FibroTest-FibroSURE™: towards a universal biomarker of liver fibrosis?

Plasma ALS and Gal-3BP differentiate early from advanced liver fibrosis in MASLD patients

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) is estimated to affect 30% of the world's population, and its prevalence is increasing in line with obesity. Liver fibrosis is closely related to mortality, making it the most important clinical parameter for MASLD. It is currently assessed by liver biopsy - an invasive procedure that has some limitations. There is thus an urgent need for a reliable non-invasive means to diagnose earlier MASLD stages.

METHODS

A discovery study was performed on 158 plasma samples from histologically-characterised MASLD patients using mass spectrometry (MS)-based quantitative proteomics. Differentially abundant proteins were selected for verification by ELISA in the same cohort. They were subsequently validated in an independent MASLD cohort (n = 200).

RESULTS

From the 72 proteins differentially abundant between patients with early (F0-2) and advanced fibrosis (F3-4), we selected Insulin-like growth factor-binding protein complex acid labile subunit (ALS) and Galectin-3-binding protein (Gal-3BP) for further study. In our validation cohort, AUROCs with 95% CIs of 0.744 [0.673 - 0.816] and 0.735 [0.661 - 0.81] were obtained for ALS and Gal-3BP, respectively. Combining ALS and Gal-3BP improved the assessment of advanced liver fibrosis, giving an AUROC of 0.796 [0.731. 0.862]. The {ALS; Gal-3BP} model surpassed classic fibrosis panels in predicting advanced liver fibrosis.

CONCLUSIONS

Further investigations with complementary cohorts will be needed to confirm the usefulness of ALS and Gal-3BP individually and in combination with other biomarkers for diagnosis of liver fibrosis. With the availability of ELISA assays, these findings could be rapidly clinically translated, providing direct benefits for patients.

Nonalcoholic fatty liver disease: use of diagnostic biomarkers and modalities in clinical practice

INTRODUCTION

The global burden of liver disease is increasing, and nonalcoholic fatty liver disease (NAFLD) is among the most common chronic liver diseases in Asia, Europe, North and South America. The field of noninvasive diagnostic and their role in staging, but also predicting outcome is evolving rapidly. There is a high-unmet need to stage patients with NAFLD and to identify the subset of patients at risk of progression to end-stage liver disease.

AREAS COVERED

The review covers all established diagnostic blood-based and imaging biomarkers to stage and grade NAFLD. Noninvasive surrogate scores are put into perspective of the available evidence and recommended use. The outlook includes genetics, combined algorithms, and artificial intelligence that will allow clinicians to guide and support the management in both early and later disease stages.

EXPERT OPINION

In the future, these diagnostics tests will help clinicians to establish patient care pathways and support the identification of relevant subgroups for monitoring and pharmacotherapy. In addition, researchers will be guided to better understand available scores and support the development of future prediction systems. These will likely include multiparametric aspects of the disease and machine learning algorithms will refine their use and integration with large datasets.

FibroTest for Evaluating Fibrosis in Non-Alcoholic Fatty Liver Disease Patients: A Systematic Review and Meta-Analysis

(1) Background: FibroTest™ is a multi-marker panel, suggested by guidelines as one of the surrogate markers with acceptable performance for detecting fibrosis in patients with non-alcoholic fatty liver disease (NAFLD). A number of studies evaluating this test have been published after publication of the guidelines. This study aims to produce summary estimates of FibroTest™ diagnostic accuracy. (2) Methods: Five databases were searched for studies that evaluated FibroTest™ against liver biopsy as the reference standard in NAFLD patients. Two authors independently screened the references, extracted data, and assessed the quality of included studies. Meta-analyses of the accuracy in detecting different levels of fibrosis were performed using the bivariate random-effects model and the linear mixed-effects multiple thresholds model. (3) Results: From ten included studies, seven were eligible for inclusion in our meta-analysis. Five studies were included in the meta-analysis of FibroTest™ in detecting advanced fibrosis and five in significant fibrosis, resulting in an AUC of 0.77 for both target conditions. The meta-analysis of three studies resulted in an AUC of 0.69 in detecting any fibrosis, while analysis of three other studies showed higher accuracy in cirrhosis (AUC: 0.92). (4) Conclusions: Our meta-analysis showed acceptable performance (AUC > 0.80) of FibroTest™ only in detecting cirrhosis. We observed more limited performance of the test in detecting significant and advanced fibrosis in NAFLD patients. Further primary studies with high methodological quality are required to validate the reliability of the test for detecting different fibrosis levels and to compare the performance of the test in different settings.

Imaging biomarkers of diffuse liver disease: current status

We are happy to introduce this special issue of Abdominal Radiology on "diffuse liver disease". We have invited imaging experts to discuss various topics pertaining to diffuse liver disease, covering a vast array of imaging techniques including ultrasound (US), CT, MRI and new molecular imaging agents. Below, we briefly discussed the current status, limitations, and future directions of imaging biomarkers of diffuse liver disease.

Detecting liver fibrosis using a machine learning-based approach to the quantification of the heart-induced deformation in tagged MR images

Liver disease causes millions of deaths per year worldwide, and approximately half of these cases are due to cirrhosis, which is an advanced stage of liver fibrosis that can be accompanied by liver failure and portal hypertension. Early detection of liver fibrosis helps in improving its treatment and prevents its progression to cirrhosis. In this work, we present a novel noninvasive method to detect liver fibrosis from tagged MRI images using a machine learning-based approach. Specifically, coronal and sagittal tagged MRI imaging are analyzed separately to capture cardiac-induced deformation of the liver. The liver is manually delineated and a novel image feature, namely, the histogram of the peak strain (HPS) value, is computed from the segmented liver region and is used to classify the liver as being either normal or fibrotic. Classification is achieved using a support vector machine algorithm. The in vivo study included 15 healthy volunteers (10 males; age range 30-45 years) and 22 patients (15 males; age range 25-50 years) with liver fibrosis verified and graded by transient elastography, and 10 patients only had a liver biopsy and were diagnosed with a score of F3-F4. The proposed method demonstrates the usefulness and efficiency of extracting the HPS features from the sagittal slices for patients with moderate fibrosis. Cross-validation of the method showed an accuracy of 83.7% (specificity = 86.6%, sensitivity = 81.8%).

