Screening for liver disease using non-invasive biomarkers (FibroTest, SteatoTest and NashTest) in patients with hyperlipidaemia

Postmortem survey of haemoglobin A1c, non-alcoholic steatohepatitis and liver fibrosis within a general population

AIMS

Non-alcoholic steatohepatitis (NASH), fatty liver disease and fibrosis are associated with diabetes mellitus and obesity. Previous autopsy series have reported prevalence of fatty liver disease to be 11%-24%. Recent studies, using imaging and serology, suggest a prevalence of 20%-35%, NASH of 5% and advanced fibrosis of 2%-3%. We examined the prevalence of NASH and liver fibrosis in a general autopsy population.

METHODS

A cross-sectional study of consecutive, adult, medicolegal autopsies over a 1-year period was conducted. Liver sections were scored for fibrosis, inflammation and steatosis using a modified NASH scoring system. Stepwise logistic regression was used to identify associations between NASH or moderate/severe fibrosis and several clinicopathological parameters, including postmortem haemoglobin A1c (HbA1c).

RESULTS

Of 376 cases, 86 (22.9%) were classified as NASH. Prevalence of diabetes mellitus, body mass index (BMI) and postmortem HbA1c were significantly higher in NASH cases (39.5%, 32.3 kg/m2 and 6.88%) than non-NASH cases (12.1%, 27.0 kg/m2 and 5.73%). Decedents with moderate/severe fibrosis (6.9%) had higher prevalence of diabetes, BMI and HbA1c (50%, 31.4 kg/m2 and 6.7%) compared with those with no/mild fibrosis (16%, 28 kg/m2 and 5.9%). HbA1c ≥7% was found to be an independent predictor of NASH (OR 5.11, 95% CI 2.61 to 9.98) and advanced fibrosis (OR 3.94, 95% CI 1.63 to 9.53).

CONCLUSIONS

NASH and advanced fibrosis were higher in our general adult autopsy population compared with previously published estimates. This is a large series with histological evaluation showing that HbA1c >7.0% is independently associated with NASH and advanced fibrosis.

Role of non-invasive methods in detecting liver impairment in familial Mediterranean fever adult patients with persistent hepatic cytolysis

Familial Mediterranean fever (FMF) patients may have hepatic cytolysis, although its origin is not formally elucidated. We aimed to evaluate liver involvement in familial Mediterranean fever (FMF) using non-invasive methods. All adult FMF patients harboring two non-ambiguous mutations of the MEFV gene with hepatic cytolysis were identified in a French tertiary adult center for FMF. Liver impairment was explored with FibroMax (a non-invasive method to estimate hepatic steatosis, necrosis, inflammation and fibrosis) and liver ultrasound. Among 520 FMF adult patients, 43 had persistent hepatic cytolysis and 20 patients were included (11 women, median age at inclusion: 49.5 years). According to the FibroMax results, patients were classified as having steatosis, fibrosis, and possible or definite nonalcoholic steato-hepatitis in 10 (50%), 9 (45%) and 7 (35%) of cases, respectively. The score of steatosis did not seem associated with the usual metabolic risk factors. No significant association was found between the cumulated dose of colchicine and any of the scores included in FibroMax. In adult FMF patients with persistent hepatic cytolysis, steatosis is the first cause to consider even in the absence of usual metabolic risk factors, suggesting other mechanisms. Colchicine did not seem to be involved in this toxicity.

A Step Closer to the "Fourth 90": A Practical Narrative Review of Diagnosis and Management of Nutritional Issues of People Living with HIV

The quality of life of people living with HIV (PLWH) has remarkably increased thanks to the introduction of combined antiretroviral therapy. Still, PLWH are exposed to an increased risk of cardiovascular diseases, diabetes, chronic kidney disease, and liver disease. Hence, the purpose of this review is to summarize the current knowledge about diagnosis and nutritional management with specific indication of macro and micronutrients intake for the main comorbidities of PLWH. In fact, a prompt diagnosis and management of lifestyle behaviors are fundamental steps to reach the “fourth 90”. To achieve an early diagnosis of these comorbidities, clinicians have at their disposal algorithms such as the Framingham Score to assess cardiovascular risk; transient elastography and liver biopsy to detect NAFLD and NASH; and markers such as the oral glucose tolerance test and GFR to identify glucose impairment and renal failure, respectively. Furthermore, maintenance of ideal body weight is the goal for reducing cardiovascular risk and to improve diabetes, steatosis and fibrosis; while Mediterranean and low-carbohydrate diets are the dietetic approaches proposed for cardioprotective effects and for glycemic control, respectively. Conversely, diet management of chronic kidney disease requires different nutritional assessment, especially regarding protein intake, according to disease stage and eventually concomitant diabetes.

Semaglutide for the treatment of non-alcoholic steatohepatitis: Trial design and comparison of non-invasive biomarkers

Non-alcoholic steatohepatitis (NASH) is a chronic liver disease. There is a clear need to develop pharmacological treatment for patients with NASH as well as biomarkers that can diagnose the disease. We describe a trial of semaglutide treatment for NASH, identify key patient characteristics and compare the relationship of patient characteristics and non-invasive biomarkers/scores. NCT02970942 is a randomised, double-blind, placebo-controlled, multi-national Phase 2 trial of daily subcutaneous semaglutide (0.1 mg, 0.2 mg, 0.4 mg) in patients with biopsy-confirmed NASH, F1-F3 fibrosis, NAFLD Activity Score ≥ 4, and body mass index (BMI) > 25 kg/m². Exploratory analyses were performed to evaluate correlations between baseline parameters and biomarkers in NASH. Mean (standard deviation [SD]) age of 320 randomised patients was 55 (11) years, mean BMI was 36 (6) kg/m², and 199 (62%) had type 2 diabetes. Of the total patients, 28% had F1 fibrosis, 23% had F2 fibrosis and 49% had F3 fibrosis. The highest area under the receiver operating characteristic curve (0.69) for accuracy in classifying fibrosis stage, F2-3 versus F1, was observed for Fib-4 and Enhanced Liver Fibrosis (ELF). No substantial correlation between BMI or other clinical or biochemical parameters and fibrosis stage was observed. In this large Phase 2 trial of semaglutide treatment for NASH, the clinical profile of enrolled patients was typical for patients with NASH. Of the investigated biomarkers/scores, ELF and Fib-4 showed the most apparent correlation in classifying fibrosis stage, but had only moderate predictive value.

The diagnostic conundrum in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) has become the most common liver alteration worldwide. It encompasses a spectrum of disorders that range from simple steatosis to a progressive form, defined non-alcoholic steatohepatitis (NASH), that can lead to advanced fibrosis and eventually cirrhosis and hepatocellular carcinoma. On liver histology, NASH is characterized by the concomitant presence of significant fat accumulation and inflammatory reaction with hepatocellular injury. Until now, liver biopsy is still required to differentiate simple steatosis from NASH and evaluate the degree of liver fibrosis. Unfortunately, this technique has well-known limitations, including invasiveness and expensiveness. Moreover, it may be biased by sampling error and intra- or inter-observed variability. Furthermore, due to the increasing prevalence of NAFLD worldwide, to program a systematic screening with liver biopsy is not imaginable. In recent years, different techniques were developed and validated with the aim of non-invasively identifying NASH and assess liver fibrosis degrees. The non-invasive tests range from simple blood-tests analyses to composite scores and complex imaging techniques. Nevertheless, even if they could represent cost-effective strategies for diagnosing NASH, advanced fibrosis and cirrhosis, their accuracy and consequent usefulness are to be discussed. With this aim, in this review the authors summarize the current state of non-invasive assessment of NAFLD. In particular, in addition to the well-established tests, the authors describe the future perspectives in this field, reporting the latest tests based on OMICS, gut-miocrobioma and micro-RNAs. Finally, the authors provide an accurate assessment of how these non-invasive tools perform in clinical practice depending on the clinical context, with the aim of giving the clinicians a useful tool to try to resolve the diagnostic conundrum of NAFLD.

