Serum ferritin levels can predict long-term outcomes in patients with metabolic dysfunction-associated steatotic liver disease

OBJECTIVE

Hyperferritinaemia is associated with liver fibrosis severity in patients with metabolic dysfunction-associated steatotic liver disease (MASLD), but the longitudinal implications have not been thoroughly investigated. We assessed the role of serum ferritin in predicting long-term outcomes or death.

DESIGN

We evaluated the relationship between baseline serum ferritin and longitudinal events in a multicentre cohort of 1342 patients. Four survival models considering ferritin with confounders or non-invasive scoring systems were applied with repeated five-fold cross-validation schema. Prediction performance was evaluated in terms of Harrell's C-index and its improvement by including ferritin as a covariate.

RESULTS

Median follow-up time was 96 months. Liver-related events occurred in 7.7%, hepatocellular carcinoma in 1.9%, cardiovascular events in 10.9%, extrahepatic cancers in 8.3% and all-cause mortality in 5.8%. Hyperferritinaemia was associated with a 50% increased risk of liver-related events and 27% of all-cause mortality. A stepwise increase in baseline ferritin thresholds was associated with a statistical increase in C-index, ranging between 0.02 (lasso-penalised Cox regression) and 0.03 (ridge-penalised Cox regression); the risk of developing liver-related events mainly increased from threshold 215.5 µg/L (median HR=1.71 and C-index=0.71) and the risk of overall mortality from threshold 272 µg/L (median HR=1.49 and C-index=0.70). The inclusion of serum ferritin thresholds (215.5 µg/L and 272 µg/L) in predictive models increased the performance of Fibrosis-4 and Non-Alcoholic Fatty Liver Disease Fibrosis Score in the longitudinal risk assessment of liver-related events (C-indices>0.71) and overall mortality (C-indices>0.65).

CONCLUSIONS

This study supports the potential use of serum ferritin values for predicting the long-term prognosis of patients with MASLD.

Liver stiffness thresholds to predict disease progression and clinical outcomes in bridging fibrosis and cirrhosis

OBJECTIVE

In retrospective studies, liver stiffness (LS) by vibration-controlled transient elastography (VCTE) is associated with the risk of liver decompensation in patients with non-alcoholic steatohepatitis (NASH), but prospective data in biopsy-confirmed cohorts with advanced fibrosis are limited. We aimed to establish thresholds for LS by VCTE that predict progression to cirrhosis among patients with bridging fibrosis and hepatic decompensation among patients with cirrhosis due to NASH.

DESIGN

We used data from four randomised placebo-controlled trials of selonsertib and simtuzumab in participants with advanced fibrosis (F3-F4). The trials were discontinued due to lack of efficacy. Liver fibrosis was staged centrally at baseline and week 48 (selonsertib study) or week 96 (simtuzumab study). Associations between LS by VCTE with disease progression were determined using Cox proportional hazards regression analysis.

RESULTS

Progression to cirrhosis occurred in 16% (103/664) of participants with bridging fibrosis and adjudicated liver-related events occurred in 4% (27/734) of participants with baseline cirrhosis. The optimal baseline LS thresholds were ≥16.6 kPa for predicting progression to cirrhosis, and ≥30.7 kPa for predicting liver-related events. Baseline LS ≥16.6 kPa (adjusted HR 3.99; 95% CI 2.66 to 5.98, p<0.0001) and a ≥5 kPa (and ≥20%) increase (adjusted HR 1.98; 95% CI 1.20 to 3.26, p=0.008) were independent predictors of progression to cirrhosis in participants with bridging fibrosis, while baseline LS ≥30.7 kPa (adjusted HR 10.13, 95% CI 4.38 to 23.41, p<0.0001) predicted liver-related events in participants with cirrhosis.

CONCLUSION

The LS thresholds identified in this study may be useful for risk stratification of NASH patients with advanced fibrosis.

