Comparison of non-invasive assessment to diagnose liver fibrosis in chronic hepatitis B and C patients

Liver stiffness measured by virtual touch quantification predicts the occurrence of posthepatectomy refractory ascites in patients with hepatocellular carcinoma

PURPOSE

This study assessed the significance of measuring liver stiffness using virtual touch quantification before hepatectomy to predict posthepatectomy refractory ascites.

METHODS

A total of 267 patients with hepatocellular carcinoma who underwent hepatectomy were prospectively analyzed. Liver stiffness was defined as the median value of the virtual touch quantification (Vs; m/s) by acoustic radio-force-impulse-based virtual touch.

RESULTS

A multivariate analysis showed that Vs and the aspartate aminotransferase-to-platelet ratio index were independent risk factors for postoperative refractory ascites (odds ratio = 3.27 and 3.08, respectively). The cutoff value for Vs was 1.52 m/s (sensitivity: 59.5%, specificity: 88.6%) as determined by the analysis of the receiver-operating characteristic curve, and the area under the receiver-operating characteristic curve was 0.79. The cutoff value for the aspartate aminotransferase-to-platelet ratio was 0.952 (sensitivity: 65.5%, specificity: 82.9%), and the area under the receiver-operating characteristic curve was 0.75.

CONCLUSIONS

Vs is an independent risk factor for refractory ascites after hepatectomy. The measurement of liver stiffness by virtual touch quantification before hepatectomy can help estimate the risk of postoperative refractory ascites. Nonsurgical treatments should be considered for the management of patients who are at high risk for refractory ascites.

Role of plasmonics in detection of deadliest viruses: a review

Viruses have threatened animal and human lives since a long time ago all over the world. Some of these tiny particles have caused disastrous pandemics that killed a large number of people with subsequent economic downturns. In addition, the quarantine situation itself encounters the challenges like the deficiency in the online educational system, psychiatric problems and poor international relations. Although viruses have a rather simple protein structure, they have structural heterogeneity with a high tendency to mutation that impedes their study. On top of the breadth of such worldwide worrying issues, there are profound scientific gaps, and several unanswered questions, like lack of vaccines or antivirals to combat these pathogens. Various detection techniques like the nucleic acid test, immunoassay, and microscopy have been developed; however, there is a tradeoff between their advantages and disadvantages like safety in sample collecting, invasiveness, sensitivity, response time, etc. One of the highly resolved techniques that can provide early-stage detection with fast experiment duration is plasmonics. This optical technique has the capability to detect viral proteins and genomes at the early stage via highly sensitive interaction between the biological target and the plasmonic chip. The efficiency of this technique could be proved using commercialized techniques like reverse transcription polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) techniques. In this study, we aim to review the role of plasmonic technique in the detection of 11 deadliest viruses besides 2 common genital viruses for the human being. This is a rapidly moving topic of research, and a review article that encompasses the current findings may be useful for guiding strategies to deal with the pandemics. By investigating the potential aspects of this technique, we hope that this study could open new avenues toward the application of point-of-care techniques for virus detection at early stage that may inhibit the progressively hygienic threats.

APRI and FIB-4 performance to assess liver fibrosis against predefined Fibroscan values in chronic hepatitis C virus infection

Backgrounds and Aims:

Chronic hepatitis C (CHC) infection can leads to chronic liver disease, fibrosis, then cirrhosis, and, finally, hepatocellular carcinoma (HCC); moreover, it is the most common indication for liver transplantation. Liver biopsy is still the gold standard method for the staging of liver fibrosis as it is an invasive procedure with complications. There are some noninvasive methods such as fibroscan that are now the investigation of choice; FIB-4 and aminotransferase to platelet ratio index (APRI) are other noninvasive tools to assess liver fibrosis by using aspartate aminotransferase (AST), alanine aminotransferase (ALT), platelet count, and age. This study aims to evaluate the efficacy and performance of FIB-4 and APRI against fibroscan in patients infected with the hepatitis C virus.

Method:

It is a cross-sectional study that was conducted in a tertiary health care center in Uttar Pradesh, India, from January 2017 to January 2020. Fibroscan was done for all patients. A blood sample was used to determine AST, ALT, and platelet count. FIB-4 and APRI were calculated from laboratory data.

Result:

187 of the 487 patients in the study have F0-F1 fibrosis, 69 have F2, 53 have F3 fibrosis, and 178 have cirrhosis. Based on receiver operating characteristic (ROC) analysis, single optimum cut-offs for diagnosing significant fibrosis and cirrhosis were 1.2 for APRI and 2.25 for FIB-4.

Conclusions:

Compared with Fibroscan, APRI and FIB-4 showed good performance in detecting the patients without liver fibrosis as well as satisfactory performance in detecting significant fibrosis. These scores should be used in combination with other noninvasive scores for an accurate assessment of liver fibrosis.

Predicting Liver Fibrosis in the Hepatitis C Population: Concordance Analysis Between Noninvasive Scoring Systems and Percutaneous Liver Biopsy

Background

Due to the slow progression of many chronic liver diseases, including hepatitis C, it is not practical or safe to monitor disease progression by serial liver biopsies. Noninvasive laboratory scoring systems based on routine laboratory tests are appealing surrogate markers of liver fibrosis for the staging and monitoring of chronic liver diseases such as hepatitis C.

Methods

We explored the accuracy of three scoring systems: the fibrosis-4 score (FIB-4), the aspartate aminotransferase to platelet ratio index (APRI score), and the aspartate aminotransferase to alanine aminotransferase ratio (AAR) in 496 patients with chronic hepatitis C virus (HCV) infection who had undergone percutaneous liver biopsy at a viral hepatitis clinic in Shreveport, Louisiana.

Results

For FIB-4, the area under the receiver operating characteristic curve (AUROC) for hepatic fibrosis stages ≥ 1, ≥ 2, ≥ 3, and 4 (cirrhosis) ranged from 0.74 (95% CI, 0.678 - 0.802) to 0.802 (95% CI, 0.751 - 0.854). At a cutoff value of 1.45, FIB-4 was 82% sensitive for advanced fibrosis or cirrhosis (stage 3 or 4) but was only 58% specific for these findings. Increasing the FIB-4 cutoff value to 3.25 reduced the sensitivity for detecting advanced fibrosis or cirrhosis to 39%, but this higher cutoff was 92% specific for these findings. Corresponding AUROCs for the APRI and AAR scores were inferior to FIB-4.

Conclusion

The FIB-4 index outperformed APRI and AAR in our HCV infected population in predicting severe fibrosis or cirrhosis.

Hyaluronic acid inhibition by 4-methylumbelliferone reduces the expression of cancer stem cells markers during hepatocarcinogenesis

Hyaluronic acid (HA) is a glycosaminoglycan of extracellular matrix related to cell surface which interacts with various cell types. To understand the role of HA during hepatocarcinogenesis, we assessed the effect of the inhibition of HA deposition and its association with heterogeneous hepatocellular carcinoma (HCC) cells. In this study, we used transgenic mice C57BL/6J-Tg(Alb1HBV)44Bri/J (HBV-TG) and normal C57BL/6 J (WT) for in vivo study, while HCC cells Huh7 and JHH6 as in vitro models. Both models were treated with an HA inhibitor 4-methylumbelliferone (4MU). We observed that 4MU treatments in animal model down-regulated the mRNA expressions of HA-related genes Has3 and Hyal2 only in HBV-TG but not in normal WT. As observed in vivo, in HCC cell lines, the HAS2 mRNA expression was down-regulated in Huh7 while HAS3 in JHH6, both with or without the presence of extrinsic HA. Interestingly, in both models, the expressions of various cancer stem cells (CD44, CD90, CD133, and EpCAM) were also decreased. Further, histological analysis showed that 4MU treatment with dose 25 mg/kg/day reduced fibrosis, inflammation, and steatosis in vivo, in addition to be pro-apoptotic. We concluded that the inhibition of HA reduced the expressions of HA-related genes and stem cells markers in both models, indicating a possible modulation of cells-to-cells and cells-to-matrix interaction.

