Roniel Cabrera

An immunomodulatory role for CD4+CD25+ regulatory T lymphocytes in hepatitis C virus infection

The CD4+CD25+ regulatory T lymphocytes have been implicated in suppressing T cell immune responses. Our aim was to characterize the frequency, phenotype, function, and specificity of CD4+CD25+ T cells in hepatitis C virus (HCV) infection. Peripheral CD4+CD25+ cells from recovered (n = 15), chronic infected (n = 30), and normal control (n = 15) subjects were analyzed ex vivo for quantitation, phenotype, and effect on HCV‐specific interferon gamma production and proliferation. CD4+CD25+ specificity was determined by intracellular cytokine staining for interleukin 10 (IL‐10). A higher proportion of CD4+CD25+ were found in chronic infection (mean, 3.02%) when compared with recovered (1.64%, P = .001) and normal controls (2.27%, P = .02). CD4+CD25+ cells display CD45ROhigh, CD45RAlow, CD28high, CD62Lhigh, and CD95high phenotype. HCV‐specific interferon gamma activity was enhanced in peripheral blood mononuclear cells depleted of CD4+CD25+ and suppressed in peripheral blood mononuclear cells enriched with CD4+CD25+. Depletion of CD4+CD25+ cells also enhanced HCV‐specific CD4+ and CD8+ T cell proliferation. Cytokine analysis suggested CD4+CD25+ cells secrete transforming growth factor beta (TGF‐β1) and IL‐10. The inhibitory role for TGF‐β1 was confirmed by anti–TGF‐β1. Transwell studies showed CD4+CD25+ mediated suppression to be dose dependent and requiring cell contact. CD4+CD25+ cells showed HCV‐specificity through IL‐10 production, with a frequency ranging from 1.9% to 5.3%. A positive correlation was detected between CD4+CD25+ T cell frequency and HCV RNA titer, whereas an inverse relation was found with liver inflammatory activity. In conclusion, CD4+CD25+ T lymphocytes constitute a highly differentiated population and appear to play a role in viral persistence by suppressing HCV‐specific T cell responses in a cell–cell contact manner. (HEPATOLOGY 2004;40:1062–1071.)

Review article: the management of hepatocellular carcinoma.

Aliment Pharmacol Ther 31, 461–476

Cyclosporine suppresses hepatitis C virus in vitro and increases the chance of a sustained virological response after liver transplantation.

Cyclosporine is an immunosuppressive agent widely used in the management of liver transplant recipients. Cyclosporine has been shown to have antiviral activities against HIV, herpes simplex, and vaccinia viruses. The aim of this study was to determine the effect of Cyclosporine in viral clearance in the liver transplant recipients during therapy with combination of interferon and ribavirin, and to determine the anti‐viral potential of Cyclosporine in vitro. Immunosuppression consisted of either Cyclosporine or Tacrolimus‐based therapy. Both groups received therapy with interferon and ribavirin for 48 weeks when evidence of progressive histologic disease was determined. We found that subjects on Cyclosporine‐based immunosuppression (n = 56) had a higher sustained virological response of 46% compared to 27% in the patients on Tacrolimus‐based therapy (n=59, P = 0.03). In vitro studies were performed to evaluate the antiviral effect of Cyclosporine in the replicon system. These studies showed that Cyclosporine inhibits hepatitis C viral replication in a dose‐dependent manner. Combination of Cyclosporine with interferon showed additive effect, and its function is independent of interferon signaling pathways. In conclusion, Cyclosporine may offer an advantage to Tacrolimus in those patients undergoing interferon‐based therapy and should be studied in a prospective randomized trial. Liver Transpl 12:51–57, 2006.

One-year protocol liver biopsy can stratify fibrosis progression in liver transplant recipients with recurrent hepatitis C infection:

Determinants of progression to cirrhosis in hepatitis C virus (HCV) infection have been well described in the immunocompetent population but remain poorly defined in liver transplant (LT) recipients. This cohort study determines the factors contributing to the development of fibrosis and its rate of progression in the allograft. Predictive factors analyzed include: demographics, host and donor factors, surgery‐related variables (cold and warm ischemia time), rejection episodes, cytomegalovirus infection (CMV), and immunosuppression. Over 12 years, 842 adult LTs were performed at our institution; 358 for the indication of HCV. A total of 264 patients underwent protocol liver biopsies at month 4 and yearly after LT. Using the modified Knodell system of Ishak for staging fibrosis, the median fibrosis progression rate was .8 units/year (P < .001). Rapid fibrosis progression (>.8 units/year) was best identified by liver histology performed at 1 year. Donor age > 55 years was associated with rapid fibrosis progression and development of cirrhosis (P < .001). In contrast, donor age < 35 years was associated with slower progression of fibrosis (P = .003). Risk factors for graft loss due to recurrent HCV included recipient age > 35 years (P = .01), donor age > 55 years (P = .005), and use of female donor allografts (P = .03). In conclusion, fibrosis progression in HCV‐infected LT recipients occurs at a rate of .8 units/year. Increased donor age has a major impact on disease progression, graft failure, and patient survival. A liver biopsy performed at 1 year posttransplant can help identify those patients more likely to develop progressive disease and may allow better targeting of antiviral therapy. (Liver Transpl 2004;10:1240–1247.)

