ARFI, FibroScan, ELF, and their combinations in the assessment of liver fibrosis: a prospective study

Performance of Enhanced Liver Fibrosis test and comparison with transient elastography in the identification of liver fibrosis in patients with chronic hepatitis B infection

Assessment of liver fibrosis is important in determining prognosis, disease progression and need for treatment in patients with chronic hepatitis B (CHB). Limitations to the use of liver biopsy in assessing fibrosis are well recognized, and noninvasive tests are being increasingly evaluated including transient elastography (TE) and serum markers such as the Enhanced Liver Fibrosis (ELF) test. We assessed performance of ELF and TE in detecting liver fibrosis with reference to liver histology in a cohort of patients with CHB (n = 182), and compared the performance of these modalities. Median age was 46 and mean AST 70 IU/L. Cirrhosis was reported in 20% of liver biopsies. Both modalities performed well in assessing fibrosis at all stages. Area under receiver operator characteristic (AUROC) curves for detecting METAVIR fibrosis stages F ≥ 1, F ≥ 2, F ≥ 3 and F4 were 0.77, 0.82, 0.80 and 0.83 for ELF and 0.86, 0.86, 0.90 and 0.95 for TE. TE performed significantly better in the assessment of severe fibrosis (AUROC 0.80 for ELF and 0.90 for TE, P < 0.01) and cirrhosis (0.83 for ELF and 0.95 for TE, P < 0.01). This study demonstrates that ELF has good performance in detection of liver fibrosis in patients with CHB, and when compared, TE performs better in detection of severe fibrosis/cirrhosis.

Post-operative imaging in liver transplantation: State-of-the-art and future perspectives

Orthotopic liver transplantation (OLT) represents a major treatment for end-stage chronic liver disease, as well as selected cases of hepatocellular carcinoma and acute liver failure. The ever-increasing development of imaging modalities significantly contributed, over the last decades, to the management of recipients both in the pre-operative and post-operative period, thus impacting on graft and patients survival. When properly used, imaging modalities such as ultrasound, multidetector computed tomography, magnetic resonance imaging (MRI) and procedures of direct cholangiography are capable to provide rapid and reliable recognition and treatment of vascular and biliary complications occurring after OLT. Less defined is the role for imaging in assessing primary graft dysfunction (including rejection) or chronic allograft disease after OLT, e.g., hepatitis C virus (HCV) recurrence. This paper: (1) describes specific characteristic of the above imaging modalities and the rationale for their use in clinical practice; (2) illustrates main imaging findings related to post-OLT complications in adult patients; and (3) reviews future perspectives emerging in the surveillance of recipients with HCV recurrence, with special emphasis on MRI.

Biomarkers of liver fibrosis

Liver fibrosis is the final common pathway for almost all causes of chronic liver injury. Liver fibrosis is now known to be a dynamic process having significant potential for resolution. Therefore, fibrosis prediction is an essential part of the assessment and management of patients with chronic liver disease. As such, there is strong demand for reliable liver biomarkers that provide insight into disease etiology, diagnosis, therapy, and prognosis in lieu of more invasive approaches such as liver biopsy. Current diagnostic strategies range from use of serum biomarkers to more advanced imaging techniques including transient elastography and magnetic resonance imaging. In addition to these modalities, there are other approaches including the use of novel, but yet to be validated, biomarkers. In this chapter, we discuss the biomarkers of liver fibrosis including the use of invasive and noninvasive biomarkers and disease-specific biomarkers in various chronic liver diseases.

Point shear wave elastography method for assessing liver stiffness

AIM

To estimate the validity of the point shear-wave elastography method by evaluating its reproducibility and accuracy for assessing liver stiffness.

METHODS

This was a single-center, cross-sectional study. Consecutive patients with chronic viral hepatitis scheduled for liver biopsy (LB) (Group 1) and healthy volunteers (Group 2) were studied. In each subject 10 consecutive point shear-wave elastography (PSWE) measurements were performed using the iU22 ultrasound system (Philips Medical Systems, Bothell, WA, United States). Patients in Group 1 underwent PSWE, transient elastography (TE) using FibroScan (Echosens, Paris, France) and ultrasound-assisted LB. For the assessment of PSWE reproducibility two expert raters (rater 1 and rater 2) independently performed the examinations. The performance of PSWE was compared to that of TE using LB as a reference standard. Fibrosis was staged according to the METAVIR scoring system. Receiver operating characteristic curve analyses were performed to calculate the area under the receiver operating characteristic curve (AUC) for F ≥ 2, F ≥ 3 and F = 4. The intraobserver and interobserver reproducibility of PSWE were assessed by calculating Lin's concordance correlation coefficient.

