[Show abstract][Hide abstract] ABSTRACT: Unlabelled:
Interleukin (IL)-17 is a proinflammatory and fibrogenic cytokine mainly produced by T-helper (Th)17 lymphocytes, together with the hepatoprotective and antifibrogenic cytokine, IL-22. Cannabinoid receptor 2 (CB2) is predominantly expressed in immune cells and displays anti-inflammatory and antifibrogenic effects. In the present study, we further investigated the mechanism underlying antifibrogenic properties of CB2 receptor and explored its effect on the profibrogenic properties of IL-17. After bile duct ligation (BDL), the hepatic expression of Th17 markers and IL-17 production were enhanced in CB2(-/-) mice, as compared to wild-type (WT) counterparts, and correlated with increased fibrosis in these animals. In contrast, IL-22-induced expression was similar in both animal groups. Inhibition of Th17 differentiation by digoxin lowered Th17 marker gene expression and IL-17 production and strongly reduced liver fibrosis in CB2(-/-) BDL mice. In vitro, differentiation of CD4(+) naïve T cells into Th17 lymphocytes was decreased by the CB2 agonist, JWH-133, and was associated with reduced Th17 marker messenger RNA expression and IL-17 production, without modification of IL-22 release. The inhibitory effect of JWH-133 on IL-17 production relied on signal transducer and activator of transcription (STAT)5 phosphorylation. Indeed, STAT5 phosphorylation and translocation into the nucleus was enhanced in JWH133-treated Th17 lymphocytes, and the addition of a STAT5 inhibitor reversed the inhibitory effect of the CB2 agonist on IL-17 production, without affecting IL-22 levels. Finally, in vitro studies also demonstrated that CB2 receptor activation in macrophages and hepatic myofibroblasts blunts IL-17-induced proinflammatory gene expression.
These data demonstrate that CB2 receptor activation decreases liver fibrosis by selectively reducing IL-17 production by Th17 lymphocytes via a STAT5-dependent pathway, and by blunting the proinflammatory effects of IL-17 on its target cells, while preserving IL-22 production.
[Show abstract][Hide abstract] ABSTRACT: We aimed to determine the best algorithms for the diagnosis of significant fibrosis in chronic hepatitis C (CHC) patients using all available parameters and tests.
We used the database from our study of 507 patients with histologically proven CHC in which fibrosis was evaluated by liver biopsy (Metavir) and tests: Fibrometer®, Fibrotest®, Hepascore®, Apri, ELFG, MP3, Forn's, hyaluronic acid, tissue inhibitor of metalloproteinase-1 (TIMP1), MMP1, collagen IV and when possible Fibroscan™. For the first test we used 90% negative predictive value to exclude patients with F≤1, next an induction algorithm was applied giving the best tests with at least 80% positive predictive value for the diagnosis of F≥2. The algorithms were computed using the R Software C4.5 program to select the best tests and cut-offs. The algorithm was automatically induced without premises on the part of the investigators. We also examined the inter-observer variations after independent review of liver biopsies by two pathologists. A medico-economic analysis compared the screening strategies with liver biopsy.
In "intention to diagnose" the best algorithms for F≥2 were Fibrometer ®, Fibrotest®, or Hepascore® in first intention with the ELFG score in second intention for indeterminate cases. The percentage of avoided biopsies varied between 50% (Fibrotest® or Fibrometer®+ELFG) and 51% (Hepascore®+ELFG). In "per-analysis" Fibroscan™+ELFG avoided liver biopsy in 55% of cases. The diagnostic performance of these screening strategies was statistically superior to the usual combinations (Fibrometer® or Fibrotest®+Fibroscan™) and was cost effective. We note that the consensual review of liver biopsies between the two pathologists was mainly in favor of F1 (64-69%).
The ELFG test could replace Fibroscan in most currently used algorithms for the diagnosis of significant fibrosis including for those patients for whom Fibroscan™ is unusable.
[Show abstract][Hide abstract] ABSTRACT: Demographic, laboratory, and histological characteristics of the 507 CHC patients having all the blood tests and the 396 CHC patients with all the tests and reliable Fibroscan™.
