Rifaat Safadi

Long‐term entecavir therapy results in the reversal of fibrosis/cirrhosis and continued histological improvement in patients with chronic hepatitis B

One year of treatment with entecavir (0.5 mg daily) in nucleoside‐naive patients with hepatitis B e antigen (HBeAg)‐positive or HBeAg‐negative chronic hepatitis B (CHB) resulted in significantly improved liver histology and virological and biochemical endpoints in comparison with lamivudine. Patients who received at least 3 years of cumulative entecavir therapy in phase 3 studies and a long‐term rollover study and underwent long‐term liver biopsy were evaluated for improvements in histological appearance. Sixty‐nine patients [50 HBeAg‐positive and 19 HBeAg‐negative] receiving entecavir therapy underwent long‐term liver biopsy (median time of biopsy = 6 years, range = 3‐7 years). Histological improvement was analyzed for 57 patients who had adequate baseline biopsy samples, baseline Knodell necroinflammatory scores ≥2, and adequate long‐term biopsy samples. At the time of long‐term biopsy, all patients in the cohort had a hepatitis B virus DNA level <300 copies/mL, and 86% had a normalized alanine aminotransferase level. Histological improvement (≥2‐point decrease in the Knodell necroinflammatory score and no worsening of the Knodell fibrosis score) was observed in 96% of patients, and a ≥1‐point improvement in the Ishak fibrosis score was found in 88% of patients, including all 10 patients with advanced fibrosis or cirrhosis at the phase 3 baseline. Conclusion: The majority of nucleoside‐naive patients with CHB who were treated with entecavir in this long‐term cohort achieved substantial histological improvement and regression of fibrosis or cirrhosis. (HEPATOLOGY 2010)

Activation of hepatic stellate cells after phagocytosis of lymphocytes: A novel pathway of fibrogenesis.

Increased CD8‐T lymphocytes and reduced natural killer (NK) cells contribute to hepatic fibrosis. We have characterized pathways regulating the interactions of human hepatic stellate cells (HSCs) with specific lymphocyte subsets in vivo and in vitro. Fluorescence‐activated cell sorting (FACS) was used to characterize human peripheral blood lymphocytes (PBLs) and intrahepatic lymphocytes (IHLs) obtained from healthy controls and from patients with either hepatitis B virus (HBV) or hepatitis C virus (HCV) with advanced fibrosis. Liver sections were analyzed by immunohistochemistry and confocal microscopy. To investigate in vitro interactions, PBLs from healthy controls or patients with HCV cirrhosis were co‐cultured with an immortalized human HSC line (LX2 cells) or with primary HSCs. Significant alterations in lymphocyte distribution were identified in IHLs but not PBLs. The hepatic CD4/CD8 ratio and NK cells were significantly reduced in HBV/HCV patients. Expression of alpha‐smooth muscle actin and infiltration of CD4, CD8, and NK cells were readily apparent in liver sections from patients with cirrhosis but not in healthy controls. Lymphocytes from each subset were in proximity to HSCs primarily within the periportal regions, and some were directly attached or engulfed. In culture, HSC activation was stimulated by HCV‐derived CD8‐subsets but attenuated by NK cells. Confocal microscopy identified lymphocyte phagocytosis within HSCs that was completely prevented by blocking intracellular adhesion molecule 1 (ICAM‐1) and integrin molecules, or by irradiation of HSCs. LX2 knockdown of either Cdc42 or Rac1 [members of the Rho‐guanosine triphosphatase (GTPase) family] prevented both phagocytosis and the activation of HSC by HCV‐derived lymphocytes. Conclusion: The CD4/CD8 ratio and NK cells are significantly decreased in livers with advanced human fibrosis. Moreover, disease‐associated but not healthy lymphocytes are engulfed by cultured HSCs, which is mediated by the Rac1 and Cdc42 pathways. Ingestion of lymphocytes by HSCs in hepatic fibrosis is a novel and potentially important pathway regulating the impact of lymphocytes on the course of hepatic fibrosis. (HEPATOLOGY 2008.)