Hepatocellular carcinoma: current trends in worldwide epidemiology, risk factors, diagnosis, and therapeutics

Hepatocellular carcinoma (HCC) is a common malignancy in developing countries and its incidence is on the rise in the developing world. The epidemiology of this cancer is unique since its risk factors, including hepatitis C and B, have been clearly established. The current trends in the shifting incidence of HCC in different regions of the world can be explained partly by the changing prevalence of hepatitis. Early detection offers the only hope for curative treatment for patients with HCC, hence effective screening strategies for high-risk patients is of utmost importance. Liver transplantation and surgical resection remains the cornerstone of curative treatment. But major advances in locoregional therapies and molecular-targeted therapies for the treatment of advanced HCC have occurred recently. In this review, current trends in the worldwide epidemiology, surveillance, diagnosis, standard treatments, and the emerging therapies for HCC are discussed.

Pilot study: fenofibrate for patients with primary biliary cirrhosis and an incomplete response to ursodeoxycholic acid

Aliment Pharmacol Ther 2011; 33: 235–242

The natural history of hepatitis C cirrhosis after liver transplantation

Hepatitis C after liver transplantation leads to graft cirrhosis in up to 30% of patients within 5 years, but limited data exist regarding the clinical course of cirrhosis after transplantation. The aims of this study were to report the natural history of hepatitis C cirrhosis after liver transplantation and to identify risk factors for decompensation and survival. Hepatitis C patients underwent protocol liver biopsies yearly after liver transplantation. After cirrhosis was identified by biopsy, the outcomes of interest were the development of decompensation, death, or retransplantation for hepatitis C. Kaplan‐Meier and Cox regression analysis was used to determine survival and risk factors for decompensation and mortality. Out of 502 liver transplants performed for hepatitis C, 88 patients (18%) had cirrhosis within 3.7 years. Seventy‐one patients were compensated at diagnosis. The cumulative probability of decompensation 1 year after cirrhosis was 30%. A Model for End‐Stage Liver disease score ≥ 16 was predictive of decompensation and poor survival, whereas successful interferon treatment was found to reduce this risk (relative risk = 0.05). Once decompensation occurred, 1‐year survival was 46%. In conclusion, the results confirm an accelerated natural history of hepatitis C cirrhosis after liver transplantation and demonstrate poor survival after decompensation. The Model for End‐Stage Liver Disease can stratify risk for decompensation and survival, whereas successful antiviral therapy may be protective. Liver Transpl 15:1063–1071, 2009.

The combination of sorafenib with transarterial chemoembolisation for hepatocellular carcinoma

Aliment Pharmacol Ther 2011; 34: 205–213

Kinase inhibitor Sorafenib modulates immunosuppressive cell populations in a murine liver cancer model.

Accumulating evidence suggests that regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSC) are elevated in cancer patients and tumor-bearing hosts, and that depletion of Tregs and MDSC may enhance the anti-tumor immunity of the host. Sorafenib, a novel multi-kinase inhibitor, is approved for the treatment of several human cancers, including advanced hepatocellular carcinoma (HCC). Sorafenib is believed to inhibit tumor growth via anti-angiogenesis, cell cycle arrest, and inducing apoptosis. However, the impact of Sorafenib on immune cell populations in tumor-bearing hosts is unclear. In this report, we show that Tregs and MDSC are increased in the spleens and bone marrows of the BALB/c mice with liver hepatoma. The increase in Tregs and MDSC was positively correlated with tumor burden. Treatment of Sorafenib not only inhibited HCC cell growth in mice but also significantly decreased the suppressive immune cell populations: Tregs and MDSC. In conclusion, our study strongly suggests that Sorafenib can enhance anti-tumor immunity via modulating immunosuppressive cell populations in the murine liver cancer model.

Current and future treatments for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) represents a unique challenge for physicians and patients. There is no definitively curative treatment. Rather, many treatment and management modalities exist with differing advantages and disadvantages. Both current guidelines and individual patient concerns must be taken into account in order to properly manage HCC. In addition, quality of life issues are particularly complex in patients with HCC and these concerns must also be factored into treatment strategies. Thus, considering all the options and their various pros and cons can quickly become complex for both clinicians and patients. In this review, we systematically discuss the current treatment modalities available for HCC, detailing relevant clinical data, risks and rewards and overall outcomes for each approach. Surgical options discussed include resection, transplantation and ablation. We also discuss the radiation modalities: conformal radiotherapy, yttrium 90 microspheres and proton and heavy ion radiotherapy. The biologic agent Sorafenib is discussed as a promising new approach, and recent clinical trials are reviewed. We then detail currently described molecular pathways implicated in the initiation and progression of HCC, and we explore the potential of each pathway as an avenue for drug exploitation. We hope this comprehensive and forward-looking review enables both clinicians and patients to understand various options and thereby make more informed decisions regarding this disease.