[Show abstract][Hide abstract] ABSTRACT: Background:
Liver stiffness measurement (LSM) by transient elastography (TE) (FibroScan) is a validated method of quantifying liver fibrosis in non-transplanted patients with hepatitis C virus (HCV). It could be useful in follow-up after liver transplantation (LT). The aim of this study was to assess the diagnostic accuracy of LSM in evaluating liver fibrosis after LT in patients with and without recurrent HCV.
Patients and methods:
Forty-three patients (mean age 57.6 ± 9.9 years), 28 (65.1%) HCV-positive patients and 15 (34.9%) HCV-negative patients underwent gold standard liver biopsy and TE 55.8 ± 4.9 months after transplantation. Liver fibrosis was scored on biopsy specimens according to METAVIR (F0-F4). Accuracy of TE and optimal stiffness cut-off values for fibrosis staging were determined by a receiver-operating characteristics (ROC) curve analysis.
Median stiffness values were significantly different for METAVIR score less than 2 (5.8 kPa) vs. METAVIR score greater to equal to 2 (9.6 kPa) (P<0.001). The area under the ROC curve was 0.83 for METAVIR score greater to equal to 2 (95%CI: 0.71-0.95). The optimal stiffness cut-off value was 7 kPa for METAVIR scores greater to equal to 2. The results were similar whether the patients had recurrent HCV infection or not.
These results indicate that transient elastography accurately identifies LT recipients with significant fibrosis, irrespective of HCV status. It is a promising non-invasive tool to assess graft fibrosis progression after LT in patients with HCV recurrence, as well as for screening of late graft fibrosis of other etiologies. Transient elastography could reduce the use of invasive protocol biopsies.
Full-text · Article · Jan 2013 · Gastroentérologie Clinique et Biologique
[Show abstract][Hide abstract] ABSTRACT: Hepatic fibrosis, the major complication of virtually all types of chronic liver damage, usually begins in portal areas, and its severity has been correlated to liver progenitor cells (LPC) expansion from periportal areas, even if the primary targets of injury are intralobular hepatocytes. The aim of this study was to determine the potential fibrogenic role of LPC, using a new experimental model in which rat liver fibrosis was induced by chronic carbon tetrachloride (CCl(4)) administration for 6 weeks, in combination with chronic acetylaminofluorene treatment (AAF), which promotes activation of LPC compartment. Treatment with CCl(4) alone caused a significant increase in serum transaminase activity as well as liver fibrosis initiating around central veins and leading to formation of incomplete centro-central septa with sparse fibrogenic cells expressing α-smooth muscle actin (αSMA). In AAF/CCl(4)-treated animals, the fibrogenic response was profoundly worsened, with formation of multiple porto-central bridging septa leading to cirrhosis, whereas hepatocellular necrosis and inflammation were similar to those observed in CCl(4)-treated animals. Enhanced fibrosis in AAF/CCl(4) group was accompanied by ductule forming LPC expanding from portal areas, αSMA-positive cells accumulation in the fibrotic areas and increased expression of hepatic collagen type 1, 3 and 4 mRNA. Moreover, CK19-positive LPC expressed the most potent fibrogenic cytokine transforming growth factor-β (TGFβ) without any expression of αSMA, desmin or fibroblast-specific protein-1, demonstrating that LPC did not undergo an epithelial-mesenchymal transition. In this new experimental model, LPC, by expressing TGFβ, contributed to the accumulation of αSMA-positive myofibroblasts in the ductular reaction leading to enhanced fibrosis but also to disease progression and to a fibrotic pattern similar to that observed in humans.
[Show abstract][Hide abstract] ABSTRACT: Blood tests and transient elastography (Fibroscan™) have been developed as alternatives to liver biopsy. This ANRS HCEP-23 study compared the diagnostic accuracy of nine blood tests and transient elastography (Fibroscan™) to assess liver fibrosis, vs. liver biopsy, in untreated patients with chronic hepatitis C (CHC).
This was a multicentre prospective independent study in 19 French University hospitals of consecutive adult patients having simultaneous liver biopsy, biochemical blood tests (performed in a centralized laboratory) and Fibroscan™. Two experienced pathologists independently reviewed the liver biopsies (mean length=25±8.4 mm). Performance was assessed using ROC curves corrected by Obuchowski's method.