Diagnostic accuracy of non-invasive tests for advanced fibrosis in patients with NAFLD: an individual patient data meta-analysis

OBJECTIVE

Liver biopsy is still needed for fibrosis staging in many patients with non-alcoholic fatty liver disease. The aims of this study were to evaluate the individual diagnostic performance of liver stiffness measurement by vibration controlled transient elastography (LSM-VCTE), Fibrosis-4 Index (FIB-4) and NAFLD (non-alcoholic fatty liver disease) Fibrosis Score (NFS) and to derive diagnostic strategies that could reduce the need for liver biopsies.

DESIGN

Individual patient data meta-analysis of studies evaluating LSM-VCTE against liver histology was conducted. FIB-4 and NFS were computed where possible. Sensitivity, specificity and area under the receiver operating curve (AUROC) were calculated. Biomarkers were assessed individually and in sequential combinations.

RESULTS

Data were included from 37 primary studies (n=5735; 45% women; median age: 54 years; median body mass index: 30 kg/m²; 33% had type 2 diabetes; 30% had advanced fibrosis). AUROCs of individual LSM-VCTE, FIB-4 and NFS for advanced fibrosis were 0.85, 0.76 and 0.73. Sequential combination of FIB-4 cut-offs (<1.3; ≥2.67) followed by LSM-VCTE cut-offs (<8.0; ≥10.0 kPa) to rule-in or rule-out advanced fibrosis had sensitivity and specificity (95% CI) of 66% (63-68) and 86% (84-87) with 33% needing a biopsy to establish a final diagnosis. FIB-4 cut-offs (<1.3; ≥3.48) followed by LSM cut-offs (<8.0; ≥20.0 kPa) to rule out advanced fibrosis or rule in cirrhosis had a sensitivity of 38% (37-39) and specificity of 90% (89-91) with 19% needing biopsy.

CONCLUSION

Sequential combinations of markers with a lower cut-off to rule-out advanced fibrosis and a higher cut-off to rule-in cirrhosis can reduce the need for liver biopsies.

A219 AMINOTRANSFERASE IMPROVEMENTS IN PATIENTS WITH NON-ALCOHOLIC STEATOHEPATITIS ARE ASSOCIATED WITH FIBROSIS REGRESSION IN THE REGENERATE STUDY

Background

The interim analysis of the REGENERATE study showed obeticholic acid (OCA) 25 mg treatment significantly improved liver histology in patients with nonalcoholic steatohepatitis (NASH) and fibrosis. Elevations in aminotransferases are associated with adverse liver-related outcomes in NASH.

Aims

Here, we evaluate the utility of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) as markers of treatment response to OCA in patients with NASH.

Methods

Changes in ALT (upper limit of normal [ULN] = 55 U/L) and AST (ULN = 34 U/L) were assessed systematically at 1, 3, 6, 12, and 18 months in 931 NASH patients with stage 2 or 3 fibrosis randomized 1:1:1 to placebo (PBO), OCA 10 mg, or OCA 25 mg in REGENERATE (intent-to-treat population). Least-square mean (LSM) and 95% confidence intervals (CIs) of percentage change from baseline in ALT and AST were analyzed using a mixed-effect repeated-measures model.

Results

Baseline characteristics were well-balanced across treatment arms: ALT 79±53 U/L; AST 58±36 U/L; 44% F2, 56% F3. Aminotransferase values were &gt; ULN for ALT in 60% (7% &gt; 3xULN), and for AST in 74% (9% &gt; 3xULN) of patients. Rapid, progressive, and dose-dependent improvement in ALT and AST was seen across PBO, OCA 10 mg, and OCA 25 mg arms, which at Month 18 was: ALT LSM change (95% CI), respectively, -4.9% (-10.7–0.9), -23.2% (-28.9– -17.4) and -31.9% (-37.7– -26.1) and in AST, -8.7% (-12.1– -5.2), -13.4% (-16.8– -9.9), and -19.4 (-22.8– -15.9). ALT and AST LSM reductions in OCA arms vs PBO were seen regardless of patient ULN status at baseline. In all patients, ALT/AST reduction was associated with probability of fibrosis regression at Month 18, ranging from approximately 20%, 95% CI (14–27) to 45% (37–54) with any reduction in ALT (&gt; 0%–100%) and between approximately 20%, 95% CI (25–38) to 43% (35–57) with any reduction in AST (&gt; 0%–100%). Interestingly, even with increases of ≤ 40% in AST or ALT there was still a small probability of fibrosis regression (&lt; 20%). Analysis of changes in ALT and AST in individual patients showed that more patients had improvements on OCA than PBO at Month 18 (FIG 1).

