Diagnostic accuracy of FibroScan-AST (FAST) score for the non-invasive identification of patients with fibrotic non-alcoholic steatohepatitis: a systematic review and meta-analysis

OBJECTIVE

A simple combined score with liver stiffness, controlled attenuation parameter and serum aspartate aminotransferase (AST), the FibroScan-AST (FAST) score, has been proposed to non-invasively identify patients with fibrotic non-alcoholic steatohepatitis (NASH). We performed a systematic review and meta-analysis of published studies to evaluate the overall diagnostic accuracy of the FAST score in identifying patients with fibrotic NASH.

DESIGN

We systematically searched MEDLINE, Ovid Embase, Scopus and Cochrane Library electronic databases for full-text published articles in any language between 3 February 2020 and 30 April 2022. We included original articles that reported data for the calculation of sensitivity and specificity of the FAST score for identifying adult patients with fibrotic NASH adults, according to previously described rule-out (≤0.35) and rule-in (≥0.67) cut-offs.

RESULTS

We included 12 observational studies for a total of 5835 participants with biopsy-confirmed non-alcoholic fatty liver disease. The pooled prevalence of fibrotic NASH was 28% (95% CI 21% to 34%). The FAST score's pooled sensitivity was 89% (95% CI 82% to 93%), and the pooled specificity was 89% (95% CI 83% to 94%) according to the aforementioned rule-in/rule-out cut-offs. The negative predictive value and positive predictive value of the FAST score were 92% (95% CI 91% to 95%) and 65% (95% CI 53% to 68%), respectively. Subgroup analyses and influential bias analyses did not alter these findings.

CONCLUSION

The results of our meta-analysis show that the FAST score has a good performance for non-invasive diagnosis of fibrotic NASH. Therefore, this score can be used to efficiently identify patients who should be referred for a conclusive liver biopsy and/or consideration for treatment with emerging pharmacotherapies.

PROSPERO REGISTRATION NUMBER

CRD42022350945.

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.

Administration of Human MSC-Derived Extracellular Vesicles for the Treatment of Primary Sclerosing Cholangitis: Preclinical Data in MDR2 Knockout Mice

Primary Sclerosing Cholangitis (PSC) is a progressive liver disease for which there is no effective medical therapy. PSC belongs to the family of immune-mediated biliary disorders and it is characterized by persistent biliary inflammation and fibrosis. Here, we explored the possibility of using extracellular vesicles (EVs) derived from human, bone marrow mesenchymal stromal cells (MSCs) to target liver inflammation and reduce fibrosis in a mouse model of PSC. Five-week-old male FVB.129P2-Abcb4tm1Bor mice were intraperitoneally injected with either 100 µL of EVs (± 9.1 × 109 particles/mL) or PBS, once a week, for three consecutive weeks. One week after the last injection, mice were sacrificed and liver and blood collected for flow cytometry analysis and transaminase quantification. In FVB.129P2-Abcb4tm1Bor mice, EV administration resulted in reduced serum levels of alkaline phosphatase (ALP), bile acid (BA), and alanine aminotransferase (ALT), as well as in decreased liver fibrosis. Mechanistically, we observed that EVs reduce liver accumulation of both granulocytes and T cells and dampen VCAM-1 expression. Further analysis revealed that the therapeutic effect of EVs is accompanied by the inhibition of NFkB activation in proximity of the portal triad. Our pre-clinical experiments suggest that EVs isolated from MSCs may represent an effective therapeutic strategy to treat patients suffering from PSC.

Resolving the fibrotic niche of human liver cirrhosis at single-cell level

Liver cirrhosis is a major cause of death worldwide and is characterized by extensive fibrosis. There are currently no effective antifibrotic therapies available. To obtain a better understanding of the cellular and molecular mechanisms involved in disease pathogenesis and enable the discovery of therapeutic targets, here we profile the transcriptomes of more than 100,000 single human cells, yielding molecular definitions for non-parenchymal cell types that are found in healthy and cirrhotic human liver. We identify a scar-associated TREM2+CD9+ subpopulation of macrophages, which expands in liver fibrosis, differentiates from circulating monocytes and is pro-fibrogenic. We also define ACKR1+ and PLVAP+ endothelial cells that expand in cirrhosis, are topographically restricted to the fibrotic niche and enhance the transmigration of leucocytes. Multi-lineage modelling of ligand and receptor interactions between the scar-associated macrophages, endothelial cells and PDGFRα+ collagen-producing mesenchymal cells reveals intra-scar activity of several pro-fibrogenic pathways including TNFRSF12A, PDGFR and NOTCH signalling. Our work dissects unanticipated aspects of the cellular and molecular basis of human organ fibrosis at a single-cell level, and provides a conceptual framework for the discovery of rational therapeutic targets in liver cirrhosis.

Outcomes of liver transplantation for non-alcoholic steatohepatitis: A European Liver Transplant Registry study

BACKGROUND & AIMS

Little is known about outcomes of liver transplantation for patients with non-alcoholic steatohepatitis (NASH). We aimed to determine the frequency and outcomes of liver transplantation for patients with NASH in Europe and identify prognostic factors.

