Liver fibrosis assessment with semiquantitative indexes and image analysis quantification in sustained-responder and non-responder interferon-treated patients with chronic hepatitis C

Dual elastography to discriminate adjacent stages of fibrosis and inflammation in chronic hepatitis B: A prospective multicenter study

BACKGROUND AND AIMS

To evaluate the diagnostic performance of dual elastography (dual-elasto) in continuous differentiation of liver fibrosis and inflammation in a large prospective cohort of patients with chronic HBV.

APPROACH AND RESULTS

Adults with positive HBsAg for at least 6 months were recruited from 12 medical centers. Participants underwent dual-elasto evaluations. Biopsy was performed 3 days after dual-elasto examination. Four logistic regression models were trained and strung together into series models. Decision trees based on the series models were performed to achieve continuous differentiation of liver fibrosis and inflammation. The influence of inflammation on the fibrosis stage was also evaluated. A total of 560 patients were included in the training set and 240 in the validation set. Areas under the receiver operating characteristic curve of the series model were 0.82, 0.86, 0.93, and 0.96 to predict ≥F1, ≥F2, ≥F3, and F4 in the validation set, which were significantly higher than those of serum markers and shear wave elastography (all p < 0.05), except for the ≥ F1 levels ( p = 0.09). The AUCs of the series model were 0.93, 0.86, 0.95, and 0.84 to predict inflammation stages ≥G1, ≥G2, ≥G3, and G4, respectively. Decision trees realized 5 continuous classifications of fibrosis and inflammation. Inflammation could enhance the mild fibrosis stage classification while showing limited influences on severe fibrosis or cirrhosis diagnosis.

CONCLUSIONS

Dual-elasto demonstrated high performance in the continuous discrimination of fibrosis and inflammation in patients with HBV and could be used to diagnose mild fibrosis without the influence of inflammation.

Segmentation algorithm can be used for detecting hepatic fibrosis in SD rat

BACKGROUND

Liver fibrosis is an early stage of liver cirrhosis. As a reversible lesion before cirrhosis, liver failure, and liver cancer, it has been a target for drug discovery. Many antifibrotic candidates have shown promising results in experimental animal models; however, due to adverse clinical reactions, most antifibrotic agents are still preclinical. Therefore, rodent models have been used to examine the histopathological differences between the control and treatment groups to evaluate the efficacy of anti-fibrotic agents in non-clinical research. In addition, with improvements in digital image analysis incorporating artificial intelligence (AI), a few researchers have developed an automated quantification of fibrosis. However, the performance of multiple deep learning algorithms for the optimal quantification of hepatic fibrosis has not been evaluated. Here, we investigated three different localization algorithms, mask R-CNN, DeepLabV3⁺, and SSD, to detect hepatic fibrosis.

RESULTS

5750 images with 7503 annotations were trained using the three algorithms, and the model performance was evaluated in large-scale images and compared to the training images. The results showed that the precision values were comparable among the algorithms. However, there was a gap in the recall, leading to a difference in model accuracy. The mask R-CNN outperformed the recall value (0.93) and showed the closest prediction results to the annotation for detecting hepatic fibrosis among the algorithms. DeepLabV3⁺ also showed good performance; however, it had limitations in the misprediction of hepatic fibrosis as inflammatory cells and connective tissue. The trained SSD showed the lowest performance and was limited in predicting hepatic fibrosis compared to the other algorithms because of its low recall value (0.75).

CONCLUSIONS

We suggest it would be a more useful tool to apply segmentation algorithms in implementing AI algorithms to predict hepatic fibrosis in non-clinical studies.

Unpaired virtual histological staining using prior-guided generative adversarial networks

Fibrosis is an inevitable stage in the development of chronic liver disease and has an irreplaceable role in characterizing the degree of progression of chronic liver disease. Histopathological diagnosis is the gold standard for the interpretation of fibrosis parameters. Conventional hematoxylin-eosin (H&E) staining can only reflect the gross structure of the tissue and the distribution of hepatocytes, while Masson trichrome can highlight specific types of collagen fiber structure, thus providing the necessary structural information for fibrosis scoring. However, the expensive costs of time, economy, and patient specimens as well as the non-uniform preparation and staining process make the conversion of existing H&E staining into virtual Masson trichrome staining a solution for fibrosis evaluation. Existing translation approaches fail to extract fiber features accurately enough, and the decoder of staining is unable to converge due to the inconsistent color of physical staining. In this work, we propose a prior-guided generative adversarial network, based on unpaired data for effective Masson trichrome stained image generation from the corresponding H&E stained image. Conducted on a small training set, our method takes full advantage of prior knowledge to set up better constraints on both the encoder and the decoder. Experiments indicate the superior performance of our method that surpasses the previous approaches. For various liver diseases, our results demonstrate a high correlation between the staging of real and virtual stains (ρ=0.82; 95% CI: 0.73-0.89). In addition, our finetuning strategy is able to standardize the staining color and release the memory and computational burden, which can be employed in clinical assessment.