Global hepatitis C elimination: history, evolution, revolutionary changes and barriers to overcome

The fundamental discovery of the hepatitis C virus (HCV) in 1989 has led to winning this year's Nobel Prize in Medicine. This achievement guided all the steps in identifying the elements of the virus, in order to develop the treatment and to increase the screening solutions, which have slowed the exposure to the virus. The management of infection started with interferon-alpha (IFN-α), which has later enhanced by adding Ribavirin. Nowadays, HCV treatment is based on direct-acting antiviral agents (DAAs). Currently, HCV infection benefits of curative treatment, with which most patients can be cured. When speaking about hepatitis C future, we can say it is looking bright, considering all the progress that has been made in recent years and all the options that we have for curing all genotypes of HCV infection. The aim of this review is to sum up the historical characteristics of HCV discovery, the evolution of treatment and screening actions, gaps, and stages for achieving the international elimination target of the World Health Organization.

Prevalence of liver fibrosis in an unselected general population with high prevalence of obesity and diabetes mellitus. Time for screening?

INTRODUCTION

Cirrhosis and liver cancer are currently common causes of death worldwide. The global epidemic of obesity has increased the incidence of nonalcoholic fatty liver disease (NAFLD) and cirrhosis in recent years. Advanced fibrosis increases the morbimortality rate in NAFLD. The Mexican population has one of the highest prevalence of obesity and diabetes mellitus (DM) worldwide.

AIM

To determine the prevalence of advanced liver fibrosis in Mexican general population.

METHODS

Adult individuals, without a history of liver disease nor heavy alcohol consumption were randomly sampled from 20,919 participants of a health and nutrition survey applied to the general population. Clinical and laboratory evaluations were performed to calculate the NAFLD fibrosis score (NFS) (an extensively validated non-invasive method). Two cut-off points were used. Advanced fibrosis was defined as a result >0.676.

RESULTS

In total 695 individuals were included. The mean age was 47.8±16.4. The majority were between 20 and 50 years (59%), 70.2% were female, 35.5% showed obesity and 15.8% DM. The 93% had normal serum ALT. Based on the NFS results, 56 individuals (8.1%) had a high probability of fibrosis. Most patients from this subgroup showed normal serum ALT (92.9%), 89.3% were >45yr. old, 52% were obese and 27% suffered from DM.

CONCLUSIONS

Based on these results, 8.1% of Mexican general population without a history of liver disease is at high risk of having advanced liver fibrosis and complications and death derived from cardiovascular disease and cirrhosis. Most of them showed normal ALT serum levels.

NonInvasive Biomarkers in Nonalcoholic Fatty Liver Disease: Are We There Yet?

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. NAFLD encompasses a spectrum of disease ranging from simple steatosis (NAFL) to nonalcoholic steatohepatitis (NASH), cirrhosis and hepatocellular carcinoma. However, despite the growing recognition of this important disease burden, there are significant challenges to accurately and noninvasively diagnose the various forms of NAFLD, especially to differentiate benign steatosis from the progressive NASH. This is of utmost importance because although liver biopsy is considered the current imperfect 'gold' standard for diagnosing NASH and staging fibrosis, it is an invasive procedure with significant limitations. Although, a number of noninvasive markers have been or are currently undergoing investigation, until date, no highly sensitive and specific tests are available to differentiate NASH from simple steatosis. At the moment, further investigations are needed before prediction models or blood-based biomarkers become available and acceptable for routine clinical care. There is a great need for developing inexpensive, easily accessible, highly sensitive and specific biomarkers that permit not only the identification of patients at high risk of adverse outcomes, but also the monitoring of disease progression and response after therapeutic interventions.

Landmarks in research of nonalcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) has become the leading cause of chronic liver disease all over the world, which places a crushing burden on public health. During the past three decades, steady progress has been made in the evolving concepts of NAFLD, novel diagnostic methods to stage liver steatosis and fibrosis progression, and new pharmacological approaches for disease treatment, which have contributed to a revolutionary success. However, effective preventive and therapeutic strategies are still urgently needed. A better understanding of the research history of NAFLD will be helpful for its scientific prevention and treatment. In this review, we will discuss the progress in the understanding of the epidemiology, diagnosis, treatment, and pathogenesis of NAFLD.

Nonalcoholic fatty liver disease: Diagnostic biomarkers

Nonalcoholic fatty liver disease is a common medical condition worldwide and its prevalence has increased notably in the past few years due to the increases in prevalence of obesity and metabolic syndrome. However, diagnosis of this disease is still a matter of debate because of disease variations and pathophysiologic alterations. Specific single markers have gained considerable attention recently, among them markers related to hepatic pathophysiology, inflammation, adipocytokines and so forth. But, it seems that no single marker is sufficient for diagnosis and staging of the disease, and applying a panel including different types of tests may be more useful.

Diagnostic performance of FibroTest, SteatoTest and ActiTest in patients with NAFLD using the SAF score as histological reference

BACKGROUND

Blood tests of liver injury are less well validated in non-alcoholic fatty liver disease (NAFLD) than in patients with chronic viral hepatitis.

AIMS

To improve the validation of three blood tests used in NAFLD patients, FibroTest for fibrosis staging, SteatoTest for steatosis grading and ActiTest for inflammation activity grading.

METHODS

We pre-included new NAFLD patients with biopsy and blood tests from a single-centre cohort (FibroFrance) and from the multicentre FLIP consortium. Contemporaneous biopsies were blindly assessed using the new steatosis, activity and fibrosis (SAF) score, which provides a reliable and reproducible diagnosis and grading/staging of the three elementary features of NAFLD (steatosis, inflammatory activity) and fibrosis with reduced interobserver variability. We used nonbinary-ROC (NonBinAUROC) as the main endpoint to prevent spectrum effect and multiple testing.

RESULTS

A total of 600 patients with reliable tests and biopsies were included. The mean NonBinAUROCs (95% CI) of tests were all significant (P < 0.0001): 0.878 (0.864-0.892) for FibroTest and fibrosis stages, 0.846 (0.830-0.862) for ActiTest and activity grades, and 0.822 (0.804-0.840) for SteatoTest and steatosis grades. FibroTest had a higher NonBinAUROC than BARD (0.836; 0.820-0.852; P = 0.0001), FIB4 (0.845; 0.829-0.861; P = 0.007) but not significantly different than the NAFLD score (0.866; 0.850-0.882; P = 0.26). FibroTest had a significant difference in median values between adjacent stage F2 and stage F1 contrarily to BARD, FIB4 and NAFLD scores (Bonferroni test P < 0.05).

CONCLUSIONS

In patients with NAFLD, SteatoTest, ActiTest and FibroTest are non-invasive tests that offer an alternative to biopsy, and they correlate with the simple grading/staging of the SAF scoring system across the three elementary features of NAFLD: steatosis, inflammatory activity and fibrosis.