Transient Elastography for Significant Liver Fibrosis and Cirrhosis in Chronic Hepatitis B: A Meta-Analysis

BACKGROUND

The hepatitis B virus infection is a global health issue and the stage of liver fibrosis affects the prognosis in patients with chronic hepatitis B (CHB). We performed the meta-analysis describing diagnostic accuracy of transient elastography (TE) for predicting CHB-related fibrosis.

METHODS

We performed an adequate literature search to identify studies that assessed the diagnostic accuracy of TE in CHB patients using biopsy as reference standard. Hierarchical summary receiver-operating curves model and the bivariate mixed-effects binary regression model were applied to generate summary receiver-operating characteristic curves and pooled estimates of sensitivity and specificity.

RESULTS

The area under the summary receiver-operating curve for significant fibrosis and cirrhosis was 0.86 (95% confidence interval (CI): 0.83-0.89) and 0.92 (95% CI: 0.90-0.94), respectively. The sensitivity, specificity, and diagnostic odds ratio of TE for significant fibrosis were 0.78 (95% CI: 0.73-0.81, p < 0.01; I² = 85.59%), 0.81 (95% CI: 0.77-0.84, p < 0.01; I² = 88.20%), and 14.44 (95% CI: 10.80-19.31, p < 0.01; I² = 100%) and for cirrhosis were 0.84 (95% CI: 0.80-0.88, p < 0.01; I² = 76.67%), 0.87 (95% CI: 0.84-0.90, p < 0.01; I² = 90.89%), and 36.63 (95% CI: 25.38-52.87, p < 0.01; I² = 100%), respectively. The optimal cut-off values of TE were 7.25 kPa for diagnosing significant fibrosis and 12.4 kPa for diagnosing cirrhosis, respectively.

CONCLUSION

TE is of great value in the detection of patients with CHB-related cirrhosis but has a suboptimal accuracy in the detection of significant fibrosis.

PRO-C3: a new and more precise collagen marker for liver fibrosis in patients with chronic hepatitis C

OBJECTIVE

Detecting significant fibrosis and cirrhosis remains important in treatment and follow-up of patients with chronic hepatitis C Infection (CHC). The aim of this study was to assess the ability of PRO-C3 to identify significant fibrosis (Ishak score ≥3) and cirrhosis (Ishak score ≥5) both as a single test and as a part of algorithms.

MATERIALS AND METHODS

PRO-C3 was assessed in baseline samples from the NORDynamIC trial. 270 patients were stratified into groups according to baseline biopsy. Baseline APRI, FIB-4 and GUCI scores were available for comparison in 232 patients.

RESULTS

PRO-C3 increased with Ishak scores (p = .001). Area under the curve (AUC) for significant fibrosis was 0.75 (95% CI 0.68-0.81) and 0.76 (95% CI 0.68-0.84) for cirrhosis. FIB-4, APRI and GUCI had similar AUCs. In a PRO-C3 algorithm including age, platelet count, body mass index (BMI) and international normalised ratio (INR), the diagnostic efficacy improved to 0.85 (CI 0.80-0.89) and 0.90 (IQR 0.84-0.96) for significant fibrosis and cirrhosis, respectively.

CONCLUSIONS

In our study, PRO-C3 was an independent predictor of fibrosis stage, and may play an important role in managing CHC patients.

Comparison of serological assessments in the diagnosis of liver fibrosis in bile duct ligation mice

Liver fibrosis assessment is essential to make a prognosis and to determine the appropriate anti-fibrosis treatment. Non-invasive serum markers are widely studied in patients to assess liver fibrosis due to the limitations of liver biopsy. When using animal models to study the mechanism and intervention of hepatic fibrosis, serum markers might be useful for the continuous assessment of liver fibrosis in individual animals, which could avoid the influence of biological differences between individuals. However, it is unclear whether serum markers can assess hepatic fibrosis in the animal model. In the present study, we evaluated and compared the ability of four serum markers to assess liver fibrosis in bile duct ligation mice. According to the stages of liver fibrosis assessed by pathological changes, mice in this study were divided into five groups (F0, F1, F2, F3, and F4). Subsequently, four serum markers, aspartate aminotransferase-to-alanine aminotransferase ratio (AAR), aspartate aminotransferase-to-platelet ratio index (APRI), fibrosis index based on the 4 factors (FIB-4), and Forns Index, were calculated for each group. Furthermore, the correlations between serum markers and pathological stages and the ability of serological markers to evaluate liver fibrosis were analyzed. AAR, APRI, FIB-4, and Forns Index could significantly distinguish F0-2 from F3-4 mice. APRI, FIB-4, and Forns Index could detect F0-3 from F4 mice. Among these four markers, FIB-4 was the best able to distinguish ≥F2 and ≥F3, with area under the curve values of 0.882 and 0.92, respectively. Forns Index was best for diagnosing F4 with area under the curve value of 0.879. These results demonstrated that serum markers could be used for assessing liver fibrosis in bile duct ligation mice, and therefore, these markers might lead to more accurate diagnostic and therapeutic studies through continuous monitoring in individual animals. Impact statement The assessment of liver fibrosis is essential for making a prognosis and determining the appropriate anti-fibrosis treatment. In studies focusing on the mechanism and treatment of liver fibrosis using animal models, it would be more accurate to continuously evaluate liver fibrosis in a single animal to avoid individual biological differences. Unfortunately, it is difficult to perform continuous assessment through liver biopsy in the most commonly used rodent models. It is unclear whether serum markers, which have been used in hepatic fibrosis patients, could be used in animal models. Our results demonstrate that serum markers could be used for assessing liver fibrosis in bile duct ligation mice. This study might contribute to more accurate diagnostic and therapeutic studies through continuous monitoring in individual animals.

Noninvasive Assessment of Liver Fibrosis Stage Using Ultrasound-Based Shear Wave Velocity Measurements and Serum Algorithms in Patients With Viral Hepatitis B: A Retrospective Cohort Study

OBJECTIVES

Liver biopsy remains the reference standard for the assessment of liver fibrosis, but this procedure is invasive and can lead to complications. Thus, studies to determine the optimal noninvasive test are warranted. This study compared several noninvasive tests and their combinations for evaluating liver fibrosis stages in patients with chronic hepatitis B.

METHODS

The shear wave velocity (SWV) and laboratory indicators were collected from 174 patients with chronic hepatitis B. Formulas were applied to calculate the serum fibrosis model, including the aspartate aminotransaminase-to-platelet ratio index (APRI), fibrosis-4 index (FIB-4) and aspartate aminotransferase-to-alanine aminotransferase ratio (AAR). The diagnostic performance of all noninvasive tests was assessed in comparison with percutaneous liver biopsy, based on a receiver operating characteristic curve analysis.

RESULTS

The SWV (area under the receiver operating characteristic curve [AUC], 0.82) and APRI (AUC = 0.77) performed better than the FIB-4 (AUC = 0.62), and the AAR (AUC = 0.47) was not suitable for evaluating substantial liver fibrosis (stage ≥F2). The SWV (AUC = 0.96) was the best indicator, being superior to the APRI (AUC = 0.75) and FIB-4 (AUC = 0.74), and the AAR (AUC = 0.45) was not suitable for assessing cirrhosis (F4). Combining the SWV and APRI, the AUC improved to 0.85 for substantial liver fibrosis, and the sensitivity increased to 100% for cirrhosis.