Microcirculatory changes in the liver of patients with refractory ascites and their relationship with diabetes and alcohol

OBJECTIVES

The determinants of refractory ascites have not been fully characterized. The aims of this study were to assess liver histopathological alterations associated with refractory ascites and their relationship with comorbidities.

METHODS

Consecutive patients with cirrhosis who underwent liver transplantation were retrospectively included. Patients' characteristics at the time of listing were analysed. The native livers were reviewed and lesions associated with refractory ascites were examined.

RESULTS

Out of the 89 patients included, 30 had refractory ascites and 59 did not (including 35 without ascites and 24 with diuretic-sensitive ascites). Patients with and without refractory ascites had a similar amount of fibrous tissue and features of fatty liver disease. By contrast, microvascular changes, namely sinusoidal dilatation (P < 0.001), diffuse perisinusoidal fibrosis (P = 0.001), hepatic venous thromboses (P = 0.004) and vascular proliferation (P = 0.01) were more frequently observed in the livers of patients with refractory ascites. Diabetes (57% vs. 31%, P = 0.02) and alcohol as a causal factor for cirrhosis (80% vs. 42%, P = 0.001) were more frequent in patients with refractory ascites than in those without. By multivariate analysis, refractory ascites was independently associated with diabetes mellitus [odds ratio (OR) (95% confidence interval, CI) 6.15 (1.47-25.71); P = 0.01], alcohol as a causal factor for cirrhosis [OR (95% CI) 4.63 (1.07-20.02); P = 0.04], higher Model For End Stage Liver Diseases [OR (95% CI) 1.21 (1.05-1.38); P = 0.008] and lower serum sodium [OR (95% CI) 0.87 (0.78-0.98); P = 0.03].

CONCLUSION

Liver microcirculatory changes are associated with refractory ascites. Diabetes and alcohol may explain refractory ascites by causing microangiopathy.

SOFTWARE-ASSISTED IMAGE ANALYSIS FOR IDENTIFICATION AND QUANTIFICATION OF HEPATIC SINUSOIDAL DILATATION AND CENTRILOBULAR FIBROSIS

Background:

Heart dysfunction and liver disease often coexist because of systemic disorders. Any cause of right ventricular failure may precipitate hepatic congestion and fibrosis. Digital image technologies have been introduced to pathology diagnosis, allowing an objective quantitative assessment. The quantification of fibrous tissue in liver biopsy sections is extremely important in the classification, diagnosis and grading of chronic liver disease.

Aim:

To create a semi-automatic computerized protocol to quantify any amount of centrilobular fibrosis and sinusoidal dilatation in liver Masson’s Trichrome-stained specimen.

Method:

Once fibrosis had been established, liver samples were collected, histologically processed, stained with Masson’s trichrome, and whole-slide images were captured with an appropriated digital pathology slide scanner. After, a random selection of the regions of interest (ROI’s) was conducted. The data were subjected to software-assisted image analysis (ImageJ^®).

Results:

The analysis of 250 ROI’s allowed to empirically obtain the best application settings to identify the centrilobular fibrosis (CF) and sinusoidal lumen (SL). After the establishment of the colour threshold application settings, an in-house Macro was recorded to set the measurements (fraction area and total area) and calculate the CF and SL ratios by an automatic batch processing.

Conclusion:

Was possible to create a more detailed method that identifies and quantifies the area occupied by fibrous tissue and sinusoidal lumen in Masson’s trichrome-stained livers specimens.