Fibroscan™ was not interpretable in 113 (22%) patients. In the 382 patients having both blood tests and interpretable Fibroscan™, Fibroscan™ performed similarly to the best blood tests for the diagnosis of significant fibrosis and cirrhosis. Obuchowski's measure showed Fibrometer® (0.86), Fibrotest® (0.84), Hepascore® (0.84), and interpretable Fibroscan™ (0.84) to be the most accurate tests. The combination of Fibrotest®, Fibrometer®, or Hepascore® with Fibroscan™ or Apri increases the percentage of well classified patients from 70-73% to 80-83% for significant fibrosis, but for cirrhosis a combination offers no improvement. For the 436 patients having all the blood tests, AUROC's ranged from 0.82 (Fibrometer®) to 0.75 (Hyaluronate) for significant fibrosis, and from 0.89 (Fibrometer® and Hepascore®) to 0.83 (FIB-4) for cirrhosis.
Contrarily to blood tests, performance of Fibroscan™ was reduced due to uninterpretable results. Fibrotest®, interpretable Fibroscan™, Fibrometer®, and Hepascore® perform best and similarly for diagnosis of significant fibrosis and cirrhosis.
Full-text · Article · Jul 2011 · Journal of Hepatology
[Show abstract][Hide abstract] ABSTRACT: The severity of chronic hepatitis C (CHC) is modulated by host and environmental factors. Several reports suggest that caffeine intake exerts hepatoprotective effects in patients with chronic liver disease. The aim of this study was to evaluate the impact of caffeine consumption on activity grade and fibrosis stage in patients with CHC.
A total of 238 treatment-naïve patients with histologically-proven CHC were included in the study. Demographic, epidemiological, environmental, virological, and metabolic data were collected, including daily consumption of alcohol, cannabis, tobacco, and caffeine during the six months preceding liver biopsy. Daily caffeine consumption was estimated as the sum of mean intakes of caffeinated coffee, tea, and caffeine-containing sodas. Histological activity grade and fibrosis stage were scored according to Metavir. Patients (154 men, 84 women, mean age: 45±11 years) were categorized according to caffeine consumption quartiles: group 1 (<225 mg/day, n=59), group 2 (225-407 mg/day, n=57), group 3 (408-678 mg/day, n=62), and group 4 (>678 mg/day, n=60).
There was a significant inverse relationship between activity grade and daily caffeine consumption: activity grade>A2 was present in 78%, 61%, 52%, and 48% of patients in group 1, 2, 3, and 4, respectively (p<0.001). By multivariate analysis, daily caffeine consumption greater than 408 mg/day was associated with a lesser risk of activity grade>A2 (OR=0.32 (0.12-0.85). Caffeine intake showed no relation with fibrosis stage.
Caffeine consumption greater than 408 mg/day (3 cups or more) is associated with reduced histological activity in patients with CHC. These findings support potential hepatoprotective properties of caffeine in chronic liver diseases.
Full-text · Article · Feb 2011 · Journal of Hepatology
[Show abstract][Hide abstract] ABSTRACT: The Gas6/Axl pathway has been increasingly implicated in regeneration and tissue repair and, recently, in the control of innate immunity. In liver, we have demonstrated that Gas6 and its receptor Axl are expressed in macrophages, progenitor cells, and myofibroblasts and that Gas6 deficiency reduced inflammation and myofibroblast activation, causing delayed liver repair in response to acute injury. All these data suggest a role of Gas6/Axl signaling in pathogenesis of chronic liver diseases. In the present study, we address the role of Gas6 in steatohepatitis and progression to liver fibrosis using Gas6-deficient mice fed a choline-deficient ethionine-supplemented diet (CDE) or receiving a chronic carbon tetrachloride (CCl(4)) treatment. Gas6 deficiency attenuated hepatic steatosis by limiting CDE-induced downregulation of genes involved in β-oxidation observed in wild-type animals. Moreover, Gas6-deficient mice displayed reduction of hepatic inflammation, revealed by limited F4/80-positive macrophage infiltration, decreased expression of IL-1β, TNF-α, lymphotoxin-β, and monocyte chemotactic protein-1, and attenuated hepatic progenitor cell response to CDE diet. Gas6 deficiency reduced CDE-induced fibrogenesis and hepatic myofibroblast activation and decreased expression of TGF-β and collagen 1 mRNAs. After chronic CCl(4) injury, Gas6-deficient mice also exhibited reduced liver fibrosis as a consequence of defective macrophage recruitment compared with wild-type animals. We conclude that improvement of steatohepatitis and fibrosis in Gas6(-/-) mice is linked to an inhibition of the inflammatory response that controls lipid metabolism and myofibroblast activation. This study highlights the deleterious effect of Gas6 in the progression of steatosis to steatohepatitis and fibrosis.