Current Status in Testing for Nonalcoholic Fatty Liver Disease (NAFLD) and Nonalcoholic Steatohepatitis (NASH)

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in Western countries with almost 25% affected adults worldwide. The growing public health burden is getting evident when considering that NAFLD-related liver transplantations are predicted to almost double within the next 20 years. Typically, hepatic alterations start with simple steatosis, which easily progresses to more advanced stages such as nonalcoholic steatohepatitis (NASH), fibrosis and cirrhosis. This course of disease finally leads to end-stage liver disease such as hepatocellular carcinoma, which is associated with increased morbidity and mortality. Although clinical trials show promising results, there is actually no pharmacological agent approved to treat NASH. Another important problem associated with NASH is that presently the liver biopsy is still the gold standard in diagnosis and for disease staging and grading. Because of its invasiveness, this technique is not well accepted by patients and the method is prone to sampling error. Therefore, an urgent need exists to find reliable, accurate and noninvasive biomarkers discriminating between different disease stages or to develop innovative imaging techniques to quantify steatosis.

Advanced liver fibrosis and care continuum in emergency department patients with chronic hepatitis C

BACKGROUND

FIB-4, a non-invasive serum fibrosis index (which includes age, ALT, AST, and platelet count), is frequently available during ED visits. Our objective was to define 1-year HCV-related care outcomes of ED patients with known HCV, for the overall group, and both those with and without advanced fibrosis.

METHODS

As part of an ongoing HCV linkage-to-care (LTC) program, HCV-infected ED patients were identified retrospectively via medical record review. Components of FIB-4 were abstracted, and patients with an FIB-4 > 3.25 were classified with advanced fibrosis and characterized with regards to downstream HCV care continuum outcomes at one-year after enrollment.

RESULTS

Of the 113 patients with known HCV, 38 (33.6%) had advanced fibrosis. One-year outcomes along the HCV care continuum after ED encounter for 'all' 113, 75 'without advanced fibrosis', and 38 'advanced fibrosis' patients, respectively, were as follows: agreeing to be linked to care [106 (93.8%), 72 (96.0%), 34 (89.5%)]; LTC [38 (33.6%), 21 (28.0%), 17 (44.7%)]; treatment initiation among those linked [16 (42.1%), 9 (42.9%), 7 (41.2%)]; sustained virologic response 4 weeks post-treatment among those treated [15 (93.8%), 9 (100.0%), 6 (85.7%)]; documented all-cause mortality [10 (8.8%), 3 (4.0%), 7 (18.4%)]. Notably, 70% of those who died had advanced fibrosis. For those with advanced liver fibrosis, all-cause mortality was significantly higher, than those without (18.4% versus 4.0%, p = 0.030).

CONCLUSIONS

Over one-third of HCV-infected ED patients have advanced liver fibrosis, incomplete LTC, and higher mortality, suggesting this readily-available FIB-4 might be used to prioritize LTC services for those with advanced fibrosis.

MicroRNA-34a-5p inhibits liver fibrosis by regulating TGF-β1/Smad3 pathway in hepatic stellate cells

Liver fibrosis is a major cause of morbidity and mortality worldwide, and the outcome of various chronic liver diseases. Recent studies suggest that aberrant expression of miR-34 is involved in the progression of various liver diseases including hepatocellular carcinoma (HCC). However, it is still poorly understood whether miR-34 mediates the pathogenesis of liver fibrosis. Here, we found that the expression of microRNA-34a-5p (miR-34a-5p) was significantly decreased in patients with hepatitis B virus (HBV)-activated liver fibrosis and HCC, as well as in CC14 (Carbon tetrachloride Tetrachloromethane) induced liver fibrosis model mice. The TGF-β1/Smad3 (Transforming growth factor-β1/Smad3) pathway were significantly augmented in CC14 induced mice compared with normal control, whereas inhibitor of TGF-β1 (SB431542) significantly attenuated liver fibrosis and TGF-β1/Smad3 activation. Administration of the miR-34a-5p mimic de-activated TGF-β1/Smad3 pathway in human hepatic stellate cells (HSC), LX-2. Moreover, the target gene for miR-34a-5p, Smad4, was predicted and verified in LX-2 cells. Taken together, these data demonstrated that overexpression of miR-34 in HSCs ameliorated the development and progression of liver fibrosis by targeting Smad4 and regulating TGF-β1/Smad3 pathway. Strategies targeting miR-34a-5p may be of benefit in the treatment of liver fibrosis.

Serum soluble urokinase plasminogen activator receptor in alcoholics: relation to liver disease severity, fibrogenesis, and alcohol use

BACKGROUND AND AIM

Heavy alcohol consumption may lead to development of liver disease and the need for non-invasive parameters for detecting those at risk is widely acknowledged.

METHODS

We measured serum soluble urokinase-type plasminogen activator receptor (suPAR) levels from 63 patients with alcoholic liver disease (ALD), 57 heavy drinkers without apparent liver disease, and 39 controls who were either moderate drinkers or abstainers.