METHODS

We analysed data from patients transplanted for end-stage liver disease between January 2002 and December 2016 using the European Liver Transplant Registry database. We compared data between patients with NASH versus other aetiologies. The principle endpoints were patient and overall allograft survival.

RESULTS

Among 68,950 adults undergoing first liver transplantation, 4.0% were transplanted for NASH - an increase from 1.2% in 2002 to 8.4% in 2016. A greater proportion of patients transplanted for NASH (39.1%) had hepatocellular carcinoma (HCC) than non-NASH patients (28.9%, p <0.001). NASH was not significantly associated with survival of patients (hazard ratio [HR] 1.02, p = 0.713) or grafts (HR 0.99; p = 0.815) after accounting for available recipient and donor variables. Infection (24.0%) and cardio/cerebrovascular complications (5.3%) were the commonest causes of death in patients with NASH without HCC. Increasing recipient age (61-65 years: HR 2.07, p <0.001; >65: HR 1.72, p = 0.017), elevated model for end-stage liver disease score (>23: HR 1.48, p = 0.048) and low (<18.5 kg/m²: HR 4.29, p = 0.048) or high (>40 kg/m²: HR 1.96, p = 0.012) recipient body mass index independently predicted death in patients transplanted for NASH without HCC. Data must be interpreted in the context of absent recognised confounders, such as pre-morbid metabolic risk factors.

CONCLUSIONS

The number and proportion of liver transplants performed for NASH in Europe has increased from 2002 through 2016. HCC was more common in patients transplanted with NASH. Survival of patients and grafts in patients with NASH is comparable to that of other disease indications.

LAY SUMMARY

The prevalence of non-alcoholic fatty liver disease has increased dramatically in parallel with the worldwide increase in obesity and diabetes. Its progressive form, non-alcoholic steatohepatitis, is a growing indication for liver transplantation in Europe, with good overall outcomes reported. However, careful risk factor assessment is required to maintain favourable post-transplant outcomes in patients with non-alcoholic steatohepatitis.

Obesity in acute alcoholic hepatitis increases morbidity and mortality

BACKGROUND

Alcohol and obesity synergise to increase the risk of liver-related mortality. We examined the influence of adiposity on clinical outcomes in alcoholic hepatitis (AH) and the underlying inflammatory crosstalk between adipose tissue (AT) and the liver.

METHODS

A cohort of 233 patients with AH from the UK and USA provided data to analyse the effects of obesity in AH. Body mass index was corrected for the severity of ascites, termed cBMI. Inflammatory and metabolic profiling was undertaken by proteome analysis of human serum samples. The effect of alcohol on adipose tissue and CXCL11 expression was studied in 3 T3-derived adipocytes and in mice using the high-fat diet-plus-binge ethanol model.

FINDINGS

Obesity was common amongst patients with AH, seen in 19% of individuals. Obesity (HR 2.22, 95%CI 1.1-4.3, p = .022) and underweight (HR 2.38, 1.00-5.6, p = .049) were independently associated with mortality at 3 months. Proteome analysis demonstrated multiple metabolic and inflammatory factors differentially expressed in obese AH verse lean AH, with CXCL11 being the most elevated factor in obese AH. In vitro analysis of cultured adipocytes and in vivo analysis of mouse models showed that alcohol induced CXCL11 expression in AT, but not in liver.

INTERPRETATION

Obesity is common in AH and associated with a greater than two-fold increase in short-term mortality. Obese AH is associated with a different inflammatory phenotype, with the greatest elevation in CXCL11. These data confirm that adiposity is clinically important in acute alcohol-related liver disease and illustrate the adipose-liver inflammatory axis in AH. FUND: This work was supported in part by an EASL Sheila Sherlock Physician Scientist Fellowship. The funder played no role in gathering or analysing data or writing the manuscript. This paper presents independent research supported by the NIHR Birmingham Biomedical Research Centre at the University Hospitals Birmingham NHS Foundation Trust and the University of Birmingham. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care.

Systematic review: the natural history of alpha-1 antitrypsin deficiency, and associated liver disease

BACKGROUND

Alpha-1 antitrypsin deficiency (AATD) is estimated to affect three million people worldwide. It causes liver disease in a proportion of carriers of the PiS and PiZ allele due to the formation and retention of polymers within the endoplasmic reticulum of hepatocytes. The reason for this selective penetrance is not known. Although clinical trials are underway, liver transplantation is the only effective treatment for liver disease due to AATD.

AIMS

To report the prevalence and natural history of liver disease among individuals with AATD, and assess the outcomes of liver transplantation through systematic review.

METHODS

A comprehensive search was conducted across multiple databases. Two independent authors selected the articles and assessed bias using the Newcastle-Ottawa Scale. Data were pooled for analysis, where comparable outcomes were reported.

RESULTS

Thirty-five studies were identified related to disease progression and 12 for the treatment of AATD. Seven per cent of children were reported to develop liver cirrhosis, with 16.5% of individuals presenting in childhood requiring liver transplantation. Of those surviving to adulthood, 10.5% had liver cirrhosis and 14.7% required transplantation. Liver transplantation was the only effective treatment reported and outcomes compare favourably to other indications, with 5-year survival reported as over 90% in children and over 80% in adults.

