Impact of quality control accepted inter-laboratory variations on calculated Fibrotest/Actitest scores for the non-invasive biochemical assessment of liver fibrosis

Noninvasive Indirect Markers of Liver Fibrosis in Alcoholics

The aim of this study was to evaluate the diagnostic values of noninvasive indirect markers of liver fibrosis: APRI, GAPRI, Forns, FIB-4, Age-Platelet, and Hepascore in alcoholics. Blood samples were collected from a randomized group of 142 alcohol-dependent patients. The diagnosis of dependency was made according to the ICD-10 WHO criteria. The values of noninvasive markers were calculated with specific algorithms. The fibrosis stage was evaluated on the basis of FibroTest. The values of APRI, Forns, FIB-4, GAPRI, AP, and Hepascore differ between various stages of liver fibrosis. Patients with fibrosis stage F0 present lower values of APRI, Forns, FIB-4, GAPRI, and Hepascore in comparison to the patients with stages F1 and F0-F1. Patients with fibrosis stages < F2 have lower values of all noninvasive markers than patients with stages ≥F2. Patients with fibrosis stages ≥F2 but <F4 have lower values of APRI, Forns, FIB-4, GAPRI, and Hepascore than patients with stage F4. The values of noninvasive markers tested here differ in various stages of liver fibrosis. To our surprise, the patented marker, Hepascore, achieves a lower diagnostic value in alcoholics than simple markers involving only liver enzymes, platelet count, and cholesterol. The best marker of liver fibrosis in alcoholic patients seems to be the Forns index.

Diagnostic value of combined serum biomarkers for the evaluation of liver fibrosis in chronic hepatitis C infection: A multicenter, noninterventional, observational study

BACKGROUND/AIMS

The hepatitis C virus (HCV) infection is important cause of chronic hepatitis. Liver biopsy is considered the gold standard for assessment of fibrosis but this procedure is an invasive procedure. We aimed to evaluate the diagnostic efficiency of non-invasive serum biomarkers, separately and in combinations, on liver fibrosis in treatment-naive chronic hepatitis C (CHC) patients.

MATERIALS AND METHODS

Two hundred and sixteen treatment-naive CHC patients were enrolled from 32 locations across Turkey in this open-labelled, non-interventional prospective observational study. FibroTest®, aspartate aminotransferase-to-platelet ratio index(APRI), aspartate aminotransferase and alanine aminotransferase ratio (AAR), fibrosis index based on four factors (FIB-4), Age-platelet(AP) index and Forns index were measured and compared with Metavir scores got from liver biopsies.

RESULTS

Data from 182 patients with baseline liver biopsy were suitable for analysis. One hundred and twenty patients (65.9%) had F0-F1 fibrosis and 62 patients (34.1%) had F2-F4 fibrosis. APRI 0.732 area under the curve(AUC) indicated advanced fibrosis with 69% sensitivity and 77% specificity. FIB-4 0.732 AUC and FibroTest 0.715 AUC indicated advanced fibrosis with 69% and 78.4% sensitivity, and 75% and 71.4% specificity, respectively. The combined use of tests also led to an increase in AUC and specificity. Combinations of FibroTest with APRI and/or FIB-4, and FIB-4 with APRI were optimal for the evaluation of liver fibrosis.

CONCLUSION

Fibrotest, FIB-4, APRI, AP index and Forns index exhibit good diagnostic performance for determining liver fibrosis in CHC patients, and the use of at least two tests together will increase their diagnostic value still further.

VAP score as a novel non-invasive liver fibrosis model in patients with chronic hepatitis C

AIM

Assessment of liver fibrosis in chronic hepatitis C (CHC) patients is necessary before antiviral treatment. This study aimed to evaluate the effectiveness of eight non-invasive models (aspartate aminotransferase [AST]/alanine transaminase ratio [AAR], AST/platelet ratio index [APRI], fibrosis-cirrhosis index [FCI], fibrosis index [FI], fibrosis-4 [FIB-4] score, fibrosis quotient [FibroQ], King, and von Willebrand factor antigen (vWF-Ag)/thrombocyte ratio [VITRO] scores) for predicting fibrosis compared with liver biopsy and to create a new score for predicting different fibrosis stages with increased accuracy.