RESULTS

The highest serum suPAR concentrations were detected in patients with ALD (P < 0.001) showing high diagnostic accuracy in differentiating ALD patients from heavy drinkers without liver disease (area under curve 0.921, P < 0.001). Levels of suPAR correlated positively with serum markers of fibrogenesis (aminoterminal propeptide of type III procollagen and hyaluronic acid) (P < 0.001), with clinical (combined clinical and laboratory index P < 0.01) and morphological (combined morphological index P < 0.05) indices of liver disease severity and with the stage of fibrosis (P < 0.01). The suPAR concentrations were also elevated in heavy drinkers when compared with healthy controls (P < 0.001).

CONCLUSION

The data indicate that serum suPAR concentrations are increased as a result of heavy alcohol consumption and further with development of ALD, showing a good diagnostic performance in detecting those with liver disease. The association with the histological severity of ALD and correlation with fibrosis indicates potential of serum suPAR also as a prognostic marker in ALD.

Comparison of FIB-4 and APRI in Chinese HBV-infected patients with persistently normal ALT and mildly elevated ALT

Significant liver disease has been reported in chronic hepatitis B patients with normal alanine aminotransferase (ALT). Liver biopsy (LB) is the current gold standard for assessing hepatic inflammation and fibrosis in patients with chronic HBV. However, associated risks have led to the development of noninvasive models. Their utility in patients with normal ALT is unknown. FIB-4 and aspartate aminotransferase (AST)-to-platelet ratio index (APRI) were calculated for patients with chronic HBV infection undergoing biopsy. The performance of each model and AUROC for predicting significant fibrosis (Scheuer's score ≥ S2) were determined for the entire cohort and stratified by elevated (≥50 U/L) and normal ALT. Two-hundred and thirty-one liver biopsies were included. The number of patient with normal ALT was 140, and 22.1% had significant fibrosis. The AUROC curve for patients with normal ALT was 0.81 for FIB-4 and 0.80 for APRI, compared with 0.71 for FIB-4 and 0.72 for APRI for those with mildly elevated ALT level. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of FIB-4 were 0.63, 0.88, 0.61 and 0.93, for patients with normal ALT; the values for APRI were 0.40, 0.88, 0.33 and 0.93. Both FIB-4 and APRI are useful for identification of those without significant fibrosis. However, because they have poor PPV, LB will continue to be used for assessment of HBV-infected patients with normal ALT and mildly elevated ALT.

Eltrombopag in patients with chronic liver disease

INTRODUCTION

Thrombocytopenia may represent a barrier to optimal management of chronic liver disease patients undergoing invasive procedures, or who need to be treated with interferon-based antiviral therapy. Eltrombopag is a thrombopoietic drug that acts upon binding thrombopoietin receptor and stimulates megakaryocytopoiesis and platelet production.

AREAS COVERED

A summary of the preclinical studies and of studies carried out in patients with chronic liver disease with eltrombopag are presented in this paper. Data are based on abstracts from journal articles and international conferences found in a PubMed search of literature published up to November 2012.

EXPERT OPINION

Eltrombopag has shown to be capable of reducing the need for platelet transfusion in thrombocytopenic patients with advanced liver disease undergoing invasive procedures and help increase the sustained virological response rate to interferon-based antiviral therapy in patients with chronic hepatitis C who were poor candidates to treatment because of thrombocytopenia. In chronic liver disease patients, the possible benefits of eltrombopag administration should be accurately weighed against the adverse events profile of the drug due to possible concerns regarding the occurrence of thromboembolic events and the potential for decompensation of chronic liver disease.

Hepatitis C virus-induced oxidative stress and mitochondrial dysfunction: a focus on recent advances in proteomics

The natural history of chronic hepatitis C virus (HCV) infection presents two major aspects. On one side, the illness is by itself benign, whereas, on the other side, epidemiological evidence clearly identifies chronic HCV infection as the principal cause of cirrhosis, hepatocellular carcinoma, and extrahepatic diseases, such as autoimmune type II mixed cryoglobulinemia and some B cell non-Hodgkin's lymphomas. The mechanisms responsible for the progression of liver disease to severe liver injury are still poorly understood. Nonetheless, considerable biological data and studies from animal models suggest that oxidative stress contributes to steatohepatitis and that the increased generation of reactive oxygen and nitrogen species, together with the decreased antioxidant defense, promotes the development of hepatic and extrahepatic complications of HCV infection. The principal mechanisms causing oxidative stress in HCV-positive subjects have only been partially elucidated and have identified chronic inflammation, iron overload, ER stress, and a direct activity of HCV proteins in increasing mitochondrial ROS production, as key events. This review summarizes current knowledge regarding mechanisms of HCV-induced oxidative stress with its long-term effects in the context of HCV-related diseases, and includes a discussion of recent contributions from proteomics studies.