RESULTS

To assess the performance of PSWE, 134 consecutive patients in Group 1 were studied. The median values of PSWE and TE (in kilopascals) were 4.7 (IQR = 3.8-5.4) and 5.5 (IQR = 4.7-6.5), respectively, in patients at the F0-F1 stage and 3.5 (IQR = 3.2-4.0) and 4.4 (IQR = 3.5-4.9), respectively, in the healthy volunteers in Group 2 (P < 10(-5)). In the univariate analysis, the PSWE and TE values showed a high correlation with the fibrosis stage; low correlations with the degree of necroinflammation, aspartate aminotransferase and gamma-glutamyl transferase (GGT); and a moderate negative correlation with the platelet count. A multiple regression analysis confirmed the correlations of both PSWE and TE with fibrosis stage and GGT but not with any other variables. The following AUC values were found: 0.80 (0.71-0.87) for PSWE and 0.82 (0.73-0.89) for TE (P = 0.42); 0.88 (0.80-0.94) for PSWE and 0.95 (0.88-0.98) for TE (P = 0.06); and 0.95 (0.89-0.99) for PSWE and 0.92 (0.85-0.97) for TE (P = 0.30) for F ≥ 2, F ≥ 3 and F = 4, respectively. To assess PSWE reproducibility, 116 subjects were studied, including 47 consecutive patients scheduled for LB (Group 1) and 69 consecutive healthy volunteers (Group 2). The intraobserver agreement ranged from 0.83 (95%CI: 0.79-0.88) to 0.96 (95%CI: 0.95-0.97) for rater 1 and from 0.84 (95%CI: 0.79-0.88) to 0.96 (95%CI: 0.95-0.97) for rater 2. The interobserver agreement yielded values from 0.83 (95%CI: 0.78-0.88) to 0.93 (95%CI: 0.91-0.95).

CONCLUSION

PSWE is a reproducible method for assessing liver stiffness, and it compares with TE. Compared with patients with nonsignificant fibrosis, healthy volunteers showed significantly lower values.

Invasive and non-invasive diagnosis of cirrhosis and portal hypertension

With advances in the management and treatment of advanced liver disease, including the use of antiviral therapy, a simple, one stage description for advanced fibrotic liver disease has become inadequate. Although refining the diagnosis of cirrhosis to reflect disease heterogeneity is essential, current diagnostic tests have not kept pace with the progression of this new paradigm. Liver biopsy and hepatic venous pressure gradient measurement are the gold standards for the estimation of hepatic fibrosis and portal hypertension (PHT), respectively, and they have diagnostic and prognostic value. However, they are invasive and, as such, cannot be used repeatedly in clinical practice. The ideal noninvasive test should be safe, easy to perform, inexpensive, reproducible as well as to give numerical and accurate results in real time. It should be predictive of long term outcomes related with fibrosis and PHT to allow prognostic stratification. Recently, many types of noninvasive alternative tests have been developed and are under investigation. In particular, imaging and ultrasound based tests, such as transient elastography, have shown promising results. Although most of these noninvasive tests effectively identify severe fibrosis and PHT, the methods available for diagnosing moderate disease status are still insufficient, and further investigation is essential to predict outcomes and individualize therapy in this field.

The acoustic radiation force impulse elastography evaluation of liver fibrosis in posttransplantation dysfunction of living donor liver transplantation

BACKGROUND

The acoustic radiation force impulse elastography (ARFI) is a new technology of elastography integrated into B-mode ultrasonography. It has been a reliable method to evaluate liver fibrosis of chronic liver disease in recent years, but less applied in the posttransplantation liver. The aim of the study was to evaluate liver fibrosis by the ARFI with correlation of pathological stages in living donor liver transplantation (LDLT).

MATERIALS AND METHODS

From August 2010 to August 2012, there were 57 LDLT patients with liver biopsy (LB) due to posttransplantation dysfunction; all patients also received posttransplantation ARFI liver stiffness measurement (LSM) after transplantation for liver fibrosis staging. The ARFI elastography was performed using a Siemens Acuson S2000 ultrasound system with 4V1 transducers (Acusion, Siemens Medical Systems Co. Ltd. Erlangen, Germany). The ARFI LSM value was presented by shear wave velocity (SWV, m/s). The fibrosis staging as F0 to F4 was in accordance with the Metavir scoring system.