Fibrosis Assessment in Nonalcoholic Fatty Liver Disease (NAFLD) in 2016

Nonalcoholic fatty liver disease (NAFLD) is a spectrum of liver pathologies characterized by hepatic steatosis with a history of little to no alcohol consumption or secondary causes of hepatic steatosis. The prevalence of NAFLD is 20-25 % of the general population in the Western countries and is associated with metabolic risk factors such as obesity, diabetes mellitus, and dyslipidemia. The spectrum of disease ranges from simple steatosis to nonalcoholic steatohepatitis, fibrosis, and cirrhosis. Advanced fibrosis is the most significant predictor of mortality in NAFLD. It is crucial to assess for the presence and degree of hepatic fibrosis in order to make therapeutic decisions and predict clinical outcomes. Liver biopsy, the current gold standard to assess the liver fibrosis, has a number of drawbacks such as invasiveness, sampling error, cost, and inter-/intra-observer variability. There are currently available a number of noninvasive tests as an alternative to liver biopsy for fibrosis staging. These noninvasive fibrosis tests are increasingly used to rule out advanced fibrosis and help guide disease management. While these noninvasive tests perform relatively well for ruling out advanced fibrosis, they also have limitations. Understanding the strengths and limitations of liver biopsy and the noninvasive tests is necessary for deciding when to use the appropriate tests in the evaluation of patients with NAFLD.

Non-invasive diagnostic approach to non-alcoholic fatty liver disease: current evidence and future perspectives

Non-alcoholic fatty liver disease is a new epidemic liver disease, thus, its early diagnosis and the identification of those patients with the worst prognosis is mandatory. Liver biopsy is still the diagnostic gold standard, even if it is associated to a significant rate of complications; moreover, the interpretation of histological samples is not always univocal. Several non-invasive alternative scores have been proposed for the diagnostic approach to non-alcoholic fatty liver disease. This article evaluates the performance of the currently available non-invasive diagnostic strategies. The authors also suggest a potential diagnostic algorithm, with two or more non-invasive techniques, to increase the overall accuracy for identifying patients with worst prognosis, and to minimize the recourse to liver biopsy.

Automatic detection of cirrhosis in hospitalized patients: a pragmatic experience

BACKGROUND/AIM

We evaluated the relevance of a systematic automatic detection of cirrhosis using biochemical markers in hospitalized patients.

METHODS

We automatically calculated three free biochemical tests (APRI, Fib-4, and Forns) in patients consecutively hospitalized in our university hospital between July and September, 2010. Patients >18 years not known to suffer from chronic liver disease, were contacted to undergo liver stiffness measurement (LSM) as a reference diagnostic tool. To limit false positives, we required at least one APRI≥2 (indicating cirrhosis) and Fib-4>3.25 and/or Forns>6.9, without obvious overestimation.

RESULTS

A total of 10,035 APRI, 9903 Fib-4, and 1250 Forns were available in 4074 patients. The fibrosis tests were independently influenced by the location of the patient, especially Cardiology (Lower Forns) and Hematology/Oncology Departments (higher APRI, Fib-4, and Forns). Overall, 101 patients (2.48%) were suspected to have cirrhosis. LSM identified two cases of cirrhosis (LSM>13 kPa). In intent-to-diagnose analyses, the highest positive predictive values of the APRI, Fib-4, and Forns for the diagnosis of cirrhosis were 1.98, 1.98, and 11.76%, respectively. The positive predictive value never exceeded 50% in per-protocol analyses when considering patients with numerous positive results of the fibrosis tests.

CONCLUSION

In hospitalized patients, automatic detection of cirrhosis on the basis of APRI, Fib-4, and Forns was inefficient because of too many false-positive results.

Awareness of the severity of liver disease re-examined using software-combined biomarkers of liver fibrosis and necroinflammatory activity

BACKGROUND

Effective antiviral treatment (direct-acting antiviral agents (DAAs)), the requirement for a fibrosis score to support DDA reimbursement and a screening strategy, such as the USA baby boomer campaign, should lead to an increased awareness of liver disease severity.

OBJECTIVE

To compare the awareness of liver disease severity between the USA and France, two countries with similar access to hepatitis C virus (HCV) and hepatitis B virus (HBV) treatments, similar rules for treatment reimbursement and similar availability of validated fibrosis tests, but with different policies, as France has no screening.

METHOD

The global database of the FibroTest-ActiTest, including 1,085,657 subjects between 2002 and 2014, was retrospectively analysed. Awareness was defined as the test prescription rate and was compared between the USA and France, according to year of birth, gender and dates of DAA availability and screening campaign (2013-2014).

RESULTS

In the USA 252,688 subjects were investigated for HCV, with a dramatic increase (138%) in the test rate in 2013-2014 (119,271) compared with 2011-2012 (50,031). In France 470,762 subjects were investigated (subjects with HCV and other disease) and the rates were stable. In USA 82.4% of subjects and in France 84.6% were classified as either the highest or lowest priority. The most striking difference was the higher test rate in women born between 1935 and 1944 in France 30,384/200,672 (15.1%) compared with the USA 8035/97,079 (8.3%) (OR=1.98 (95% CI 1.93 to 2.03) p<0.0001). This resulted in twice as many cases of cirrhosis being detected, 2.6% (5191/200,672 women) and 1.3% (1303/97,079), respectively, despite the same prevalence of cirrhosis in this age group (17.1% vs 16.2%) and without any clear explanation as to why they had not been included in the USA screening.

CONCLUSIONS

This study highlighted in the USA the association between awareness of liver disease and both the HCV campaign and DAA availability. In comparison with France, there was a dramatically lower awareness of cirrhosis in the USA for women born between 1935 and 1944.

[Non-invasive assessment of fatty liver]

As the result of various harmful effects (infectious agents, metabolic diseases, unhealthy diet, obesity, toxic agents, autoimmune processes) hepatic damage may develop, which can progress towards liver steatosis, and fibrosis as well. The most common etiological factors of liver damages are hepatitis B and C infection, alcohol consumption and non-alcoholic fatty liver disease. Liver biopsy is considered as the gold standard for the diagnosis of chronic liver diseases. Due to the dangers and complications of liver biopsy, studies are focused on non-invasive markers and radiological imaging for liver steatosis, progression of fatty liver, activity of the necroinflammation and the severity of the fibrosis. Authors review the possibilities of non-invasive assessment of liver steatosis. The statistical features of the probes (positive, negative predictive values, sensitivity, specificity) are reviewed. The role of radiological imaging is also discussed. Although the non-invasive methods discussed in this article are useful to assess liver steatosis, further studies are needed to validate to follow progression of the diseases and to control therapeutic response.

Coffee consumption and nonalcoholic fatty liver onset: a prospective study in the general population

Retrospective studies suggest that coffee consumption may exert beneficial effects in patients with nonalcoholic fatty liver; however, prospective data supporting a protective role on liver steatosis development are lacking. In this study, we aimed to evaluate the association between coffee consumption and fatty liver onset in the general population. The analysis was performed both in a cross-sectional cohort (n = 347) and, prospectively, in a subcohort of patients without fatty liver at baseline and followed-up for 7 years (n = 147). Fatty liver was diagnosed with abdominal ultrasound and liver steatosis was quantified noninvasively by hepatorenal index (HRI) and SteatoTest, whereas FibroTest was used to assess fibrosis degree. A structured questionnaire on coffee consumption was administrated during a face-to-face interview. Neither the incidence nor the prevalence of fatty liver according to ultrasonography, SteatoTest, and the HRI was associated with coffee consumption. In the cross-sectional study, high coffee consumption was associated with a lower proportion of clinically significant fibrosis ≥ F2 (8.8% vs 16.3%; P = 0.038); consistently, in multivariate logistic regression analysis, high coffee consumption was associated with lower odds for significant fibrosis (odds ratio = 0.49, 95% confidence interval, 0.25-0.97; P = 0.041) and was the strongest predictor for significant fibrosis. No association was demonstrated between coffee consumption and the new onset of nonalcoholic fatty liver, but coffee intake may exert beneficial effects on fibrosis progression.