Assessment of liver fibrosis: noninvasive means

Liver biopsy, owing to its limitations and risks, is an imperfect gold standard for assessing the severity of the most frequent chronic liver diseases chronic hepatitis C (HCV), B (HBV) non alcoholic (NAFLD) and alcoholic (ALD) fatty liver diseases. This review summarizes the advantages and the limits of the available biomarkers of liver fibrosis. Among a total of 2,237 references, a total of 14 validated serum biomarkers have been identified between 1991 and 2008. Nine were not patented and five were patented. Two alternatives to liver biopsy were the most evaluated FibroTest and Fibroscan. For FibroTest, there was a total of 38 different populations including 7,985 subjects with both FibroTest and biopsy (4,600 HCV, 1,580 HBV, 267 NAFLD, 524 ALD, and 1014 mixed). For Fibroscan, there was a total of 11 published studies including 2,260 subjects (1,466 HCV, 95 cholestatic liver disease, and 699 mixed). For FibroTest, the mean diagnostic value for the diagnosis of advanced fibrosis assessed using standardized area under the ROC curves was 0.84 (95% confidence interval 0.83-0.86), without a significant difference between the causes of liver disease, hepatitis C, hepatitis B, and alcoholic or non alcoholic fatty liver disease. High-risk profiles of false negative/false positive of FibroTest, mainly Gilbert syndrome, hemolysis and acute inflammation, are present in 3% of the populations. In case of discordance between biopsy and FibroTest, half of the failures can be due to biopsy; the prognostic value of FibroTest is at least similar to that of biopsy in HCV, HBV and ALD. In conclusion this overview of evidence-based data suggests that biomarkers could be used as an alternative to liver biopsy for the first line assessment of fibrosis stage in the four most common chronic liver diseases, namely HCV, HBV, NAFLD and ALD. Neither biomarkers nor biopsy alone is sufficient for taking a definite decision in a given patient; all the clinical and biological data must be taken into account. There is no evidence based data justifying biopsy as a first line estimate of liver fibrosis. Health authorities in some countries have already approved validated biomarkers as the first line procedure for the staging of liver fibrosis.

Methodological aspects of the interpretation of non-invasive biomarkers of liver fibrosis: a 2008 update

This review summarizes the methodological aspects of the interpretation of non-invasive biomarkers in liver fibrosis. A scoring system has been updated to better compare the quality of fibrosis biomarkers. Several methodological issues are related to the classical methodology using biopsy, as this is considered the gold standard. However, from evidence-based data, it appears that the methodology needs to change to prevent flawed conclusions among key opinion leaders as well as in obsolete guidelines. As waiting for the perfect biomarker for the diagnosis of advanced fibrosis to come along is probably a waste of time, in the meantime, methods can be improved. The main proposals for improving the methodology are, to take into account the spectrum bias, to assess accuracy between adjacent stages, to compare biomarkers in the same patient, to assess the cause of failure among discordant cases and to use specific statistical methods adapted for imperfect gold standards.

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.

Fiber evanescent wave spectroscopy using the mid-infrared provides useful fingerprints for metabolic profiling in humans

Fiber evanescent wave spectroscopy (FEWS) explores the mid-infrared domain, providing information on functional chemical groups represented in the sample. Our goal is to evaluate whether spectral fingerprints obtained by FEWS might orientate clinical diagnosis. Serum samples from normal volunteers and from four groups of patients with metabolic abnormalities are analyzed by FEWS. These groups consist of iron overloaded genetic hemochromatosis (GH), iron depleted GH, cirrhosis, and dysmetabolic hepatosiderosis (DYSH). A partial least squares (PLS) logistic method is used in a training group to create a classification algorithm, thereafter applied to a test group. Patients with cirrhosis or DYSH, two groups exhibiting important metabolic disturbances, are clearly discriminated from control groups with AUROC values of 0.94+/-0.05 and 0.90+/-0.06, and sensibility/specificity of 8684% and 8787%, respectively. When pooling all groups, the PLS method contributes to discriminate controls, cirrhotic, and dysmetabolic patients. Our data demonstrate that metabolic profiling using infrared FEWS is a possible way to investigate metabolic alterations in patients.

Detection of novel biomarkers of liver cirrhosis by proteomic analysis

Hepatic cirrhosis is a life-threatening disease arising from different chronic liver disorders. One major cause for hepatic cirrhosis is chronic hepatitis C. Chronic hepatitis C is characterized by a highly variable clinical course, with at least 20% developing liver cirrhosis within 40 years. Only liver biopsy allows a reliable evaluation of the course of hepatitis C by grading inflammation and staging fibrosis, and thus serum biomarkers for hepatic fibrosis with high sensitivity and specificity are needed. To identify new candidate biomarkers for hepatic fibrosis, we performed a proteomic approach of microdissected cirrhotic septa and liver parenchyma cells. In cirrhotic septa, we detected an increasing expression of cell structure associated proteins, including actin, prolyl 4-hydroxylase, tropomyosin, calponin, transgelin, and human microfibril-associated protein 4 (MFAP-4). Tropomyosin, calponin, and transgelin reflect a contribution of activated stellate cells/myofibroblasts to chronic liver injury. The expression of tropomyosin, transgelin, and MFAP-4, an extracellular matrix associated protein, were further evaluated by immunohistochemistry. Tropomyosin and MFAP-4 demonstrated high serum levels in patients with hepatic cirrhosis of different causes.

CONCLUSION

A quantitative analysis of MFAP-4 serum levels in a large number of patients showed MFAP-4 as novel candidate biomarker with high diagnostic accuracy for prediction of nondiseased liver versus cirrhosis [area under receiver operating characteristic curve (AUC) = 0.97, P < 0.0001] as well as stage 0 versus stage 4 fibrosis (AUC = 0.84, P < 0.0001), and stages 0 to 3 versus stage 4 fibrosis (AUC = 0.76, P < 0.0001).

The accuracy of the FIB-4 index for the diagnosis of mild fibrosis in chronic hepatitis B

BACKGROUND

The Fib-4 index is a simple and inexpensive biomarker to delineate liver fibrosis in chronic hepatitis C.

AIM

To assess the accuracy of the FIB-4 index in chronic hepatitis B.

METHODS

We compared the FIB-4 index with 138 synchronous liver biopsies and with 372 synchronous FibroTest performed either in France or in an endemic area (Mayotte, an overseas collectivity of France).