No preview · Article · Feb 2011 · AJP Gastrointestinal and Liver Physiology
[Show abstract][Hide abstract] ABSTRACT: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
[Show abstract][Hide abstract] ABSTRACT: Resident macrophages and myofibroblasts derived from hepatic stellate cells play a key role in liver wound healing. We previously reported that these sinusoidal cells secrete the growth arrest-specific protein 6 (Gas6) and express Axl, one of its receptors. Here we address the role of Gas6 in the healing process during acute liver injury.
Toxic hepatitis was induced by a single carbon tetrachloride injection in Gas6 deficient (Gas6(-/-)) mice and liver recovery was compared with wild-type animals.
Gas6 deficiency did not cause any change in CCl(4)-induced liver damage. At 72 h, an efficient tissue repair was observed in wild-type animals whereas in Gas6(-/-) mice, we noticed a defective wound healing accounted by reduced Kupffer cell activation revealed by a decrease in the induction of CD14, TNF-alpha, IL6 and MCP-1. Gas6-deficiency, by limiting cytokine/chemokine release, prevents hepatocyte proliferation, recruitment of circulating monocytes and accumulation of myofibroblasts in healing areas. We also report a direct chemotactic effect of Gas6 on circulating monocytes which might explain defective macrophage infiltration in liver necrotic areas of Gas6(-/-) mice. Interestingly in Gas6(-/-) mice, we observed a high and constitutive expression of Axl and an induction of the suppressor of cytokine signaling SOCS1 after CCl(4) treatment.
The lower level of cytokines/chemokines in Gas6(-/-) mice after CCl(4) injury, is the consequence of an inhibitory signal arising from Axl receptor overexpression, leading to delayed liver repair in deficient mice.
Preview · Article · May 2009 · Journal of Hepatology
[Show abstract][Hide abstract] ABSTRACT: Primary hepatic lymphoma of mucosa-associated lymphoid tissue type is extremely rare. Only 38 cases have been reported to date. A case of a 59-year-old man with Helicobacter pylori-resistant gastric ulcers and Buerger disease who was followed up since 1999 is reported. A 2-cm hepatic nodule was incidentally found during partial gastrectomy and corresponded to mucosa-associated lymphoid tissue-type lymphoma without underlying liver disease. Molecular studies showed a clonal immunoglobulin heavy-chain gene rearrangement. Investigations for the mucosa-associated lymphoid tissue lymphoma-associated translocations t(11;18) and t(14;18), as well as the t(3;14)(q27;q32), were negative, whereas trisomy 3 and trisomy 18 were detected.
No preview · Article · Aug 2008 · International Journal of Surgical Pathology
[Show abstract][Hide abstract] ABSTRACT: Some patients receiving adefovir at the approved dose of 10 mg daily for chronic hepatitis B have a "suboptimal" virological response characterized by a slow and moderate decrease in viral replication.
We assessed the efficacy and safety of adefovir 20 mg daily in patients with hepatitis B e antigen-positive chronic hepatitis B resistant to lamivudine and a suboptimal virological response to adefovir 10 mg daily add-on.
No amino acid substitutions known to confer adefovir resistance were found in these patients. In the five treated patients, the switch from 10 mg to 20 mg of adefovir daily significantly improved antiviral efficacy (-1.78+/-0.28 log international units/mL versus -3.73+/-0.51 log international units/mL, respectively, p=0.0039), and alanine aminotransferase levels normalized in all but one of the patients. No signs of renal dysfunction occurred.