CONCLUSIONS

The SWV, APRI, and FIB-4 were valid tests for evaluating substantial liver fibrosis and cirrhosis. The combination of these tests with several noninvasive indicators is expected to enhance the assessment of liver fibrosis stages.

Pediatric Non-alcoholic Fatty Liver Disease

Childhood obesity has reached epidemic proportions, and by 2012, more than one third of American children were overweight or obese. As a result, increasingly, children are developing complications of obesity including liver disease. In fact, non-alcoholic fatty liver disease is the most common form of chronic liver disease seen in children today. Recently, there has been a burgeoning literature examining the pathogenesis, genetic markers, and role of the microbiome in this disease. On the clinical front, new modalities of diagnosing hepatic steatosis and hepatic fibrosis are being developed to provide non-invasive methods of surveillance in children. Lastly, the mainstay of treatment of pediatric non-alcoholic fatty liver disease (NAFLD) has been largely through lifestyle interventions, namely, dieting and exercise. Currently, there are a number of clinical trials examining novel lifestyle and drug therapies for NAFLD that are registered with the US National Institutes of Health ClinicalTrials.gov website.

Effect of Entecavir and Tenofovir Treatment on Noninvasive Fibrosis Scores: Which One Is Better?

Liver biopsy is the best method for detecting fibrosis grade of the liver in chronic hepatitis B. However, the invasiveness of liver biopsy complicates its routine use in follow-up of treatment. We planned to determine the usage of fibrosis predicting noninvasive scores in the follow-up of the treatment of patients with chronic hepatitis B treated with entecavir or tenofovir. Two hundred twenty-eight patients with hepatitis B with liver biopsy were included in the study. Fibrosis grade was determined by Ishak score. The laboratory data at months 0, 12, and 24 during treatment were collected and noninvasive fibrosis scores (aspartate aminotransferase to alanine aminotransferase ratio [AAR], aspartate aminotransferase to platelet ratio index [APRI], fibrosis index based on the 4 factors [FIB-4] and red cell distribution width to platelet ratio [RPR]) were calculated. Statistically significant increase in all scores and decrease in platelet count were observed as the fibrosis level increased. For differentiation of patients with fibrosis ≥grade 2, the highest sensitivity and specificity rates were shown by APRI score (sensitivity 67%, specificity 69%, and cutoff ≥0.5). FIB-4 was the most successful score for differentiation of patients with fibrosis ≥grade 3 (sensitivity 83%, specificity 74%, and cutoff ≥1.45). A significant decrease in all noninvasive fibrosis scores was observed at months 12 and 24 during treatment with both entecavir and tenofovir (P < 0.001). Among these, only the improvement in APRI score was found better in entecavir group with statistical significance (P < 0.05). APRI score was effective in demonstrating early-stage fibrosis. FIB-4, RPR, and platelet count were better in demonstrating advanced fibrosis. Although noninvasive scores cannot replace liver biopsy for diagnosis, they can be used for monitoring the response to treatment.

Transient liver elastography in unsedated control children: Impact of age and intercurrent illness

AIM

Transient elastography (TE) is a rapid, non-invasive, reproducible assessment of liver fibrosis by liver stiffness measurement (LSM). Uncertainty remains regarding utility in children, unsedated and <6 years of age. The importance of general health at the time of study has not been addressed. We report our experience of TE in unsedated control children, impact of intercurrent illness and using new published reliability criteria.

METHODS

From April 2011 to March 2013, 173 studies were performed in unsedated, healthy control children and children with intercurrent illness without detectable liver disease presenting to the Royal Children's Hospital, Brisbane, Australia. LSM reliability was assessed using interquartile range/median (IQR/M ≤ 30%) of 10 valid measurements.

RESULTS

A total of 123 (F:M, 52:71) of 173 studies (71.1%) gave reliable results. In children 0-2 years reliability was 36%, and >2 years reliable results were obtained in ~80%. LSM increased with age; 0-2 years (3.5 ± 0.5 kPa), 3-5 years (3.8 ± 0.3 kPa) and 6-11 years (4.1 ± 0.2 kPa) with healthy older children 12-18 years similar to adults (4.5 ± 0.2 kPa). LSM did not vary with gender (female, 4.5 ± 0.2 vs. male, 4.8 ± 0.2 kPa). Children with intercurrent, non-hepatological illnesses had higher LSM (5.2 ± 0.2 kPa (range, 2.8-11.1 kPa)) compared to healthy children ((4.1 ± 0.1 kPa, range, 2.1-6.3 kPa); P = 0.0001).

CONCLUSIONS

TE in unsedated children is feasible from infancy but most reliable after 2 years. Intercurrent illness increases LSM; hence, study context is important when interpreting results.

Liver Shear-Wave Velocity and Serum Fibrosis Markers to Diagnose Hepatic Fibrosis in Patients with Chronic Viral Hepatitis B

Objective

To compare several noninvasive indices of fibrosis in chronic viral hepatitis B, including liver shear-wave velocity (SWV), hyaluronic acid (HA), collagen type IV (CIV), procollagen type III (PCIII), and laminin (LN).

Materials and Methods

Acoustic radiation force impulse (ARFI) was performed in 157 patients with chronic viral hepatitis B and in 30 healthy volunteers to measure hepatic SWV (m/s) in a prospective study. Serum markers were acquired on the morning of the same day of the ARFI evaluation. Receiver operating characteristic (ROC) analysis was performed to evaluate and compare the accuracies of SWV and serum markers using METAVIR scoring from liver biopsy as a reference standard.

Results

The most accurate test for diagnosing fibrosis F ≥ 1 was SWV with the area under the ROC curve (AUC) of 0.913, followed by LN (0.744), HA (0.701), CIV (0.690), and PCIII (0.524). The best test for diagnosing F ≥ 2 was SWV (AUC of 0.851), followed by CIV (0.671), HA (0.668), LN (0.562), and PCIII (0.550). The best test for diagnosing F ≥ 3 was SWV (0.854), followed by CIV (0.693), HA (0.675), PCIII (0.591), and LN (0.548). The best test for diagnosing F = 4 was SWV (0.965), followed by CIV (0.804), PCIII (0.752), HA (0.744), and LN (0.662). SWV combined with HA and CIV did not improve diagnostic accuracy (AUC = 0.931 for F ≥ 1, 0.863 for F ≥ 2, 0.855 for F ≥ 3, 0.960 for F = 4).

Conclusion

The performance of SWV in diagnosing liver fibrosis is superior to that of serum markers. However, the combination of SWV, HA, and CIV does not increase the accuracy of diagnosing liver fibrosis and cirrhosis.

Overestimate of Fibrosis by FIBROSpect® II in African Americans Complicates the Management of their Chronic Hepatitis C

BACKGROUND

Evaluation of advanced fibrosis in patients with hepatitis C virus (HCV) infection is used to facilitate decisions on treatment strategy and to initiate additional screening measures. Unfortunately, most studies have predominately Caucasian (Cau) patients and may not be as relevant for African Americans (AA).

AIMS

This study specifically addresses the issue of defining minimal vs. significant fibrosis in African Americans (AA) with chronic hepatitis C (CHC) using noninvasive assays.

METHODS

All patients (n = 319) seen between 1 January 2008 and 30 June 2013 for whom a FibroSpect II® (FSII) assay was performed and had data for calculation of aspartate aminotransferase (AST) platelet ratio index (APRI) and Fibrosis-4 (FIB-4) were identified using the medical records.

RESULTS

When liver biopsy score and FSII assay results for the AA patients with CHC were compared, 31% of AA had advanced FSII fibrosis scores (F2-F4) despite a biopsy score of F0-F1. In contrast, 10% of Cau over-scored. The AA false positive rate was 14% for APRI and 34% for FIB-4. Combining FSII with either APRI (7% false positive) or FIB-4 (10% false positive) improved the false positive rate in AA to 7% (FSII + APRI) and 10% (FSII + FIB-4) but reduced the sensitivity for significant fibrosis.