DISCUSSION

The clinical course of liver disease in individuals with AATD remains poorly understood, but affects about 10% of those with AATD. More research is required to identify those patients at risk of developing liver disease at an early stage, and to provide alternative treatments to liver transplantation.

Utility and cost evaluation of multiparametric magnetic resonance imaging for the assessment of non-alcoholic fatty liver disease

BACKGROUND

Validated diagnostic tools that are accurate, cost effective and acceptable to patients are required for disease stratification and monitoring in NAFLD.

AIMS

To investigate the performance and cost of multiparametric MRI alongside existing biomarkers in the assessment of NAFLD.

METHODS

Adult patients undergoing standard of care liver biopsy for NAFLD were prospectively recruited at two UK liver centres and underwent multiparametric MRI, blood sampling and transient elastography withing 2 weeks of liver biopsy. Non-invasive markers were compared to histology as the gold standard.

RESULTS

Data were obtained in 50 patients and 6 healthy volunteers. Corrected T1 (cT1) correlated with NAFLD activity score (ρ = 0.514, P < .001). cT1, enhanced liver fibrosis (ELF) test and liver stiffness differentiated patients with simple steatosis and NASH with AUROC (95% CI) of 0.69 (0.50-0.88), 0.87 (0.77-0.79) and 0.82 (0.70-0.94) respectively and healthy volunteers from patients with AUROC (95% CI) of 0.93 (0.86-1.00), 0.81 (0.69-0.92) and 0.89 (0.77-1.00) respectively. For the risk stratification of NAFLD, multiparametric MRI could save £150,218 per 1000 patients compared to biopsy. Multiparametric MRI did not discriminate between individual histological fibrosis stages in this population (P = .068).

CONCLUSIONS

Multiparametric MRI accurately identified patients with steatosis, stratifies those with NASH or simple steatosis and reliably excludes clinically significant liver disease with superior negative predictive value (83.3%) to liver stiffness (42.9%) and ELF (57.1%). For the risk stratification of NAFLD, multiparametric MRI was cost effective and, combined with transient elastography, had the lowest cost per correct diagnosis.

Granulocyte colony-stimulating factor and autologous CD133-positive stem-cell therapy in liver cirrhosis (REALISTIC): an open-label, randomised, controlled phase 2 trial

BACKGROUND

Results of small-scale studies have suggested that stem-cell therapy is safe and effective in patients with liver cirrhosis, but no adequately powered randomised controlled trials have been done. We assessed the safety and efficacy of granulocyte colony-stimulating factor (G-CSF) and haemopoietic stem-cell infusions in patients with liver cirrhosis.

METHODS

This multicentre, open-label, randomised, controlled phase 2 trial was done in three UK hospitals and recruited patients with compensated liver cirrhosis and MELD scores of 11·0-15·5. Patients were randomly assigned (1:1:1) to receive standard care (control), treatment with subcutaneous G-CSF (lenograstim) 15 μg/kg for 5 days, or treatment with G-CSF for 5 days followed by leukapheresis and intravenous infusion of three doses of CD133-positive haemopoietic stem cells (0·2 × 106 cells per kg per infusion). Randomisation was done by Cancer Research UK Clinical Trials Unit staff with a minimisation algorithm that stratified by trial site and cause of liver disease. The coprimary outcomes were improvement in severity of liver disease (change in MELD) at 3 months and the trend of change in MELD score over time. Analyses were done in the modified intention-to-treat population, which included all patients who received at least one day of treatment. Safety was assessed on the basis of the treatment received. This trial was registered at Current Controlled Trials on Nov 18, 2009; ISRCTN, number 91288089; and the European Clinical Trials Database, number 2009-010335-41.

FINDINGS

Between May 18, 2010, and Feb 26, 2015, 27 patients were randomly assigned to the standard care, 26 to the G-CSF group, and 28 to the G-CSF plus stem-cell infusion group. Median change in MELD from day 0 to 90 was -0·5 (IQR -1·5 to 1·1) in the standard care group, -0·5 (-1·7 to 0·5) in the G-CSF group, and -0·5 (-1·3 to 1·0) in the G-CSF plus stem-cell infusion group. We found no evidence of differences between the treatment groups and control group in the trends of MELD change over time (p=0·55 for the G-CSF group vs standard care and p=0·75 for the G-CSF plus stem-cell infusion group vs standard care). Serious adverse events were more frequent the in G-CSF and stem-cell infusion group (12 [43%] patients) than in the G-CSF (three [11%] patients) and standard care (three [12%] patients) groups. The most common serious adverse events were ascites (two patients in the G-CSF group and two patients in the G-CSF plus stem-cell infusion group, one of whom was admitted to hospital with ascites twice), sepsis (four patients in the G-CSF plus stem-cell infusion group), and encephalopathy (three patients in the G-CSF plus stem-cell infusion group, one of whom was admitted to hospital with encephalopathy twice). Three patients died, including one in the standard care group (variceal bleed) and two in the G-CSF and stem-cell infusion group (one myocardial infarction and one progressive liver disease).

INTERPRETATION

G-CSF with or without haemopoietic stem-cell infusion did not improve liver dysfunction or fibrosis and might be associated with increased frequency of adverse events compared with standard care.