RESULTS

The FIB-4 index allowed the correct identification of patients with nil-to-moderate fibrosis with an area under the receiving operating characteristic curve of 0.81 (P < 0.001), increasing as a function of the length of the liver biopsy (up to 0.94 for liver biopsies >or=20 mm). A cut-off value <or=1.45 differentiated moderate fibrosis from severe fibrosis with a negative predictive value of 86%, a sensitivity of 71.1% and a specificity of 73.1%. Beyond 1.45, the FIB-4 index was not informative. The FIB-4 index was more precise than the AST-to-platelet ratio index and correlated with the FibroTest in 89% of the cases (kappa = 0.27, P < 0.001) to exclude severe fibrosis.

CONCLUSION

The FIB-4 index is a simple, accurate and inexpensive method to exclude significant liver fibrosis in chronic hepatitis B, a major advantage in HBV-endemic developing countries.

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.

Assessment of liver fibrosis: noninvasive means

Liver biopsy, owing to its limitations and risks, is an imperfect gold standard for assessing the severity of the most frequent chronic liver diseases chronic hepatitis C (HCV), B (HBV) non alcoholic (NAFLD) and alcoholic (ALD) fatty liver diseases. This review summarizes the advantages and the limits of the available biomarkers of liver fibrosis. Among a total of 2,237 references, a total of 14 validated serum biomarkers have been identified between 1991 and 2008. Nine were not patented and five were patented. Two alternatives to liver biopsy were the most evaluated FibroTest and Fibroscan. For FibroTest, there was a total of 38 different populations including 7,985 subjects with both FibroTest and biopsy (4,600 HCV, 1,580 HBV, 267 NAFLD, 524 ALD, and 1014 mixed). For Fibroscan, there was a total of 11 published studies including 2,260 subjects (1,466 HCV, 95 cholestatic liver disease, and 699 mixed). For FibroTest, the mean diagnostic value for the diagnosis of advanced fibrosis assessed using standardized area under the ROC curves was 0.84 (95% confidence interval 0.83-0.86), without a significant difference between the causes of liver disease, hepatitis C, hepatitis B, and alcoholic or non alcoholic fatty liver disease. High-risk profiles of false negative/false positive of FibroTest, mainly Gilbert syndrome, hemolysis and acute inflammation, are present in 3% of the populations. In case of discordance between biopsy and FibroTest, half of the failures can be due to biopsy; the prognostic value of FibroTest is at least similar to that of biopsy in HCV, HBV and ALD. In conclusion this overview of evidence-based data suggests that biomarkers could be used as an alternative to liver biopsy for the first line assessment of fibrosis stage in the four most common chronic liver diseases, namely HCV, HBV, NAFLD and ALD. Neither biomarkers nor biopsy alone is sufficient for taking a definite decision in a given patient; all the clinical and biological data must be taken into account. There is no evidence based data justifying biopsy as a first line estimate of liver fibrosis. Health authorities in some countries have already approved validated biomarkers as the first line procedure for the staging of liver fibrosis.

Hepatitis C virus infection in the elderly: epidemiology, natural history and management

Hepatitis C virus (HCV) infection frequently occurs in elderly individuals, with a prevalence in individuals aged >60 years of up to approximately 40%. Although progression to cirrhosis is accelerated and occurs more frequently in patients who acquire the infection in old age, this outcome is often not seen because most elderly infected patients acquired HCV when they were young. Data on progression of HCV infection to cirrhosis and eventually to hepatocellular carcinoma are often derived from studies of HCV-infected individuals who present or are referred to hospitals, and which are therefore likely to overestimate the seriousness of the disease; indeed, population-based studies indicate that in many elderly individuals the disease is asymptomatic and runs a fairly benign course. Treatment is based on use of pegylated interferon-alpha and ribavirin, and is overall less effective and more toxic in the elderly. Therefore, treatment should be carefully considered on an individual basis and proposed only in patients up to the age of 75 years with a significant risk of progression of liver disease, no serious co-morbidities and good life expectancy. All treated patients should be followed long term in order to assess the influence of therapy on the evolution of liver disease (decompensated cirrhosis, hepatocellular carcinoma) and survival. It is hoped that liver biopsy, which is still required in order to assess prognosis appropriately, will be replaced in the future by less invasive methods based on combinations of biochemical markers of fibrosis and/or transient elastography, and that newer and less toxic orally administered drugs for HCV infection will become available.

Hepatitis infection in the treatment of opioid dependence and abuse

Many new and existing cases of viral hepatitis infections are related to injection drug use. Transmission of these infections can result directly from the use of injection equipment that is contaminated with blood containing the hepatitis B or C virus or through sexual contact with an infected individual. In the latter case, drug use can indirectly contribute to hepatitis transmission through the dis-inhibited at-risk behavior, that is, unprotected sex with an infected partner. Individuals who inject drugs are at-risk for infection from different hepatitis viruses, hepatitis A, B, or C. Those with chronic hepatitis B virus infection also face additional risk should they become co-infected with hepatitis D virus. Protection from the transmission of hepatitis viruses A and B is best achieved by vaccination. For those with a history of or who currently inject drugs, the medical management of viral hepatitis infection comprising screening, testing, counseling and providing care and treatment is evolving. Components of the medical management of hepatitis infection, for persons considering, initiating, or receiving pharmacologic therapy for opioid addiction include: testing for hepatitis B and C infections; education and counseling regarding at-risk behavior and hepatitis transmission, acute and chronic hepatitis infection, liver disease and its care and treatment; vaccination against hepatitis A and B infection; and integrative primary care as part of the comprehensive treatment approach for recovery from opioid abuse and dependence. In addition, participation in a peer support group as part of integrated medical care enhances treatment outcomes. Liver disease is highly prevalent in patient populations seeking recovery from opioid addiction or who are currently receiving pharmacotherapy for opioid addiction. Pharmacotherapy for opioid addiction is not a contraindication to evaluation, care, or treatment of liver disease due to hepatitis virus infection. Successful pharmacotherapy for opioid addiction stabilizes patients and improves patient compliance to care and treatment regimens as well as promotes good patient outcomes. Implementation and integration of effective hepatitis prevention programs, care programs, and treatment regimens in concert with the pharmacological therapy of opioid addiction can reduce the public health burdens of hepatitis and injection drug use.