These results suggest: (i) that suboptimal responses to adefovir 10 mg daily are due to underdosing; and (ii) that increasing the adefovir dose to 20 mg daily is beneficial and safe in patients with lamivudine-resistant HBV and a suboptimal response to adefovir 10 mg daily, especially when alanine aminotransferase levels are elevated and/or the liver disease is severe or rapidly progressive. Careful monitoring of renal function is necessary.
Preview · Article · Jun 2007 · Journal of Hepatology
[Show abstract][Hide abstract] ABSTRACT: Cannabinoids present in Cannabis sativa (marijuana) exert biological effects via cannabinoid receptors CB1 and CB2. We recently demonstrated that CB1 and CB2 receptors regulate progression of experimental liver fibrosis. We therefore investigated the impact of cannabis smoking on fibrosis progression rate in patients with chronic hepatitis C (CHC). Two hundred seventy consecutive untreated patients with CHC of known duration undergoing liver biopsy were studied. Demographic, epidemiological, metabolic, and virological data were recorded, and detailed histories of cannabis, alcohol, and tobacco use over the span of hepatitis C virus infection were obtained. Fibrosis stage, steatosis, and activity grades were scored according to Metavir system. Patients were categorized as noncannabis users (52.2%), occasional users (14.8%), or daily users (33.0%), and the relationship between cannabis use and fibrosis progression rate (FPR) or fibrosis stage was assessed. On multivariate analysis, six factors were independently related to a FPR greater than 0.074 (median value of the cohort): daily cannabis use (OR = 3.4 [1.5-7.4]), Metavir activity grade A2 or higher (OR = 5.4 [2.9-10.3]), age at contamination of more than 40 years (OR = 10.5 [3.0-37.1]), genotype 3 (OR = 3.4 [1.5-7.7]), excessive alcohol intake (OR = 2.2 [1.1-4.5]), and steatosis (OR = 2.0 [1.0-4.1]). Daily cannabis use was also an independent predictor of a rapid FPR (>0.15) (OR = 3.6 [1.5-7.5]). Finally, severe fibrosis (> or =F3) was also predicted by daily cannabis use (OR = 2.5 [1.1-5.6]; P = .034), independently of Metavir activity grade, excessive alcohol intake, age at liver biopsy, steatosis, and tobacco smoking. In conclusion, daily cannabis smoking is significantly associated with fibrosis progression during CHC. Patients with ongoing CHC should be advised to refrain from regular cannabis use.
[Show abstract][Hide abstract] ABSTRACT: Two distinct forms of hepatocellular steatosis can be seen in patients with chronic hepatitis C virus (HCV) infection. Classical metabolic risk factors for hepatocellular steatosis account for the vast majority of cases of steatosis in patients infected by non-genotype 3 HCV strains. In contrast, in patients infected by HCV genotype 3, steatosis is generally induced by the virus itself through a direct cytopathic effect, the mechanisms of which remain debated. Mixed forms of steatosis can also be seen in HCV genotype 3-infected patients with metabolic risk factors. Hepatocellular steatosis appears to be associated with more rapid progression of hepatic fibrosis. However, it is unclear whether this association is due to steatosis itself, or rather to metabolic and host factors that promote steatosis and fibrosis concomitantly. This review discusses current knowledge of HCV-induced steatosis and its relation to chronic HCV-associated liver disease.
No preview · Article · Apr 2005 · The American Journal of Gastroenterology
[Show abstract][Hide abstract] ABSTRACT: All cases of hepatocellular carcinoma reported thus for in patients with nonalcoholic steatohepatitis have occurred on preexisting cirrhosis. We report the case of a 68-Year-old male patient with nonalcoholic steatohepatitis who developed hepatocellular carcinoma in the absence of cirrhosis. This observation suggests a possible relationship between nonalcoholic steatohepatitis and/or excess body weight, and hepatocellular carcinoma independent of cirrhosis. Further epidemiological studies are needed to evaluate the incidence of this association.
No preview · Article · Jun 2004 · Gastroentérologie Clinique et Biologique