CONCLUSIONS

The FSII assay overestimates fibrosis in AA and should be used with caution since these patients may not have significant fibrosis. If the APRI or FIB-4 assay is combined with the FSII assay, minimal fibrosis in AA can be defined without subjecting the patients to a subsequent biopsy.

Systematic review with meta-analysis: the diagnostic accuracy of transient elastography for the staging of liver fibrosis in patients with chronic hepatitis B

BACKGROUND

Transient elastography is a non-invasive method for staging liver fibrosis. The meta-analysis using the hierarchical models to evaluate the diagnostic accuracy of transient elastography for the staging of liver fibrosis in patients with chronic hepatitis B was rarely reported.

AIM

A meta-analysis using the hierarchical models was performed to assess transient elastography for diagnosing and stage liver fibrosis in patients with chronic hepatitis B.

METHODS

Electronic databases were searched and studies were identified to assess the diagnostic accuracy of transient elastography in CHB patients for staging fibrosis F ≥ 2, F ≥ 3 and F = 4 with liver biopsy as a reference standard. The hierarchical summary receiver operating characteristic curve and the bivariate models were performed to evaluate the diagnostic accuracy of transient elastography, and meta-regression analyses were performed to explore the heterogeneity. The quality Assessment of Diagnostic Accuracy Studies-2 tool was used to assess the quality of studies.

RESULTS

Twenty-seven studies with a total of 4386 patients were included in the meta-analysis. The summary sensitivity of transient elastography for staging fibrosis F ≥ 2, F ≥ 3 and F = 4 was 0.806 (95% CI, 0.756-0.847), 0.819 (95% CI, 0.748-0.874) and 0.863 (95% CI, 0.818-0.898), respectively, and the summary specificity was 0.824 (95% CI, 0.761-0.873), 0.866 (95% CI, 0.824-0.899) and 0.875 (95% CI, 0.840-0.903), respectively. The corresponding area under the summary receiver operating characteristic curve was 0.88 (95% CI, 0.85-0.91), 0.91 (95% CI, 0.88-0.93) and 0.93 (95% CI, 0.91-0.95), respectively. Meta-regression showed that patient age contributed to heterogeneity.

CONCLUSIONS

Transient elastography performs well to diagnose liver fibrosis in patients with chronic hepatitis B, which may reduce the use of liver biopsy.

Non-invasive assessment of liver fibrosis in chronic viral hepatitis

BACKGROUND

Hyaluronic acid (HA), ASAT to Platelet Ratio Index (APRI), ASAT/ALAT ratio, Fibrosis 4 score (FIB4) and FibroScan were studied as non-invasive markers of liver fibrosis (F) in chronic viral hepatitis B (CHB) and C (CHC), in an attempt to avoid the complications of liver puncture biopsy, considered the gold standard in the evaluation of F. The aim of our research was to study whether HA, APRI, ASAT/ALAT ratio, FIB4 and FibroScan are useful non-invasive markers in predicting severe F in Romanian patients.

PATIENTS AND METHODS

This was a prospective multicenter transversal and observational study, which included 76 patients with CHB/CHC. The independent effect of studied markers was tested using multiple binary logistic regression.

RESULTS

In patients with CHB and CHC, the APRI cut-off value for F4 was 0·70 ng/mL (Se = 77%, Sp = 78%), the FIB4 cut-off value was 2·01 (Se = 77%, Sp = 69%), and the FibroScan cut-off value was 13·15 (Se = 92%, Sp = 88%). For patients with CHB/CHC, there was a significant linear positive correlation between F and HA (r = 0·42, P = 0·001), FibroScan (r = 0·67, P < 0·001), APRI (r = 0·46, P < 0·001) and FIB4 (r = 0·51, P < 0·001). Considering age, sex and body mass index as possible confounding factors or covariates in multivariable logistic modelling, FibroScan was the unique test that able to significantly highlight the presence of F4 score in CHB/CHC patients (P = 0·009) while FIB4 test seems to have a tendency to statistical significance.

CONCLUSION

FibroScan, APRI and FIB4 are useful non-invasive tests for the evaluation of F4 in patients with CHB and CHC.

Cost-effectiveness of non-invasive methods for assessment and monitoring of liver fibrosis and cirrhosis in patients with chronic liver disease: systematic review and economic evaluation

BACKGROUND

Liver biopsy is the reference standard for diagnosing the extent of fibrosis in chronic liver disease; however, it is invasive, with the potential for serious complications. Alternatives to biopsy include non-invasive liver tests (NILTs); however, the cost-effectiveness of these needs to be established.

OBJECTIVE

To assess the diagnostic accuracy and cost-effectiveness of NILTs in patients with chronic liver disease.

DATA SOURCES

We searched various databases from 1998 to April 2012, recent conference proceedings and reference lists.

METHODS

We included studies that assessed the diagnostic accuracy of NILTs using liver biopsy as the reference standard. Diagnostic studies were assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. Meta-analysis was conducted using the bivariate random-effects model with correlation between sensitivity and specificity (whenever possible). Decision models were used to evaluate the cost-effectiveness of the NILTs. Expected costs were estimated using a NHS perspective and health outcomes were measured as quality-adjusted life-years (QALYs). Markov models were developed to estimate long-term costs and QALYs following testing, and antiviral treatment where indicated, for chronic hepatitis B (HBV) and chronic hepatitis C (HCV). NILTs were compared with each other, sequential testing strategies, biopsy and strategies including no testing. For alcoholic liver disease (ALD), we assessed the cost-effectiveness of NILTs in the context of potentially increasing abstinence from alcohol. Owing to a lack of data and treatments specifically for fibrosis in patients with non-alcoholic fatty liver disease (NAFLD), the analysis was limited to an incremental cost per correct diagnosis. An analysis of NILTs to identify patients with cirrhosis for increased monitoring was also conducted.

RESULTS

Given a cost-effectiveness threshold of £20,000 per QALY, treating everyone with HCV without prior testing was cost-effective with an incremental cost-effectiveness ratio (ICER) of £9204. This was robust in most sensitivity analyses but sensitive to the extent of treatment benefit for patients with mild fibrosis. For HBV [hepatitis B e antigen (HBeAg)-negative)] this strategy had an ICER of £28,137, which was cost-effective only if the upper bound of the standard UK cost-effectiveness threshold range (£30,000) is acceptable. For HBeAg-positive disease, two NILTs applied sequentially (hyaluronic acid and magnetic resonance elastography) were cost-effective at a £20,000 threshold (ICER: £19,612); however, the results were highly uncertain, with several test strategies having similar expected outcomes and costs. For patients with ALD, liver biopsy was the cost-effective strategy, with an ICER of £822.

LIMITATIONS

A substantial number of tests had only one study from which diagnostic accuracy was derived; therefore, there is a high risk of bias. Most NILTs did not have validated cut-offs for diagnosis of specific fibrosis stages. The findings of the ALD model were dependent on assuptions about abstinence rates assumptions and the modelling approach for NAFLD was hindered by the lack of evidence on clinically effective treatments.