Preliminar evaluation of cytokines in the hepatitis C-schistosomiasis co-infection

Evaluation of hepatic fibrosis is usually performed by histopathological examination of biopsies. However, this is an invasive and potentially dangerous procedure. Several studies have proposed serum biological markers of hepatic fibrosis. This communication evaluates the use of serum cytokines as markers of hepatic fibrosis in hepatitis C, schistosomiasis, and co-infection.

Meta-analyses of FibroTest diagnostic value in chronic liver disease

BACKGROUND

FibroTest (FT) is a biomarker of liver fibrosis initially validated in patients with chronic hepatitis C (CHC). The aim was to test two hypotheses, one, that the FT diagnostic value was similar in the three other frequent fibrotic diseases: chronic hepatitis B (CHB), alcoholic liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD); and the other, that the FT diagnostic value was similar for intermediate and extreme fibrosis stages.

METHODS

The main end points were the FT area under the ROC curves (AUROCs) for the diagnosis of bridging fibrosis (F2F3F4 vs. F0F1), standardized for the spectrum of fibrosis stages, and the comparison of FT AUROCs between adjacent stages. Two meta-analyses were performed: one combining all the published studies (random model), and one of an integrated data base combining individual data. Sensitivity analysis integrated the independency of authors, lenght of biopsy, prospective design, respect of procedures, comorbidities, and duration between biopsy and serum sampling.

RESULTS

A total of 30 studies were included which pooled 6,378 subjects with both FT and biopsy (3,501 HCV, 1,457 HBV, 267 NAFLD, 429 ALD, and 724 mixed). Individual data were analyzed in 3,282 patients. The mean standardized AUROC was 0.84 (95% CI, 0.83-0.86), without differences between causes of liver disease: HCV 0.85 (0.82-0.87), HBV 0.80 (0.77-0.84), NAFLD 0.84 (0.76-0.92), ALD 0.86 (0.80-0.92), mixed 0.85 (0.80-0.93). The AUROC for the diagnosis of the intermediate adjacent stages F2 vs. F1 (0.66; 0.63-0.68, n = 2,055) did not differ from that of the extreme stages F3 vs. F4 (0.69; 0.65-0.72, n = 817) or F1 vs. F0 (0.62; 0.59-0.65, n = 1788).

CONCLUSION

FibroTest is an effective alternative to biopsy in patients with chronic hepatitis C and B, ALD and NAFLD. The FT diagnostic value is similar for the diagnosis of intermediate and extreme fibrosis stages.

High-performance Proteomics as a Tool in Biomarker Discovery

Biomarkers allowing early detection of disease or therapy control have a huge influence in curing a disease. A wide variety of methods were applied to find new biomarkers. In contrast to methods focused on DNA or mRNA techniques, approaches considering proteins as potential biomarker candidates have the advantage that proteins are more diverse than DNA or RNA and are more reflective of a biological system. Here, we present an approach for the identification of new biomarkers relying on our experience from the past 10 years of proteomics, outlining a concept of "high-performance proteomics" This approach is based on quantitative proteome analysis using a sufficient number of clinical samples and statistical validation of proteomics data by independent methods, such as Western blot analysis or immunohistochemistry.

Portal-systemic shunting in patients with fibrosis or cirrhosis due to chronic hepatitis C: the minimal model for measuring cholate clearances and shunt

BACKGROUND

Measurement of portal inflow and portal-systemic shunt using cholate clearances could be useful in monitoring patients with liver disease.

AIM

To examine relationships of cholate clearances and shunt to cirrhosis and varices and to define minimal sampling requirements.

METHODS

Five hundred forty-eight studies were performed in 282 patients enrolled in the Hepatitis C Antiviral Long-term Treatment to prevent Cirrhosis (HALT-C) trial. Stable, non-radioactive isotopes of cholate were administered intravenously and orally, clearances (Cl(iv) and Cl(oral)) were calculated from [dose/area under curve (AUC)] and cholate shunt from [(AUC(oral):AUC(iv)) x (Dose(iv):Dose(oral)) x 100%].

RESULTS

Cholate Cl(oral) and cholate shunt correlated with prevalences of both cirrhosis and varices (P < 0.0001 for all). Peripheral venous sampling at 5, 20, 45, 60 and 90 min defined the minimal model. Linear regression of cholate shunt determined from five points within 90 min vs. the standard method of 14 points over 3 h yielded slope of 1.0 and intercept 0.5% (r(2) = 0.98, P < 0.0001). Results were identical in the 189 validation studies (slope 1.0, intercept 0.5%, r(2) = 0.99, P < 0.0001).

CONCLUSIONS

Cholate Cl(oral) and cholate shunt may be useful in monitoring patients with liver disease. The 5-point model enhances application of cholate Cl(oral) and cholate shunt in the non-invasive assessment of the portal circulation.

Up-regulated eotaxin plasma levels in chronic liver disease patients indicate hepatic inflammation, advanced fibrosis and adverse clinical course

BACKGROUND AND AIMS

Recent studies highlight the role of chemokines for the attraction of inflammatory cells in liver injury and fibrogenesis. The CC chemokine ligand 11, eotaxin (CCL11), is up-regulated in senescent human hepatic stellate cells and crucial in animal models of T-cell mediated hepatitis. The aim of this study was to analyze the role of eotaxin in chronic liver disease.