Noninvasive Assessment of Fibrosis in Patients with Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is prevalent in 20-25% of the general population and is associated with metabolic risk factors such as obesity, diabetes mellitus, and dyslipidemia. Histologically, NAFLD ranges from simple steatosis to nonalcoholic steatohepatitis (NASH), fibrosis, and cirrhosis. As NASH develops in only 10-15% of patients with NAFLD, it is not practical to biopsy all patients who present with NAFLD. Noninvasive fibrosis tests have been extensively developed recently and offer alternatives for staging fibrosis. Despite their increasing use, such tests cannot adequately differentiate simple steatosis from NASH. At present, such tests can be used as first line tests to rule out patients without advanced fibrosis and thus prevent unnecessary secondary care referrals in a significant number of patients. In this review we present the evidence for the use of noninvasive fibrosis tests in patients with NAFLD.

Prognostic value of liver fibrosis and steatosis biomarkers in type-2 diabetes and dyslipidaemia

BACKGROUND

In cardiometabolic disorders, non-alcoholic fatty liver disease is frequent and presumably associated with increased mortality and cardiovascular risk.

AIM

To evaluate the prognostic value of non-invasive biomarkers of liver fibrosis (FibroTest) and steatosis (SteatoTest) in patients with type-2 diabetes and/or dyslipidaemia.

METHODS

A total of 2312 patients with type-2 diabetes and/or dyslipidaemia were included and prospectively followed up for 5-15 years. The cardiovascular Framingham-risk score was calculated; advanced fibrosis and severe steatosis, were defined by FibroTest >0.48 and SteatoTest >0.69, respectively, as previously established.

RESULTS

During a median follow-up of 12 years, 172 patients (7.4%) died. The leading causes of mortality were cancer (31%) and cardiovascular-related death (20%). The presence of advanced fibrosis [HR (95% CI)] [2.98 (95% CI 1.78-4.99); P < 0.0001] or severe steatosis [1.86 (1.34-2.58); P = 0.0002] was associated with an increased risk of mortality. In a multivariate Cox model adjusted for confounders: the presence of advanced fibrosis was associated with overall mortality [1.95 (1.12-3.41); P = 0.02]; advanced fibrosis at baseline [n = 50/677; 1.92 (1.04-3.55); P = 0.04] and progression to advanced fibrosis during follow-up [n = 16/127; 4.8 (1.5-14.9); P = 0.007] were predictors of cardiovascular events in patients with type-2 diabetes. In patients with a Framingham-risk score ≥20%, the presence of advanced fibrosis was predictive of cardiovascular events [2.24 (1.16-4.33); P < 0.05].

CONCLUSIONS

Liver biomarkers, such as FibroTest and SteatoTest, have prognostic values in patients with metabolic disorders. FibroTest has prognostic value for predicting overall survival in patients with type-2 diabetes and/or dyslipidaemia. In type-2 diabetes, FibroTest predicted cardiovascular events and improved the Framingham-risk score.

Review article: the diagnosis of non-alcoholic fatty liver disease -- availability and accuracy of non-invasive methods

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) encompasses a wide spectrum of clinical conditions, actually representing an emerging disease of great clinical interest. Currently, its diagnosis requires liver biopsy, an invasive procedure not free from potential complications. However, several non-invasive diagnostic strategies have been proposed as potential diagnostic alternatives, each with different sensitivities and accuracies.

AIM

To review non-invasive diagnostic parameters and tools for NAFLD diagnosis and to formulate a diagnostic and prognostic algorithm for a better classification of patients.

METHODS

A literature search was carried out on MEDLINE, EMBASE, Web of Science and Scopus for articles and abstracts in English. The search terms used included 'NAFLD', 'non invasive method and NAFLD', 'transient elastography' and 'liver fibrosis'. The articles cited were selected based on their relevancy to the objective of the review.

RESULTS

Ultrasonography still represents the first-line diagnostic tool for simple liver steatosis; its sensitivity could be enhanced by the complex biochemical score SteatoTest. Serum cytokeratin-18 is a promising and accurate non-invasive parameter (AUROCs: 0.83; 0.91) for the diagnosis of non-alcoholic steatohepatitis (NASH). The staging of liver fibrosis still represents the most important prognostic problem: the most accurate estimating methods are FibroMeter, FIB-4, NAFLD fibrosis score (AUROCs: 0.94; 0.86; 0.82) and transient elastography (AUROC: 0.84-1.00).

CONCLUSIONS

Different non-invasive parameters are available for the accurate diagnosis and prognostic stratification of non-alcoholic fatty liver disease which, if employed in a sequential algorithm, may lead to a reduced use of invasive methods, i.e. liver biopsy.

Comparison of fatty liver index with noninvasive methods for steatosis detection and quantification

AIM: To compare noninvasive methods presently used for steatosis detection and quantification in nonalcoholic fatty liver disease (NAFLD).

METHODS: Cross-sectional study of subjects from the general population, a subgroup from the First Israeli National Health Survey, without excessive alcohol consumption or viral hepatitis. All subjects underwent anthropometric measurements and fasting blood tests. Evaluation of liver fat was performed using four noninvasive methods: the SteatoTest; the fatty liver index (FLI); regular abdominal ultrasound (AUS); and the hepatorenal ultrasound index (HRI). Two of the noninvasive methods have been validated vs liver biopsy and were considered as the reference methods: the HRI, the ratio between the median brightness level of the liver and right kidney cortex; and the SteatoTest, a biochemical surrogate marker of liver steatosis. The FLI is calculated by an algorithm based on triglycerides, body mass index, γ-glutamyl-transpeptidase and waist circumference, that has been validated only vs AUS. FLI < 30 rules out and FLI ≥ 60 rules in fatty liver.

RESULTS: Three hundred and thirty-eight volunteers met the inclusion and exclusion criteria and had valid tests. The prevalence rate of NAFLD was 31.1% according to AUS. The FLI was very strongly correlated with SteatoTest (r = 0.91, P < 0.001) and to a lesser but significant degree with HRI (r = 0.55, P < 0.001). HRI and SteatoTest were significantly correlated (r = 0.52, P < 0.001). The κ between diagnosis of fatty liver by SteatoTest (≥ S2) and by FLI (≥ 60) was 0.74, which represented good agreement. The sensitivity of FLI vs SteatoTest was 85.5%, specificity 92.6%, positive predictive value (PPV) 74.7%, and negative predictive value (NPV) 96.1%. Most subjects (84.2%) with FLI < 60 had S0 and none had S3-S4. The κ between diagnosis of fatty liver by HRI (≥ 1.5) and by FLI (≥ 60) was 0.43, which represented only moderate agreement. The sensitivity of FLI vs HRI was 56.3%, specificity 86.5%, PPV 57.0%, and NPV 86.1%. The diagnostic accuracy of FLI for steatosis > 5%, as predicted by SteatoTest, yielded an area under the receiver operating characteristic curve (AUROC) of 0.97 (95% CI: 0.95-0.98). The diagnostic accuracy of FLI for steatosis > 5%, as predicted by HRI, yielded an AUROC of 0.82 (95% CI: 0.77-0.87). The κ between diagnosis of fatty liver by AUS and by FLI (≥ 60) was 0.48 for the entire sample. However, after exclusion of all subjects with an intermediate FLI score of 30-60, the κ between diagnosis of fatty liver by AUS and by FLI either ≥ 60 or < 30 was 0.65, representing good agreement. Excluding all the subjects with an intermediate FLI score, the sensitivity of FLI was 80.3% and the specificity 87.3%. Only 8.5% of those with FLI < 30 had fatty liver on AUS, but 27.8% of those with FLI ≥ 60 had normal liver on AUS.