Conclusions

OCA resulted in consistent dose-dependent improvement of ALT and AST. Patients with reductions in ALT or AST were up to twice as likely to have fibrosis improvement than those whose ALT or AST increased. The REGENERATE study is ongoing and will continue through clinical outcomes for verification and description of clinical benefits of OCA in treatment of NASH.

Funding Agencies

None

Caucasian lean subjects with non-alcoholic fatty liver disease share long-term prognosis of non-lean: time for reappraisal of BMI-driven approach?

OBJECTIVE

The full phenotypic expression of non-alcoholic fatty liver disease (NAFLD) in lean subjects is incompletely characterised. We aimed to investigate prevalence, characteristics and long-term prognosis of Caucasian lean subjects with NAFLD.

DESIGN

The study cohort comprises 1339 biopsy-proven NAFLD subjects from four countries (Italy, UK, Spain and Australia), stratified into lean and non-lean (body mass index (BMI) </≥25 kg/m²). Liver/non-liver-related events and survival free of transplantation were recorded during the follow-up, compared by log-rank testing and reported by adjusted HR.

RESULTS

Lean patients represented 14.4% of the cohort and were predominantly of Italian origin (89%). They had less severe histological disease (lean vs non-lean: non-alcoholic steatohepatitis 54.1% vs 71.2% p<0.001; advanced fibrosis 10.1% vs 25.2% p<0.001), lower prevalence of diabetes (9.2% vs 31.4%, p<0.001), but no significant differences in the prevalence of the PNPLA3 I148M variant (p=0.57). During a median follow-up of 94 months (>10 483 person-years), 4.7% of lean vs 7.7% of non-lean patients reported liver-related events (p=0.37). No difference in survival was observed compared with non-lean NAFLD (p=0.069).

CONCLUSIONS

Caucasian lean subjects with NAFLD may progress to advanced liver disease, develop metabolic comorbidities and experience cardiovascular disease (CVD) as well as liver-related mortality, independent of longitudinal progression to obesity and PNPLA3 genotype. These patients represent one end of a wide spectrum of phenotypic expression of NAFLD where the disease manifests at lower overall BMI thresholds.

LAY SUMMARY

NAFLD may affect and progress in both obese and lean individuals. Lean subjects are predominantly males, have a younger age at diagnosis and are more prevalent in some geographic areas. During the follow-up, lean subjects can develop hepatic and extrahepatic disease, including metabolic comorbidities, in the absence of weight gain. These patients represent one end of a wide spectrum of phenotypic expression of NAFLD.

Key features of the environment promoting liver cancer in the absence of cirrhosis

The prevalence of obesity and non-alcoholic fatty liver disease (NAFLD) associated hepatocellular carcinoma (HCC) is rising, even in the absence of cirrhosis. We aimed to develop a murine model that would facilitate further understanding of NAFLD-HCC pathogenesis. A total of 144 C3H/He mice were fed either control or American lifestyle (ALIOS) diet, with or without interventions, for up to 48 weeks of age. Gross, liver histology, immunohistochemistry (IHC) and RNA-sequencing data were interpreted alongside human datasets. The ALIOS diet promoted obesity, elevated liver weight, impaired glucose tolerance, non-alcoholic fatty liver disease (NAFLD) and spontaneous HCC. Liver weight, fasting blood glucose, steatosis, lobular inflammation and lipogranulomas were associated with development of HCC, as were markers of hepatocyte proliferation and DNA damage. An antioxidant diminished cellular injury, fibrosis and DNA damage, but not lobular inflammation, lipogranulomas, proliferation and HCC development. An acquired CD44 phenotype in macrophages was associated with type 2 diabetes and NAFLD-HCC. In this diet induced NASH and HCC (DINAH) model, key features of obesity associated NAFLD-HCC have been reproduced, highlighting roles for hepatic steatosis and proliferation, with the acquisition of lobular inflammation and CD44 positive macrophages in the development of HCC-even in the absence of progressive injury and fibrosis.