RESULTS

A total of 57 patients had both posttransplantation LB and effective ARFI fibrosis staging for correlation. The ARFI LSM value increased with severity of liver fibrosis and had significant linear correlation with the results of histological fibrosis staging. The ARFI LSM sensitivities (Se), specificities (Sp), and cutoff values based on receiver-operator characteristic curve were F0: 0.75 m/s (Se: 93.8%, Sp: 4%), F1: 1.06 m/s (Se: 95.5%, Sp: 25.7%), F2: 1.81 m/s (Se: 50%, Sp: 83.6%) and F3: 2.33 m/s (Se: 100%, Sp: 92.9%). Predictive value of ARFI LSM reported a significant difference between early fibrosis stage (F0-F1) and advanced fibrosis stage (F ≧ 2) (P < .05).

CONCLUSION

In this study, ARFI demonstrated a strong linear correlation and severity of liver fibrosis with LB pathologic staging. ARFI can be an alternative and compensatory method for frequent LB in the posttransplantation liver.

Non-invasive prediction of forthcoming cirrhosis-related complications

In patients with chronic liver diseases, identification of significant liver fibrosis and cirrhosis is essential for determining treatment strategies, assessing therapeutic response, and stratifying long-term prognosis. Although liver biopsy remains the reference standard for evaluating the extent of liver fibrosis in patients with chronic liver diseases, several non-invasive methods have been developed as alternatives to liver biopsies. Some of these non-invasive methods have demonstrated clinical accuracy for diagnosing significant fibrosis or cirrhosis in many cross-sectional studies with the histological fibrosis stage as a reference standard. However, non-invasive methods cannot be fully validated through cross-sectional studies since liver biopsy is not a perfect surrogate endpoint marker. Accordingly, recent studies have focused on assessing the performance of non-invasive methods through long-term, longitudinal, follow-up studies with solid clinical endpoints related to advanced stages of liver fibrosis and cirrhosis. As a result, current view is that these alternative methods can independently predict future cirrhosis-related complications, such as hepatic decompensation, liver failure, hepatocellular carcinoma, or liver-related death. The clinical role of non-invasive models seems to be shifting from a simple tool for predicting the extent of fibrosis to a surveillance tool for predicting future liver-related events. In this article, we will summarize recent longitudinal studies of non-invasive methods for predicting forthcoming complications related to liver cirrhosis and discuss the clinical value of currently available non-invasive methods based on evidence from the literature.

Review article: The prevention and reversal of hepatic fibrosis in autoimmune hepatitis

BACKGROUND

Immunosuppressive treatment of autoimmune hepatitis can prevent or reverse hepatic fibrosis, but these anti-fibrotic effects are inconsistent secondary gains.

AIM

To describe the anti-fibrotic effects of current therapies for autoimmune hepatitis, discuss the pathogenic mechanisms of hepatic fibrosis that might be targeted by anti-fibrotic interventions, indicate the non-invasive diagnostic tests of hepatic fibrosis that must be validated in autoimmune hepatitis and to suggest promising treatment opportunities.

METHODS

Studies cited in PubMed from 1972 to 2013 for autoimmune hepatitis, hepatic fibrosis, cirrhosis, anti-fibrotic therapy and non-invasive tests of hepatic fibrosis were selected.

RESULTS

Hepatic fibrosis improves in 53-57% of corticosteroid-treated patients with autoimmune hepatitis; progressive fibrosis slows or is prevented in 79%; and cirrhosis may be reversed. Progressive hepatic fibrosis is associated with liver inflammation, and the inability to fully suppress inflammatory activity within 12 months is associated with progression to cirrhosis (54%) and death or need for liver transplantation (15%). Liver tissue examination remains the gold standard for assessing hepatic fibrosis, but laboratory and radiological tests may be useful non-invasive methods to measure the fibrotic response. Severe liver inflammation can confound radiological assessments, and the preferred non-invasive test in autoimmune hepatitis is uncertain. Individualised treatment adjustments and adjunctive anti-fibrotic therapies are poised for study in this disease.

CONCLUSIONS

The prevention and reversal of hepatic fibrosis are achievable objectives in autoimmune hepatitis. Strategies that evaluate individualised therapies adjusted to the rapidity and completeness of the inflammatory response, and the use of adjunctive anti-fibrotic interventions, must be evaluated.