Involvement of the CXCL12/CXCR4 pathway in the advanced liver disease that is associated with hepatitis C virus or hepatitis B virus

Chronic hepatitis C virus (HCV) and hepatitis B virus (HBV) infection is accompanied by inflammation and fibrosis eventually leading to cirrhosis. The chemokine CXCL12 is involved in chronic inflammatory conditions. The role of the CXCL12/CXCR4 pathway in HCV‐ and HBV‐associated liver inflammation and fibrosis was therefore studied. The levels and tissue localization of CXCL12 in liver and plasma of HCV and HBV patients were tested using immunohistochemistry and ELISA. The expression and function of CXCR4 on liver‐infiltrating lymphocytes (LIL) were tested by FACS and transwell migration assays. We found that CXCL12 is expressed by bile duct epithelial cells in normal liver tissue. Bile duct proliferation and liver fibrosis in chronic HCV and HBV infection result in the anatomical re‐distribution of CXCL12 in the liver. Moreover, CXCL12 is up‐regulated in the endothelium of neo‐blood‐vessels formed in active inflammatory foci and is significantly elevated, compared with controls, in the plasma of patients with advanced liver fibrosis. Complementing these observations were others indicating that over 50% of LIL express CXCR4 and, in response to CXCL12, migrated and adhered to fibronectin. These observations suggest an important role for the CXCL12/CXCR4 pathway in recruitment and retention of immune cells in the liver during chronic HCV and HBV infection.

Lamivudine treatment for acute severe hepatitis B: a pilot study.

Abstract: Background: Experience with lamivudine treatment of immunocompetent patients with acute hepatitis B is limited.

NKp46-mediated killing of human and mouse hepatic stellate cells attenuates liver fibrosis

Background Liver fibrosis, which involves activation of hepatic stellate cells (HSC), is a major health problem and is the end outcome of all chronic liver diseases. The liver is populated with lymphocytes, among which are natural killer (NK) cells, whose activity is controlled by inhibitory and activating receptors. NKp46, one of the major NK activating receptors expressed by NK cells, is also a specific NK marker that discriminates NK cells from all other lymphocyte subsets. It recognises viral haemagglutinins and unknown cellular ligands. Methods The anti-fibrotic activity of the NKp46 receptor was assessed in vivo and in vitro using NKp46-deficient mice (NCR1gfp/gfp), the carbon tetrachloride model and in vitro NK killing assays. Primary murine and human HSC were stained for the expression of the NKp46 ligand using fusion proteins composed of the extracellular portions of the murine and human NKp46 receptors fused to human IgG1. Results It was shown that murine HSC express a ligand for the murine orthologue of the NKp46 receptor, NCR1. NCR1 inhibited liver fibrosis in vivo; in vitro, murine HSC were killed in an NCR1-dependent manner. In humans it was shown that human HSC also express a ligand for the human NKp46 receptor and that the killing of human HSC is NKp46 dependent. Conclusions In addition to NKG2D, NKp46/NCR1 play an important role in inhibition of liver fibrosis. This suggests that fibrosis can be better controlled through the manipulation of NKp46 activity.