A217 NONINVASIVE ASSESSMENTS TO IDENTIFY PATIENTS WITH ADVANCED FIBROSIS DUE TO NASH: SCREENED POPULATION FROM THE REGENERATE TRIAL

Aims

We explored the ability of noninvasive tests (NITs) to identify patients (pts) with advanced fibrosis due to NASH.

Methods

All screened pts from the ongoing phase 3 REGENERATE with available histology data were included. Five NITs were evaluated using established literature cutoffs to identify or exclude advanced fibrosis (values between upper and lower thresholds were considered indeterminate): Aspartate Transaminase-to-Platelet Ratio Index (APRI; ≥0.57, ≤0.84), Enhanced Liver Fibrosis (ELF; ≥7.7, &lt;9.8), Fibrosis-4 (FIB-4; ≥1.30, &lt;2.67), NAFLD fibrosis score (NFS; ≥−1.455, &lt;0.676), and Transient Elastography (TE; ≥7.9 kPa, &lt;9.6 kPa). Three testing methods applied were single NIT, 2 simultaneous NITs weighted equally (NFS+ELF, FIB-4+ELF, NFS+TE, FIB-4+TE), and 2 sequential NITs with the second test performed only if the first test was indeterminate (NFS→ELF, FIB-4→ELF, NFS→TE, FIB-4→TE).

Results

4133 pts in the REGENERATE screened population had an available biopsy (baseline liver biopsy: F0, 15.5%; F1, 27.2%; F2, 21.2%; F3, 29.6%; F4, 6.5%). Of these, 96% had FIB-4, NFS, and APRI, 41% had TE, and 28% had ELF. Single NITs with upper thresholds demonstrating strong specificity for identification of advanced fibrosis were FIB-4 (97%), NFS (94%), and APRI (86%); NITs with lower thresholds demonstrating good sensitivity for identification of early fibrosis were ELF (100%) and TE (88%). Evaluation of 2 simultaneous NITs resulted in a greater percentage of pts in the indeterminate zone. Application of 2 sequential tests improved the accuracy of identification and reduced misclassification vs 2 simultaneous tests.

Conclusions

Sequential NIT strategies may decrease liver biopsy rates while maintaining the accuracy of noninvasive diagnosis in pts with advanced fibrosis due to NASH.

Funding Agencies

Intercept Pharmaceuticals

The PDGFRα-laminin B1-keratin 19 cascade drives tumor progression at the invasive front of human hepatocellular carcinoma

Human hepatocellular carcinomas (HCCs) expressing the biliary/hepatic progenitor cell marker keratin 19 (K19) have been linked with a poor prognosis and exhibit an increase in platelet-derived growth factor receptor α (PDGFRα) and laminin beta 1 (LAMB1) expression. PDGFRα has been reported to induce de novo synthesis of LAMB1 protein in a Sjogren syndrome antigen B (La/SSB)-dependent manner in a murine metastasis model. However, the role of this cascade in human HCC remains unclear. This study focused on the functional role of the PDGFRα-La/SSB-LAMB1 pathway and its molecular link to K19 expression in human HCC. In surgical HCC specimens from a cohort of 136 patients, PDGFRα expression correlated with K19 expression, microvascular invasion and metastatic spread. In addition, PDGFRα expression in pre-operative needle biopsy specimens predicted poor overall survival during a 5-year follow-up period. Consecutive histological staining demonstrated that the signaling components of the PDGFRα-La/SSB-LAMB1 pathway were strongly expressed at the invasive front. K19-positive HCC cells displayed high levels of α2β1 integrin (ITG) receptor, both in vitro and in vivo. In vitro activation of PDGFRα signaling triggered the translocation of nuclear La/SSB into the cytoplasm, enhanced the protein synthesis of LAMB1 by activating its internal ribosome entry site, which in turn led to increased secretion of laminin-111. This effect was abrogated by the PDGFRα-specific inhibitor crenolanib. Importantly LAMB1 stimulated ITG-dependent focal adhesion kinase/Src proto-oncogene non-receptor tyrosine kinase signaling. It also promoted the ITG-specific downstream target Rho-associated coiled-coil containing protein kinase 2, induced K19 expression in an autocrine manner, invadopodia formation and cell invasion. Finally, we showed that the knockdown of LAMB1 or K19 in subcutaneous xenograft mouse models resulted in significant loss of cells invading the surrounding stromal tissue and reduced HepG2 colonization into lung and liver after tail vein injection. The PDGFRα-LAMB1 pathway supports tumor progression at the invasive front of human HCC through K19 expression.