FUNDING

National Institute of Health Research, The Sir Jules Thorn Charitable Trust.

Review article: new treatments in non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease is the fastest growing cause of liver disease in the Western world, yet there is no approved pharmacotherapy. While lifestyle modifications remain the mainstay of treatment, only a proportion of individuals are able to make or sustain them, and so more treatment options are required.

AIM

To review the potential benefit of drugs used in clinical practice, those entering phase II trials, and compounds being investigated in pre-clinical studies.

METHODS

A literature search was performed using PubMed to identify relevant studies; linked references were also reviewed.

RESULTS

Vitamin E and pioglitazone have shown efficacy in non-alcoholic steatohepatitis (NASH), but long-term safety concerns, specifically bladder cancer and osteoporosis with pioglitazone, have limited their use. GLP-1 analogues and SGLT-2 inhibitors are currently approved for use in diabetes, have shown early efficacy in NASH and also have beneficial cardiovascular effects. Peroxisome proliferator-activator receptors and FXR agonists have potent effects on lipogenesis, inflammation and fibrosis, respectively, with their efficacy and safety being currently tested in phase 3. As inflammation and apoptosis are key features of NASH agents modulating these pathways are of interest; CCR2/5 antagonists downregulate inflammatory pathways and reduce fibrosis with caspase and apoptosis signal-regulating kinase 1 inhibitors reducing apoptosis and fibrosis.

CONCLUSIONS

Rising demand and an improved understanding of NASH pathophysiology has led to a surge in development of new therapies. Tailoring pharmacotherapy to the dominant pathogenic pathway in a given patient along with use of combination therapy is likely to represent the future direction in treatment of patients with NASH.

REpeated AutoLogous Infusions of STem cells In Cirrhosis (REALISTIC): a multicentre, phase II, open-label, randomised controlled trial of repeated autologous infusions of granulocyte colony-stimulating factor (GCSF) mobilised CD133+ bone marrow stem cells in patients with cirrhosis. A study protocol for a randomised controlled trial

INTRODUCTION

Liver disease mortality and morbidity are rapidly rising and liver transplantation is limited by organ availability. Small scale human studies have shown that stem cell therapy is safe and feasible and has suggested clinical benefit. No published studies have yet examined the effect of stem cell therapy in a randomised controlled trial and evaluated the effect of repeated therapy.

METHODS AND ANALYSIS

Patients with liver cirrhosis will be randomised to one of three trial groups: group 1: Control group, Standard conservative management; group 2 treatment: granulocyte colony-stimulating factor (G-CSF; lenograstim) 15 µg/kg body weight daily on days 1-5; group 3 treatment: G-CSF 15 µg/kg body weight daily on days 1-5 followed by leukapheresis, isolation and aliquoting of CD133+ cells. Patients will receive an infusion of freshly isolated CD133+ cells immediately and frozen doses at days 30 and 60 via peripheral vein (0.2×10(6) cells/kg for each of the three doses). Primary objective is to demonstrate an improvement in the severity of liver disease over 3 months using either G-CSF alone or G-CSF followed by repeated infusions of haematopoietic stem cells compared with standard conservative management. The trial is powered to answer two hypotheses of each treatment compared to control but not powered to detect smaller expected differences between the two treatment groups. As such, the overall α=0.05 for the trial is split equally between the two hypotheses. Conventionally, to detect a relevant standardised effect size of 0.8 point reduction in Model for End-stage Liver Disease score using two-sided α=0.05(overall α=0.1 split equally between the two hypotheses) and 80% power requires 27 participants to be randomised per group (81 participants in total).

ETHICS AND DISSEMINATION

The trial is registered at Current Controlled Trials on 18 November 2009 (ISRCTN number 91288089, EuDRACT number 2009-010335-41). The findings of this trial will be disseminated to patients and through peer-reviewed publications and international presentations.

Abdominal subcutaneous adipose tissue insulin resistance and lipolysis in patients with non-alcoholic steatohepatitis

BACKGROUND

Systemic insulin resistance (IR) is a primary feature in non-alcoholic steatohepatitis (NASH), however, there remain limited data on tissue-specific insulin sensitivity in vivo.

METHODS

We examined tissue-specific (adipose, muscle and liver) insulin sensitivity and inflammation in 16 European Caucasian patients with biopsy-confirmed NASH and in 15 healthy controls. All underwent a two-step hyperinsulinaemic euglycaemic clamp incorporating stable isotope measurements of carbohydrate and lipid metabolism with concomitant subcutaneous adipose tissue (SAT) microdialysis.

RESULTS

Hepatic and muscle insulin sensitivity were decreased in patients with NASH compared with controls, as demonstrated by reduced suppression of hepatic glucose production and glucose disposal (Gd) rates following insulin infusion. In addition, rates of lipolysis were higher in NASH patients with impaired insulin-mediated suppression of free fatty acid levels. At a tissue specific level, abdominal SAT in patients with NASH was severely insulin resistant, requiring >sixfold more insulin to cause ½-maximal suppression of glycerol release when compared with healthy controls. Furthermore, patients with NASH had significantly higher circulating levels of pro-inflammatory adipocytokines than controls.

