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

Performance of MAST, FAST, and MEFIB in predicting metabolic dysfunction-associated steatohepatitis

BACKGROUND AND AIM

To identify individuals with metabolic dysfunction-associated steatohepatitis (MASH) or "at-risk" MASH among patients with metabolic dysfunction-associated steatotic liver disease (MASLD), three noninvasive models are available with satisfactory efficiency, which include magnetic resonance imaging [MRI]- AST (MAST), FibroScan-AST (FAST score), and magnetic resonance elastography [MRE] plus FIB-4 (MEFIB). We aimed to evaluate the most accurate approach for diagnosing MASH or "at-risk" MASH.

METHODS

We included 108 biopsy-proven MASLD patients who underwent simultaneous assessment of MRE, MRI proton density fat fraction (MRI-PDFF), and FibroScan scans. Compared with the histological diagnosis, we analyzed the AUC of each model and assessed the accuracy.

RESULTS

Our study cohort consisted of 64.8% of MASH and 25.9% of "at-risk" MASH. When analyzing the performance of each model for the diagnostic accuracy of MASH, we found that the AUC [95% CI] of MAST was comparable to FAST (0.803 [0.719-0.886] vs 0.799 [0.707-0.891], P = 0.930) and better than MEFIB (0.671 [0.571-0.772], P = 0.005). Similar findings were observed in the "at-risk" MASH patients. The AUCs [95% CI] for MAST, FAST, and MEFIB were 0.810 [0.719-0.900], 0.782 [0.689-0.874], and 0.729 [0.619-0.838], respectively. The models of MAST and FAST had comparable AUCs (P = 0.347), which were statistically significantly higher than that of MEFIB (P = 0.041). Additionally, the cutoffs for diagnosis of MASH were lower than "at-risk" MASH.

CONCLUSION

MAST and FAST performed better than MEFIB in diagnosing "at-risk" MASH and MASH using lower cutoff values. Our findings provided evidence for selecting the most accurate noninvasive model to identify patients with MASH or at-risk MASH.

FibroScan-AST (FAST) Score for Nonalcoholic Steatohepatitis - Validation in an Indian Cohort

Background

The FibroScan-AST (FAST) score was recently described to detect patients with nonalcoholic steatohepatitis (NASH) having elevated nonalcoholic fatty liver disease (NAFLD) activity score (NAS ≥ 4) and significant fibrosis (≥ F2) on liver biopsy (NASH+ NAS ≥ 4 + F ≥ 2).

Aim

The aim of this study was to validate the FAST score in Indian patients with NAFLD and to derive optimal cut-offs.

Methods

Sixty patients with biopsy-proven NAFLD [men: 38 (63.3%), age 40 (32-52) years] with all parameters for assessing the FAST score within 3 months of liver histology were retrospectively analysed.

Results

Histological NASH was present in 17 patients (28.3%), while 11 (18.3%) patients had NASH + NAS ≥ 4 + F ≥ 2. The area under the curve (AUROC) of the FAST score for discriminating NASH + NAS ≥ 4 + F ≥ 2 was 0.81. Using cut-offs by Newsome et al, the rule-out cut-off (FAST: ≤ 0.35) had a negative predictive value (NPV) of 0.88 [sensitivity: 0.91, specificity: 0.14, negative likelihood ratio (LR): 0.64], while the rule-in cut-off (FAST: ≥ 0.67) had a positive predictive value (PPV) of 0.33 (sensitivity: 0.73, specificity: 0.67, positive LR: 2.22). Fifteen (25%) patients were correctly classified as per histology, while 28 (46.67%) patients fell in the grey zone. On recalculating the optimal cut-offs for our patients, the rule-out cut-off (FAST: ≤ 0.55) had an NPV of 0.95 (sensitivity: 0.90, specificity: 0.45, negative LR: 0.21), while the optimal rule-in cut-off (FAST: ≥ 0.78) had a PPV of 0.70 (sensitivity: 0.64, specificity 0.94, positive LR: 10.39). With these cut-offs, 27 (45%) patients fell in the grey zone and 29 (48.3%) were correctly classified as per histology, performing better than the cut-offs by Newsome et al (P < 0.001).

Conclusion

The FAST score demonstrates good AUROC for detecting NASH with significant fibrosis and inflammation on histology. Cut-offs should be recalibrated based on prevalence of disease.

Lay summary

India has a high burden of NAFLD with an estimated 25 million patients at potential risk for significant liver disease. Liver biopsy remains the gold standard for diagnosing NASH, although its application in routine clinical practice is limited. Noninvasive tests for the simultaneous detection of steatosis, inflammation and fibrosis are thus the need of the hour. The FAST score has been recently suggested for the noninvasive detection of NASH with significant fibrosis (≥ F2) and inflammation (NAS ≥ 4) on liver biopsy. We validated the utility of the FAST score for detecting NASH with significant fibrosis and inflammation on liver biopsy in Indian patients with NAFLD. This noninvasive, easy-to-use and nonproprietary FAST score can correctly classify disease severity in more than 50% patients. However, our results suggest that cut-offs should be recalibrated based on the anticipated prevalence of NASH + NAS ≥ 4 + F ≥ 2 in the given population.