Republished: Non-alcoholic fatty liver disease: a practical approach to treatment

Non-alcoholic fatty liver disease (NAFLD) affects up to a third of the population in many developed countries. Between 10% and 30% of patients with NAFLD have non-alcoholic steatohepatitis (NASH) that can progress to cirrhosis. There are metabolic risk factors common to both NAFLD and cardiovascular disease, so patients with NASH have an increased risk of liver-related and cardiovascular death. Management of patients with NAFLD depends largely on the stage of disease, emphasising the importance of careful risk stratification. There are four main areas to focus on when thinking about management strategies in NAFLD: lifestyle modification, targeting the components of the metabolic syndrome, liver-directed pharmacotherapy for high risk patients and managing the complications of cirrhosis.

Republished: Non-alcoholic fatty liver disease: non-invasive investigation and risk stratification

Non-alcoholic fatty liver disease (NAFLD) encompasses a histological spectrum of liver disease, from simple steatosis through to cirrhosis. As the worldwide rates of obesity have increased, NAFLD has become the commonest cause of liver disease in many developed countries, affecting up to a third of the population. The majority of patients have simple steatosis that carries a relatively benign prognosis. However, a significant minority have non-alcoholic steatohepatitis, and have increased liver related and cardiovascular mortality. Identifying those at risk of progressive disease is crucial. Liver biopsy remains the gold standard investigation for assessing stage of disease but its invasive nature makes it impractical for widespread use as a prognostic tool. Non-invasive tools for diagnosis and disease staging are required, reserving liver biopsy for those patients where it offers clinically relevant additional information. This review discusses the non-invasive modalities available for assessing steatosis, steatohepatitis and fibrosis. We propose a pragmatic approach for the assessment of patients with NAFLD to identify those at high risk of progressive disease who require referral to specialist services.

Non-alcoholic fatty liver disease: a practical approach to treatment

Non-alcoholic fatty liver disease (NAFLD) affects up to a third of the population in many developed countries. Between 10% and 30% of patients with NAFLD have non-alcoholic steatohepatitis (NASH) that can progress to cirrhosis. There are metabolic risk factors common to both NAFLD and cardiovascular disease, so patients with NASH have an increased risk of liver-related and cardiovascular death. Management of patients with NAFLD depends largely on the stage of disease, emphasising the importance of careful risk stratification. There are four main areas to focus on when thinking about management strategies in NAFLD: lifestyle modification, targeting the components of the metabolic syndrome, liver-directed pharmacotherapy for high risk patients and managing the complications of cirrhosis.

Carriage of the PNPLA3 rs738409 C >G polymorphism confers an increased risk of non-alcoholic fatty liver disease associated hepatocellular carcinoma

BACKGROUND & AIMS

Subtle inter-patient genetic variation and environmental factors combine to determine disease progression in non-alcoholic fatty liver disease (NAFLD). Carriage of the PNPLA3 rs738409 c.444C >G minor allele (encoding the I148M variant) has been robustly associated with advanced NAFLD. Although most hepatocellular carcinoma (HCC) is related to chronic viral hepatitis or alcoholic liver disease, the incidence of NAFLD-related HCC is increasing. We examined whether rs738409 C >G was associated with HCC-risk in patients with NAFLD.

METHODS

PNPLA3 rs738409 genotype was determined by allelic discrimination in 100 European Caucasians with NAFLD-related HCC and 275 controls with histologically characterised NAFLD.