CONCLUSION

NASH patients have profound IR in the liver, muscle and in particular adipose tissues. This study represents the first in vivo description of dysfunctional SAT in patients with NASH.

Stem cells for liver regeneration

The liver has a unique capacity to repair following injury, which is largely achieved by proliferation of hepatocytes. However, in situations of chronic or overwhelming liver injury, additional repair mechanisms, namely liver progenitor or oval cells, are activated. These cells, located in the canals of Hering, express markers for both hepatocytes and biliary cells and have the capacity to differentiate down both hepatocyte and biliary lineages. Previous work has suggested that the administration of autologous or allogeneic cell therapies such as haematopoietic or mesenchymal stem cells can augment liver repair by either stimulating endogenous repair mechanisms or by suppressing ongoing damage. A better understanding of how cell therapies can promote liver regeneration will lead to the refinement of these therapeutic approaches and also develop new pharmacological agents for liver repair.

Birmingham and Lambeth Liver Evaluation Testing Strategies (BALLETS): a prospective cohort study

OBJECTIVE

To evaluate mildly abnormal liver function test (LFT) results in general practice among patients who do not have known liver disease.

DESIGN

Prospective cohort study of people with abnormal LFT results identified in primary care. Participants were intensively investigated using a common protocol and followed up for 2 years. Substudies investigated the psychological sequelae of abnormal test results, clinicians' reasons for testing, decision options when LFT results were abnormal and early detection of liver fibrosis.

SETTING

Eleven primary-care practices: eight in Birmingham and three in Lambeth.

PARTICIPANTS

Adults with abnormal LFT results who did not have pre-existing or obvious liver disease. Eight analytes were included in the panel of LFTs.

MAIN OUTCOME MEASURES

Statistical tests were used to identify the interactions between clinical features, the initial pattern of abnormal LFT results and (1) specific viral, genetic and autoimmune diseases, such as viral hepatitis, haemochromatosis and primary biliary cirrhosis; (2) a range of other serious diseases, such as metastatic cancer and hypothyroidism; (3) 'fatty liver' not associated with the above; and (4) the absence of detectable disease.

RESULTS

Fewer than 5% of people with abnormal LFT results had a specific disease of the liver, and many of these were unlikely to need treatment. The diagnostic potential of the LFT panel is largely subsumed into just two analytes: alanine aminotransferase (ALT) and alkaline phosphatase (ALP). Gamma-glutamyltransferase (GGT) offers a small increase in sensitivity at the margin at the cost of a large loss of specificity. Eighty-four per cent of abnormal LFT results remain abnormal on retesting 1 month later. In many cases, carrying out a definitive or specific test will be more efficient than repeating LFTs, with a view to specific testing only if the test remains abnormal. An ultrasound diagnosis of 'fatty liver' was present in nearly 40% of patients with abnormal LFTs and a small amount of weight loss over 2 years was associated with a reduced incidence of liver fat. There was a J-shaped relationship between alcohol intake and fatty liver in men. An abnormal LFT result causes temporary anxiety, which does not appear to promote sustained behaviour change.

CONCLUSIONS

Liver disease is rare among people with abnormal LFT results in primary care. Only two analytes (ALT and ALP) are helpful in identifying the majority of liver disease. GGT adds little information in return for a high false-positive rate but it is sensitive to alcohol intake. LFT results seldom revert from abnormal to normal over a 1-month period, and modelling shows that repeating an abnormal LFT panel, as recommended in the current guidelines, is inefficient. LFTs are often undertaken to meet perceived patient need for a blood test, but as they are neither specific nor indicative of any particular disease they are among the least suitable tests for this purpose. Obesity and raised ALT provide strong evidence for a presumptive diagnosis of 'fatty' liver. Abnormal LFTs and 'fatty' liver provoke only short-term anxiety and neither is associated with sustained weight loss. Even a small amount of weight loss reduces liver fat.

FUTURE WORK RECOMMENDATIONS

(1) the cases of 'fatty liver' and controls should be followed up in the long term to identify features that predict development of hepatosteatosis and then cirrhosis; (2) the acceptability of replacing the traditional six- to eight-analyte LFT panel with a drop down menu including the ALT/ALP combination should be evaluated.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Safety and efficacy of liraglutide in patients with type 2 diabetes and elevated liver enzymes: individual patient data meta-analysis of the LEAD program

BACKGROUND

Non-alcoholic fatty liver disease has reached epidemic proportions in type 2 diabetes (T2D). Glucagon-like peptide-1 analogues are licensed in T2D, yet little data exist on efficacy and safety in liver injury.

AIM

To assess the safety and efficacy of 26-week liraglutide on liver parameters in comparison with active-placebo.

METHODS

Individual patient data meta-analysis was performed using patient-level data combined from six 26-week, phase-III, randomised controlled T2D trials, which comprise the 'Liraglutide Effect and Action in Diabetes' (LEAD) program. The LEAD-2 sub-study was analysed to assess the effect on CT-measured hepatic steatosis.