FibroScan-AST (FAST) score for the non-invasive identification of patients with non-alcoholic steatohepatitis with significant activity and fibrosis: a prospective derivation and global validation study

BACKGROUND

The burden of non-alcoholic fatty liver disease (NAFLD) is increasing globally, and a major priority is to identify patients with non-alcoholic steatohepatitis (NASH) who are at greater risk of progression to cirrhosis, and who will be candidates for clinical trials and emerging new pharmacotherapies. We aimed to develop a score to identify patients with NASH, elevated NAFLD activity score (NAS≥4), and advanced fibrosis (stage 2 or higher [F≥2]).

METHODS

This prospective study included a derivation cohort before validation in multiple international cohorts. The derivation cohort was a cross-sectional, multicentre study of patients aged 18 years or older, scheduled to have a liver biopsy for suspicion of NAFLD at seven tertiary care liver centres in England. This was a prespecified secondary outcome of a study for which the primary endpoints have already been reported. Liver stiffness measurement (LSM) by vibration-controlled transient elastography and controlled attenuation parameter (CAP) measured by FibroScan device were combined with aspartate aminotransferase (AST), alanine aminotransferase (ALT), or AST:ALT ratio. To identify those patients with NASH, an elevated NAS, and significant fibrosis, the best fitting multivariable logistic regression model was identified and internally validated using boot-strapping. Score calibration and discrimination performance were determined in both the derivation dataset in England, and seven independent international (France, USA, China, Malaysia, Turkey) histologically confirmed cohorts of patients with NAFLD (external validation cohorts). This study is registered with ClinicalTrials.gov, number NCT01985009.

FINDINGS

Between March 20, 2014, and Jan 17, 2017, 350 patients with suspected NAFLD attending liver clinics in England were prospectively enrolled in the derivation cohort. The most predictive model combined LSM, CAP, and AST, and was designated FAST (FibroScan-AST). Performance was satisfactory in the derivation dataset (C-statistic 0·80, 95% CI 0·76-0·85) and was well calibrated. In external validation cohorts, calibration of the score was satisfactory and discrimination was good across the full range of validation cohorts (C-statistic range 0·74-0·95, 0·85; 95% CI 0·83-0·87 in the pooled external validation patients' cohort; n=1026). Cutoff was 0·35 for sensitivity of 0·90 or greater and 0·67 for specificity of 0·90 or greater in the derivation cohort, leading to a positive predictive value (PPV) of 0·83 (84/101) and a negative predictive value (NPV) of 0·85 (93/110). In the external validation cohorts, PPV ranged from 0·33 to 0·81 and NPV from 0·73 to 1·0.

INTERPRETATION

The FAST score provides an efficient way to non-invasively identify patients at risk of progressive NASH for clinical trials or treatments when they become available, and thereby reduce unnecessary liver biopsy in patients unlikely to have significant disease.

FUNDING

Echosens and UK National Institute for Health Research.

A simple bedside blood test (Fibrofast; FIB-5) is superior to FIB-4 index for the differentiation between non-significant and significant fibrosis in patients with chronic hepatitis C

INTRODUCTION

A simple non-invasive score (Fibrofast, FIB-5) was developed using five routine laboratory tests (ALT, AST, alkaline phosphatase, albumin and platelets count) for the detection of significant hepatic fibrosis in patients with chronic hepatitis C. The FIB-4 index is a non-invasive test for the assessment of liver fibrosis, and a score of ≤1.45 enables the correct identification of patients who have non-significant (F0-1) from significant fibrosis (F2-4), and could avoid liver biopsy. The aim of this study was to compare the performance characteristics of FIB-5 and FIB-4 to differentiate between non-significant and significant fibrosis.

METHOD

A cross-sectional study included 604 chronic HCV patients. All liver biopsies were scored using the METAVIR system. Both FIB-5 and FIB-4 scores were measured and the performance characteristics were calculated using the ROC curve.

RESULTS

The performance characteristics of FIB-5 at ≥7.5 and FIB-4 at ≤1.45 for the differentiation between non-significant fibrosis and significant fibrosis were: specificity 94.4%, PPV 85.7%, and specificity 54.9%, PPV 55.7% respectively.

CONCLUSION

FIB-5 score at the new cutoff is superior to FIB-4 index for the differentiation between non-significant and significant fibrosis.

Multiple approaches to assess fourteen non-invasive serum indexes for the diagnosis of liver fibrosis in chronic hepatitis C patients

BACKGROUND

The aim of this study was to compare fourteen non-invasive indexes/scores: AAR, APRI, Fibroindex, MODEL3, Forns index, FIB4, GUCI, FI, FCI, Pohl score, AP index, CDS, HGM-1 and HGM-2, in order to diagnose the hepatic fibrosis stage in a survey of patients with chronic hepatitis C.

METHODS

84 patients with chronic hepatitis C were studied. Liver fibrosis was staged according to the Scheuer scoring system. The diagnostic accuracy of these indexes/scores was evaluated by AUROC, contingency tables and logistic regression analysis.