Evolution of the liver biopsy and its future

Liver biopsies are commonly used to evaluate a wide variety of medical disorders, including neoplasms and post-transplant complications. However, its use is being impacted by improved clinical diagnosis of disorders, and non-invasive methods for evaluating liver tissue and as a result the indications of a liver biopsy have undergone major changes in the last decade. The evolution of highly effective treatments for some of the common indications for liver biopsy in the last decade (e.g., viral hepatitis B and C) has led to a decline in the number of liver biopsies in recent years. At the same time, the emergence of better technologies for histologic evaluation, tissue content analysis and genomics are among the many new and exciting developments in the field that hold great promise for the future and are going to shape the indications for a liver biopsy in the future. Recent advances in slide scanners now allow creation of "digital/virtual" slides that have image of the entire tissue section present in a slide [whole slide imaging (WSI)]. WSI can now be done very rapidly and at very high resolution, allowing its use in routine clinical practice. In addition, a variety of technologies have been developed in recent years that use different light sources and/or microscopes allowing visualization of tissues in a completely different way. One such technique that is applicable to liver specimens combines multiphoton microscopy (MPM) with advanced clearing and fluorescent stains known as Clearing Histology with MultiPhoton Microscopy (CHiMP). Although it has not yet been extensively validated, the technique has the potential to decrease inefficiency, reduce artifacts, and increase data while being readily integrable into clinical workflows. Another technology that can provide rapid and in-depth characterization of thousands of molecules in a tissue sample, including liver tissues, is matrix assisted laser desorption/ionization (MALDI) mass spectrometry. MALDI has already been applied in a clinical research setting with promising diagnostic and prognostic capabilities, as well as being able to elucidate mechanisms of liver diseases that may be targeted for the development of new therapies. The logical next step in huge data sets obtained from such advanced analysis of liver tissues is the application of machine learning (ML) algorithms and application of artificial intelligence (AI), for automated generation of diagnoses and prognoses. This review discusses the evolving role of liver biopsies in clinical practice over the decades, and describes newer technologies that are likely to have a significant impact on how they will be used in the future.

Microscope-Based Automated Quantification of Liver Fibrosis in Mice Using a Deep Learning Algorithm

In preclinical studies that involve animal models for hepatic fibrosis, accurate quantification of the fibrosis is of utmost importance. The use of digital image analysis based on deep learning artificial intelligence (AI) algorithms can facilitate accurate evaluation of liver fibrosis in these models. In the present study, we compared the quantitative evaluation of collagen proportionate area in the carbon tetrachloride model of liver fibrosis in the mouse by a newly developed AI algorithm to the semiquantitative assessment of liver fibrosis performed by a board-certified toxicologic pathologist. We found an excellent correlation between the 2 methods of assessment, most evident in the higher magnification (×40) as compared to the lower magnification (×10). These findings strengthen the confidence of using digital tools in the toxicologic pathology field as an adjunct to an expert toxicologic pathologist.

Appraising diagnostic performance of ELF test by pathological staging and digital quantification of liver fibrosis

INTRODUCTION AND OBJECTIVES

A crucial issue when appraising the performance of non-invasive markers is the limitations of the reference standard they are compared to. Digital image analysis (DIA) was suggested as a reproducible approach expressing fibrosis numerically as a proportionate area (PA) (%). We aimed to evaluate ELF test with direct reference to PA (%), thereby explore the improvement in accuracy to discriminate significant fibrosis which may actually have been underestimated by categorical pathological staging.

MATERIALS AND METHODS

PA (%) data were obtained by DIA of trichrome-stained liver biopsies of 52 chronic hepatitis patients. Paired serum samples of patients and additional 36 controls were performed to measure ELF test. Diagnostic performance characteristics of ELF test was derived in predicting significant fibrosis in the patient cohort, and also, in distinguishing healthy controls from patients with significant fibrosis.

RESULTS

We found an AUROC value of 0.73 for ELF to predict significant fibrosis as assessed by DIA and a lower AUROC value of 0.66 when assessed by conventional pathology. Importantly, ELF test provided considerably high diagnostic accuracy to discriminate healthy controls from patients with significant fibrosis defined by Ishak F≥2 and TPA≥5% (AUROCs 0.93 and 0.94, respectively) with optimal ELF cut-off point of 8.4 for both.

CONCLUSIONS

Digital quantification could represent a better reference standard than conventional pathology allowing a better discriminatory capability for ELF test. ELF test provided high diagnostic accuracy to discriminate healthy controls from patients with significant fibrosis suggesting a role as a screening strategy in the community setting.