Shear wave elastography for evaluation of liver fibrosis

The prognosis and management of chronic viral hepatitis mainly depend on the extent of liver fibrosis, particularly in chronic hepatitis C. Liver histologic analysis is still considered the reference standard in the assessment of liver fibrosis despite the interobserver and interobserver variability in staging and some morbidity and mortality risks. Thus, noninvasive methods for assessing liver fibrosis are of great clinical interest. In the last decade, ultrasound-based techniques to estimate the stage of liver fibrosis have become commercially available. They all have the capability to noninvasively evaluate differences in the elastic properties of soft tissues by measuring tissue behavior when a mechanical stress is applied. Shear wave elastography relies on the generation of shear waves determined by the displacement of tissues induced by the force of a focused ultrasound beam or by an external push. This article reviews the results that have been obtained with shear wave elastography for assessment of liver fibrosis.

Non-invasive diagnosis of hepatitis B virus-related cirrhosis

Chronic hepatitis B (CHB) infection is a major public health problem associated with significant morbidity and mortality worldwide. Twenty-three percent of patients with CHB progress naturally to liver cirrhosis, which was earlier thought to be irreversible. However, it is now known that cirrhosis can in fact be reversed by treatment with oral anti-nucleotide drugs. Thus, early and accurate diagnosis of cirrhosis is important to allow an appropriate treatment strategy to be chosen and to predict the prognosis of patients with CHB. Liver biopsy is the reference standard for assessment of liver fibrosis. However, the method is invasive, and is associated with pain and complications that can be fatal. In addition, intra- and inter-observer variability compromises the accuracy of liver biopsy data. Only small tissue samples are obtained and fibrosis is heterogeneous in such samples. This confounds the two types of observer variability mentioned above. Such limitations have encouraged development of non-invasive methods for assessment of fibrosis. These include measurements of serum biomarkers of fibrosis; and assessment of liver stiffness via transient elastography, acoustic radiation force impulse imaging, real-time elastography, or magnetic resonance elastography. Although significant advances have been made, most work to date has addressed the diagnostic utility of these techniques in the context of cirrhosis caused by chronic hepatitis C infection. In the present review, we examine the advantages afforded by use of non-invasive methods to diagnose cirrhosis in patients with CHB infections and the utility of such methods in clinical practice.

Evaluation of abnormal liver tests

The routine use of serum biochemical tests allows for the detection of acute and chronic liver injury before the onset of symptoms. These tests consist of markers of hepatocellular injury (aminotransferases and APs); tests of liver metabolism (total bilirubin); and tests of liver synthetic function (serum albumin and PT). Noninvasive tests for assessment of liver fibrosis are promising tools for diagnosis and prognosis of patients with chronic liver disease. A comprehensive history, physical examination, and assessment of pattern of liver injury with additional laboratory and imaging testing establish the cause of hepatobiliary disease in most cases.

[Serum markers of liver fibrosis in patients with chronic hepatitis C infection. Prognostic value of noninvasive markers of fibrosis in liver transplantation]

Liver fibrosis must be evaluated in patients with chronic hepatitis C, since its severity will affect prognosis and the indication of antiviral therapy. Combining serological markers of fibrosis in algorithms or scores can identify a substantial number of patients with significant fibrosis and most patients with liver cirrhosis, thus potentially avoiding a large number of biopsies. Although these algorithms should be interpreted with caution, due to their possible limitations, their high reproducibility, applicability and availability make them an essential tool in the current evaluation of patients with chronic hepatitis C infection. In contrast, serological markers have been found to be less effective in the diagnosis of fibrosis in the context of recurrent hepatitis C infection after liver transplantation. However, an algorithm for direct markers has shown excellent predictive ability in liver transplant recipients with hepatitis C. Consequently, this algorithm seems to be an excellent tool to establish prognosis and indicate antiviral therapy.