RESULTS

The best AUROCs (>0.9) to discriminate cirrhosis (F=4), were observed for CDS, FI, AAR, MODEL3, FIB4, HGM-2 and FCI. To discriminate at least advance fibrosis (F≥3), the best AUROCs (>0.89) were for CDS, FI, FIB4, HGM2-2, MODEL3 and FCI. To discriminate at least significant fibrosis (F≥2), the best AUROCs (>0.8) were for FIB4, GUCI, APRI, FI, Forns index, HGM-2 and FCI. Contingency tables and logistic regression analysis supported the results obtained by AUROC.

CONCLUSIONS

This study compares the diagnostic performance of fourteen indexes for the diagnosis of liver fibrosis stage in the same group of CHC patients. These results allow the selection of the best indexes for further studies in larger populations, in order to build diagnostic algorithms as an alternative to liver biopsy for fibrosis staging in patients with chronic HCV infection. These algorithms would allow to take therapeutical decisions and the continuous follow-up of hepatic fibrosis in these patients.

Strategies and endpoints of antifibrotic drug trials: Summary and recommendations from the AASLD Emerging Trends Conference, Chicago, June 2014

There is an urgent need to develop antifibrotic therapies for chronic liver disease, and clarify which endpoints in antifibrotic trials will be acceptable to regulatory agencies. The American Association for the Study of Liver Diseases sponsored an endpoints conference to help accelerate the efficient testing of antifibrotic agents and develop recommendations on clinical trial design for liver fibrosis. In this review, we summarize the salient and novel elements of this conference and provide directions for future clinical trial design. The article follows the structure of the conference and is organized into five areas: (1) antifibrotic trial design; (2) preclinical proof-of-concept studies; (3) pharmacological targets, including rationale and lessons to learn; (4) rational drug design and development; and (5) consensus and recommendations on design of clinical trials in liver fibrosis. Expert overviews and collaborative discussions helped to summarize the key unmet needs and directions for the future, including: (1) greater clarification of at-risk populations and study groups; (2) standardization of all elements of drug discovery and testing; (3) standardization of clinical trial approaches; (4) accelerated development of improved noninvasive markers; and (5) need for exploration of potential off-target toxicities of future antifibrotic drugs.

Prevalence of steatosis and insulin resistance in patients with chronic hepatitis B compared with chronic hepatitis C and non-alcoholic fatty liver disease

The association of NAFLD with chronic hepatitis C (CHC) has been extensively studied but little is known about its coexistence with chronic hepatitis B (CHB).

AIMS

To investigate the prevalence and determinants of steatosis and insulin resistance (IR) in CHB and its consequences on liver injury compared with CHC and NAFLD.

METHODS

Patients with CHB (N=110), CHC (N=111) and NAFLD (N=136) were evaluated by biomarkers of steatosis (SteatoTest>0.38 as a surrogate for steatosis >5%), IR (HOMA-IR>2.7 as a surrogate for IR) and fibrosis (FibroTest>0.48 as a surrogate for significant fibrosis, ≥F2).

RESULTS

HOMA-IR gradually increased in CHB, CHC and NAFLD: 2.3±1.8; 3±2.6 and 3.8±2.7 (p<0.001). The prevalence of steatosis >5% was 21% (CHB), 43% (CHC) and 82% (NAFLD), (p<0.001). The prevalence of fibrosis≥F2 was 10% (CHB), 42% (CHC) and 21% (NAFLD), p<0.001. In CHB, IR was related to host and not viral factors. CHB patients with steatosis had higher BMI (29±5.7kg/m(2) vs. 24±4kg/m(2), p<0.001), waist circumference (96±14cm vs. 84±11cm, p=0.001) and HOMA-IR (3.9±2.6 vs. 1.8±1.2, p<0.001) than those without steatosis. HOMA-IR independently predicted steatosis in CHB (OR=1.9, 95% CI, 1.09-3.27, p<0.05) and CHC (OR=1.38; 95% CI, 1.07-1.78, p<0.02). In CHB, metabolic risk factors and HOMA-IR were not associated with significant fibrosis. HOMA-IR was an independent predictor of fibrosis in CHC.

CONCLUSIONS

Steatosis may co-exist in CHB patients but with a lower prevalence than in CHC and NAFLD. In CHB steatosis is related to host and not viral factors, and is not associated with the severity of fibrosis.

Serum iron markers in patients with chronic hepatitis C infection

BACKGROUND

Patients with chronic hepatitis C (CHC) often have elevated serum iron markers, which may worsen liver injury.

OBJECTIVES

The aim of this study was to investigate the possible correlations between iron metabolism serum markers, HCV viral load, and liver disease severity in treatment-naive patients with chronic hepatitis C infection.

PATIENTS AND METHODS

Eighty five patients with untreated hepatitis C chronic infection were investigated.

RESULTS

Twenty one patients (24.7%) had elevated serum iron levels, and 29 subjects (34.1%) had severe liver fibrosis. Significantly elevated levels of serum iron (P < 0.05) and ferritin (P < 0.001), associated with lower levels of TIBC (P < 0.05) were detected in patients with severe fibrosis compared to no/mild fibrosis. Severe necroinflammatory activity was also significantly correlated with serum iron (P < 0.001), TIBC (P < 0.05), and ferritin levels (P < 0.001). Using multiple linear regression analysis, serum levels of ferritin and transferrin were the independent variables selected as being good predictors for advanced fibrosis and severe necroinflammatory activity. No significant correlations were detected between HCV viral load and iron markers.