METHODS

We prospectively studied 127 treatment-naive CHC patients who underwent liver biopsy. The AAR, APRI, FCI, FI, FIB-4, FibroQ, King and VITRO scores were calculated and correlated with fibrosis stages. A new score (VAP) was derived from vWF-Ag, AST, and platelets: [VAP = (AST (U/L) × vWF-Ag)/platelets (10⁹ /L)].

RESULTS

Apart from AAR, readily available scores were correlated with liver fibrosis stages. VITRO (r = 0.62) and APRI (r = 0.46) showed the closest correlation. Our new (VAP) score significantly correlated with fibrosis stages (r = 0.702, P < 0.001). Compared to other scores, VAP had the highest area under the receiver operating characteristic curve, with 0.854, 0.921, 0.849, and 0.861 for mild (F1), significant (≥F2), advanced (≥F3) fibrosis, and cirrhosis (F4) respectively. At a cut-off value >1, VAP had 75.2% sensitivity and 100% positive predictive value for predicting mild fibrosis. At a cut-off value >2.3 for predicting cirrhosis, VAP had 73% sensitivity and 81.7% positive predictive value.

CONCLUSIONS

The VAP score is a novel model that had higher diagnostic performance to predict different fibrosis stages and subclinical cirrhosis among CHC patients compared to the other studied scores and hence may offer a useful strategy to stratify patients who would benefit from direct-acting antivirals.

Monitoring fibrogenic progression in the liver

The clinical course of chronic liver diseases is significantly dependent on the progression rate of fibrosis which is the unstructured replacement of injured parenchyma by extracellular matrix. Despite intensive studies, the clinical opportunities for patients with fibrosing liver diseases have not improved. This will be changed by increasing knowledge of new pathogenetic mechanisms, which complement the "canonical principle" of fibrogenesis. The latter is based on the activation of hepatic stellate cells and their transdifferentiation to myofibroblasts induced by hepatocellular injury and consecutive inflammatory mediators such as TGF-β. Stellate cells express a broad spectrum of matrix components. New mechanisms indicate that the heterogeneous pool of (myo-)fibroblasts can be supplemented by epithelial-mesenchymal transition (EMT) from cholangiocytes and potentially also from hepatocytes to fibroblasts, by influx of bone marrow-derived fibrocytes in the damaged liver tissue and by differentiation of a subgroup of monocytes to fibroblasts after homing in the damaged tissue. These processes are regulated by the cytokines TGF-β and BMP-7, chemokines, colony-stimulating factors, metalloproteinases and numerous trapping proteins. They offer innovative diagnostic and therapeutic options. As an example, modulation of TGF-β/BMP-7 ratio changes the rate of EMT, and so the simultaneous determination of these parameters and of the connective tissue growth factor (CTGF) in serum might provide information on fibrogenic activity. Also, proteomic and glycomic approaches of serum are under investigation to set up specific protein profiles in patients with liver fibrosis. The aim of this article is to present the current pathogenetic concepts of liver fibrosis and to discuss established and novel diagnostic approaches to reflect the process of hepatic fibrogenesis in the medical laboratory.

Connective tissue growth factor (CTGF/CCN2) in serum is an indicator of fibrogenic progression and malignant transformation in patients with chronic hepatitis B infection