CONCLUSION: FLI has striking agreement with SteatoTest and moderate agreements with AUS or HRI. However, if intermediate values are excluded FLI has high diagnostic value vs AUS.

Esteato-hepatite não-alcoólica em pré-operatório de bypass gástrico: ausência de correlação com grau de obesidade

RACIONAL: Alterações metabólicas têm elevada correlação com formas graves da doença hepática gordurosa não-alcoólica. Todavia, ainda não há método não-invasivo que promova sua adequada estratificação sendo que a biópsia permanece como meio diagnóstico ideal. OBJETIVO: Avaliar a prevalência dessa doença em obesos no pré-operatório de bypass gástrico em Y-de-Roux e correlacionar fatores metabólicos com a histopatologia hepática. MÉTODOS: Do total de 47 pacientes, foram incluídos 35 em pré-operatório e excluídos 12 devido à doenças hepáticas e ingestão alcoólica >80 g/semana. Foi realizada avaliação clínico-laboratorial antes da operação e biópsia hepática transoperatória. A intensidade da esteatohepatite foi classificada nos graus: I (leve a moderada), II (difusa e inflamatória), III (fibrose periportal) e IV (cirrose). Foram comparadas as seguintes variáveis: tempo de obesidade, índice de massa corpórea, relação cintura-quadril, diabete melito tipo 2, hipertensão arterial e dislipidemia. RESULTADOS: Trinta e cinco pacientes (68,6% mulheres, média de idade de 37 anos) foram avaliados. O índice de massa corpórea médio pré-operatório foi de 53,04 kg/m2. Esteatohepatite não-alcoólica foi encontrada em 31 pacientes (88,6%), sendo grau I 32,2% (n=10), grau II 45,2% (n=14), e grau III 25,6% (n=7). A relação cintura-quadril mostrou associação com esteatose hepática; hipertrigliceridemia foi o marcador que melhor se correlacionou com maior grau; não houve correlação entre aminotransferase e a intensidade da doença; houve correlação da intensidade com fatores relacionados à resistência insulínica. CONCLUSÃO: Esteatohepatite não-alcoólica tem elevada prevalência em obesos graves, porém não foi observada correlação positiva entre aminotransferases e o grau de obesidade com histopatologia hepática. Hipertrigliceridemia e relação cintura-quadril correlacionaram-se positivamente com a intensidade de doença.

Finasteride and methadone use and risk of advanced hepatitis C related liver disease

AIM

We evaluated the association between two medications that alter bioavailable androgen levels, finasteride and methadone, and risk of advanced HCV-related liver disease.

BACKGROUND

Males have strikingly greater cirrhosis risk across disease etiologies, including hepatitis C virus (HCV) infection.

METHODS

In a cross-sectional study in HCV+ male veterans, we determined medication use by up to 15-year medical record review, and hepatic pathology by the FibroSURE-ActiTest (F3/F4-F4, advanced vs. F0-F3, mild fibrosis; and A2/A3-A3, advanced vs. A0-A2, mild inflammation). We performed race-adjusted and race-stratified multivariate analyses.

RESULTS

Among 571 HCV+ males, 43 % were White and 57 % African-American. There were non-significant decreased risks with finasteride use (OR(adj advanced fibrosis) = 0.75, 95 % CI 0.39-1.45 and OR(adj advanced inflammation) = 0.74, 95 % CI 0.41-1.43). For methadone, there was a non-significant 41 % increased advanced fibrosis risk in Whites and 51 % reduced risk in AA. White male methadone-users had 2.1-fold excess advanced inflammation risk (p = 0.15).

CONCLUSIONS

Our preliminary study results suggest finasteride use is not significantly associated with a decreased risk of advanced hepatic fibrosis or inflammation in HCV+ males. The ethnically-divergent results for methadone associated fibrosis risk and finding of potentially increased inflammation risk in White males suggests the need for additional research.

Validation of liver fibrosis biomarker (FibroTest) for assessing liver fibrosis progression: proof of concept and first application in a large population

BACKGROUND & AIMS

Time-dependent statistics have been used to assess liver fibrosis progression (LFP) in liver diseases from birth to first biopsy, in a limited number of patients. Non-invasive biomarkers such as FibroTest (FT) should allow the estimation of LFP on larger populations. We aimed at validating this concept by comparing LFP using FT vs. biopsy (P1) and then at applying the non-invasive method to a large population (P2).

METHODS

In P1, LFP was assessed using biopsy and FT in 2472 untreated patients: 770 with chronic hepatitis C, 723 with hepatitis B, 761 with non-alcoholic fatty liver disease (NAFLD), and 218 with alcoholic fatty liver disease (ALD). In P2, 342,346 interpretable FT prospectively measured were used. LFP was estimated using transition rates (cumulative hazard rate) to cirrhosis (F4) or to minimal fibrosis (>F0).

RESULTS

In P1, there was a significant concordance between FT and biopsy estimates of hazards with intraclass correlation (ICC)=0.961 (95% CI 0.948-0.970) and 0.899 (95% CI 0.135-0.969) for F4 and >F0, respectively. This concordance persisted according to the disease and the gender. The more rapid LFP to F4 (biopsy/FT) was observed for men with ALD (1.44/1.62), and the slower for women with NAFLD (0.09/0.02). In P2, the LFP started to increase for men at the age of 30 years. The cumulative fibrosis progression rate to minimal fibrosis in women crossed the "man curve" around the age of 80 years. The following factors were associated with LFP to F4 (all p<0.0001): male gender (Relative Risk=3.29), HIV co-infection (2.33), and residency in Middle East (2.67) or Eastern Europe (2.15).

CONCLUSIONS

Validated biomarkers such as FibroTest should allow powerful analysis of fibrosis progression in chronic liver diseases and better identification of risk factors.

The association between adipocytokines and biomarkers for nonalcoholic fatty liver disease-induced liver injury: a study in the general population

BACKGROUND AND AIM

Leptin and adiponectin have been implicated in the development of nonalcoholic fatty liver disease (NAFLD). However, the usefulness of adipocytokines as a screening tool for nonalcoholic steatohepatitis (NASH) and fibrosis could not be evaluated in the general population due to the invasive nature of liver biopsy. The aim was to evaluate the association between adipocytokines and presumed liver injury in the general population using noninvasive biomarkers.

METHODS

A cross-sectional study of 375 individuals, sampled from the National Health Survey was conducted. The exclusion criterion was any known secondary etiology for liver disease. Anthropometrics, serum leptin, adiponectin, insulin, lipids, and FibroMax were measured.

RESULTS

Three hundred and thirty-eight individuals met the inclusion criteria and had valid FibroMax. Fibrosis diagnosed by the FibroTest was found in 25.7% of the patients, of whom 12.8% had significant fibrosis. Steatohepatitis was diagnosed by the NASH test in 0.9% and borderline NASH in 31.4% of the patients. Adiponectin was an independent negative correlate of borderline NASH [odds ratio (OR): 0.92; 95% confidence interval (CI): 0.86-0.98/1 µg/ml] together with high-density lipoprotein, and leptin was a positive correlate (OR: 1.03; CI: 1.01-1.06/1 ng/ml), together with abdominal obesity, serum triglycerides, and HbA1C. The OR for borderline NASH was 20.7 (CI: 7.5-57.5) when both high leptin (upper quartile) and suboptimal adiponectin were present, adjusting for age and sex. The FibroTest was not associated with leptin and adiponectin. The strongest predictors for fibrosis were age, sex, abdominal obesity, and insulin.