CONCLUSIONS

This study revealed that serum iron markers (especially ferritin and transferrin) might be used as surrogate markers for both liver fibrosis and necroinflammatory activity.Patients with chronic hepatitis C (CHC) often have elevated serum iron markers, which may worsen liver injury.

Transient elastography is a useful noninvasive tool for the evaluation of fibrosis in paediatric chronic liver disease

BACKGROUND

Outcome of liver disease in children is mainly determined by severity and progression of liver fibrosis. Liver biopsy is the accepted standard for evaluating fibrosis but is limited by the need for sedation in children, sampling error, and risks including bleeding. The aim of the present study was to compare tools for noninvasive assessment of liver fibrosis in a paediatric cohort.

METHODS

Children undergoing liver biopsy for chronic liver disease were recruited and underwent transient elastography (TE). Liver biopsies were scored by a hepatohistopathologist from F0 (no fibrosis) to F4 (cirrhosis). TE was compared with biopsy score.

RESULTS

During the study period, 104 children (62 boys) were enrolled (median age 13.6 years). Diagnosis was autoimmune liver disease in 27; nonalcoholic fatty liver disease in 37; posttransplant in 16; hepatitis B/C in 8; Wilson disease in 5; and the remainder, miscellaneous. TE was successful in all but 7 patients and was a good discriminator of significant fibrosis (≥ F2) (P < 0.001), severe fibrosis (≥ F3) (P < 0.001), and cirrhosis (F4) (P = 0.003). The area under the receiver operating characteristic curve for the prediction of ≥ F2, ≥ F3, and F4 using TE was 0.78, 0.79, and 0.96, respectively. TE performed best in children with autoimmune liver disease and in those posttransplant.

CONCLUSIONS

The present study demonstrates that TE is a reliable tool in distinguishing different stages of liver fibrosis in paediatric patients. Thus, TE may serve as a useful adjunct to liver biopsy for diagnostic purposes providing a reliable method of noninvasively monitoring liver disease progression in children.

Noninvasive assessment of hepatic fibrosis in Egyptian patients with chronic hepatitis C virus infection

AIM

To evaluate the accuracy of specific biochemical markers for the assessment of hepatic fibrosis in patients with chronic hepatitis C virus (HCV) infection.

METHODS

One hundred and fifty-four patients with chronic HCV infection were included in this study; 124 patients were non-cirrhotic, and 30 were cirrhotic. The following measurements were obtained in all patients: serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), albumin, total bilirubin, prothrombin time and concentration, complete blood count, hepatitis B surface antigen (HBsAg), HCVAb, HCV-RNA by quantitative polymerase chain reaction, abdominal ultrasound and ultrasonic-guided liver biopsy. The following ratios, scores and indices were calculated and compared with the results of the histopathological examination: AST/ALT ratio (AAR), age platelet index (API), AST to platelet ratio index (APRI), cirrhosis discriminating score (CDS), Pohl score, Göteborg University Cirrhosis Index (GUCI).

RESULTS

AAR, APRI, API and GUCI demonstrated good diagnostic accuracy of liver cirrhosis (80.5%, 79.2%, 76.6% and 80.5%, respectively); P values were: < 0.01, < 0.05, < 0.001 and < 0.001, respectively. Among the studied parameters, AAR and GUCI gave the highest diagnostic accuracy (80.5%) with cutoff values of 1.2 and 1.5, respectively. APRI, API and GUCI were significantly correlated with the stage of fibrosis (P < 0.001) and the grade of activity (P < 0.001, < 0.001 and < 0.005, respectively), while CDS only correlated significantly with the stage of fibrosis (P < 0.001) and not with the degree of activity (P > 0.05). In addition, we found significant correlations for the AAR, APRI, API, GUCI and Pohl score between the non-cirrhotic (F0, F1, F2, F3) and cirrhotic (F4) groups (P values: < 0.001, < 0.05, < 0.001, < 0.001 and < 0.005, respectively; CDS did not demonstrate significant correlation (P > 0.05).

CONCLUSION

The use of AAR, APRI, API, GUCI and Pohl score measurements may decrease the need for liver biopsies in diagnosing cirrhosis, especially in Egypt, where resources are limited.

Performance of biomarkers FibroTest, ActiTest, SteatoTest, and NashTest in patients with severe obesity: meta analysis of individual patient data

BACKGROUND

Liver biopsy is considered as the gold standard for assessing non-alcoholic fatty liver disease (NAFLD) histologic lesions in patients with severe obesity. The aim of this study was to perform an overview of 3 studies which assessed the performance of non-invasive markers of fibrosis (FibroTest), steatosis (SteatoTest) and steato-hepatitis (NashTest, ActiTest) in these patients.

METHODS

494 patients with interpretable biopsy and biomarkers using of three prospective cohorts of patients with severe obesity (BMI >35 kg/m2) were included. Histology (NAS score) and the biochemical measurements were blinded to any other characteristics. The area under the ROC curves (AUROC), sensitivity, specificity, positive and negative predictive values were assessed. Weighted AUROC (wAUROC Obuchowski method) was used to prevent multiple testing and spectrum effect. Two meta-analyses were performed; one used the individual patient, and the other a classical meta-analysis.