Efficacy of HGF carried by ultrasound microbubble-cationic nano-liposomes complex for treating hepatic fibrosis in a bile duct ligation rat model, and its relationship with the diffusion-weighted MRI parameters

Hepatic fibrosis is a major consequence of liver aggression. Finding novel ways for counteracting this damaging process, and for evaluating fibrosis with a non-invasive imaging approach, represent important therapeutic and diagnostic challenges. Hepatocyte growth factor (HGF) is an anti-fibrosis cell growth factor that induces apoptosis in activated hepatic stellate cells, reduces excessive collagen deposition, and stimulates hepatocyte regeneration. Thus, using HGF in gene therapy against liver fibrosis is an attractive approach. The aims of the present study were: (i) to explore the efficacy of treating liver fibrosis using HGF expression vector carried by a novel ultrasound microbubble delivery system; (ii) to explore the diagnostic interest of diffusion-weighted MRI (DWI-MRI) in evaluating liver fibrosis. We established a rat model of hepatic fibrosis. The rats were administered HGF linked to novel ultrasound micro-bubbles. Progression of hepatic fibrosis was evaluated by histopathology, hydroxyproline content, and DWI-MRI to determine the apparent diffusion coefficient (ADC). Our targeted gene therapy produced a significant anti-fibrosis effect, as shown by liver histology and significant reduction of hydroxyproline content. Moreover, using DWI-MRI, the b value (diffusion gradient factor) was equal to 300s/mm(2), and the ADC values significantly decreased as the severity of hepatic fibrosis increased. Using this methodology, F0-F2 could be distinguished from F3 and F4 (P<0.01). This is the first in vivo report of using an ultrasound microbubble-cationic nano-liposome complex for gene delivery. The data indicate that, this approach is efficient to counteract the fibrosis process. DWI-MRI appears a promising imaging technique for evaluating liver fibrosis.

Liver elastography, comments on EFSUMB elastography guidelines 2013

Recently the European Federation of Societies for Ultrasound in Medicine and Biology Guidelines and Recommendations have been published assessing the clinical use of ultrasound elastography. The document is intended to form a reference and to guide clinical users in a practical way. They give practical advice for the use and interpretation. Liver disease forms the largest section, reflecting published experience to date including evidence from meta-analyses with shear wave and strain elastography. In this review comments and illustrations on the guidelines are given.

Meta-analysis: ARFI elastography versus transient elastography for the evaluation of liver fibrosis

AIMS

This meta-analysis aims to compare the diagnostic performance of acoustic radiation force impulse (ARFI) elastography and transient elastography (TE) in the assessment of liver fibrosis using liver biopsy (LB) as 'gold-standard'.

METHODS

PubMed, Medline, Lilacs, Scopus, Ovid, EMBASE, Cochrane and Medscape databases were searched for all studies published until 31 May 2012 that evaluated the liver stiffness by means of ARFI, TE and LB. Information abstracted from each study according to a fixed protocol included study design and methodological characteristics, patient characteristics, interventions, outcomes and missing outcome data.

RESULTS

Thirteen studies (11 full-length articles and 2 abstracts) including 1163 patients with chronic hepatopathies were included in the analysis. Inability to obtain reliable measurements was more than thrice as high for TE as that of ARFI (6.6% vs. 2.1%, P < 0.001). For detection of significant fibrosis, (F ≥ 2) the summary sensitivity (Se) was 0.74 (95% CI: 0.66-0.80) and specificity (Sp) was 0.83 (95% CI: 0.75-0.89) for ARFI, while for TE the Se was 0.78 (95% CI: 0.72-0.83) and Sp was 0.84 (95% CI: 0.75-0.90). For the diagnosis of cirrhosis, the summary Se was 0.87 (95% CI: 0.79-0.92) and Sp was 0.87 (95% CI: 0.81-0.91) for ARFI elastography, and, respectively, 0.89 (95% CI: 0.80-0.94) and 0.87 (95% CI: 0.82-0.91) for TE. The diagnostic odds ratio of ARFI and TE did not differ significantly in the detection of significant fibrosis [mean difference in rDOR = 0.27 (95% CI: 0.69-0.14)] and cirrhosis [mean difference in rDOR = 0.12 (95% CI: 0.29-0.52)].

CONCLUSION

Acoustic radiation force impulse elastography seems to be a good method for assessing liver fibrosis, and shows higher rate of reliable measurements and similar predictive value to TE for significant fibrosis and cirrhosis.