CONCLUSION

Low adiponectin and high leptin and the combination of both have a strong independent association with presumed early-stage NASH. However, early-stage fibrosis cannot be predicted by these adipocytokines.

Subjects with sonographical hepatic steatosis should be excluded from studies to establish upper reference levels of serum transaminases

BACKGROUND AND AIMS

Correct upper reference limits (URL) of serum liver enzyme activities are used to select individuals in whom further diagnostic procedures for suspected liver disorders are warranted and to compare the prevalence and incidence of increased serum liver enzyme levels within and among populations. We sought to establish URL in a general adult population by not only generating a disease-free population but also further excluding subjects with ultrasonographical diagnosis of hepatic steatosis.

METHODS

We used data from 4,242 subjects (2,154 women) aged 20-79 years recruited for the population-based Study of Health in Pomerania. A reference population was selected comprising 1,953 subjects (1,129 women). Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and γ-glutamyltransferase (GGT) were measured photometrically.

RESULTS

The exclusion of 630 subjects with hepatic steatosis and 20 subjects with equivocal data on liver ultrasound from the reference population predominantly affected the URL for serum ALT and GGT levels in younger age groups. URL for serum ALT, AST and GGT levels were 1.00 μmol/L/s (60 U/L), 0.55 μmol/L/s (33 U/L) and 1.11 μmol/L/s (67 U/L), respectively, in men as well as 0.57 μmol/L/s (34 U/L), μmol/L/s (25 U/L) and μmol/L/s (39 U/L), respectively, in women.

CONCLUSIONS

URL for serum liver enzyme activities are higher than recommended previously. Creating a reference population for establishing URL for serum liver enzyme activities should include liver ultrasound in order to exclude subjects with subclinical hepatic steatosis.

A biomarker panel for non-alcoholic steatohepatitis (NASH) and NASH-related fibrosis

BACKGROUND

Patients with biopsy-proven NASH and especially those with fibrosis are at risk for progressive liver disease, emphasizing the clinical importance of developing non-invasive biomarkers for NASH and NASH-related fibrosis.

AIM

This study examines the performance of a new biomarker panel for NASH and NASH-related fibrosis with a combination of clinical and laboratory variables.

METHODS

Enrolled patients had biopsy-proven NAFLD. Clinical data, laboratory data, and serum samples were collected at the time of biopsy. Fasting serum was assayed for adiponectin, resistin, glucose, M30, M65, Tissue inhibitor of metalloproteinases-1 (Timp-1), ProCollagen 3 N-terminal peptide (PIIINP), and hyaluronic acid (HA). Regression models predictive of NASH, NASH-related fibrosis, and NASH-related advanced fibrosis were designed and cross-validated.

RESULTS

Of the 79 enrolled NAFLD patients, 40 had biopsy-proven NASH and 39 had non-NASH NAFLD. Clinical and laboratory data were from this cohort were used to develop a NAFLD Diagnostic Panel that includes three models (models for NASH, NASH-related fibrosis, and NASH-related advanced fibrosis). The model for predicting NASH includes diabetes, gender, BMI, triglycerides, M30 (apoptosis), and M65-M30 (necrosis) [AUC: 0.81, 95% CI, 0.70-0.89, 300 p value <9E 301 (-06)]. The NASH-related fibrosis prediction model includes the same predictors [AUC: 0.80, 95% CI 0.68-0.88, 307 p value <0.00014]. Finally, the NASH-related advanced fibrosis model includes type 2 diabetes, serum triglycerides, Timp-1, and AST [AUC: 0.81, 95% CI, 0.70-0.89; p value, 0.000062].

CONCLUSIONS

This NAFLD Diagnostic Panel based on a clinical and laboratory data has good performance characteristics and is easy to use. This biomarker panel could become useful in the management of patients with NAFLD.

Evaluation of Biomarkers of NAFLD in a Cohort of Morbidly Obese Patients

Hepatocyte apoptosis is a key event in nonalcoholic fatty liver disease (NAFLD), and serum apoptotic markers are emerging as surrogate markers for NAFLD. We studied the role of caspase-cleaved cytokeratin18 in the diagnosis of fibrosis in a cohort of 127 morbidly obese patients and also performed a review of the literature biomarkers of NAFLD and fibrosis. Here, we found that cleaved caspase 18 correlated with liver steatosis and liver injury as assessed by serum transaminase levels. Furthermore, hepatocyte apoptosis as assessed by cleaved CK18 and TUNEL staining correlated with the extent of fibrosis as assessed by Sirius Red staining and serum hyaluronic acid. These results underscore the important role of hepatocyte apoptosis in the pathogenesis of fibrosis in NAFLD, which led to the utilization of surrogate markers for apoptosis in the noninvasive diagnosis of NAFLD. We furthermore reviewed current literature of biomarkers of NAFLD and fibrosis.

Serum prolidase enzyme activity and its relation to histopathological findings in patients with non-alcoholic steatohepatitis

The aim of this study was to investigate serum prolidase enzyme activity and to find out its association with liver biopsy specimens' histopathological findings in patients with nonalcoholic steatohepatitis (NASH), which may progress to liver fibrosis and cirrhosis. Thirty-six patients with biopsy-proven NASH and 29 healthy controls were enrolled. Serum prolidase enzyme activity was measured spectrophotometrically. Serum prolidase enzyme activity was significantly higher in patients with NASH than controls (P=0.016). A significant correlation was observed between serum prolidase enzyme activity and fibrosis score in patients with NASH (r=0.661, P<0.001). Serum prolidase activity seems to be correlated with the level of fibrosis. Monitoring serum prolidase activity may be a useful adjunctive tool in predicting liver fibrosis, especially in the absence of advanced fibrosis and other conditions, which may affect the interpretation of prolidase activity.

Circulating markers of liver fibrosis progression

INTRODUCTION

Fibrogenesis is a typical reaction of the liver to injury. In the case of overstimulation of fibrogenesis clinically significant fibrosis and, eventually, cirrhosis occur. Treatment of liver cirrhosis is limited, therefore it is important to screen and monitor patients at risk of cirrhosis. Noninvasive parameters are ideal for this purpose due to their risk profile and repeatability.

METHODS

Systematic review of literature.

RESULTS

Among large number of proposed biomarkers, there is a distinct difference between two groups or classes. Class I biomarkers are associated with the process of fibrogenesis, their presence in the serum is the result of the increased turnover of extracellular matrix. Class II biomarkers and their combinations are mostly markers of liver function or structural damage. We have identified 27 Class I and 13 Class II biomarkers that have been proposed in the literature. We have evaluated in detail those which reached limited clinical application.

CONCLUSION

General clinical acceptance of these biomarkers is low because of various drawbacks. Simple and readily available biomarkers have low accuracy in predicting liver fibrosis and more advanced markers have low cost-benefit ratio. Therefore liver biopsy remains the "gold standard" for diagnosis of fibrosis. However potential noninvasive alternatives exist and their implementation could be valuable.

Prevalence of liver fibrosis and risk factors in a general population using non-invasive biomarkers (FibroTest)

BACKGROUND

FibroTest and elastography have been validated as biomarkers of liver fibrosis in the most frequent chronic liver diseases and in the fibrosis screening of patients with diabetes. One challenge was to use them for estimating the prevalence of fibrosis, identifying independent risk factors and to propose screening strategies in the general population.