RESULTS

Prevalence of advanced fibrosis (bridging) was 9.9%, advanced steatosis (>33%) 54.2%, and steato-hepatitis (NAS score >4) 17.2%. The mean wAUROCs were: FibroTest for advanced fibrosis (95%CI; significance)  =  0.85 (0.83-0.87; P<0.0001); SteatoTest for advanced steatosis = 0.80 (0.79-0.83); and ActiTest for steato-hepatitis = 0.84 (0.82-0.86; P<0.0001). Using the classical meta-analysis (random effect model) the mean AUROCs were: FibroTest = 0.72 (0.63-0.79; P<0.0001); SteatoTest = 0.71 (0.66-0.75; P<0.0001); and ActiTest = 0.74 (0.68-0.79; P<0.0001). Despite more metabolic risk factors in one cohort, results were similar according to gender, presence of diabetes and between the 3 cohorts.

CONCLUSION

In patients with severe obesity, a significant diagnostic performance of FibroTest, SteatoTest and ActiTest was observed for liver lesions.

FibroTest and Fibroscan performances revisited in patients with chronic hepatitis C. Impact of the spectrum effect and the applicability rate

BACKGROUND

Two widely used biomarkers of fibrosis, FibroTest and liver stiffness measurement (LSM), have been mostly validated in patients with chronic hepatitis C (CHC) using the standard area under the ROC curve (sAUROC) which is not the most appropriate method due to the risk of fibrosis spectrum effect. Furthermore the performance of these biomarkers have not been assessed in "intention to diagnose" which takes into account the failures and non-reliable results.

AIM

The aim was to compare the accuracy of FibroTest and LSM for the diagnosis of fibrosis using sAUROC, the pairwise comparison of fibrosis stages by Obuchowski measure (wAUROC), and these AUROCs reassessed after taking into account the applicability rates.

METHODS

One thousand two hundred and eighty-nine patients with CHC and 604 healthy volunteers were analyzed. The performances of biomarkers assessed were compared in a patients-only group (P1: n=1289), in a population combining both patients and healthy volunteers (P2: n=1893) and in a simulated population (P3: n=1893) with the prevalence of stages observed in a reference population, to demonstrate the impact of spectrum effect. Applicability rates were estimated prospectively in 24,872 consecutive FibroTest and in 13,669 consecutive LSM examinations.

RESULTS

Using wAUROC, the conclusions of studies with reliable results in P1 were different than in those of P2 and in P3. There was a lower performance of FibroTest versus LSM in P1 (0.864 [0.855-0.873] vs. 0.883 [0.874-0.892]; P=0.002) which was not found in P2 (0.893 [0.887-0.900] vs. 0.894 [0.887-0.901]; P=0.86) and in P3 (0.899 [0.893-0.905] vs 0.902 [0.895-0.909]; P=0.60). Using the sAUROC, in P1, P2 and P3, there was no significant difference between FibroTest and LSM performance for advanced fibrosis and a lower performance of FibroTest versus LSM for cirrhosis. In intention to diagnose, using wAUROCs performances were higher for FibroTest vs. LSM in P1 (0.857 [0.848-0.866] vs. 0.814 [0.807-0.821]; P<0.0001) and P2 (0.885 [0.879-0.892] vs. 0.743 [0.737-0.749]; P<0.0001), without difference in P3 (0.891 [0.885-0.897] vs. 0.894 [0.887-0.901]; P=0.90). Using sAUROC, the significant differences in favor of FibroTest vs LSM persisted also for the diagnosis of advanced fibrosis, both in P1 and P2 (P<0.0001) and for the diagnosis of cirrhosis in P1 (P<0.001).

CONCLUSION

When the spectrum effects and applicability rates were taken into account, LSM had lower performance results than FibroTest for the diagnosis of fibrosis stages.

Noninvasive Markers of Hepatic Fibrosis in Chronic Hepatitis B

A serum biomarker (FibroTest; Biopredictive, Paris, France; FibroSure; LabCorp, Burlington, USA) and liver stiffness measurement (LSM) by Fibroscan (Echosens, Paris, France) have been extensively validated in chronic hepatitis C. This review updates the clinical validation of serum biomarkers and LSM in patients with chronic hepatitis B (CHB). One meta-analysis combined all published studies and another used a database combining FibroTest individual data. Sensitivity analysis assessed the impact of several factors, including authors' independence, length of biopsy, ethnicity, hepatitis B early antigen status, viral load, and alanine aminotransferase value. Only two biomarkers had several validations: FibroTest (8 studies, 1,842 patients), and Fibroscan (5 studies, 618 patients). For the diagnosis of advanced fibrosis, the standardized area under the receiver operating curve was 0.84 (0.79-0.86) for FibroTest and 0.89 (0.83-0.96) for LSM, without significant difference. No significant factors of variability were identified for FibroTest's performance. In conclusion, FibroTest and LSM were the most validated biomarkers of fibrosis in CHB. However, the reliability of Fibroscan must be better assessed.

Applicability and precautions of use of liver injury biomarker FibroTest. A reappraisal at 7 years of age

BACKGROUND

FibroTest (FT) is a validated biomarker of fibrosis. To assess the applicability rate and to reduce the risk of false positives/negatives (RFPN), security algorithms were developed. The aims were to estimate the prevalence of RFPN and of proven failures, and to identify factors associated with their occurrences.