Amelioration of hepatic fibrosis by NK cell activation

Background and aims Interactions between hepatic stellate cells (HSCs) and immune cell subsets have emerged as important determinants of liver fibrosis progression and regression. Natural killer (NK) cells have an antifibrotic activity through killing of activated HSCs. In liver injury NK cell expression of activating/inhibitory killer immunoglobulin-related receptors (aKIR/iKIR) and their ratio are significantly increased, while class I major histocompatibilty (MHC) expression by activated HSCs is decreased. The aim of this study was to amplify the antifibrotic activity of NK cells and ameliorate hepatic fibrosis by iKIR silencing. Methods Human lymphocytes from patients with hepatitis C virus (HCV) infection were transfected with specific iKIR small interfering RNAs (siRNAs) or non-silencing control siRNAs, then co-cultured with a human HSC line and assessed for fibrogenic activity. To induce hepatic fibrosis, carbon tetrachloride was administrated to BALBc SCID-Beige male mice (lacking B/T/NK cells) for 4 weeks. Splenocytes from naive SCID donors (lacking B/T cells but with preserved NK cells) were transfected in vitro with either iKIR siRNA or non-silencing control siRNA, and then were transferred to the fibrotic SCID-Beige recipients. Results Transfection with iKIR or positive control siRNAs (mice and human) decreased mRNA expression of iKIR and mitogen-acivated protein kinase 1 (MAPK1). Consequently, total NK cells and NK cell degranulation were increased (p=0.01), consistent with NK cell stimulation. Compared with healthy lymphocytes, when HCV lymphocytes were transfected with non-silencing control siRNA and co-cultured with HSCs there was increased α-smooth muscle actin (αSMA) expression, reflecting HSC activation. Expression of αSMA in co-cultures was attenuated when HCV lymphocytes were transfected with iKIR siRNA. In SCID-Beige recipients, hepatic fibrosis and serum alanine aminotransferase (ALT) levels were significantly attenuated as a result of receiving iKIR siRNA. Conclusions iKIR knockdown stimulates NK cells and promotes their antifibrogenic activity in mice and human co-cultures. These findings have implications for possible immune therapeutic strategies in patients with advanced liver disease.

Lymphocyte–hepatic stellate cell proximity suggests a direct interaction

Recent functional research studies suggest an anti‐fibrotic role for natural killer (NK) cells coupled with a profibrotic role for CD8 cells. However, the morphological cellular interplay between the different cell types is less clear. To investigate lymphocyte/hepatic stellate cell (HSC) interactions, hepatic fibrosis was induced by administering carbon tetrachloride (CCl4) intraperitoneally (i.p.) for 4 weeks in C57Bl/6 mice. Animals were killed at 0, 1, 2, 3 and 4 weeks. Liver sections were stained for Sirius red. Confocal microscopy was used to evaluate alpha smooth‐muscle actin (αSMA) and lymphocyte subsets in liver sections. At weeks 0 and 4, liver protein extracts were assessed for αSMA by Western blotting and isolated liver lymphocytes as well as HSC were analysed by fluorescence activated cell sorter (FACS). Similar to the results obtained from classical Sirius red staining and αSMA blotting, analysis of liver sections by confocal microscopy revealed a marked and continuous accumulation of αSMA staining along sequential experimental check‐points after administering CCl4. Although the number of all liver lymphocyte subsets increased following fibrosis induction, FACS analysis revealed an increase in the distribution of liver CD8 subsets and a decrease of CD4 T cells. Confocal microscopy showed a significant early appearance of CD8 and NK cells, and to a lesser extent CD4 T cells, appearing only from week 2. Lymphocytes were seen in proximity only to HSC, mainly in the periportal area and along fibrotic septa, suggesting a direct interaction. Notably, lymphocyte subsets were undetectable in naive liver sections. Freshly isolated HCS show high expression of major histocompatibility complex (MHC) class II and CD11c. In the animal model of hepatic fibrosis, lymphocytes infiltrate into the liver parenchyma and it is thought that they attach directly to activated HSC. Because HSCs express CD11c/class II molecules, interactions involving them might reflect that HSCs have an antigen‐presenting capacity.

Hypoglycemia in patients with renal failure

Of a total of 1545 admissions of end stage renal failure (ESRD) patients, fifty-six (3.6%) were admitted during a ten-year period with hypo glycemia. Thirty-eight of them were diabetic while the others were non-diabetic patients. The most common etiology found to be drug-induced hypoglycemia in 26 (46%) patients. In 22 (39%) cases, sepsis was the contributing cause of hypoglycemia. Severe malnutrition caused 7% of hypoglycemic episodes. Of the patients, 18 (32%) with ESRD eventually died, none of them were from the drug induced group. However, mortality rate in the sepsis induced hypoglycemia group was 66% and of the malnutrition group 17% of the deaths. Thus, hypoglycemia is frequent in ESRD patients, and is fatal if associated with either sepsis or malnutrition.