CONCLUSIONS

Treating everyone without NILTs is cost-effective for patients with HCV, but only for HBeAg-negative if the higher cost-effectiveness threshold is appropriate. For HBeAg-positive, two NILTs applied sequentially were cost-effective but highly uncertain. Further evidence for treatment effectiveness is required for ALD and NAFLD.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42011001561.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Non-invasive diagnosis of liver fibrosis and cirrhosis

The evaluation and follow up of liver fibrosis and cirrhosis have been traditionally performed by liver biopsy. However, during the last 20 years, it has become evident that this “gold-standard” is imperfect; even according to its proponents, it is only “the best” among available methods. Attempts at uncovering non-invasive diagnostic tools have yielded multiple scores, formulae, and imaging modalities. All are better tolerated, safer, more acceptable to the patient, and can be repeated essentially as often as required. Most are much less expensive than liver biopsy. Consequently, their use is growing, and in some countries the number of biopsies performed, at least for routine evaluation of hepatitis B and C, has declined sharply. However, the accuracy and diagnostic value of most, if not all, of these methods remains controversial. In this review for the practicing physician, we analyze established and novel biomarkers and physical techniques. We may be witnessing in recent years the beginning of the end of the first phase for the development of non-invasive markers. Early evidence suggests that they might be at least as good as liver biopsy. Novel experimental markers and imaging techniques could produce a dramatic change in diagnosis in the near future.

Hyaluronic acid as a non-invasive biomarker of liver fibrosis

Chronic liver diseases may cause inflammation and progressive scarring, over time leading to irreversible hepatic damage (cirrhosis). As a result, the need to assess and closely monitor individuals for risk factors of components of matrix deposition and degradation, as well as the severity of the fibrosis using biomarkers, has been increasingly recognized.

AIM

Our aim is to review the use of biomarker for diagnosing and defining the severity of liver fibrosis.

METHODS

A systematic literature review was done using the terms "hyaluronic acid" and "liver fibrosis" as well as the name of each biomarker or algorithm known to be employed. PubMed and Google Scholar were searched, and English language articles indexed between January 2010 and October 2014 in which HA was used as a marker of liver fibrosis were retrieved, regardless of the underlying liver disease. Each author read the publications separately and the results were analyzed and discussed.

RESULTS

Biomarkers offer a potential prognostic or diagnostic indicator for disease manifestation, progression, or both. Serum biomarkers, including HA, have been used for many years. Emerging biomarkers such as metalloproteinases have been proposed as tools that provide valuable complementary information to that obtained from traditional biomarkers. Moreover, markers of extracellular matrix degradation provide powerful predictions of risk. In order for biomarkers to be clinically useful in accurately diagnosing and treating disorders, age-specific reference intervals that account for differences in gender and ethnic origin are a necessity.

CONCLUSIONS

This review attempts to provide a comprehensive analysis of the emerging risk biomarkers of liver fibrosis and to describe the clinical significance and analytical considerations of each biomarker pointing out sentinel features of disease progression.

Potential associations between perihepatic lymph node enlargement and liver fibrosis, hepatocellular injury or hepatocarcinogenesis in chronic hepatitis B virus infection

AIM

Although perihepatic lymph node enlargement (PLNE) is frequently observed in chronic liver disease, little is known about PLNE in chronic hepatitis B virus (HBV) infection. We aimed to evaluate this issue.

METHODS

We originally enrolled a consecutive 502 patients with chronic HBV infection. Among them, 288 patients without history of interferon-based or nucleoside analog treatment and hepatocellular carcinoma (HCC) were primarily analyzed.

RESULTS

PLNE was detected in 27 of 288 (9.4%) patients, which was fewer than that in chronic hepatitis C patients but more than that in subjects undertaking a general health examination as previously reported. The presence of PLNE was significantly associated with a higher probability of having an aspartate aminotransferase (AST) platelet ratio index of more than 1.5 (11.1% vs 1.5%, P = 0.01), a higher AST level (38.0 vs 26.8 U/L, P = 0.001), a higher alanine aminotransferase level (50.1 vs 28.0 U/L, P < 0.0001), and a lower platelet count (18.6 vs 20.6 × 10(4) /μL, P = 0.048) after adjustment for sex and age. However, in our original sample (n = 502), PLNE was observed in 1.4% of the patients with HCC and/or its history whereas 9.2% of the patients without HCC, and the proportion was significantly lower in patients with HCC and/or its history (P = 0.03).

CONCLUSION

PLNE was associated with liver fibrosis and hepatocellular injury, but was negatively associated with HCC in chronic HBV infection.

Serum HBsAg and HBeAg levels are associated with liver pathological stages in the immune clearance phase of hepatitis B virus chronic infection

The association between hepatitis B surface antigen (HBsAg) and hepatitis B 'e' antigen (HBeAg) levels and liver inflammation and fibrosis in patients with chronic hepatitis B (CHB) in the immune clearance (IC) remains elusive. The aim of the present study was to investigate whether HBsAg and HBeAg levels were associated with liver inflammation and fibrosis in CHB patients during the IC phase. Kendall's rank correlation analysis and receiver operating characteristic curves were used to determine the correlation between HBsAg, HBeAg and liver pathological stages. Multivariate analysis by forward logistic regression was used to analyze significant predictors of cirrhosis. A liver pathology‑predicting model (IC model), which used routinely assessed markers in combination with HBsAg and HBeAg levels, was constructed. There were significantly positive correlations between the HBsAg and HBeAg levels (γ=0.317, P<0.001), and between the HBsAg and HBV‑DNA levels (γ=0.489, P<0.001). However, there was no correlation between the HBsAg and alanine aminotransferase levels. HBsAg and HBeAg levels differed significantly at various liver pathological stages and declined progressively in advanced liver pathological stages. Multivariate logistic regression analysis showed that age, HBsAg and HBeAg levels as well as the international normalized ratio (INR) were independent predictors of liver fibrosis during the IC phase. The IC model had a specificity and sensitivity of 88.64 and 78.24%, respectively, a positive predictive value of 48.15% and negative predictive value of 96.79%. In conclusion, HBsAg and HBeAg levels were negatively and indirectly correlated with liver inflammation and fibrosis in CHB patients in the IC phase. The IC model reliably predicted the probability of liver cirrhosis.

Impact of contacting study authors to obtain additional data for systematic reviews: diagnostic accuracy studies for hepatic fibrosis

BACKGROUND

Seventeen of 172 included studies in a recent systematic review of blood tests for hepatic fibrosis or cirrhosis reported diagnostic accuracy results discordant from 2 × 2 tables, and 60 studies reported inadequate data to construct 2 × 2 tables. This study explores the yield of contacting authors of diagnostic accuracy studies and impact on the systematic review findings.

METHODS

Sixty-six corresponding authors were sent letters requesting additional information or clarification of data from 77 studies. Data received from the authors were synthesized with data included in the previous review, and diagnostic accuracy sensitivities, specificities, and positive and likelihood ratios were recalculated.

RESULTS

Of the 66 authors, 68% were successfully contacted and 42% provided additional data for 29 out of 77 studies (38%). All authors who provided data at all did so by the third emailed request (ten authors provided data after one request). Authors of more recent studies were more likely to be located and provide data compared to authors of older studies. The effects of requests for additional data on the conclusions regarding the utility of blood tests to identify patients with clinically significant fibrosis or cirrhosis were generally small for ten out of 12 tests. Additional data resulted in reclassification (using median likelihood ratio estimates) from less useful to moderately useful or vice versa for the remaining two blood tests and enabled the calculation of an estimate for a third blood test for which previously the data had been insufficient to do so. We did not identify a clear pattern for the directional impact of additional data on estimates of diagnostic accuracy.

CONCLUSIONS

We successfully contacted and received results from 42% of authors who provided data for 38% of included studies. Contacting authors of studies evaluating the diagnostic accuracy of serum biomarkers for hepatic fibrosis and cirrhosis in hepatitis C patients impacted conclusions regarding diagnostic utility for two blood tests and enabled the calculation of an estimate for a third blood test. Despite relatively extensive efforts, we were unable to obtain data to resolve discrepancies or complete 2 × 2 tables for 62% of studies.