METHODS

We prospectively studied 7,463 consecutive subjects aged 40 years or older. Subjects with presumed advanced fibrosis (FibroTest greater than 0.48) were re-investigated in a tertiary center.

RESULTS

The sample characteristics were similar to those of the French population. FibroTest was interpretable in 99.6%. The prevalence of presumed fibrosis was 2.8%, (209/7,463), including cirrhosis in 0.3% (25/7,463); 105/209 (50%) subjects with presumed fibrosis accepted re-investigation. Fibrosis was confirmed in 50, still suspected in 27, indeterminate in 25 and not confirmed with false positive FibroTest or false negative elastography in 3 subjects. False negative rate of FibroTest estimated using elastography was 0.4% (3/766). The attributable causes for confirmed fibrosis were both alcoholic and nonalcoholic fatty liver disease (NAFLD) in 66%, NAFLD in 13%, alcohol in 9%, HCV in 6%, and other in 6%. Factors independently associated (all P < 0.003) with confirmed fibrosis were age, male gender, waist circumference, HCV antibody and alcohol consumption estimated using carbohydrate-deficient transferrin, enabling efficient screening-oriented strategies to be compared and proposed.

CONCLUSIONS

Biomarkers have permitted to estimate prevalence of advanced fibrosis around 2.8% in a general population aged 40 years or older, and several risk factors which may be used for the validation of selective or non-selective screening strategies.

Hepatic complications of obesity

Obesity is associated with a spectrum of chronic liver disease. Because obesity increases the risk for advanced forms of liver disease (ie, cirrhosis and liver cancer), the obesity epidemic is emerging as a major factor underlying the burden of liver disease in the United States and many other countries. This article reviews mechanisms that mediate the pathogenesis of obesity-related liver disease, summarizes clinical evidence that demonstrates obesity-related liver disease can be life-threatening, and discusses whether or not treatments for obesity or related comorbidities impact liver disease outcomes.

Comparison of noninvasive markers of fibrosis in patients with nonalcoholic fatty liver disease

BACKGROUND & AIMS

There is a need for a reliable and inexpensive noninvasive marker of hepatic fibrosis in patients with nonalcoholic fatty liver disease (NAFLD). We compared the performance of the FIB4 index (based on age, aspartate aminotransferase [AST] and alanine aminotransferase [ALT] levels, and platelet counts) with 6 other non-invasive markers of fibrosis in patients with NAFLD.

METHODS

Using a nation-wide database of 541 adults with NAFLD, jackknife-validated areas under receiver operating characteristic curves (AUROC) of FIB4 and 7 other markers were compared. The sensitivity at 90% specificity, 80% positive predictive value, and 90% negative predictive values were determined along with cutoffs for advanced fibrosis.

RESULTS

The median FIB4 score was 1.11 (interquartile range = 0.74-1.67). The jackknife-validated AUROC for FIB4 was 0.802 (95% confidence interval [CI], 0.758-0.847), which was higher than that of the NAFLD fibrosis score (0.768; 95% CI, 0.720-0.816; P = .09), Goteburg University Cirrhosis Index (0.743; 95% CI, 0.695-0.791; P < .01), AST:ALT ratio (0.742; 95% CI, 0.690-0.794; P < .015), AST:platelet ratio index (0.730; 95% CI, 0.681-0.779; P < .001), AST:platelet ratio (0.720; 95% CI, 0.669-0.770; P < .001), body mass index, AST:ALT, diabetes (BARD) score (0.70; P < .001), or cirrhosis discriminant score (0.666; 95% CI, 0.614-0.718; P < .001). For a fixed specificity of 90% (FIB4 = 1.93), the sensitivity in identifying advanced fibrosis was only 50% (95% CI, 46-55). A FIB4 > or = 2.67 had an 80% positive predictive value and a FIB4 index < or = 1.30 had a 90% negative predictive value.

CONCLUSIONS

The FIB4 index is superior to 7 other noninvasive markers of fibrosis in patients with NAFLD; however its performance characteristics highlight the need for even better noninvasive markers.

[Nonalcoholic fatty liver disease: 30 years research changed NASH]

Since the first description of nonalcoholic steatohepatitis (NASH) in 1980, much progress has been made towards its individualisation as a liver disease with potentially serious consequences. The identification of insulin resistance as a major determinant of steatogenesis and possibly of liver disease progression helped to identify a cause of this condition, which was amenable to therapeutic intervention and prompted screening for liver injury in patients with metabolic risk factors. The demonstration that steatohepatitis can coexist with other liver diseases with a detrimental effect on liver fibrosis helped this condition to be recognized as an independent hepatic disease no longer depending on exclusion of other chronic liver conditions. The robust increase in liver-related mortality, the fact that cirrhosis is a frequent and independent cause of death, as well as the significant decrease in overall mortality clearly showed the potential for severity of steatohepatitis. The data showing that steatohepatitis worsens insulin resistance and increases the risk for cardiovascular events and mortality forged the concept of extrahepatic complications of fat. Future research should focus on devising non-invasive strategies for screening of patients at risk, on understanding the natural history and risk factors of cirrhosis and hepatic carcinogenesis, and on optimizing therapeutic strategies integrating diet and lifestyle changes with targeted pharmacological agents.

Recent advances in nonalcoholic fatty liver disease

PURPOSE OF REVIEW

This review focuses on recent advances in the study of the epidemiology, pathogenesis, natural history and treatment of nonalcoholic fatty liver disease (NAFLD).

RECENT FINDINGS

Study of hepatic lipid metabolism with respect to the contribution of de-novo lipogenesis to hepatic steatosis and insulin resistance and the dysregulation of cellular adaptive response to stress, that is, the unfolded protein response has added to our current understanding of NAFLD. microRNA has recently emerged and has been shown to be differentially expressed in patients with nonalcoholic steatohepatitis. Its mechanism of action remains to be further explored. There is no proven pharmacotherapy for the treatment of NAFLD. Lifestyle intervention to achieve weight loss and increase exercise is persistently associated with improved liver histology. The diagnostic utility of noninvasive markers and imaging modalities in assessing fibrosis remains to be elucidated.

SUMMARY

The underlying mechanism and pathogenesis of NAFLD remain elusive. Although research effort has advanced the understanding of the natural history, pathogenesis and management of the disease, there is no proven therapy for this medical condition. At present, treatment concentrates on managing underlying metabolic risk factors.

Non-invasive diagnosis of steatosis and fibrosis

The prognosis and management of liver disease greatly depends on the amount of liver fibrosis. Non-alcoholic fatty liver disease (NAFLD), ranging from simple steatosis to non-alcoholic steatohepatitis (NASH), is emerging as a major cause of liver disease in Western countries because of the increasing prevalence of obesity and type 2 diabetes. A key issue in patients with NAFLD is the differentiation of NASH from simple steatosis. It is particularly important to identify NASH patients as they are at greatest risk of developing complications such as cirrhosis, liver failure and hepatocellular carcinoma. The limitations of liver biopsy (invasive procedure, sampling errors, interobserver variability and non-dynamic fibrosis evaluation) have stimulated the search for non-invasive approaches for the assessment of steatosis and liver fibrosis in patients with NAFLD. A variety of methods, including serum markers, imaging techniques such as ultrasound, CT, MRI and measurement of liver stiffness by transient elastography, have been proposed for the non-invasive assessment of steatosis and hepatic fibrosis. This review discusses the advantages and limitations of these different methods in clinical practice.