METHODS

Four populations were studied: 954 blood donors (P1), 7,494 healthy volunteers (P2), 345,695 consecutive worldwide sera (P3), including 24,872 sera analyzed in a tertiary care centre (GHPS) (P4). Analytical procedures of laboratories with RFPN > 5% and charts of P4 patients in with RFPN were reviewed.

RESULTS

The prevalence of RFPN was 0.52% (5/954; 95%CI 0.17-1.22) in P1, 0.51% (38/7494; 0.36-0.70) in P2, and 0.97% (3349/345695; 0.94-1.00) in P3. Three a priori high-risk populations were confirmed: 1.97% in P4, 1.77% in HIV centre and 2.61% in Sub-Saharan origin subjects. RFPN was mostly associated with low haptoglobin (0.46%), and high apolipoproteinA1 (0.21%). A traceability study of a P3 laboratory with RFPFN > 5% permitted to correct analytical procedures.

CONCLUSION

The mean applicability rate of Fibrotest was 99.03%. Independent factors associated with the high risk of false positives/negatives were HIV center, subSaharan origin, and a tertiary care reference centre, although the applicability rate remained above 97%.

FibroTest is an independent predictor of virologic response in chronic hepatitis C patients retreated with pegylated interferon alfa-2b and ribavirin in the EPIC³ program

BACKGROUND & AIMS

EPIC-3 is a prospective, international study that has demonstrated the efficacy of PEG-IFN alfa-2b plus weight-based ribavirin in patients with chronic hepatitis C and significant fibrosis who previously failed any interferon-alfa/ribavirin therapy. The aim of the present study was to assess FibroTest (FT), a validated non-invasive marker of fibrosis in treatment-naive patients, as a possible alternative to biopsy as the baseline predictor of subsequent early virologic (EVR) and sustained virologic response (SVR) in previously treated patients.

METHODS

Of 2312 patients enrolled, 1459 had an available baseline FT, biopsy, and complete data. Uni- (UV) and multi-variable (MV) analyses were performed using FT and biopsy.

RESULTS

Baseline characteristics were similar as in the overall population; METAVIR stage: 28% F2, 29% F3, and 43% F4, previous relapsers 29%, previous PEG-IFN regimen 41%, high baseline viral load (BVL) 64%. 506 patients (35%) had undetectable HCV-RNA at TW12 (TW12neg), with 58% achieving SVR. The accuracy of FT was similar to that in naive patients: AUROC curve for the diagnosis of F4 vs F2=0.80 (p<0.00001). Five baseline factors were associated (p<0.001) with SVR in UV and MV analyses (odds ratio: UV/MV): fibrosis stage estimated using FT (4.5/5.9) or biopsy (1.5/1.6), genotype 2/3 (4.5/5.1), BVL (1.5/1.3), prior relapse (1.6/1.6), previous treatment with non-PEG-IFN (2.6/2.0). These same factors were associated (p ≤ 0.001) with EVR. Among patients TW12neg, two independent factors remained highly predictive of SVR by MV analysis (p ≤ 0.001): genotype 2/3 (odds ratio=2.9), fibrosis estimated with FT (4.3) or by biopsy (1.5).

CONCLUSIONS

FibroTest at baseline is a possible non-invasive alternative to biopsy for the prediction of EVR at 12 weeks and SVR, in patients with previous failures and advanced fibrosis, retreated with PEG-IFN alfa-2b and ribavirin.

Biomarkers of liver injury for hepatitis clinical trials: a meta-analysis of longitudinal studies

BACKGROUND

Liver biopsy and virological end points are standard references for assessing the effect of viral hepatitis treatments. We aimed to review evidence-based published data of biomarkers that have been validated as non-invasive alternatives to biopsy as end points for HBV and HCV infection trials.

METHODS

Studies were included if there were at least two repeated estimates of fibrosis per patient using biomarkers with at least two studies and a control group. Meta-analysis of the percentage of fibrosis progression per year (pFPy) was performed.

RESULTS

Two biomarkers were included, FibroTest and liver stiffness measurement (LSM; FibroScan. A total of 1,413 patients with chronic hepatitis C (11 populations) and 772 with chronic hepatitis B (6 populations) were analysed. In a comparison of HCV patients with controls, the FibroTest pFPy was -18% (95% confidence interval [CI] -23--14; P<0.001) in treated patients and the LSM pFPy was -15% (95% CI -28--1; P=0.01), both with differences according to virological responses. In HBV patients, there was a significant decrease of the pFPy only in patients with baseline advanced fibrosis (mean difference -5% [95% CI -10--0.1]; P=0.02). In patients with advanced fibrosis, stratified by virological response, there were similar differences between pFPy estimated either using FibroTest or biopsy, both in HCV and HBV infections. Repeated LSM in HBV patients had an early variability related to necroinflammatory activity.

CONCLUSIONS

In patients with chronic hepatitis C and B, the treatment effect on fibrosis progression rate was similarly estimated using FibroTest or biopsy. The same concordance was observed for FibroScan but with a possible overestimation of the fibrosis regression during the first weeks of treatment.