RESULTS

Of 4442 patients analysed, 2241 (50.8%) patients had an abnormal ALT at baseline [mean ALT 33.8(14.9) IU/L in females; 47.3(18.3) IU/L in males]. Liraglutide 1.8 mg reduced ALT in these patients vs. placebo (-8.20 vs. -5.01 IU/L; P = 0.003), and was dose-dependent (no significant differences vs. placebo with liraglutide 0.6 or 1.2 mg). This effect was lost after adjusting for liraglutide's reduction in weight (mean ALT difference vs. placebo -1.41 IU/L, P = 0.21) and HbA1c (+0.57 IU/L, P = 0.63). Adverse effects with 1.8 mg liraglutide were similar between patients with and without baseline abnormal ALT. In LEAD-2 sub-study, liraglutide 1.8 mg showed a trend towards improving hepatic steatosis vs. placebo (liver-to-spleen attenuation ratio +0.10 vs. 0.00; P = 0.07). This difference was reduced when correcting for changes in weight (+0.06, P = 0.25) and HbA(1c) (0.00, P = 0.93).

CONCLUSIONS

Twenty-six weeks' liraglutide 1.8 mg is safe, well tolerated and improves liver enzymes in patients with type 2 diabetes. This effect appears to be mediated by its action on weight loss and glycaemic control.

Long-term impact of liver transplantation on respiratory function and nutritional status in children and adults with cystic fibrosis

Early liver transplant (LT) has been advocated for patients with cystic fibrosis liver disease (CFLD) and evidence of deterioration in nutritional state and respiratory function to prevent further decline. However, the impact of single LT on long-term respiratory function and nutritional status has not been adequately addressed. We performed a retrospective analysis of the outcomes of 40 (21 adult/19 pediatric) patients with CFLD transplanted between 1987 and 2009 with median follow-up of 47.8 months (range 4-180). One and five-year actuarial survival rates were 85%/64% for adult and 90%/85% for pediatric LT cohorts, respectively. Lung function remained stable until 4 years (FEV(1) % predicted; pretransplant 48.4% vs. 45.9%, 4 years posttransplant) but declined by 5 years (42.4%). Up to 4 years posttransplant mean annual decline in FEV(1) % was lower (0.74%; p = 0.04) compared with the predicted 3% annual decline in CF patients with comorbidity including diabetes. Number of courses of intravenous antibiotics was reduced following LT, from 3.9/year pretransplant to 1.1/year, 5 years posttransplant. Body mass index was preserved posttransplant; 18.0 kg/m(2) (range 15-24.3) pretransplant versus 19.6 kg/m(2) (range 16.4-22.7) 5 years posttransplant. In conclusion, LT is an effective treatment for selected patients with cirrhosis due to CFLD, stabilizing aspects of long-term lung function and preserving nutritional status.

Current therapeutic strategies in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) encompasses a spectrum of disease ranging from simple steatosis through steatohepatitis (NASH) to increasing fibrosis and eventual cirrhosis. NAFLD is the hepatic manifestation of the metabolic syndrome and has now become the most common cause of liver disease in Western countries, with the more advanced stages of disease being associated with an increased risk of liver-related morbidity and mortality. The optimal management of patients with NAFLD remains a clinical challenge. The aim of this study is to describe established and emerging strategies for the treatment of NAFLD. Relevant research and review articles were identified by searching PubMed. Selected articles referenced in these publications were also examined. Good quality randomized controlled studies have demonstrated the need for multifaceted lifestyle interventions in patients with NAFLD including the need for diet, exercise and behavioural counselling. Despite several trials of pharmacological agents, no highly effective treatment yet exists, with surgery representing the mainstay for advanced disease. A multidisciplinary approach, with a major focus on lifestyle change, represents best treatment pending the development of new therapeutic options.

Systematic review: the diagnosis and staging of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) has become the most prevalent cause of liver disease in Western countries. The development of non-alcoholic steatohepatitis (NASH) and fibrosis identifies an at-risk group with increased risk of cardiovascular and liver-related deaths. The identification and management of this at-risk group remains a clinical challenge.

AIM

To perform a systematic review of the established and emerging strategies for the diagnosis and staging of NAFLD.

METHODS

Relevant research and review articles were identified by searching PubMed, MEDLINE and EMBASE.

RESULTS

There has been a substantial development of non-invasive risk scores, biomarker panels and radiological modalities to identify at-risk patients with NAFLD without recourse to liver biopsy on a routine basis. These modalities and algorithms have improved significantly in their diagnosis and staging of fibrosis and NASH in patients with NAFLD, and will likely impact on the number of patients undergoing liver biopsy.

CONCLUSIONS

Staging for NAFLD can now be performed by a combination of radiological and laboratory techniques, greatly reducing the requirement for invasive liver biopsy.

Critical review of clinical trials of bone marrow stem cells in liver disease

Morbidity and mortality from cirrhosis is increasing rapidly in the Western world. Currently the only effective treatment is liver transplantation, an increasingly limited and expensive resource. Consequently, there has been great hope that stem cells may offer new therapeutic approaches in the management of liver disease. In this review we critically appraise the 11 published clinical studies of bone marrow stem cells in liver disease, and focus on the unresolved issues regarding their role. We outline the different mechanisms by which stem cells may impact on liver disease, as well as highlight the importance of the type of stem cell chosen. There are multiple different stem cell populations that have, in rodent studies, been shown to have differing effects on liver regeneration and fibrogenesis/degradation. Thus, choice of cell should reflect the desired or expected mechanism of action. The importance, and methods, of studying the fate of stem cells infused in clinical studies is emphasized as we seek to translate observations in rodents into the clinical setting. Finally, we discuss which cohorts of patients with liver disease would benefit from stem cell therapy, as well as establish minimum criteria for future clinical trials of stem cells.