METHODS

Plasma eotaxin levels of 111 patients with chronic liver disease were correlated with clinical presentation, laboratory parameters, liver histology and clinical course in a 6-year follow-up.

RESULTS

Eotaxin concentrations were significantly up-regulated in patients with liver cirrhosis and increased according to Child-Pugh and model of end-stage liver disease (MELD) score. Eotaxin correlated with the hepatic biosynthetic capacity and other inflammatory cytokines. High eotaxin was associated with hepatic necroinflammation and fibrosis in liver histology. In patients with typical clinical complications of cirrhosis, eotaxin was found to be increased. High eotaxin indicated an unfavorable prognosis in 6-year follow-up.

CONCLUSIONS

High eotaxin expression may be involved in the pathogenesis of chronic liver diseases. Plasma eotaxin levels correlate with the degree of liver cirrhosis and could serve as an additional biomarker indicating histological hepatic necroinflammation and fibrosis as well as an adverse clinical course.

Rating of CCl(4)-induced rat liver fibrosis by blood serum glycomics

BACKGROUND

Non-invasive staging of human liver fibrosis is a desirable objective that remains under extensive evaluation. Animal model systems are often used for studying human liver disease and screening antifibrotic compounds. The aim of the present study was to investigate the potential use of serum N-glycan profiles to evaluate liver fibrosis in a rat model.

METHODS

Liver fibrosis and cirrhosis were induced in rats by oral administration of CCl(4). Liver injury was assessed biochemically (alanine aminotransferase [ALT] activity, aspartate aminotransferase [AST] activity and total bilirubin) and histologically. The N-glycan profile (GlycoTest) was performed using DNA sequencer-assisted-fluorophore-assisted carbohydrate electrophoresis technology. In parallel, the effect of cotreatment with antifibrotic interferon-gamma (IFN-gamma) was studied.

RESULTS

The biopsy scoring system showed that CCl(4) induced early fibrosis (F < 1-2) in rats after 3 weeks of treatment, and cirrhosis (F4) after 12 weeks. Significant increases in ALT activity, AST activity and total bilirubin levels were detected only after 12 weeks of CCl(4) treatment. GlycoTest showed three glycans were significantly altered in the CCl(4)-goup. Peak 3 started at week 6, at an early stage in fibrosis development (F < 1-2), whereas peaks 4 and 5 occurred at week 9, at which time mild liver fibrosis (F = 1-2) had developed. The changes in the CCl(4)-IFN-gamma group were intermediate between the CCl(4)- and the control groups.

CONCLUSION

The GlycoTest is much more sensitive than biochemical tests for evaluating liver fibrosis/cirrhosis in the rat model. The test can also be used as a non-invasive marker for screening and monitoring the antifibrotic activity of potential therapeutic compounds.

FIB-4: an inexpensive and accurate marker of fibrosis in HCV infection. comparison with liver biopsy and fibrotest

To optimize the management of patients with chronic hepatitis C virus (HCV) infection, noninvasive tests to determine the degree of hepatic fibrosis have been developed. The aims of this study were (1) to validate a simple, inexpensive, noninvasive test called FIB-4, which combines standard biochemical values (platelets, ALT, AST) and age, in a series of 847 liver biopsies performed in HCV-monoinfected patients; and (2) to compare the results of 780 FIB-4 and FibroTests performed the same day in a series of 592 HCV-infected patients. The FIB-4 index enabled the correct identification of patients with severe fibrosis (F3-F4) and cirrhosis with an area under the receiver operating characteristic curve of 0.85 (95% CI 0.82-0.89) and 0.91 (95% CI 0.86-0.93), respectively. An FIB-4 index <1.45 had a negative predictive value of 94.7% to exclude severe fibrosis with a sensitivity of 74.3%. An FIB-4 index higher than 3.25 had a positive predictive value to confirm the existence of a significant fibrosis (F3-F4) of 82.1% with a specificity of 98.2%. Using these ranges, 72.8% of the 847 liver biopsies were correctly classified. The FIB-4 index was strongly correlated to the FibroTest results for a score <1.45 or >3.25 (kappa = 0.561, P < 0.01). A FIB-4 value <1.45 or >3.25 (64.6% of the cases) was concordant with FibroTest results in 92.1% and 76%, respectively.

CONCLUSION

For values outside 1.45-3.25, the FIB-4 index is a simple, accurate, and inexpensive method for assessing liver fibrosis and proved to be concordant with FibroTest results.

Hepatitis C virus: Virology, diagnosis and management of antiviral therapy

Hepatitis C virus (HCV) infects approximately 170 million individuals worldwide. Prevention of HCV infection complications is based on antiviral therapy with the combination of pegylated interferon alfa and ribavirin. The use of serological and virological tests has become essential in the management of HCV infection in order to diagnose infection, guide treatment decisions and assess the virological response to antiviral therapy. Anti-HCV antibody testing and HCV RNA testing are used to diagnose acute and chronic hepatitis C. The HCV genotype should be systematically determined before treatment, as it determines the indication, the duration of treatment, the dose of ribavirin and the virological monitoring procedure. HCV RNA monitoring during therapy is used to tailor treatment duration in HCV genotype 1 infection, and molecular assays are used to assess the end-of-treatment and, most importantly the sustained virological response, i.e. the endpoint of therapy.