The diagnostic value of the FIB-4 index for staging hepatitis B-related fibrosis: a meta-analysis

Background

Liver fibrosis stage is an important factor in determining prognosis and need for treatment in patients infected with hepatitis B virus (HBV). Liver biopsies are typically used to assess liver fibrosis; however, noninvasive alternatives such as the FIB-4 index have also been developed.

Aims

To quantify the accuracy of the FIB-4 index in the diagnosis of HBV related fibrosis and cirrhosis.

Methods

A meta-analysis of studies comparing the diagnostic accuracy of the FIB-4 index vs. liver biopsy in HBV-infected patients was performed using studies retrieved from the following databases: PubMed, Ovid, EMBASE, the Cochrane Library, the Chinese National Knowledge Infrastructure and the Chinese Biology Medicine disc. A hierarchical summary receiver operating curves model and bivariate model were used to produce summary receiver operating characteristic curves and pooled estimates of sensitivity and specificity. The heterogeneity was explored with meta-regression analysis. Publication bias was detected using Egger’s test and the trim and fill method.

Results

12 studies (N = 1,908) and 10 studies (N = 2,105) were included in the meta-analysis for significant fibrosis and cirrhosis, respectively. For significant fibrosis, the area under the hierarchical summary receiver operating curve (AUHSROC) was 0.78 (95% CI = 0.74–0.81). The recommended cutoff value was between 1.45 and 1.62, and the AUHSROC, summary sensitivity and specificity were 0.78 (95% CI = 0.74–0.81), 0.65 (95% CI = 0.56–0.73) and 0.77 (95% CI = 0.7–0.83), respectively. For cirrhosis, the AUHSROC was 0.89 (95% CI = 0.85–0.91). The recommended cutoff value was between 2.9 and 3.6, and the AUHSROC, summary sensitivity and specificity were 0.96 (95% CI = 0.92–1.00), 0.42 (95% CI = 0.36–0.48) and 0.96 (95% CI = 0.95–0.97), respectively. No publication bias was detected.

Conclusions

The FIB-4 index is valuable for detecting significant fibrosis and cirrhosis in HBV-infected patients, but has suboptimal accuracy in excluding fibrosis and cirrhosis.

Prospective evaluation of FibroTest®, FibroMeter®, and HepaScore® for staging liver fibrosis in chronic hepatitis B: comparison with hepatitis C

BACKGROUND & AIMS

Fibrosis blood tests have been validated in chronic hepatitis C. Their diagnostic accuracy is less documented in hepatitis B. The aim of this study was to describe the diagnostic performance of FibroTest®, FibroMeter®, and HepaScore® for liver fibrosis in hepatitis B compared to hepatitis C.

METHODS

510 patients mono-infected with hepatitis B or C and matched on fibrosis stage were included. Blood tests were performed the day of the liver biopsy. Histological lesions were staged according to METAVIR.

RESULTS

Fibrosis stages were distributed as followed: F0 n=76, F1 n=192, F2 n=132, F3 n=54, F4 n=56. Overall diagnostic performance of blood tests were similar between hepatitis B and C with AUROC ranging from 0.75 to 0.84 for significant fibrosis, 0.82 to 0.85 for extensive fibrosis and 0.84 to 0.87 for cirrhosis. Optimal cut-offs were consistently lower in hepatitis B compared to hepatitis C, especially for the diagnosis of extensive fibrosis and cirrhosis, with decreased sensitivity and negative predictive values. More hepatitis B than C patients with F ⩾3 were underestimated: FibroTest®: 47% vs. 26%, FibroMeter®: 24% vs. 6%, HepaScore®: 41% vs. 24%, p<0.01. Multivariate analysis showed that hepatitis B (0R 3.4, 95% CI 1.2-19.2, p<0.02) and low γGT (OR 7.3, 95% CI 2.0-27.0, p<0.003) were associated with fibrosis underestimation.

CONCLUSION

Overall the diagnostic performance of blood tests is similar in hepatitis B and C. The risk of underestimating significant fibrosis and cirrhosis is however greater in hepatitis B and cannot be entirely corrected by the use of more stringent cut-offs.

The effectiveness of noninvasive biomarkers to predict hepatitis B-related significant fibrosis and cirrhosis: a systematic review and meta-analysis of diagnostic test accuracy

Noninvasive biomarkers have been developed to predict hepatitis B virus (HBV)-related fibrosis owing to the significant limitations of liver biopsy. Those biomarkers were initially derived from evaluation of hepatitis C virus (HCV)-related fibrosis, and their accuracy among HBV-infected patients was under constant debate. A systematic review was conducted on records in PubMed, EMBASE and the Cochrane Library electronic databases, up until April 1st, 2013, in order to systematically assess the effectiveness and accuracy of these biomarkers for predicting HBV-related fibrosis. The questionnaire for quality assessment of diagnostic accuracy studies (QUADAS) was used. Out of 115 articles evaluated for eligibility, 79 studies satisfied the pre-determined inclusion criteria for meta-analysis. Eventually, our final data set for the meta-analysis contained 30 studies. The areas under the SROC curve for APRI, FIB-4, and FibroTest of significant fibrosis were 0.77, 0.75, and 0.84, respectively. For cirrhosis, the areas under the SROC curve for APRI, FIB-4 and FibroTest were 0.75, 0.87, and 0.90, respectively. The heterogeneity of FIB-4 and FibroTest were not statistically significant. The heterogeneity of APRI for detecting significant fibrosis was affected by median age (P = 0.0211), and for cirrhosis was affected by etiology (P = 0.0159). Based on the analysis we claim that FibroTest has excellent diagnostic accuracy for identification of HBV-related significant fibrosis and cirrhosis. FIB-4 has modest benefits and may be suitable for wider scope implementation.

FibroTest/Fibrosure for significant liver fibrosis and cirrhosis in chronic hepatitis B: a meta-analysis

OBJECTIVES

Extent of liver fibrosis is one of the most important factors in determining prognosis and the need for active treatment in chronic hepatitis B (CHB). Noninvasive alternatives such as FibroTest/Fibrosure (FT) have been developed in order to overcome the shortcomings of liver biopsy (LB). We aimed to systematically review studies describing the diagnostic accuracy of FT for predicting CHB-related fibrosis.

METHODS

MEDLINE and EMBASE searches and hand searching methods were performed to identify studies that assessed the diagnostic accuracy of FibroTest in HB patients using LB as a reference standard. We used a hierarchical summary receiver operating curves model and the bivariate model to produce summary receiver operating characteristic curves and pooled estimates of sensitivity and specificity.

RESULTS

We included 16 studies (N=2494) and 13 studies (N=1754) in the heterogenous meta-analysis for liver fibrosis and cirrhosis, respectively. The area under the hierarchical summary receiver operating curve for significant liver fibrosis and for all included studies was 0.84 (95% confidence interval (CI): 0.78-0.88). At the FT threshold of 0.48, the sensitivity, specificity, and diagnostic odds ratio (DOR) of FT for significant fibrosis were 61 (48-72%), 80 (72-86%), and 6.2% (3.3-11.9), respectively. The area under the hierarchical summary receiver operating curve for liver cirrhosis and for all included studies was 0.87 (95% CI: 0.85-0.90). At the FT threshold of 0.74, the sensitivity, specificity, and DOR of FT for cirrhosis were 62 (47-75%), 91 (88-93%), and 15.7% (8.6-28.8), respectively.

CONCLUSIONS

FibroTest is of value in exclusion of patients with CHB-related cirrhosis, but has suboptimal accuracy in the detection of significant fibrosis and cirrhosis. It is necessary to further improve the test or combine it with other noninvasive modalities in order to improve accuracy.

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.