A biochemical prognostic model of outcome in paracetamol-induced acute liver injury

BACKGROUND

The aim of this study was to develop a prognostic model of outcome for patients with paracetamol induced acute liver injury based on admission parameters

METHODS

We used a cohort of 97 patients admitted to the Scottish Liver Transplant Unit between 1997 and 1998 to identify biochemical prognostic markers of outcome and thus create a prognostic model. Blood samples were taken on admission for analysis. The model was subsequently validated by testing it on a second cohort of 86 patients admitted between 1999 and 2000.

RESULTS

The following were identified as independent variables of poor prognosis (death/ transplant); phenylalanine, pyruvate, alanine, acetate, calcium, haemoglobin and lactate. A prognostic model was then constructed by stepwise forward logistic regression analysis: (400xPyruvate mmols/L)+(50xPhenylalanine (mmols/L)-(4 x Hemoglobin (g/dL). A value of <16 had an accuracy of 93% in predicting death correctly. When applied to the validation cohort this model had a positive predictive value of 91%, a negative predictive value of 94%, a sensitivity of 91%, and a specificity of 94%. On the same population overall, the positive and negative predictive value of the King's criteria were 94% and 93% respectively, whereas their sensitivity and specificity were 88% and 96% respectively.

CONCLUSIONS

Using admission characteristics our model is able to identify patients who die from paracetamol overdose fulminant hepatic failure as accurately as King's College criteria, but at a much earlier stage in their condition.

Referral patterns and social deprivation in paracetamol-induced liver injury in Scotland

Paracetamol overdose is the commonest cause of acute liver failure in the UK, which has led to measures to restrict its sale. We aimed to establish whether changes in the referral of patients with paracetamol-induced acute liver failure have occurred since the introduction of legislation. We compared data from patients admitted to the Scottish Liver Transplantation Unit in 1992-98 with those admitted in 1998-2001. The incidence of paracetamol-induced liver failure, severity of patients' illness, and outcome did not differ between the groups. Patients with paracetamol-induced acute liver failure had higher Carstairs scores (1.99 [95% CI 1.33-2.65]; n=190) than patients with non-paracetamol acute liver failure (0.02 [-0.79 to 0.84]; n=68). We have shown an association between paracetamol-induced acute liver failure and social deprivation.

Which hepatocyte will it be? Hepatocyte choice for bioartificial liver support systems

Liver failure, notwithstanding advances in medical management, remains a cause of considerable morbidity and mortality in the developed world. Although bioartificial liver (BAL) support systems offer the potential of significant therapeutic benefit for such patients, many issues relating to their use are still to be resolved. In this review, these issues are examined in terms of the functions required, the cells of choice in such a system, and the most appropriate environment to optimize the function of such cells. The major functions identified to date for a BAL are ammonia detoxification and biotransformation of toxic compounds, although this somewhat belies the complexity of the functions required. Two practical choices for cell type within such a system are xenogenic hepatocytes and immortalized human hepatocyte lines. Both these choices have drawbacks, such as the transmission of zoonoses and malignant infiltration, respectively. Finally, improvements in culture conditions, such as supplemented media, biodegradable scaffolds, and coculture, offer the possibility of prolonging the differentiated function of hepatocytes in a BAL.

Low serum retinol levels are associated with hepatocellular carcinoma in patients with chronic liver disease

BACKGROUND

Retinol and other vitamin A derivatives affect the differentiation and growth of many tissues and have anti-tumour properties.

AIM

To investigate serum retinol levels in patients with liver disease and hepatocellular carcinoma (HCC) and to assess its importance as a risk factor for the development of HCC.

METHODS

Serum retinol levels were measured in healthy volunteers and 175 patients (34 with chronic hepatitis C, 117 with cirrhosis, and 24 with HCC.

RESULTS

The serum retinol levels (mean +/- s.e.) in ng/mL, were 972.1 +/- 37.7 in the control group and 647 +/- 41.1 in patients with chronic hepatitis C. Serum retinol levels in patients with cirrhosis and HCC were lower than in patients with cirrhosis alone (365.8 +/- 43.1 vs. 438.9 +/- 22.1, P < 0.04). In particular, there was a more significant difference in serum retinol levels between Child-Pugh grade A patients with cirrhosis and Child-Pugh grade A patients with cirrhosis/HCC (serum retinol levels 532.4 +/- 26.7 vs. 366.1 +/- 86.4, P < 0.03). There was a significant difference in serum retinol levels between normal controls and all patients' groups (P < 0.001). There were significantly lower serum retinol levels in cholestatic Child-Pugh grade A patients with cirrhosis compared with noncholestatic Child-Pugh grade A patients with cirrhosis/HCC (411.5 +/- 30.3 vs. 579.7 +/- 32.7, P < 0.0004). Sixty percent of patients with Child-Pugh grade A cirrhosis/HCC had serum retinol levels below 350 ng/mL compared with only 18.4% of cirrhotics without HCC (chi 2-test, P=0.01). No correlation was found between serum retinol levels and alpha FP or any other liver function tests, apart from serum albumin, which showed a positive correlation (r=0.61 P < 0.018).