Still a challenging medical problem is the non-invasive monitoring of patients with a variety of chronic liver diseases being on risk to develop fibrosis, cirrhosis, and, finally, primary liver cell carcinoma. Previously, we have shown that CTGF/CCN2, a down-stream mediator of TGF-β, in serum might be a promising non-invasive biomarker of fibrosis, which is extended in the following study to cirrhosis and liver cell carcinoma. Healthy individuals (n=56), as well as fibrotic (n=77), cirrhotic (n=17), and HCC-patients (n=72) with chronic hepatitis B (HBV) infection, clinically, biochemically and histopathologically well characterized and classified, were included for the measurements of CTGF-concentrations in serum using a newly developed CTGF-enzyme immunoassay. A statistical significant increase of the mean serum CTGF-concentrations was associated with different stages of fibrosis, ranging from 15.9 μg/L (S0), 20.3 μg/L (S1/2) to 36.9 μg/L (S3/4). The highest CTGF-concentrations were measured in cirrhotic patients (43.6 μg/L), compared to healthy subjects (17.7 μg/L), followed by a decrease in cirrhotic HCC-patients (38.5 μg/L; p=0.001). Of note, HCC patients without underlying cirrhosis (n=8) had CTGF levels (13.5±13.2 μg/L) comparable to those in healthy controls. No statistical relation between CTGF levels and parameters of liver injury (e.g. AST, ALT) was noticed, but CTGF levels are correlated negatively with serum albumin levels (p=0.007) and platelet counts (p=0.0032), respectively. The latter was negatively correlated with the stage of fibrosis (p=0.025). In HCC patients, CTGF concentrations decreased with tumor progression and size, with lower levels in TNM stage II (30.5 μg/L) and stage III (33.6 μg/L) compared to TNM stage I (41.6 μg/L). Our data suggest a valuable diagnostic impact of CTGF in serum for the follow-up of patients suffering from chronic liver diseases developing fibrosis, cirrhosis and finally HCC. CTGF serum levels in HCC are most likely due to underlying fibrosis/cirrhosis but not due to malignancy per se.

Therapeutic approach to the treatment-naive patient with hepatitis C virus genotype 1 infection: a step-by-step approach

Recent advances in the treatment of hepatitis C virus infection (HCV) have led to high rates of viral cure. However, the use of newly approved protease inhibitors with activity against HCV still requires careful patient selection, counseling, and decision making before initiation of treatment. Laboratory work-up, staging of liver disease, and careful review of comorbid conditions is mandatory. Patients with cirrhosis may require treatment regimens that differ from those without cirrhosis. Because pegylated interferon alfa and ribavirin remain a key part of the treatment regimen, absolute and relative contraindications to their use must be considered. Management of common adverse events including anemia and rash must be embraced by the healthcare provider.

Comparison of accuracy of fibrosis degree classifications by liver biopsy and non-invasive tests in chronic hepatitis C

BACKGROUND

Non-invasive tests have been constructed and evaluated mainly for binary diagnoses such as significant fibrosis. Recently, detailed fibrosis classifications for several non-invasive tests have been developed, but their accuracy has not been thoroughly evaluated in comparison to liver biopsy, especially in clinical practice and for Fibroscan. Therefore, the main aim of the present study was to evaluate the accuracy of detailed fibrosis classifications available for non-invasive tests and liver biopsy. The secondary aim was to validate these accuracies in independent populations.

METHODS

Four HCV populations provided 2,068 patients with liver biopsy, four different pathologist skill-levels and non-invasive tests. Results were expressed as percentages of correctly classified patients.

RESULTS

In population #1 including 205 patients and comparing liver biopsy (reference: consensus reading by two experts) and blood tests, Metavir fibrosis (FM) stage accuracy was 64.4% in local pathologists vs. 82.2% (p < 10-3) in single expert pathologist. Significant discrepancy (≥ 2FM vs reference histological result) rates were: Fibrotest: 17.2%, FibroMeter2G: 5.6%, local pathologists: 4.9%, FibroMeter3G: 0.5%, expert pathologist: 0% (p < 10-3). In population #2 including 1,056 patients and comparing blood tests, the discrepancy scores, taking into account the error magnitude, of detailed fibrosis classification were significantly different between FibroMeter2G (0.30 ± 0.55) and FibroMeter3G (0.14 ± 0.37, p < 10-3) or Fibrotest (0.84 ± 0.80, p < 10-3). In population #3 (and #4) including 458 (359) patients and comparing blood tests and Fibroscan, accuracies of detailed fibrosis classification were, respectively: Fibrotest: 42.5% (33.5%), Fibroscan: 64.9% (50.7%), FibroMeter2G: 68.7% (68.2%), FibroMeter3G: 77.1% (83.4%), p < 10-3 (p < 10-3). Significant discrepancy (≥ 2 FM) rates were, respectively: Fibrotest: 21.3% (22.2%), Fibroscan: 12.9% (12.3%), FibroMeter2G: 5.7% (6.0%), FibroMeter3G: 0.9% (0.9%), p < 10-3 (p < 10-3).