Biomarkers of liver fibrosis

Liver biopsy, due to its limitations and risks, is an imperfect gold standard for assessing the severity of the most frequent chronic liver diseases. This chapter summarized the advantages and the limits of the available biomarkers of liver fibrosis. Among a total of 2237 references, a total of 14 validated biomarkers have been identified between 1991 and 2007. Nine were not patented and five were patented. FibroTest (FT) was the most studied test with 33 different populations including 6549 patients and 925 controls. The mean diagnostic value for the diagnosis of advanced fibrosis assessed using standardized area under the receiver operating characteristics (ROC) curves was 0.84 [95% confidence interval (CI), 0.83-0.86], without significant difference between the causes of liver disease, hepatitis C, hepatitis B, alcoholic or nonalcoholic fatty liver disease. High-risk profiles of false negative/positive of FT are present in 3% of populations, mainly Gilbert syndrome, hemolysis, and acute inflammation. FT has higher accuracy than aspartate aminotransferase/platelets ratio index (APRI), the most used nonpatented test. No significant difference has been observed between the five patented tests. A quality score has been assessed in order to compare the quality of fibrosis biomarkers. Neither biomarkers nor biopsy are sufficient alone to take definitive decision in a given patient and all the clinical and biological data must be taken into account. Due to the evidence-based data, health authorities in some countries have already approved validated biomarkers as first-line procedure for the staging of liver fibrosis. This overview of evidence-based data suggests that biomarkers could be used as an alternative to liver biopsy for the assessment of fibrosis stage in the four more common chronic liver diseases: C virus (HCV), hepatitis B virus (HBV), hepatitis nonalcoholic fatty liver disease (NAFLD), and alcoholic liver disease (ALD). Neither biomarkers nor biopsy are sufficient alone to take definitive decision in a given patient and all the clinical and biological data must be taken into account.

A novel diagnostic biomarker panel for obesity-related nonalcoholic steatohepatitis (NASH)

BACKGROUND

Within the spectrum of nonalcoholic fatty liver disease (NAFLD), only patients with nonalcoholic steatohepatitis (NASH) show convincing evidence for progression. To date, liver biopsy remains the gold standard for the diagnosis of NASH; however, liver biopsy is expensive and associated with a small risk, emphasizing the urgent need for noninvasive diagnostic biomarkers. Recent findings suggest a role for apoptosis and adipocytokines in the pathogenesis of NASH. The aim of this study was to develop a noninvasive diagnostic biomarker for NASH.

METHODS

The study included 101 patients with liver biopsies who were tested with enzyme-linked immunosorbent assay (ELISA)-based assays. Of these, 69 were included in the biomarker development set and 32 were included in the biomarker validation set. Clinical data and serum samples were collected at the time of biopsy. Fasting serum samples were assayed for adiponectin, resistin, insulin, glucose, TNF-alpha, IL-6, IL-8, cytokeratin CK-18 (M65 antigen), and caspase-cleaved CK-18 (M30 antigen).

RESULTS

Data analysis revealed that the levels of M30 antigen (cleaved CK-18) predicted histological NASH with 70% sensitivity and 83.7% specificity and area under the curve (AUC) = 0.711, p < 10(-4), whereas the predictive value of the levels of intact CK-18 (M65) was higher (63.6% sensitivity and 89.4% specificity and AUC = 0.814, p < 10(-4)). Histological NASH could be predicted by a combination of Cleaved CK-18, a product of the subtraction of Cleaved CK-18 level from intact CK-18 level, serum adiponectin, and serum resistin with a sensitivity of 95.45% sensitivity, specificity of 70.21%, and AUC of 0.908 (p < 10(-4)). Blinded validation of this model confirmed its reliability for separating NASH from simple steatosis.

CONCLUSIONS

Four ELISA-based tests were combined to form a simple diagnostic biomarker for NASH.

Recent advances in nonalcholic fatty liver disease

PURPOSE OF REVIEW

The purpose of this review is to summarize recent advances in defining the clinical features, pathophysiology, natural history, and treatment of nonalcoholic fatty liver disease.

RECENT FINDINGS

Nonalcoholic fatty liver disease is present in approximately 30% of the US population. A histologic grading and staging system has been developed and validated. Nonalcoholic fatty liver disease increases the risk of developing the metabolic syndrome. The presence and severity of nonalcoholic fatty liver disease correlates with the severity of obesity, fat distribution, age, and presence of other features of the metabolic syndrome. Fifteen to 20% of subjects with nonalcoholic steatohepatitis develop cirrhosis. Hepatic steatosis is associated with an increase in both free fatty acid delivery to the liver for re-esterification and increased de-novo lipogenesis. Several mechanisms of hepatocyte injury and death including free fatty acid toxicity, increased free cholesterol, cytokine-mediated injury and activation of the unfolded protein response have been defined. While many therapeutic targets have been identified and pilot studies performed, a definitive treatment for nonalcoholic steatohepatitis remains to be established.

SUMMARY

Nonalcoholic fatty liver disease is a widely prevalent disease that is critically linked to insulin resistance and the metabolic syndrome. While much new information on the pathogenesis and natural history of nonalcoholic steatohepatitis is available, an effective therapy remains to be established.

Biomarkers of hepatic fibrosis, fibrogenesis and genetic pre-disposition pending between fiction and reality

Fibrosis is a frequent, life-threatening complication of most chronic liver diseases. Despite major achievements in the understanding of its pathogenesis, the translation of this knowledge into clinical practice is still limited. In particular, non-invasive and reliable (serum-) biomarkers indicating the activity of fibrogenesis are scarce. Class I biomarkers are defined as serum components having a direct relation to the mechanism of fibrogenesis, either as secreted matrix-related components of activated hepatic stellate cells and fibroblasts or as mediators of extracellular matrix (ECM) synthesis or turnover. They reflect primarily the activity of the fibrogenic process. Many of them, however, proved to be disappointing with regard to sensitivity and speci-ficity. Up to now hyaluronan turned out to be the relative best type I serum marker. Class II biomarkers comprise in general rather simple standard laboratory tests, which are grouped into panels. They fulfil most criteria for detection and staging of fibrosis and to a lesser extent grading of fibrogenic activity. More than 20 scores are currently available, among which Fibrotest™ is the most popular one. However, the diagnostic use of many of these scores is still limited and standardization of the assays is only partially realized. Combining of panel markers in sequential algorithms might increase their diagnostic validity. The translation of genetic pre-disposition biomarkers into clinical practice has not yet started, but some polymorphisms indicate a link to progression and outcome of fibrogenesis. Parallel to serum markers non-invasive physical techniques, for example, transient elastography, are developed, which can be combined with serum tests and profiling of serum proteins and glycans.

FibroMAX: towards a new universal biomarker of liver disease?

Among the noninvasive alternatives to liver biopsy, several studies have demonstrated the predictive value and a better benefit-to-risk ratio than biopsy of five combinations of simple serum biochemical markers (the super combination being FibroMAX (BioPredictive, Paris, France) in patients at risk of chronic liver diseases: FibroTest (BioPredictive) for the quantitative assessment of fibrosis; SteatoTest (BioPredictive) for the quantitative assessment of steatosis; ActiTest (BioPredictive) for the quantitative assessment of necroinflammatory activity in chronic viral hepatitis C and B; NashTest (BioPredictive) for the categorical diagnosis of nonalcoholic steatohepatitis; and AshTest for the quantitative assessment of alcoholic steatohepatitis (also known in the USA as HCV-FibroSURE, HBV-FibroSURE, ASH-FibroSURE and NASH-FibroSURE; LabCorp, NC, USA). The possible causes of false-negative and false-positive results are also better identified. These tests, which are now available in 50 countries, can facilitate the screening and management of the most frequent liver diseases.