Treatment decisions and contemporary versus pending treatments for hepatitis C

The primary aim of antiviral therapy for chronic hepatitis C (CHC) is the prevention of progressive disease. A response to interferon (IFN) treatment is associated with an improvement in all-cause mortality and liver-related mortality from hepatitis C. Unless contraindicated, patients with CHC are thus potential candidates for treatment. Improved response rates are observed in patients with HCV genotype 1 infection treated with first-generation protease inhibitors. However, treatment with current first-generation protease inhibitors and IFN is complex and can result in appreciable adverse effects. The advent of potent, pan-genotypic all-oral direct-acting antiviral (DAA) regimens necessitates a critical examination of the immediate application of PEG-IFN, ribavirin and DAA regimens in patients with CHC. Current guidelines and position statements do not make clear recommendations, and are behind the emerging data. Some aspects of the conundrums facing physicians and patients are summarized in this Review. Cirrhosis presents an immediate threat of disease, and ideally treatment should be targeted at those patients who have advancing or advanced disease; unfortunately, a disparity exists, as response rates are reduced in patients with cirrhosis and the risks of adverse events are increased. On balance, patients with mild disease could consider deferring treatment.

Serum ceruloplasmin levels correlate negatively with liver fibrosis in males with chronic hepatitis B: a new noninvasive model for predicting liver fibrosis in HBV-related liver disease

AIMS

This study aimed to investigate associations between ceruloplasmin (CP) levels, inflammation grade and fibrosis stages in patients with chronic hepatitis B (CHB) and to establish a noninvasive model to predict cirrhosis.

METHODS

Liver biopsy samples and sera were collected from 198 CHB patients randomized into a training group (n=109) and a validation group (n=89). CP levels were determined using nephelometric immunoassays. Relationships between CP and liver inflammation and fibrosis were analyzed by Spearman rank correlation. Receiver operator characteristic (ROC) curves were used to evaluate the diagnostic value of CP for determining liver fibrosis in CHB. The liver pathology-predictive model was built using multivariate logistic regression analysis to identify relevant indicators.

RESULTS

CP levels were lower in males than in females, lower in patients with inflammation stage G4 compared to other stages and lower in cirrhotic compared to non-cirrhotic patients. Using area under the curve (AUC) values, CP levels distinguished different stages of inflammation and fibrosis. Multivariate analysis showed that CP levels were all significantly associated with cirrhosis in males. A model was developed combining routine laboratory markers APPCI (alpha-fetoprotein [AFP], prothrombin time, and platelets [PLT] with CP) to predict fibrosis in CHB patients. The APPCI had a significantly greater AUC than FIB-4 (aspartate aminotransferase [AST]/ alanine aminotransferase [ALT]/PLT/age), APRI (AST/PLT ratio index), GPI (globin/PLT), and APGA (AST/PLT/gammaglutamyl transpeptidase [GGT]) models (all P-values<0.001).

CONCLUSIONS

CP levels correlate negatively and indirectly with inflammation and fibrosis stages in male CHB patients. The APPCI model uses routine laboratory variables with CP to accurately predict liver fibrosis in CHB.

Assessment of hepatic detoxification activity: proposal of an improved variant of the (13)c-methacetin breath test

Breath tests based on the administration of a (13)C-labeled drug and subsequent monitoring of (13)CO2 in the breath (quantified as DOB - delta over baseline) liberated from the drug during hepatic CPY-dependent detoxification are important tools in liver function diagnostics. The capability of such breath tests to reliably indicate hepatic CYP performance is limited by the fact that (13)CO2 is not exclusively exhaled but also exchanged with other compartments of the body. In order to assess this bias caused by variations of individual systemic CO2 kinetics we administered intravenously the test drug (13)C-methacetin to 25 clinically liver-healthy individuals and monitored progress curves of DOB and the plasma concentration of (13)C-methacetin. Applying compartment modelling we estimated for each individual a set of kinetic parameters characterizing the time-dependent exchange of the drug and of CO2 with the liver and non-hepatic body compartments. This analysis revealed that individual variations in the kinetics of CO2 may account for up to 30% deviation of DOB curve parameters from their mean at otherwise identical (13)C-methacetin metabolization rates. In order to correct for this bias we introduced a novel detoxification score which ideally should be assessed from the DOB curve of a 2-step test ("2DOB") which is initialized with the injection of a standard dose of (13)C-labeled bicarbonate (in order to provide information on the actual CO2 status of the individual) followed by injection of the (13)C-labeled test drug (the common procedure). Computer simulations suggest that the predictive power of the proposed 2DOB breath test to reliably quantity the CYP-specific hepatic detoxification activity should be significantly higher compared to the conventional breath test.

Application and limitations of transient liver elastography in children

OBJECTIVES

Transient elastography (TE) using the FibroScan has gained popularity recently for the noninvasive diagnosis of hepatic fibrosis. Data on its use in children younger than 6 years are still scarce, and the influence of technical aspects such as probe choice and site of measurement on FibroScan results is not clear. Our study aims to clarify some technical issues concerning the use of the FibroScan in children and to deliver normal FibroScan values for reference.

METHODS

TE was performed in 527 children (229 girls, ages 0.1-17.8 [median 6.0] years, including 400 healthy controls). Feasibility of different sites of measurements, paired comparison of probe settings, and pre- and postprandial measurements were systematically performed. Sedated versus unsedated measurements were compared in age- and sex-matched cohorts.

RESULTS

Success rate of TE in our population was 90%, but decreased to 83% in children younger than 24 months even in ideal conditions. General anesthesia significantly increased liver stiffness in healthy children (5.4 [3-9.5] vs 4.2 [2.8-8.15] kPa; P < 0.01). Probe choice equally influenced results in paired comparisons (S1 5.5 [3.5-17.9] vs S2 4.8 [2.1-15.4] kPa; P < 0.01), as did food intake (5.9 [3.6-75] vs 5.4 [3.6-63.9] kPa; P = 0.015). Inter- and intraobserver agreements were good. Normal liver stiffness was 4.5 (2.5-8.9) kPa and did not vary significantly with age or sex.

CONCLUSIONS

TE is feasible even in extremely young children, but confounding influences on test results such as probe choice, sedation, or food intake need to be taken into account when interpreting results.

Development of a non-invasive fibrosis test for chronic hepatitis B patients and comparison with other unpatented scores

BACKGROUND

Despite the availability of patented non-invasive methods, evaluation of the degrees of liver fibrosis remains difficult when conducting a retrospective study. Such inadequacy is largely caused by requirement of biochemical parameters rarely performed in routine clinical tests. We developed a novel fibrosis HB-F score using commonly performed tests for HBV infected patients.

METHODS

424 patients with chronic HBV infection were included. Using clinical and virological data, HB-F score was developed from a training cohort (n = 213) and validated in a separate cohort (n = 211). The performance was compared with five other unpatented scores using ROC curves.

RESULTS

Univariate and multivariate analysis revealed that age, AST/ALT ratio, platelet count and prothrombin time prolongation were significantly associated with the ISHAK fibrosis score, and were used to calculate the HB-F score. When HB-F was used to assess prominent fibrosis and cirrhosis, the AUC was 0.81 and 0.80 respectively in the training cohort, and 0.80 and 0.76 respectively in the validation cohort. HB-F had the highest AUC compared with other scores. Furthermore, in assessing paired liver biopsies with increase or decrease of ISHAK scores, HB-F showed significant change in the same direction.

CONCLUSIONS

A new non-invasive score was developed, which could be used to assess severity of liver fibrosis in retrospective longitudinal studies in HBV patients.

