E.S. Zafrani

Daily cannabis smoking as a risk factor for progression of fibrosis in chronic hepatitis C

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 (≥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. (HEPATOLOGY 2005;.)

Comparison of nine blood tests and transient elastography for liver fibrosis in chronic hepatitis C: the ANRS HCEP-23 study.

BACKGROUND & AIMSnBlood 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).nnnMETHODSnThis 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 Obuchowskis method.nnnRESULTSnFibroscan™ 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. Obuchowskis 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, AUROCs 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.nnnCONCLUSIONSnContrarily 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.

Different mechanisms of steatosis in hepatitis C virus genotypes 1 and 3 infections

Summary.u2002 This study reports evidence that hepatocellular steatosis, a frequent histological feature of chronic hepatitis C, is principally metabolic in hepatitis C virus (HCV) genotype 1‐infected patients, whereas it is principally virus‐induced in HCV genotype 3‐infected patients. Multivariate analysis of data on 176 patients with chronic hepatitis C revealed that the severity of steatosis was independently related to HCV RNA load alone in patients infected by HCV genotype 3, whereas it was independently related to the body mass index, daily alcohol intake and histological activity grade (but not viral load) in patients infected by HCV genotype 1. These findings suggest that steatosis is a cytopathic lesion induced by HCV genotype 3, whereas HCV genotype 1 is not steatogenic per se or at the usual in vivo expression levels.

Impact of moderate alcohol consumption on histological activity and fibrosis in patients with chronic hepatitis C, and specific influence of steatosis: a prospective study

Aim : To evaluate the effects of minimal to moderate alcohol consumption on the severity of histological lesions in patients with chronic hepatitis C.

Histopathologic impact of GB virus C infection on chronic hepatitis C.

BACKGROUND & AIMSnDual infection by hepatitis GB virus type C (GBV-C) and hepatitis C virus (HCV) is common. To assess the histopathologic impact of GBV-C infection on liver lesions, liver biopsy specimens of 105 patients chronically infected with HCV, 17 of whom (15%) were also infected with GBV-C, were reviewed.nnnMETHODSnSemiquantitative histopathologic assessment of liver lesions was performed using the Knodells score and the METAVIR grading system.nnnRESULTSnHepatitis activity was mild, moderate, or severe in 3 (18%), 11 (64%), and 3 (18%) patients, respectively, infected with GBV-C and HCV vs. 26 (29%), 56 (64%), and 6 (7%) patients, respectively, infected with HCV alone (no significant difference). Cirrhosis was present in 4 (24%) coinfected patients vs. 19 (22%) HCV-positive patients (no significant difference). No significant difference in fibrosis, presence of portal lymphoid aggregates, steatosis, and hemosiderosis was observed between the two groups. There was no significant difference in the evaluation of each item of the Knodells score.nnnCONCLUSIONSnThis detailed histopathologic evaluation of GBV-C infection in chronic hepatitis C shows that GBV-C infection does not affect histopathologic severity and characteristics of chronic hepatitis C, thus suggesting a minor role of GBV-C infection in liver disease.

Association of caffeine intake and histological features of chronic hepatitis C

BACKGROUND & AIMSnThe 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.nnnMETHODSnA 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).nnnRESULTSnThere 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.nnnCONCLUSIONSnCaffeine 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.

Cannabinoid receptor 2 counteracts interleukin‐17‐induced immune and fibrogenic responses in mouse liver

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. Conclusion: 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. (Hepatology 2014;58:296–306)

Liver precursor cells increase hepatic fibrosis induced by chronic carbon tetrachloride intoxication in rats

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 (CCl4) administration for 6 weeks, in combination with chronic acetylaminofluorene treatment (AAF), which promotes activation of LPC compartment. Treatment with CCl4 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/CCl4-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 CCl4-treated animals. Enhanced fibrosis in AAF/CCl4 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.

Growth arrest-specific protein 6 deficiency impairs liver tissue repair after acute toxic hepatitis in mice

BACKGROUND/AIMSnResident 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.nnnMETHODSnToxic hepatitis was induced by a single carbon tetrachloride injection in Gas6 deficient (Gas6(-/-)) mice and liver recovery was compared with wild-type animals.nnnRESULTSnGas6 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.nnnCONCLUSIONSnThe 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.

GB virus C (GBV-C) infection in patients with chronic hepatitis C. Influence on liver disease and on hepatitis virus behaviour: Effect of interferon alfa therapy

The aim of this study was to evaluate, in patients with chronic hepatitis C, 1) the prevalence and the epidemiological characteristics of GB virus C (GBV‐C) infection, 2) the influence of GBV‐C on hepatitis C virus (HCV) infection, 3) the pathogenicity of GBV‐C in the absence of treatment and under interferon therapy, and 4) the effect of interferon alfa on GBV‐C and HCV replications. One hundred fifteen patients with chronic hepatitis C were studied. Before treatment, they were tested for GBV‐C RNA by PCR and GBV‐C genotype was determined for positive samples. Pretreatment information was collected, including age, gender, source of HCV, estimated duration of HCV infection, alanine aminotransferase and gamma‐glutamyl transpeptidase activities, cirrhosis and Knodells score on liver biopsy, HCV genotype, HCV viral burden and anti‐HCV core IgM antibodies. The genetic complexity of the hypervariable region 1 (HVR1) of HCV was studied by PCR‐Single Strand Conformation Polymorphism. All patients were treated with 3 to 9 mega units of interferon alfa‐2a three times per week for 3 to 6 months. The influence of GBV‐C on the evolution of ALT and HCV replication during and after treatment was studied, and GBV‐C and HCV RNA were monitored monthly by PCR during this period. Eighteen patients (16%) were GBV‐C RNA‐positive. Among 11 samples studied, GBV‐C genotype 2a was present in 9 cases, 2b in one case and type 3 in one case. GBV‐C RNA‐positive patients were significantly younger than GBV‐C RNA‐negative ones (38.4 ± 11.5 vs. 47.4 ± 14.0, P = 0.012), a result independent of the route of transmission and the disease duration. No difference between GBV‐C RNA‐positive and ‐negative patients was found for other epidemiological parameters (e.g. gender, risk factor for parenteral viral infections, disease duration and HCV genotypes), or for the characteristics of HCV infection and related liver disease (e.g. HCV RNA level, genetic complexity of the HVR1, anti‐HCV core IgM, alanine aminotransferase and gamma‐glutamyl transpeptidase activities, cirrhosis and Knodells score). GBV‐C did not influence the rates of ALT normalization at months 3, 6 and 12 and of sustained hepatitis C virological response at month 12 of treatment follow‐up. During treatment, GBV‐C viremia became undetectable in 12 patients (67%) but relapse occurred after treatment withdrawal in all the nine patients with sufficient follow‐up. In the remaining six patients (33%), GBV‐C resisted interferon. Whatever the effect of interferon on GBV‐C replication, the ALT levels correlated with the presence of HCV RNA. In conclusion, GBV‐C infection is frequent in patients with chronic hepatitis C, who are mainly, but not exclusively, infected by GBV‐C genotype 2a. GBV‐C positive patients are significantly younger than GBV‐C negative ones. GBV‐C does not seem to affect HCV replication, liver disease and responses of HCV infection and liver disease to interferon therapy. GBV‐C is sensitive to 3 mega units of interferon alfa administered three times per week in two‐thirds of the patients, but relapse is constant with this dosage after treatment withdrawal. J. Med. Virol. 54:26–37, 1998.