RESULTS

Genotype frequencies were significantly different between NAFLD-HCC cases (CC=28, CG=43, GG=29) and NAFLD-controls (CC=125, CG=117, GG=33) (p=0.0001). In multivariate analysis adjusted for age, gender, diabetes, BMI, and presence of cirrhosis, carriage of each copy of the rs738409 minor (G) allele conferred an additive risk for HCC (adjusted OR 2.26 [95% CI 1.23-4.14], p=0.0082), with GG homozygotes exhibiting a 5-fold [1.47-17.29], p=0.01 increased risk over CC. When compared to the UK general population (1958 British Birth Cohort, n=1476), the risk-effect was more pronounced (GC vs. CC: unadjusted OR 2.52 [1.55-4.10], p=0.0002; GG vs. CC: OR 12.19 [6.89-21.58], p<0.0001).

CONCLUSIONS

Carriage of the PNPLA3 rs738409 C >G polymorphism is not only associated with greater risk of progressive steatohepatitis and fibrosis but also of HCC. If validated, these findings suggest that PNPLA3 genotyping has the potential to contribute to multi-factorial patient-risk stratification, identifying those to whom HCC surveillance may be targeted.

Low Levels of 25-Hydroxy Vitamin D are Independently Associated with the Risk of Bacterial Infection in Cirrhotic Patients

OBJECTIVES:

Low levels of vitamin D are associated with a higher mortality in cirrhotic patients, but the role of this deficiency is still unknown. The purpose of this study was to assess the levels of vitamin D in cirrhotic patients with and without bacterial infection.

METHODS:

25-hydroxy (25-OH) vitamin D was assessed by immunoassay in 88 patients hospitalized in our hepatology unit.

RESULTS:

The causes of cirrhosis were mainly alcohol (70%), hepatitis C (10%), or both (9%). Infections (n=38) mainly included bacteriemia (21%), urinary tract infections (24%), and spontaneous bacterial peritonitis (29%). A severe deficiency in vitamin D (<10 ng/ml) was observed in 56.8% of patients. Infections were more frequent in patients with a severe deficiency compared with the others (54 vs. 29%, P=0.02). A severe deficiency in vitamin D was a predictive factor of infection (odds ratio=5.44 (1.35–21.97), P=0.017) independently of the Child–Pugh score (odds ratio=2.09 (1.47–2.97) P=0.00004) and the C-reactive protein level (odds ratio=1.03 (1.002–1.052), P=0.03) in a logistic regression also including the alanine amino transferase (not significant). By a Cox regression analysis, only the presence of an infection was significantly associated with mortality (relative risk=3.24 (1.20–8.76), P=0.02) in a model also associating the Child–Pugh score (not significant) and the presence of a severe deficiency in vitamin D (not significant).

CONCLUSIONS:

Low levels of 25-OH vitamin D were independently associated with bacterial infections in cirrhotic patients. The impact of 25-OH vitamin D supplementation on the infection rate and death of cirrhotic patients should be assessed in randomized trials.

Non-alcoholic fatty liver disease: non-invasive investigation and risk stratification

Non-alcoholic fatty liver disease (NAFLD) encompasses a histological spectrum of liver disease, from simple steatosis through to cirrhosis. As the worldwide rates of obesity have increased, NAFLD has become the commonest cause of liver disease in many developed countries, affecting up to a third of the population. The majority of patients have simple steatosis that carries a relatively benign prognosis. However, a significant minority have non-alcoholic steatohepatitis, and have increased liver related and cardiovascular mortality. Identifying those at risk of progressive disease is crucial. Liver biopsy remains the gold standard investigation for assessing stage of disease but its invasive nature makes it impractical for widespread use as a prognostic tool. Non-invasive tools for diagnosis and disease staging are required, reserving liver biopsy for those patients where it offers clinically relevant additional information. This review discusses the non-invasive modalities available for assessing steatosis, steatohepatitis and fibrosis. We propose a pragmatic approach for the assessment of patients with NAFLD to identify those at high risk of progressive disease who require referral to specialist services.