Perspectives on fibrosis progression in hepatitis C: an à la carte approach to risk factors and staging of fibrosis

The morbidity and mortality of chronic hepatitis C is related to progressive fibrosis and the development of cirrhosis. The development of fibrosis in patients with HCV is highly influenced by immune status, host response to the virus and associated factors, such as, age, sex, alcohol intake, diabetes, obesity and coinfection with other viruses. The rate of fibrosis progression differs depending on several factors, including the stage of fibrosis and the time since infection. Routine assessment of fibrosis through biopsy every 3-5 years has poor patient acceptance and reliability, and might result in missed opportunities to improve or modify treatment priorities. Enhanced understanding of the pathophysiology of liver fibrosis in HCV infection has led to the development of a number of non-invasive assessment modalities. The ideal test would discriminate fibrosis in the categories none/early (stages 0/1), intermediate (stage 2) and advanced fibrosis/cirrhosis (stages 3/4) and be readily available, inexpensive and accurate. Biomarker tests utilize individual or combined serum markers to determine the degree of fibrosis. Other strategies combine biomarkers with clinical variables, such as patient age or utilize liver imaging or functional assessments. Incorporation of appropriately validated non-invasive assessments of liver fibrosis will likely improve the clinical care of patients with HCV infection.

Noninvasive assessment of hepatic fibrosis and necroinflammatory activity in Egyptian children with chronic hepatitis C virus infection using FibroTest and ActiTest

BACKGROUND

Hepatitis C virus (HCV) is a major cause of chronic hepatitis and hepatic fibrosis. Liver biopsy, because of its limitations and risks, might be considered an imperfect gold standard for assessing the severity of chronic liver diseases. In this study, we aimed to prospectively validate FibroTest (FT) and ActiTest (AT) as noninvasive serum biochemical markers for assessment of the degree of hepatic fibrosis and necroinflammatory activity respectively, in pediatric patients with chronic HCV infection and compare them to liver biopsy.

METHODS

Fifty patients, aged 2 to 18 years, with chronic HCV infection were prospectively enrolled. Two assessments were carried out, within 24-h duration, one of a liver biopsy specimen and the other FT and AT measured in serum sample.

FINDINGS

A highly significant linear trend and correlation were found between FT-related fibrosis and fibrosis stage by METAVIR scoring on histopathological examination. A highly significant correlation was also found between AT and necroinflammatory histological activity using METAVIR as well. The FT area under the receiver operating characteristic curve (AUROC) is 0.97, SE=0.02 which can diagnose patients with mild stage of fibrosis, thus discriminating them from those with no (or minimal) fibrosis. The AT can successfully discriminate between patients with moderate activity and those with mild activity with AUROC=0.93, SE=0.06.

CONCLUSION

FT and AT are potential noninvasive methods for assessment of hepatic fibrosis and necroinflammatory activity in pediatric patients with chronic HCV infection in comparison with liver biopsy.

ActiTest accuracy for the assessment of histological activity grades in patients with chronic hepatitis C, an overview using Obuchowski measure

BACKGROUND

ActiTest (AT) is a biomarker of liver necro-inflammatory histological activity validated in patients with chronic hepatitis C (HCV).

AIM

The aim was to assess the accuracy of AT in comparison with alanine aminotransferase (ALT) the standard of care.

METHODS

Methods used an integrated database of individual data and the new recommended Obuchowski measures. An updated "classical" meta-analysis of AT validation studies was also performed. The main end points were the area under the ROC curves (AUROCs) for the diagnosis of each histological activity grade defined using METAVIR scoring system. To avoid repeated tests and the spectrum effect of activity grades prevalence, the comparison of AT and ALT accuracies used the Obuchowski method.

RESULTS

For the individual analysis, a total of 1250 patients were included and for the meta-analysis six studies (2017 patients) were included. The overall accuracy of AT for the diagnosis of any activity grade (Obuchowski measure=0.850) was significantly higher than the accuracy of ALT (Obuchowski measure=0.837; P=0.009). The updated standard meta-analysis confirmed the accuracy of AT (p<0.0001) both in independent AUROC=0.79 (95% CI, 0.73-0.85) and in non independent studies AUROC=0.74 (95% CI, 0.67-0.81).

CONCLUSIONS

The accuracy of AT for grading the necro-inflammatory activity of patients with HCV was significantly higher than ALT serum activity alone, the standard biomarker.

Noninvasive tools to assess liver disease

PURPOSE OF REVIEW

Improved understanding of the pathophysiology of fibrosis and recent technological advances have resulted in the development of several serum biomarkers and imaging tools as noninvasive alternatives to biopsy. This review highlights some of the recent advances and potential application of these tools in clinical practice.

RECENT FINDINGS

Several newer approaches have been used to improve the semiquantitative histological assessment of fibrosis in relation to biomarker development. These include statistical considerations, smooth muscle actin morphometry, and emerging microscopy techniques to quantify fibrillar collagen. Serum marker panels, initially developed for determining disease stage in chronic hepatitis C infection, have now been adapted for use in nonalcoholic fatty liver disease. Genetic markers of disease progression have been validated, and newer proteomic technologies are increasingly being applied towards biomarker discovery. A sequential approach or the combination of serum markers and transient elastography is able to significantly reduce the need for biopsy for the diagnosis of cirrhosis. Serum markers also appear to provide useful prognostic information in end-stage liver disease. Newer imaging methods and breath tests require further validation, but appear promising adjunctive techniques for prediction of advanced stage fibrosis and providing functional assessment.