CONCLUSIONS

The accuracy in detailed fibrosis classification of the best-performing blood test outperforms liver biopsy read by a local pathologist, i.e., in clinical practice; however, the classification precision is apparently lesser. This detailed classification accuracy is much lower than that of significant fibrosis with Fibroscan and even Fibrotest but higher with FibroMeter3G. FibroMeter classification accuracy was significantly higher than those of other non-invasive tests. Finally, for hepatitis C evaluation in clinical practice, fibrosis degree can be evaluated using an accurate blood test.

Comparison of accuracy of fibrosis degree classifications by liver biopsy and non-invasive tests in chronic hepatitis C

Background

Non-invasive tests have been constructed and evaluated mainly for binary diagnoses such as significant fibrosis. Recently, detailed fibrosis classifications for several non-invasive tests have been developed, but their accuracy has not been thoroughly evaluated in comparison to liver biopsy, especially in clinical practice and for Fibroscan. Therefore, the main aim of the present study was to evaluate the accuracy of detailed fibrosis classifications available for non-invasive tests and liver biopsy. The secondary aim was to validate these accuracies in independent populations.

Methods

Four HCV populations provided 2,068 patients with liver biopsy, four different pathologist skill-levels and non-invasive tests. Results were expressed as percentages of correctly classified patients.

Results

In population #1 including 205 patients and comparing liver biopsy (reference: consensus reading by two experts) and blood tests, Metavir fibrosis (F_M) stage accuracy was 64.4% in local pathologists vs. 82.2% (p < 10^-3) in single expert pathologist. Significant discrepancy (≥ 2F_M vs reference histological result) rates were: Fibrotest: 17.2%, FibroMeter^2G: 5.6%, local pathologists: 4.9%, FibroMeter^3G: 0.5%, expert pathologist: 0% (p < 10^-3). In population #2 including 1,056 patients and comparing blood tests, the discrepancy scores, taking into account the error magnitude, of detailed fibrosis classification were significantly different between FibroMeter^2G (0.30 ± 0.55) and FibroMeter^3G (0.14 ± 0.37, p < 10^-3) or Fibrotest (0.84 ± 0.80, p < 10^-3). In population #3 (and #4) including 458 (359) patients and comparing blood tests and Fibroscan, accuracies of detailed fibrosis classification were, respectively: Fibrotest: 42.5% (33.5%), Fibroscan: 64.9% (50.7%), FibroMeter^2G: 68.7% (68.2%), FibroMeter^3G: 77.1% (83.4%), p < 10^-3 (p < 10^-3). Significant discrepancy (≥ 2 F_M) rates were, respectively: Fibrotest: 21.3% (22.2%), Fibroscan: 12.9% (12.3%), FibroMeter^2G: 5.7% (6.0%), FibroMeter^3G: 0.9% (0.9%), p < 10^-3 (p < 10^-3).

Conclusions

The accuracy in detailed fibrosis classification of the best-performing blood test outperforms liver biopsy read by a local pathologist, i.e., in clinical practice; however, the classification precision is apparently lesser. This detailed classification accuracy is much lower than that of significant fibrosis with Fibroscan and even Fibrotest but higher with FibroMeter^3G. FibroMeter classification accuracy was significantly higher than those of other non-invasive tests. Finally, for hepatitis C evaluation in clinical practice, fibrosis degree can be evaluated using an accurate blood test.