Hypercoagulability in cirrhosis: causes and consequences

Decreased levels of most coagulation factors and thrombocytopenia are the main haemostatic abnormalities of cirrhosis. As a consequence, this condition was, until recently, considered as the prototype acquired coagulopathy responsible for bleeding. However, recent evidence suggests that it should, rather, be regarded as a condition associated with normal or even increased thrombin generation. The bleeding events that occur in these patients should, therefore, be explained by the superimposed conditions that frequently occur in this setting. Due to elevated levels of factor VIII (procoagulant driver) in combination with decreased protein C (anticoagulant driver), which are typically found in patients with cirrhosis, a procoagulant imbalance, defined as a partial resistance to the in vitro anticoagulant action of thrombomodulin, can be demonstrated. Whether this in vitro hypercoagulability is truly representative of what occurs in vivo remains to be established. However, the hypothesis that it may have clinical consequences is attractive and deserves attention. The possible consequences that we discuss herein include whether (i) cirrhosis is a condition associated with increased risk of venous thromboembolism or portal vein thrombosis; (ii) the hypercoagulability associated with cirrhosis has any other role outside coagulation (i.e. progression of liver fibrosis); and (iii) anticoagulation should be used in cirrhosis. Although apparently provocative, considering anticoagulation as a therapeutic option in patients with cirrhosis is now supported by a rationale of increasing strength. There may be subgroups of patients who benefit from anticoagulation to treat or prevent thrombosis and to slow hepatic fibrosis. Clinical studies are warranted to explore these therapeutic options.

A missense mutation in the non-neural G-protein alpha-subunit isoforms modulates susceptibility to obesity

OBJECTIVE

The Gnas transcription unit located within an imprinting region encodes several proteins, including the G-protein alpha-subunit, Gsalpha, its isoform XLalphas and their variant truncated neural forms GsalphaN1 and XLN1. Gsalpha and GsalphaN1 are expressed predominantly from the maternally derived allele in some tissues, whereas XLalphas and XLN1 are expressed exclusively from the paternally derived allele. The relative contribution of full-length Gsalpha and XLalphas, and truncated forms GsalphaN1 and XLN1 to phenotype is unknown. The edematous-small point mutation (Oed-Sml) in exon 6 of Gnas lies downstream of GsalphaN1 and XLN1, but affects full-length Gsalpha and XLalphas, allowing us to address the role of full-length Gsalpha and XLalphas. The aim of this study was therefore to determine the metabolic phenotypes of Oed and Sml mice, and to correlate phenotypes with affected transcripts.

METHODS

Mice were fed standard or high-fat diets and weighed regularly. Fat mass was determined by DEXA analysis. Indirect calorimetry was used to measure metabolic rate. Glucose was measured in tolerance tests and biochemical parameters in fasted plasma samples. Histological analysis of fat and liver was carried out post mortem.

RESULTS

Oed mice are obese on either diet and have a reduced metabolic rate. Sml mice are lean and are resistant to a high-fat diet and have an increased metabolic rate.

CONCLUSION

Adult Oed and Sml mice have opposite metabolic phenotypes. On maternal inheritance, the obese Oed phenotype can be attributed to non-functional full-length Gsalpha. In contrast, on paternal inheritance, Sml mice were small and resistant to the development of obesity on a high-fat diet, effects that can be attributed to mutant XLalphas. Thus, the neural isoforms, GsalphaN1 and XLN1, do not appear to play a role in these metabolic phenotypes.

Coagulation status modulates murine hepatic fibrogenesis: implications for the development of novel therapies

BACKGROUND

There is strong evidence demonstrating that coagulation system activation contributes to wound healing and promotes organ fibrosis. Several epidemiological studies have now shown that prothrombotic status, including carriage of the factor (F)V Leiden mutation, is associated with rapid progression of hepatic fibrosis.

OBJECTIVES

To assess the effect of a procoagulant state on progression of hepatic fibrosis in a controlled environment and to test whether anticoagulation could attenuate fibrogenesis.

METHODS

We investigated the effects of coagulation status on liver fibrosis development in a mouse model of chronic toxic liver injury. Prothrombotic FV Leiden mutant mice, C57BL/6 control animals and anticoagulated mice were studied after chronic exposure to carbon tetrachloride.