The use of transient elastography and non-invasive serum markers of fibrosis in pediatric liver transplant recipients

The use of non-invasive markers to diagnose liver allograft fibrosis is not well established in children after LTx. TE, FT, and ELF score were performed in 117 liver-transplanted children (60M, 8.9 [0.5-18.5] yr) and 336 healthy controls. Liver biopsy was available in 36 children. Results of histology and non-invasive markers were compared using correlation coefficient or Mann-Whitney U-test as appropriate. TE correlated best with histological degree of fibrosis (r = 0.85 vs. r = 0.04 [FT] or r = -0.38 [ELF]). Liver stiffness values for transplanted children without fibrosis were significantly higher than those of healthy controls (7.55 [5.4-20.4] kPa vs. 4.5 [2.5-8.9] kPa). Presence of rejection was a potent confounder for the performance of TE. Both TE and FT reflected clinical changes (acute rejection, cholestasis, increasing fibrosis) in a total of 16 patients who underwent serial measurements. TE correlates better with histological degree of fibrosis in liver-transplanted children than FT or ELF, but an individual baseline value needs to be determined for each patient. Normal or cutoff values for pathological degrees of fibrosis cannot be transferred from non-transplanted children. Follow-up studies, preferably with protocol biopsies, might help to improve the diagnostic quality of TE.

Acoustic radiation force impulse of the liver

Acoustic radiation force impulse (ARFI) imaging is a new and promising ultrasound-based diagnostic technique that, evaluating the wave propagation speed, allows the assessment of the tissue stiffness. ARFI is implemented in the ultrasound scanner. By short-duration acoustic radiation forces (less than 1 ms), localized displacements are generated in a selected region of interest not requiring any external compression so reducing the operator dependency. The generated wave scan provides qualitative or quantitative (wave velocity values) responses. Several non-invasive methods for assessing the staging of fibrosis are used, in order to avoid liver biopsy. Liver function tests and transient elastography are non-invasive, sensitive and accurate tools for the assessment of liver fibrosis and for the discrimination between cirrhotic and non-cirrhotic liver. Many published studies analyse ARFI performance and feasibility in studying diffuse liver diseases and compare them to other diagnostic imaging modalities such as conventional ultrasonography and transient elastography. Solid focal liver lesions, both benign and malignant, are common findings during abdominal examinations. The accurate characterization and differential diagnosis are important aims of all the imaging modalities available today. Only few papers describe the application of ARFI technology in the study of solid focal liver lesions, with different results. In the present study, the existing literature, to the best of our knowledge, about ARFI application on diffuse and focal liver pathology has been evaluated and results and statistical analyses have been compared, bringing to the conclusion that ARFI can be used in the study of the liver with similar accuracy as transient elastography in diagnosing significant fibrosis or cirrhosis and has got some advantages in respect to transient elastography since it does not require separate equipment, better displays anatomical structures and measurements can be successfully carried out almost in every patient.

The Enhanced Liver Fibrosis (ELF) score: normal values, influence factors and proposed cut-off values

BACKGROUND & AIMS

Progressive fibrosis is a major cause of morbidity and mortality in chronic liver disease. To replace liver biopsy for disease staging, multiple serum markers are under evaluation with multiparametric panels yielding the most promising results. The Enhanced Liver Fibrosis (ELF) score is an ECM marker set consisting of tissue inhibitor of metalloproteinases 1 (TIMP-1), amino-terminal propeptide of type III procollagen (PIIINP) and hyaluronic acid (HA) showing good correlations with fibrosis stages in chronic liver disease.

METHODS

The ELF score was measured in 400 healthy controls and 79 chronic hepatitis C patients using an ADVIA Centaur automated system. The ELF score was calculated using the published algorithm combining TIMP-1, PIIINP and HA values. Patients' fibrosis stage was defined histologically. ROC analyses were performed to study marker validity. Reference values and influence factors for the ELF score were validated.

RESULTS

ELF score reference values ranged from 6.7 to 9.8 and were significantly higher for men vs. women (7.0-9.9 vs. 6.6-9.3, respectively). Afternoon values were slightly higher than morning values (6.7-9.9 vs. 6.6-9.5, respectively). Age was a notable influence factor. We identified three cut-off values: 7.7 for a high sensitivity exclusion of fibrosis, 9.8 for a high specificity identification of fibrosis (sensitivity 69%, specificity 98% for moderate fibrosis), and 11.3 to discriminate cirrhosis (sensitivity 83%, specificity 97%). ELF score validity was superior to the results of the single tests.

CONCLUSIONS

The ELF score can predict moderate fibrosis and cirrhosis. However, influence factors such as gender and age need to be taken into account.

