral agent association.

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.

Interactions between cytomegalovirus, human herpesvirus-6, and the recurrence of hepatitis C after liver transplantation

Recurrence of hepatitis C (HCV) following liver transplantation is common. Herpesvirus reactivation following transplant may have an immunomodulatory effect resulting in increased HCV replication. We studied whether cytomegalovirus (CMV) and human herpesvirus-6 (HHV-6) may be associated with HCV recurrence and viral load after transplant. We prospectively followed 66 HCV liver-transplant recipients with serial viral load testing for CMV and HHV-6. Infection and viral load were correlated with the development of biopsy-proven HCV recurrence and HCV viral loads. Histologic recurrence of HCV occurred in 41/66 (62.1%) patients. In the primary analysis, CMV infection and disease, and HHV-6 infection were not associated with HCV recurrence. Peak CMV and HHV-6 viral loads were not significantly different in patients with and without recurrence. No correlation was observed between HCV viral loads at 1 and 3 months post-transplant and peak HHV-6 or CMV viral loads. In a subgroup analysis, HHV-6 infection was associated with the development of more severe recurrence (hepatitis and/or fibrosis score > or = 2) (p = 0.01). Also, fibrosis scores at last follow up were higher in patients with CMV disease (1.67 vs. 0.56; p = 0.016) and in patients with HHV-6 infection (1.18 vs. 0.55; p = 0.031). In conclusion, HHV-6 and CMV infection and viral load were not associated with increased overall rates of HCV recurrence or HCV viral load after liver transplantation but may be associated with more severe forms of recurrence.

Update on the Management of Hepatitis C in Liver Transplant Recipients

Hepatic failure due to hepatitis C is the leading indicator for orthotopic liver transplantation (OLT) in the United States. Unfortunately, recurrent hepatitis C virus infection is essentially universal following orthotopic liver transplantation. Although significant advances have been made in the past decade for the treatment of hepatitis C, a similar level of success has not yet been achieved for most hepatitis C virus-infected liver transplant recipients. In addition, deleterious side effects of the currently available antiviral agents continue to significantly hamper their use. Several recent reports, however, indicate that newer immunosuppressive regimens combined with novel modifications of existing treatment paradigms will likely lead to improved clinical outcomes for the hepatitis C virus-infected liver transplant recipient.