CONCLUSIONS

There was a progressive reduction in serum retinol levels from controls to patients with liver cirrhosis. Those patients with cirrhosis and HCC had significantly lower values than patients with cirrhosis alone. Serum retinol levels may be a risk factor for the development of HCC.

An improved ex vivo method of primary porcine hepatocyte isolation for use in bioartificial liver systems

INTRODUCTION

Primary porcine hepatocytes are commonly, used in bioartificial liver devices and for in vitro studies of hepatocyte function. Although in vivo isolation of porcine hepatocytes can give high yield and viability, such methods are time-consuming and expensive, requiring specialist surgical facilities.

AIM

To develop a simple, low-cost, high viability, high yield, reproducible ex vivo method for obtaining functional porcine hepatocytes for use in bioartificial liver systems.

METHODS

Weanling piglets (12 kg) were killed with pentobarbitone sodium, the infra-hepatic inferior vena cava was clamped and the supra-hepatic inferior vena cava cannulated. The whole liver was retrogradely perfused in situ with cold saline and excised, followed by an ex vivo open-loop and re-circulating perfusion method (at 37 degrees C) in five steps. The liver was disrupted, sequentially filtered in washing buffer, purified by centrifugation and resuspended in Williams E medium. Viability and cell number were assessed using trypan blue exclusion. The cells were subsequently cultured in serum-free chemically-defined medium and function was assessed.

RESULTS

The time interval from when the animals were killed to the final cell wash was 105+/-5 min (n = 20). Cell viability was 85+/-6% with a yield of (2.4+/-0.5) x 10(10) from 12+/-1 kg piglets using 0.03% (w/v) collagenase (n = 20). Hepatocytes from all isolations were successfully plated and grown in monolayer culture. In freshly isolated hepatocytes (day 0) total protein content (TP) was 1.2+/-0.1 mg/10(6) cells (n = 5) and 1.2+/-0.3 mg/10(6) cells (n = 5) for day 2 monolayer cultures, corresponding to approximately 9x10(6) hepatocytes per dish. The percentage of total LDH released into the medium was 13+/-4% for day 0 and 8+/-4% at day 2; conversely, intracellular LDH activities were 87+/-4% and 92+/-4% of the total, respectively. The urea synthesis rate was 196+/-36 nmol/h/mg total protein at day 0 (n = 5) and 292+/-62 nmol/h/mg protein (n = 9) at day 2. The total P450 content was 99+/-11 pmol/mg total protein for fresh cells (n = 5) and maintained at 89+/-35 pmol/mg total protein in day 2 cultures.

CONCLUSIONS

This ex vivo method provides a high viability, high yield, cost-effective and rapid technique for isolating functional porcine hepatocytes with high plating efficiency, which compares favourably with results obtained using complex in vivo techniques.

Animal models of fulminant hepatic failure: a critical evaluation

Few conditions in medicine are more dramatic or more devastating than acute liver failure. Our understanding and treatment of this condition have been limited by the lack of satisfactory animal models. The most widely used models consist of surgical anhepatic and devascularization procedures and hepatotoxins, such as galactosamine and acetaminophen. Potential disadvantages with surgical models are their inability to recreate the inflammatory milieu that exists in acute liver failure and their reliance on surgical expertise. Models using hepatotoxins are free of such constraints. Galactosamine-induced hepatotoxicity is more predictable than acetaminophen, but its cost and lack of a human equivalent clinical syndrome has restricted its use. Acetaminophen-based models offer the greatest potential but have proven the most difficult to develop because of difficulties with reproducibility and refractory anemia. Although progress has been made, research must continue in this area to establish an animal model with minimal disadvantages that would accurately reflect the clinical syndrome seen in humans.

Platelet basal cytosolic calcium: the influence of plasma factors in cirrhosis

BACKGROUND

Platelet cytosolic calcium is necessary for normal platelet function, and may reflect intracellular signalling in vascular smooth muscle cells.

METHODS

The cytosolic calcium of platelets from patients with cirrhosis and control subjects was measured in contact with plasma from either source, using FURA 2AM.

RESULTS

The basal cytosolic calcium of patients with cirrhosis was found to be significantly lower than that of control subjects (95.7 +/- 10.0 cf. 128.0 +/- 7.8 nmol/l; p = 0.02). When platelets from control subjects were incubated for 45 min with freshly obtained plasma from patients with cirrhosis, the control platelet cytosolic calcium fell to concentrations similar to those of patient platelets (93.0 +/- 7.8 nmol/l; p < 0.005). Such an effect was not observed if patient serum or plasma that had previously been frozen was used. When patient platelets were incubated with fresh control subject plasma, the platelet cytosolic calcium increased (165.4 +/- 19.9 nmol/l; p = 0.01).

CONCLUSION

These results indicate that a plasma-borne factor, sensitive to freezing, is responsible for the abnormalities of platelet calcium signalling noted in cirrhosis.