Clinical utility of 13C-liver-function breath tests for assessment of hepatic function

13C-Liver-function breath tests have been used in clinical diagnostics and, to a limited extent, to investigate hepatic function. From a practical perspective, tests such as the 13C-aminopyrine and 13C-methacetin breath tests are simple to administer, safe, and relatively inexpensive to perform. Surprisingly, they have not entered the mainstream of clinical practice, because they are perceived to lack the specificity and adequate precision needed to give accurate results in real time. The dynamic nature of 13C-liver-function breath tests, their possible versatility in terms of assessing a range of different liver functions, and the ease with which they can be repeated to follow relative changes in liver function with time, all imply the potential for wider clinical application. Therefore, there is a need for these tests to be critically evaluated and their potential clinical application be tested systematically against defined objectives. We describe refinements in the methodology of the tests and propose several situations in which currently reliable methods for assessment of liver function do not exist and where 13C-liver-function breath tests might be of use. We propose that use has been constrained by practical methodological considerations which could be addressed to offer tests better suited to routine application in the out-patient or community setting.

Interobserver discrepancy in liver fibrosis using transient elastography

Transient elastography is a useful method to assess liver fibrosis, but uncertainties still exist regarding reliability and reproducibility of the technique. We aimed to improve knowledge on interobserver variability with the procedure and tried to find factors associated with such variability. This was a cross-sectional study to compare the results of transient elastography performed by two different operators, one test made just after the other. We assessed both results with correlation tests and with repeated parametric or nonparametric tests, as needed. We also carried out a multivariate analysis to find factors associated with discrepancy in the results obtained by the two operators. We included a total of 333 pairs of transient elastography tests, belonging to 274 different patients. A total of 325 pairs of tests (97.6%) were valid. Results of the first and the second tests were, respectively, median (and interquartile range) of direct measurement 6.2 (4.6-10.6) and 6.0 (4.4-10.1) kPa (P = 0.012), and mean ± standard deviation of log(10) of direct measurement 0.892 ± 0.316 and 0.871 ± 0.324 (P = 0.001). In 87 pairs of tests (26.7%), a discrepancy of at least 2 kPa between both results was found, and in 15 pairs of tests (4.6%), a discrepancy of at least 10 kPa was found. Discordance of at least one stage between both measurements was noted in 74 pairs of tests (22.8%). An association was found between higher stiffness and discrepancy between both operators (P < 0.001). Although transient elastography is a very convenient test to assess liver fibrosis in clinical practice, interobserver discrepancy in results is common and represents a significant problem with the technique. Discrepant results are more common in patients with higher values of stiffness.

Globulin-platelet model predicts minimal fibrosis and cirrhosis in chronic hepatitis B virus infected patients

AIM: To establish a simple model consisting of the routine laboratory variables to predict both minimal fibrosis and cirrhosis in chronic hepatitis B virus (HBV)-infected patients.

METHODS: We retrospectively investigated 114 chronic HBV-infected patients who underwent liver biopsy in two different hospitals. Thirteen parameters were analyzed by step-wise regression analysis and correlation analysis. A new fibrosis index [globulin/platelet (GP) model] was developed, including globulin (GLOB) and platelet count (PLT). GP model = GLOB (g/mL) × 100/PLT (× 10⁹/L). We evaluated the receiver operating characteristics analysis used to predict minimal fibrosis and compared six other available models.

RESULTS: Thirteen clinical biochemical and hematological variables [sex, age, PLT, alanine aminotransferase, aspartate aminotransferase (AST), albumin, GLOB, total bilirubin (T.bil), direct bilirubin (D.bil), glutamyltransferase, alkaline phosphatase, HBV DNA and prothrombin time (PT)] were analyzed according to three stages of liver fibrosis (F0-F1, F2-F3 and F4). Bivariate Spearman’s rank correlation analysis showed that six variables, including age, PLT, T.bil, D.bil, GLOB and PT, were correlated with the three fibrosis stages (FS). Correlation coefficients were 0.23, -0.412, 0.208, 0.220, 0.314 and 0.212; and P value was 0.014, < 0.001, 0.026, 0.018, 0.001 and 0.024, respectively. Univariate analysis revealed that only PLT and GLOB were significantly different in the three FS (PLT: F = 11.772, P < 0.001; GLOB: F = 6.612, P = 0.002). Step-wise multiple regression analysis showed that PLT and GLOB were also independently correlated with FS (R² = 0.237). By Spearman’s rank correlation analysis, GP model was significantly correlated with the three FS (r = 0.466, P < 0.001). The median values in F0-F1, F2-F3 and F4 were 1.461, 1.720 and 2.634. Compared with the six available models (fibrosis index, AST-platelet ratio, FIB-4, fibrosis-cirrhosis index and age-AST model and age-PLT ratio), GP model showed a highest correlation coefficient. The sensitivity and positive predictive value at a cutoff value < 1.68 for predicting minimal fibrosis F0-F1 were 72.4% and 71.2%, respectively. The specificity and negative predictive value at a cutoff value < 2.53 for the prediction of cirrhosis were 84.5% and 96.7%. The area under the curve (AUC) of GP model for predicting minimal fibrosis and cirrhosis was 0.762 [95% confidence interval (CI): 0.676-0.848] and 0.781 (95% CI: 0.638-0.924). Although the differences were not statistically significant between GP model and the other models (P all > 0.05), the AUC of GP model was the largest among the seven models.

CONCLUSION: By establishing a simple model using available laboratory variables, chronic HBV-infected patients with minimal fibrosis and cirrhosis can be diagnosed accurately, and the clinical application of this model may reduce the need for liver biopsy in HBV-infected patients.

Prospective validation of FibroTest in comparison with liver stiffness for predicting liver fibrosis in Asian subjects with chronic hepatitis B

BACKGROUND AND AIMS

Diagnostic values of FibroTest (FT) for hepatic fibrosis have rarely been assessed in Asian chronic hepatitis B (CHB) patients. We aimed to validate its diagnostic performances in comparison with liver stiffness (LS).

METHODS

From 2008 to 2010, 194 CHB patients who underwent liver biopsies along with FT and transient elastography were prospectively enrolled. Fibrosis stage was assessed according to the Batts and Ludwig system.

RESULTS

To predict significant fibrosis (F≥2), advanced fibrosis (F≥3), and cirrhosis (F = 4), areas under receiver operating characteristic curves (AUROCs) of FT were 0.903, 0.907, and 0.866, comparable to those of LS (0.873, 0.897, and 0.910, respectively). Optimized cutoffs of FT to maximize sum of sensitivity and specificity were 0.32, 0.52, and 0.68 for F≥2, F≥3, and F = 4, while those of LS were 8.8, 10.2, and 14.1 kPa, respectively. According to FT and LS cutoffs, 123 (63.4%) and 124 (63.9%) patients were correctly classified consistent with histological fibrosis (F1, F2, F3, and F4), respectively. Overall concordance between each fibrosis stage estimated by FT and LS was observed in 111 patients, where 88 were correctly classified with histological results. A combination formula adding LS to FT (LS+FT) showed similar AUROC levels (0.885, 0.905, and 0.915), while another multiplying LS by FT (LS×FT) showed the best AUROCs (0.941, 0.931, and 0.929 for F≥2, F≥3, and F4, respectively).

CONCLUSIONS

FT provides good fibrosis prediction, with comparable outcomes to LS in Asian CHB patients. FT substantially reduces need for liver biopsy, especially when used in combination with LS.

Flow injection/sequential injection analysis systems: potential use as tools for rapid liver diseases biomarker study

Flow injection/sequential injection analysis (FIA/SIA) systems are suitable for carrying out automatic wet chemical/biochemical reactions with reduced volume and time consumption. Various parts of the system such as pump, valve, and reactor may be built or adapted from available materials. Therefore the systems can be at lower cost as compared to other instrumentation-based analysis systems. Their applications for determination of biomarkers for liver diseases have been demonstrated in various formats of operation but only a few and limited types of biomarkers have been used as model analytes. This paper summarizes these applications for different types of reactions as a guide for using flow-based systems in more biomarker and/or multibiomarker studies.