Novel biomarker candidates to predict hepatic fibrosis in hepatitis C identified by serum proteomics

BACKGROUND

Liver biopsy remains the gold standard to assess hepatic fibrosis. It is desirable to predict hepatic fibrosis without the need for invasive liver biopsy. Proteomic techniques allow unbiased assessment of proteins and might be useful to identify proteins related to hepatic fibrosis.

AIMS

We utilized two different proteomic methods to identify serum proteins as candidate biomarkers to predict hepatic fibrosis stage in patients with chronic hepatitis C virus (HCV) infection.

METHODS

Serum was obtained from 24 people with chronic HCV at time of liver biopsy and from 6 normals. Liver biopsy fibrosis was staged 1-4 (Batts-Ludwig). Pooled serum samples (six in each of four fibrosis groups and controls) were analyzed with 4- and 8-plex isobaric tags for relative and absolute quantitation (iTRAQ), determining protein identification (ID) and ratios of relative protein abundance. Nonpooled samples were analyzed with two-dimensional (2-D) gels and difference in gel electrophoresis (DIGE) comparing different samples on the same gel and across gels. Spots varying among groups were measured with densitometry, excised, digested, and submitted for tandem mass spectrometry (MS/MS) protein ID.

RESULTS

iTRAQ identified 305 proteins (minimum 99% ID confidence); 66 were increased or decreased compared with controls. Some proteins were increased or decreased for specific fibrosis scores. From 704 DIGE protein spots, 66 were chosen, 41 excised, and 135 proteins identified, since one gel spot often identified more than one protein.

CONCLUSIONS

Both proteomic methods identified two proteins as biomarker candidates for predicting hepatic fibrosis: complement C4-A and inter-alpha-trypsin inhibitor heavy chain H4.

LecT-Hepa: A triplex lectin-antibody sandwich immunoassay for estimating the progression dynamics of liver fibrosis assisted by a bedside clinical chemistry analyzer and an automated pretreatment machine

BACKGROUND

A quantitative analysis of glyco-alteration in serum glycoproteins provides glyco-parameters for estimating the progression of liver fibrosis. In the analysis of glycans, a manual pretreatment process for clinical specimens leads to a complicated manipulation and loss-of-clinical implementation of the assay.

METHOD

We evaluated an automated triplex lectin-antibody sandwich immunoassay assisted by an automated protein purification system (ED-01) and a bedside clinical chemistry analyzer (HISCL) for the acquisition of two glyco-parameters (AOL/DSA and MAL/DSA) derived from a fibrosis-related glyco-alteration of serum alpha1-acid glycoprotein (AGP).

RESULTS

We adjusted the auto-machines with their accuracy set to CV <5.0% (ED-01) and <1.0% (HISCL). AGP samples were enriched from 275 serum specimens. Two glyco-parameters obtained by HISCL showed a linear correlation with that from a reported assay (R>0.90). The formula for monitoring fibrosis (LecT-Hepa) was given by a combination of the glyco-parameters. This correlated with the fibrosis stage from biopsy (R=0.68) and diagnosed severe fibrosis and cirrhosis. It was superior to that of FIB-4 index.

CONCLUSIONS

We automated a multilectin-assisted immunoassay with an order of magnitude reduction of operation time without any loss-of-accuracy. LecT-Hepa is a reliable method to assess fibrosis-dynamics from moderate fibrosis to cirrhosis.

Assessment of new hyaluronic acid assays and their impact on FibroMeter scores

BACKGROUND

We compared three hyaluronic acid (HA) assays and analyzed the impact of their variations on FibroMeter scores.

METHODS

In a test group of 165 patients, HA levels were assessed with the commonly used ELISA assay from Corgenix, a new ELISA assay from Teco and an immunoturbidimetry assay from Wako, this latter tested across three different instruments. Five different FibroMeter scores were calculated.