RESULTS

Carriage of the FV Leiden mutation caused a significant increase in hepatic fibrosis. Anticoagulation with warfarin significantly reduced fibrosis progression in wild-type mice but was less effective against the profibrotic FV Leiden mutation. Changes in the fibrosis scores were mirrored by changes in liver hydroxyproline content and hepatic stellate cell activation detected by alpha-smooth muscle actin expression.

CONCLUSIONS

These results demonstrate that coagulation status has a strong influence on hepatic fibrogenesis. It is likely that thrombin signaling through the proteinase-activated receptor 1 (PAR(1)) receptor expressed on hepatic stellate cells is responsible for this relationship. These results represent the first reported use of anticoagulation to slow hepatic fibrogenesis and suggest a potential novel anti-fibrotic therapeutic approach for the future.

Hypercoagulation and thrombophilia in liver disease

A complex balance exists between endogenous procoagulants and the anticoagulant system in liver disease patients. Hypercoagulable events occur in cirrhosis patients despite the well-known bleeding diathesis of liver disease. These events may be clinically evident, such as in portal vein thrombosis or pulmonary embolism, but these conditions may also be a silent contributor to certain disease states, such as portopulmonary hypertension or parenchymal extinction with liver atrophy as well as thrombosis of extracorporeal circuits in dialysis or liver assist devices. Moreover, liver disease-related hypercoagulability may contribute to vascular disease in the increasingly common condition of non-alcoholic fatty liver disease. Despite the incidence of these problems, there are few widely accessible and practical laboratory tests to evaluate the risk of a hypercoagulable event in cirrhosis patients. Furthermore, there is little research on the use of commonly accepted anticoagulants in patients with liver disease. This article is a result of an international symposium on coagulation disorders in liver disease and addresses several areas of specific interest in hypercoagulation in liver disease. Critical areas lacking clinical information are highlighted and future areas of research interest are defined with an aim to foster clinical research in this field.

The safe use of percutaneous gastrostomy for enteral nutrition in patients with Crohn's disease

OBJECTIVE

To determine the safety of percutaneous endoscopic gastrostomy (PEG) tube placement for nutritional support and/or defined therapeutic enteral nutrition (TEN) in adult patients with Crohn's disease.

DESIGN

A prospective, observational study of patients with Crohn's disease in whom PEG tubes were placed for nutritional support or TEN.

SETTING

A specialist nutrition clinic at a gastroenterology tertiary referral centre in Harrow, UK.

PARTICIPANTS

Nine patients with Crohn's disease. Seven patients had nutritional failure and were unable to tolerate nasogastric feeding, and two patients were recruited in whom TEN therapy for active disease was indicated. The age range was 21-52 years (median, 30 years). Five patients were female; all had had previous ileo-colonic resections, one had a gastro-enterostomy and one had a non-healing Crohn's-related gastric ulcer.

INTERVENTIONS

PEG insertion (Fresenius, Frecka 9 Fr) was performed at endoscopy with intravenous sedation. Follow-up with tubes in situ was for a median of 37 weeks (range, 4-276 weeks), and for a further median of 80 weeks (range, 52-120 weeks) in those whose tubes have been removed.

MAIN OUTCOME MEASURES

The level of disease activity, nutritional status/body mass index and any complications associated with PEG tube placement were recorded.

RESULTS

PEG was achieved in all patients; the only complication was a minor superficial entry site infection. Five patients continue to use PEG feeding to good effect, including healing of the Crohn's-associated ulcer. One patient now eats normally having regained target weight, and three require parenteral nutrition, having failed to achieve nutritional sufficiency despite an optimal enteral regimen via the PEG. An adverse body image in one of these patients (an opiate abuser with a long psychiatric history) was probably contributory to PEG failure. There was no peristomal or fistulous disease.

CONCLUSIONS

Although nutrition via PEG is not always successful, failures are of enteral nutrition, and not of the means. PEG use in selected patients with Crohn's disease appears safe and can prove a useful addition to therapeutic options.