The role of ultrasound elastographic techniques in chronic liver disease: current status and future perspectives

This review illustrates the state of the art clinical applications and the future perspectives of ultrasound elastographic methods for the evaluation of chronic liver diseases, including the most widely used and validated technique, transient elastography, followed by shear wave elastography and strain imaging elastography. Liver ultrasound elastography allows the non-invasive evaluation of liver stiffness, providing information regarding the stage of fibrosis, comparable to liver biopsy which is still considered the gold standard; in this way, it can help physicians in managing patients, including the decision as to when to start antiviral treatment. The characterization of focal liver lesions and the prognostic role of the elastographic technique in the prediction of complications of cirrhosis are still under investigation.

Ultrasonic characterization of the nonlinear properties of canine livers by measuring shear wave speed and axial strain with increasing portal venous pressure

Elevated hepatic venous pressure is the primary source of complications in advancing liver disease. Ultrasound imaging is ideal for potential noninvasive hepatic pressure measurements as it is widely used for liver imaging. Specifically, ultrasound based stiffness measures may be useful for clinically monitoring pressure, but the mechanism by which liver stiffness increases with hepatic pressure has not been well characterized. This study is designed to elucidate the nonlinear properties of the liver during pressurization by measuring both hepatic shear wave speed (SWS) and strain with increasing pressure. Tissue deformation during hepatic pressurization was tracked in 8 canine livers using successively acquired 3-D B-mode volumes and compared with concurrently measured SWS. When portal venous pressure was increased from clinically normal (0-5mmHg) to pressures representing highly diseased states at 20mmHg, the liver was observed to expand with axial strain measures up to 10%. At the same time, SWS estimates were observed to increase from 1.5-2m/s at 0-5mmHg (baseline) to 3.25-3.5m/s at 20mmHg.

Non-invasive assessment of liver fibrosis in patients with chronic hepatitis B

In patients with chronic hepatitis B (CHB), liver fibrosis assessment is essential not only for determining prognosis but also for identifying patients who should receive treatment. Liver biopsy is limited by its invasiveness and sampling error. To explore effective non-invasive methods for liver fibrosis assessment, we reviewed international literature published over the past decade that focused on patients with CHB. Biomarker panels such as API, FIB-4, Forns Index, HepaScore, FibroMeter, FibroTest, Zeng Index and Hui Index detect advanced fibrosis and cirrhosis with fairly satisfactory accuracy with area under the receiver-operating characteristics curve higher than 0.85. However, most panels and the suggested cutoffs have not been independently validated. Transient elastography is accurate in detecting advanced fibrosis and cirrhosis, and the relative cutoffs have been defined. False-positive results may, however, occur in cases of active necroinflammation and cholestasis. Other promising imaging methods such as acoustic radiation force impulse and magnetic resonance elastography still require further validating studies. We conclude that transient elastography, FibroTest and API are the most widely validated. Transient elastography has been validated as the most useful non-invasive method for liver fibrosis assessment. To improve non-invasive performance of detecting liver fibrosis, a combined application of transient elastography and biomarkers may be the preferred course of action.

Protein fingerprinting of the extracellular matrix remodelling in a rat model of liver fibrosis--a serological evaluation

BACKGROUND/AIM

We investigated nine novel biomarkers of extracellular matrix (ECM) remodelling in a rat model of liver fibrosis.

METHODS

Liver fibrosis was induced in 52 male Wistar rats by inhalation of carbon tetrachloride and the level of hepatic fibrosis was assessed by Sirius red staining compared with controls. The novel serum biochemical markers assessed in the model were type I-(C1M), type III-(C3M), type IV-(C4M) and type VI-(C6M) collagen, citrullinated vimentin (VICM) and biglycan (BGM) all protein fragments generated by matrix metalloproteinases; and formation markers of type III-(P3NP), type VI (P4NP 7S) and type V (P5CP) collagen; hepatic mRNA type I collagen alpha-1 chain levels, serum potassium, sodium, osmolarity, alanine aminotransferase, lactate dehydrogenase, albumin and creatinine.

RESULTS

Stratification of the CCl(4) -treated rats according to total hepatic collagen showed that the degradation markers were significantly elevated in mild to severe fibrosis except for C6M which was also elevated in early fibrosis (P < 0.05). The highest Z-scores in early and moderate fibrosis were provided by P4NP 7S and alanine aminotransferase. All nine markers of ECM remodelling were highly related to the extent of liver fibrosis induced by CCl(4) . The novel collagen formation marker, P4NP 7S, was reliable for the detection of early fibrosis, while the combination of the two markers, C6M and P5CP provided the best correlation with hepatic fibrosis in all fibrosis levels.