Clinical virology of hepatitis C virus

Hepatitis C virus (HCV) infects approximately 170 million individuals worldwide. Prevention of HCV-infection complications is based on antiviral therapy with the combination of pegylated interferon-α and ribavirin. The use of serological and virological tests has become essential in the management of HCV infection. These tests diagnose infection, guide treatment decisions and assess the virological response to antiviral therapy. Anti-HCV antibody testing and HCV-RNA testing are used to diagnose acute and chronic hepatitis C. The HCV genotype should be systematically determined before treatment, as it determines the indication, duration of treatment, dose of ribavirin and virological monitoring procedure. HCV-RNA monitoring during therapy is used to tailor treatment duration in HCV genotype 1 infection, and molecular assays are used to assess the end-of-treatment and, most importantly, the sustained virological response, for example the end point of therapy.

N/A

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Diagnostic value of biochemical markers (FibroTest-FibroSURE) for the prediction of liver fibrosis in patients with non-alcoholic fatty liver disease

BACKGROUND

Liver biopsy is considered as the gold standard for assessing non-alcoholic fatty liver disease (NAFLD) histologic lesions. The aim of this study was to determine the diagnostic utility of non-invasive markers of fibrosis, validated in chronic viral hepatitis and alcoholic liver disease (FibroTest, FT), in patients with NAFLD.

METHODS

170 patients with suspected NAFLD were prospectively included in a reference center (Group 1), 97 in a multicenter study (Group 2) and 954 blood donors as controls. Fibrosis was assessed on a 5 stage histological scale validated by Kleiner et al from F0 = none, F1 = perisinusoidal or periportal, F2 = perisinusoidal and portal/periportal, F3 = bridging and F4 = cirrhosis. Histology and the biochemical measurements were blinded to any other characteristics. The area under the ROC curves (AUROC), sensitivity (Se), specificity (Sp), positive and negative predictive values (PPV, NPV) were assessed.

RESULTS

In both groups FT has elevated and not different AUROCs for the diagnosis of advanced fibrosis (F2F3F4): 0.86 (95%CI 0.77-0.91) versus 0.75 (95%CI 0.61-0.83; P = 0.10), and for F3F4: 0.92 (95%CI 0.83-0.96) versus 0.81 (95%CI 0.64-0.91; P = 0.12) in Group 1 and Group 2 respectively. When the 2 groups were pooled together a FT cutoff of 0.30 had a 90% NPV for advanced fibrosis (Se 77%); a FT cutoff of 0.70 had a 73% PPV for advanced fibrosis (Sp 98%).

CONCLUSION

In patients with NAFLD, FibroTest, a simple and non-invasive quantitative estimate of liver fibrosis reliably predicts advanced fibrosis.

Therapy of hepatitis C: from empiricism to eradication

The complications of chronic hepatitis C virus infection can be prevented by antiviral therapy. The initial choice of interferon alfa and, subsequently, ribavirin as potential treatments for chronic hepatitis C was empirical. Nevertheless, the combination of pegylated interferon alfa and ribavirin has become the standard treatment of chronic hepatitis C. Since the advent of interferon-based therapy, enormous progress has been made in understanding the mechanisms of treatment efficacy and failure, and in everyday patient management. The principal advances are: a better understanding of hepatitis C virus steady-state kinetics and the antiviral mechanisms of interferon and ribavirin; easier treatment decisions thanks to novel assays to assess liver disease severity and the virological characteristics of infection; a better use of virological tests to tailor therapy; a better management of adverse effects; a better understanding of virological treatment failure; and a better management of "special" populations, including patients with decompensated cirrhosis and end-stage liver disease, liver transplant recipients, hemodialysis patients and renal transplant recipients, human immunodeficiency virus-coinfected patients, intravenous drug users and patients on opiate replacement therapy, or virological non responders to previous therapies. Steady-state HCV kinetics offers several potential targets for new drugs. These targets should ideally be hit simultaneously in order to achieve viral eradication within a reasonable time frame. Future drugs for HCV infection will belong to four main categories, including new interferons, alternatives to ribavirin, specific HCV inhibitors, and immune modulators. New treatments and vaccines might make it possible to eradicate HCV in the future.

Hepatitis C virus serologic and virologic tests and clinical diagnosis of HCV-related liver disease

The use of serological and virological tests has become essential in the management of hepatitis C virus (HCV) infection in order to diagnose infection, guide treatment decisions and assess the virological response to antiviral therapy. Virological tools include serological assays for anti-HCV antibody detection and serological determination of the HCV genotype, and molecular assays that detect and quantify HCV RNA and determine the HCV genotype. Anti-HCV antibody testing and HCV RNA testing are used to diagnose acute and chronic hepatitis C. Only patients with detectable HCV RNA should be considered for pegylated interferon alfa and ribavirin therapy and the HCV genotype should be systematically determined before treatment, as it determines the indication, the duration of treatment, the dose of ribavirin and the virological monitoring procedure. HCV RNA monitoring during therapy is used to tailor treatment duration in HCV genotype 1 infection, and molecular assays are used to assess the end-of-treatment and, most importantly the sustained virological response, i.e. the endpoint of therapy.

Chronic hepatitis C virus infection in older adults

Most of the older adults with chronic hepatitis C virus infection acquired the disease earlier in life. These patients often present with complications of liver disease, mainly cirrhosis and hepatocellular carcinoma. The burden of chronic hepatitis C virus infection in elderly persons is expected to increase significantly in the United States during the next 2 decades. It seems important that, for elderly patients with chronic hepatitis C, the risk-benefit of combination antiviral therapy consisting of pegylated interferon and ribavirin should be assessed on an individual basis. Assessment should be performed in all cases before considering treatment, and it should include evaluation of the degree of liver fibrosis by means of liver biopsy or, possibly, by means of noninvasive methods. Novel antiviral drugs that may have fewer adverse effects, such as protease inhibitors, may serve as potential alternatives. It is recommended that elderly patients (up to the age of 75 years) be included in randomized trials of chronic hepatitis C virus infection treatment.