SUMMARY

Current noninvasive tools have potential diagnostic and prognostic utility for end-stage liver disease. Adapting these methods into clinical practice remains a challenge.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Staging of liver fibrosis in chronic hepatitis B patients with a composite predictive model: A comparative study

AIM: To evaluate the efficacy of 6 noninvasive liver fibrosis models and to identify the most valuable model for the prediction of liver fibrosis stage in chronic hepatitis B (CHB) patients.

METHODS: Seventy-eight CHB patients were consecutively enrolled in this study. Liver biopsy was performed and blood serum was obtained at admission. Histological diagnosis was made according to the METAVIR system. Significant fibrosis was defined as stage score ≥ 2, severe fibrosis as stage score ≥ 3. The diagnostic accuracy of 6 noninvasive liver fibrosis models, including serum aspartate aminotransferase (AST) to platelet ratio index (APRI), FIB-4, Forn’s index, Fibrometer, Hepascore, and Shanghai Liver Fibrosis Group’s index (SLFG), was investigated.

RESULTS: The APRI, FIB-4 and Forn’s index under receiver operating characteristic curve (AUROC) for significant fibrosis were 0.71, 0.75 and 0.79, respectively, with a diagnosis accuracy of 67%, 77% and 80%, respectively, and 0.80, 0.87 and 0.86, respectively, under the AUROC for severe fibrosis. The Hepascore, SLFG, and Fibrometer were 0.80, 0.83 and 0.85, respectively under the AUROC for significant fibrosis (P < 0.01). The diagnosis accuracy of Hepascore and SLFG was 86% and 88%, respectively. The Hepascore, SLFG, and Fibrometer were 0.95, 0.93, and 0.94, respectively, under the AUROC for severe fibrosis (P < 0.01).

CONCLUSION: The models containing direct serum markers have a better diagnostic value than those not containing direct serum markers.

Non-invasive evaluation of the fibrosis stage in chronic hepatitis C: a comparative analysis of nine scoring methods

OBJECTIVE

Liver biopsy is an invasive procedure and new surrogate markers to assess fibrosis are needed. We performed a comparative external evaluation of nine non-invasive scores of liver fibrosis and tried to identify other potential biochemical markers of low-stage liver fibrosis in chronic hepatitis C (CHC).

MATERIAL AND METHODS

We included 429 previously untreated consecutive patients from a single centre who underwent a liver biopsy between January 1999 and April 2009. Biopsies were evaluated for the stage of fibrosis according to the METAVIR scoring method.

RESULTS

None of the evaluated scores were adequate to disclose null-low fibrosis due to a lack of specificity at the proposed cut-offs and the poor sensitivity of lower cut-offs. Serum ferritin and cholesterol values were found to be independently related to the fibrosis stage and their inclusion in the best performing scores at lower cut-off values (the APRI and King's scores) improved the sensitivity for null-low fibrosis by 8% with a specificity >or= 93%.

CONCLUSIONS

Approximately 30% of patients with null-low fibrosis may be accurately identified by supplementing current scores with new independent variables (serum ferritin and cholesterol), thus obviating the need for a liver biopsy.

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.

FibroTest-ActiTest as a non-invasive marker of liver fibrosis

FibroTest (FT) is a biomarker of liver fibrosis initially validated in patients with chronic hepatitis C (CHC) and subsequently assessed in other frequent liver diseases, including chronic hepatitis B (CHB), alcoholic liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD). The primary aim of the present study was to update a previous meta-analysis of FT diagnostic value, and to summarize its advantages and limitations. The secondary aim was to provide an overview of the prognostic value of FT in CHC, CHB and ALD. For diagnostic value, the main endpoint was the FT area under the ROC curves (AUROCs) for the diagnosis of bridging fibrosis (F2/F3/F4 vs F0/F1), standardized for the spectrum of fibrosis. Sensitivity analysis integrated the non-standardized observed AUROCs, the independency of authors, size (length) of biopsy, prospective design, correctness of procedures, co-morbidities, and timelag between biopsy and serum sampling. For prognostic value, the main endpoint was the FT AUROC for the prognostic value of liver complications or death related to liver disease. A total of 38 diagnostic studies were included, which pooled 7985 subjects who had undergone both FT and biopsy (4600 HCV, 1580 HBV, 267 NAFLD, 524 ALD and 1014 mixed). The mean standardized AUROC was 0.84 (95% CI, 0.83-0.86), with no differences in terms of causes of liver disease: HCV 0.84 (0.82-0.87); HBV 0.81 (0.78-0.83); NAFLD 0.84 (0.76-0.92); ALD 0.87 (0.82-0.92); and mixed 0.85 (0.81-0.89). Three prognostic studies were also included. FT was found to have higher or similar prognostic value compared with biopsy in patients with CHC, CHB or ALD. FibroTest is an effective alternative to biopsy in patients with chronic hepatitis C or B, ALD or NAFLD. Indeed, the prognostic performance of FibroTest was at least as accurate as that of biopsy in patients with chronic hepatitis C or B, or ALD.

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.