CONCLUSION

As the markers can be used for translational science, these markers may provide valuable information for the evaluation of liver fibrosis in clinical settings.

Strategies for biomarker discovery in fibrotic disease

The discovery and development of biomarkers for fibrotic diseases have potential utility in clinical decision-making as well as in pharmaceutical research and development. This review describes strategies for identifying diagnostic, prognostic and theranostic biomarkers. A range of technologies and platforms for biomarker discovery are highlighted, including several with specific relevance for fibrosis. Some challenges specific to fibrotic diseases are outlined including; benchmarking biomarkers against imperfect clinical measures of fibrosis, the complexity resulting from diverse aetiologies and target organs, and the availability of samples (including biopsy) from well-characterised patients with fibrotic disease. To overcome these challenges collaboration amongst clinical specialities as well as between academia and industry is essential. This article is part of a Special Issue entitled: Fibrosis: Translation of basic research to human disease.

Biopsy-controlled liver fibrosis staging using the enhanced liver fibrosis (ELF) score compared to transient elastography

BACKGROUND AND AIMS

Chronic liver diseases are characterized by inflammatory and fibrotic liver injuries that often result in liver cirrhosis with its associated complications such as portal hypertension and hepatocellular carcinoma. Liver biopsy still represents the reference standard for fibrosis staging, although transient elastography is increasingly used for non-invasive monitoring of fibrosis progression. However, this method is not generally available and is associated with technical limitations emphasizing the need for serological biomarkers staging of liver fibrosis. The enhanced liver fibrosis (ELF) score was shown to accurately predict significant liver fibrosis in different liver diseases, although extracellular matrix components detected by this score may not only mirror the extent of liver fibrosis but also inflammatory processes.

METHODS

In this prospective biopsy-controlled study we evaluated the utility of the ELF score in comparison to transient elastography to predict different stages of fibrosis in 102 patients with chronic liver diseases.

RESULTS

Both techniques revealed similar area under receiver operating characteristic curve values for prediction of advanced fibrosis stages. Compared to transient elastography, the ELF score showed a broader overlap between low and moderate fibrosis stages and a stronger correlation with inflammatory liver injury.

CONCLUSIONS

Both the ELF score as well as transient elastography allowed for high quality fibrosis staging. However, the ELF score was less discriminative in low and moderate fibrosis stages and appeared more strongly influenced by inflammatory liver injury. This should be considered when making clinical interpretations on the basis of ELF score values.

Prospective validation of ELF test in comparison with Fibroscan and FibroTest to predict liver fibrosis in Asian subjects with chronic hepatitis B

BACKGROUND AND AIMS

Liver stiffness measurement (LSM) and FibroTest (FT) are frequently used as non-invasive alternatives for fibrosis staging to liver biopsy. However, to date, diagnostic performances of Enhanced Liver Fibrosis (ELF) test, which consists of hyaluronic acid, aminoterminal propeptide of procollagen type-III, and tissue inhibitor of matrix metalloproteinases-1, have not been compared to those of LSM and FT in Asian chronic hepatitis B (CHB) patients.

METHODS

Between June 2010 and November 2011, we prospectively enrolled 170 CHB patients who underwent liver biopsies along with LSM, FT, and ELF. The Batts system was used to assess fibrosis stages.

RESULTS

Areas under receiver operating characteristic curves (AUROCs) to predict significant fibrosis (F≥2), advanced fibrosis (F≥3), and cirrhosis (F = 4) were 0.901, 0.860, and 0.862 for ELF, respectively; 0.937, 0.956, and 0.963 for LSM; and 0.896, 0.921, and 0.881 for FT. AUROCs to predict F≥2 were similar between each other, whereas LSM and FT had better AUROCs than ELF for predicting F≥3 (both p<0.05), and LSM predicted F4 more accurately than ELF (p<0.05). Optimized cutoffs of ELF to maximize sum of sensitivity and specificity were 8.5, 9.4, and 10.1 for F≥2, F≥3, and F = 4, respectively. Using suggested ELF, LSM and FT cutoffs to diagnose F1, F2, F3, and F4, 91 (53.5%), 117 (68.8%), and 110 (64.7%) patients, respectively, were correctly classified according to histological results.

CONCLUSIONS

ELF demonstrated considerable diagnostic value in fibrosis staging in Asian CHB patients, especially in predicting F≥2. However, LSM consistently provided better performance for predicting F≥3 and F4.