Treatment of chronic hepatitis B virus infection via oral immune regulation toward hepatitis B virus proteins.

OBJECTIVES:Hepatitis B virus (HBV) is a noncytopathic virus, and hepatocellular injury is mediated by a defective host antiviral immune response. We have previously shown that antiviral immunity can be modulated through oral feeding of viral proteins. The aims of this study were to determine the safety and efficacy of treatment of patients with chronic HBV by means of p.o. administration of HBV envelope proteins.METHODS:A total of 42 chronic HBV patients were treated p.o. with HBV envelope proteins (HBsAg+preS1+preS2), three times/wk for 20–30 wk, and followed for an additional 20 wk. Patients were monitored for HBV-DNA levels, liver enzymes, and liver histology. HBV-directed T cell immune modulation was assessed in vitro by HBV specific T cell-proliferation, cytotoxicity, IFNγ, and IL10 ELISPOT assays, and reverse transcription–polymerase chain reaction cytokines assay.RESULTS:Favorable response in one of the primary endpoints was achieved in 28/42 patients (66.6%) by means of p.o. immune regulation. A significant decrease in viral load was observed in 15 patients (35.7%). HBsAg/HBcAg biopsy scores improved in 41% and 57.1% of patients, respectively. Histological improvement in liver necroinflammatory score was noted in 12/40 patients (30%). In all, 80% showed biochemical response. Five of 19 HBeAg positive patients (26.3%) became negative for HBeAg. A favorable augmentation in anti-HBV specific T cell response, with increased HbsAg specific T cell proliferation (78%), cytotoxicity (75%), and IFNγ positive T cell clones (62.9%) was noted. In addition, a decrease in the IL10 γ positive T cell clones was achieved (48.1%). Natural killer T (NKT) lymphocytes increased significantly in all treated patients.CONCLUSIONS:Immune regulation of the anti-HBV immune response via p.o. administration of HBV envelope proteins alleviated the immune-mediated liver injury while augmenting the effective antiviral immunity.

Telbivudine plus pegylated interferon alfa-2a in a randomized study in chronic hepatitis B is associated with an unexpected high rate of peripheral neuropathy

BACKGROUND & AIMS This study investigated the antiviral efficacy and safety of telbivudine in combination with pegylated interferon (PegIFN) alpha-2a in chronic hepatitis B (CHB) patients. METHODS This was a randomized, open-label, multicentre study, in treatment-naïve patients with HBeAg-positive CHB, comparing the efficacy and safety of telbivudine in combination with PegIFN alpha-2a with telbivudine monotherapy and PegIFN alpha-2a monotherapy. The study was terminated early due to increased rates of peripheral neuropathy in the combination-therapy group. RESULTS Of the 159 patients randomized (from 300 planned) 50 were assigned to combination therapy, 55 to telbivudine, 54 to PegIFN, and 110 (18, 49, and 43, respectively) reached week 24. Peripheral neuropathy occurred in 7/50, 1/54, and 0/54 patients in the three groups of safety populations, respectively. No relationship between the occurrence of peripheral neuropathy and other variables (e.g., pharmacokinetic data, treatment efficacy, ALT levels, creatine kinase elevations) were observed. At week 24, undetectable HBV DNA (<300 copies/ml) was achieved by 71% (12/17), 35% (17/48), and 7% (3/42) of patients, with available data receiving combination therapy, telbivudine monotherapy and PegIFN monotherapy, respectively (p = 0.022 for combination therapy vs. telbivudine; p<0.0001 for combination therapy vs. PegIFN). CONCLUSIONS Combination therapy carried an increased risk of peripheral neuropathy. Despite the rapid and profound reductions in HBV DNA levels, combination therapy with telbivudine and PegIFN should not be used.