RESULTS

Correlation across the three assays (r(s) between 0.969 and 0.995) was very good. Means of differences (d) were lower when the immunoturbidimetry assay was compared on different instruments: d between -3.4 and 2.0 μg/L. However, a higher value for HA measurement was observed with Corgenix assay, compared to the other two assays (Teco and Wako): d between 27.1 and 36.4 μg/L. The assessment also demonstrated that HA variations had very little impact on FibroMeter scores: 0.0117 for virus and 0.0416 for alcoholic fibrosis scores, and between 0.58 and 1.71 for the area of fibrosis (expressed in percentage).

CONCLUSIONS

The two new assays found lower values of HA, as compared to the Corgenix assay. However, these differences had very little impact on FibroMeter scores and had no impact on clinical evaluation of liver fibrosis.

Non-invasive assessment of liver fibrosis: it is time for laboratory medicine

Chronic liver diseases (CLDs) represent a major cause of morbidity and mortality worldwide. In all etiologies of CLDs, staging of liver fibrosis is essential for both prognosis and management. Until a few years ago, liver biopsy was the only tool for the diagnosis of liver fibrosis in patients with CLDs. However, liver biopsy is an invasive and costly procedure. More recently, various serum biomarkers and laboratory tests have been proposed as surrogates of liver histology. Due to inadequate diagnostic accuracy or to lack of sufficient validation, guidelines still do not recommend them as a substitute for liver biopsy that is still considered the gold standard for the diagnosis of liver fibrosis. Notably, non-invasive serum biomarkers, when combined, may reduce by 50%-80% the number of liver biopsies needed for correctly classifying hepatic fibrosis. However, liver biopsy cannot be avoided completely, but should be used in those cases in which non-invasive methods show poor accuracy. In this view, serum biomarkers and liver biopsy represent a union between laboratory medicine and hepatology.

Optimization and robustness of blood tests for liver fibrosis and cirrhosis

OBJECTIVES

To optimize the performance and feasibility of fibrosis blood tests and evaluate their robustness.

DESIGN AND METHODS

The derivation population included 1056 HCV patients with liver biopsy and blood markers. Validation populations included 984 patients with various viral hepatitis causes, and Fibroscan and/or liver biopsy and/or blood markers.

RESULTS

The bootstrap method validated the markers of the original FibroMeter(2G), but not those of Fibrotest and Hepascore, and provided a hyaluronate-free FibroMeter(3G). AUROCs for significant fibrosis were: FibroMeter(2G): 0.853 vs. FibroMeter(3G): 0.851, p=0.489. Compared to FibroMeter(2G), FibroMeter(3G) had a significantly higher patient rate with predictive values ≥90% for significant fibrosis. Accuracy for fibrosis stage classification was: Fibrotest: 37.9%, FibroMeter(2G): 74.9%, and FibroMeter(3G): 86.9% (p<10(-3)).

CONCLUSION

The bootstrap method validated FibroMeter(2G) and provided a cheaper and more feasible hyaluronate-free FibroMeter(3G) with comparable performance. Compared to binary diagnosis, fibrosis stage classification increased discrimination, with an increased accuracy to 87% for FibroMeter(3G).

Liver biopsy for histological assessment: The case in favor

Liver biopsy (LB) is the gold standard method for assessment of liver histology. It provides valuable, otherwise unobtainable information, regarding the degree of fibrosis, parenchymal integrity, degree and pattern of inflammation, bile duct status and deposition of materials and minerals in the liver. This information provides immense help in the diagnosis and prognostication of a variety of liver diseases. With careful selection of patients, and performance of the procedure appropriately, the complications become exceptionally rare in current clinical practice. Furthermore, the limitations of sampling error and inter-/intra-observer variability may be avoided by obtaining adequate tissue specimen and having it reviewed by an experienced liver pathologist. Current noninvasive tools are unqualified to replace LB in clinical practice in the face of specific limitations for each tool, compounded by a poorer performance towards the assessment of the degree of liver fibrosis, particularly for intermediate stages.