Quantitative assessment of liver fibrosis by digital image analysis reveals correlation with qualitative clinical fibrosis staging in liver transplant patients

Technologies for digitizing tissues provide important quantitative data for liver histopathology investigation. We aimed to assess liver fibrosis degree with quantitative morphometric measurements of histopathological sections utilizing digital image analysis (DIA) and to further investigate if a correlation with histopathologic scoring (Scheuer staging) exists. A retrospective study of patients with at least two post-liver transplant biopsies having a Scheuer stage of ≤ 2 at baseline were gathered. Portal tract fibrotic percentage (%) and size (μm²) were measured by DIA, while clinical fibrosis score was measured by the Scheuer system. Correlations between DIA measurements and Scheuer scores were computed by Spearman correlation analysis. Differences between mean levels of fibrosis (score, size, and percentage) at baseline versus second visit were computed by Student’s t-test. P values < 0.05 were considered significant. Of 22 patients who met the study criteria, 54 biopsies were included for analysis. Average levels ±standard error [S.E.] of portal tract fibrotic percentage (%) and size (μm²) progressed from 46.5 ± 3.6% at baseline to 61.8 ± 3.8% at the second visit (P = 0.005 by Student’s t-test), and from 28,075 ± 3,232 μm² at base line to 67,146 ± 10,639 μm² at the second visit (P = 0.002 by Student’s t-test), respectively. Average levels of Scheuer fibrosis scores progressed from 0.55±0.19 at baseline to 1.14±0.26 at the second visit (P = 0.02 by Student’s t-test). Portal tract fibrotic percentage (%) and portal tract fibrotic size were directly correlated with clinical Scheuer fibrosis stage, with Spearman correlation coefficient and P value computed as r = 0.70, P < 0.0001 and r = 0.41, P = 0.002, respectively. Digital quantitative assessment of portal triad size and fibrosis percentage demonstrates a strong correlation with visually assessed histologic stage of liver fibrosis and complements the standard assessment for allograft monitoring, suggesting the utility of future WSI analysis.

Automated quantification and architectural pattern detection of hepatic fibrosis in NAFLD

Accurate detection and quantification of hepatic fibrosis remain essential for assessing the severity of non-alcoholic fatty liver disease (NAFLD) and its response to therapy in clinical practice and research studies. Our aim was to develop an integrated artificial intelligence-based automated tool to detect and quantify hepatic fibrosis and assess its architectural pattern in NAFLD liver biopsies. Digital images of the trichrome-stained slides of liver biopsies from patients with NAFLD and different severity of fibrosis were used. Two expert liver pathologists semi-quantitatively assessed the severity of fibrosis in these biopsies and using a web applet provided a total of 987 annotations of different fibrosis types for developing, training and testing supervised machine learning models to detect fibrosis. The collagen proportionate area (CPA) was measured and correlated with each of the pathologists semi-quantitative fibrosis scores. Models were created and tested to detect each of six potential fibrosis patterns. There was good to excellent correlation between CPA and the pathologist score of fibrosis stage. The coefficient of determination (R²) of automated CPA with the pathologist stages ranged from 0.60 to 0.86. There was considerable overlap in the calculated CPA across different fibrosis stages. For identification of fibrosis patterns, the models areas under the receiver operator curve were 78.6% for detection of periportal fibrosis, 83.3% for pericellular fibrosis, 86.4% for portal fibrosis and >90% for detection of normal fibrosis, bridging fibrosis, and presence of nodule/cirrhosis. In conclusion, an integrated automated tool could accurately quantify hepatic fibrosis and determine its architectural patterns in NAFLD liver biopsies.

Whole Slide Imaging and Its Applications to Histopathological Studies of Liver Disorders

Histological analysis of hepatic tissue specimens is essential for evaluating the pathology of several liver disorders such as chronic liver diseases, hepatocellular carcinomas, liver steatosis, and infectious liver diseases. Manual examination of histological slides on the microscope is a classically used method to study these disorders. However, it is considered time-consuming, limited, and associated with intra- and inter-observer variability. Emerging technologies such as whole slide imaging (WSI), also termed virtual microscopy, have increasingly been used to improve the assessment of histological features with applications in both clinical and research laboratories. WSI enables the acquisition of the tissue morphology/pathology from glass slides and translates it into a digital form comparable to a conventional microscope, but with several advantages such as easy image accessibility and storage, portability, sharing, annotation, qualitative and quantitative image analysis, and use for educational purposes. WSI-generated images simultaneously provide high resolution and a wide field of observation that can cover the entire section, extending any single field of view. In this review, we summarize current knowledge on the application of WSI to histopathological analyses of liver disorders as well as to understand liver biology. We address how WSI may improve the assessment and quantification of multiple histological parameters in the liver, and help diagnose several hepatic conditions with important clinical implications. The WSI technical limitations are also discussed.

Quantification of Liver Fibrosis—A Comparative Study

Liver disease has been targeted as the fifth most common cause of death worldwide and tends to steadily rise. In the last three decades, several publications focused on the quantification of liver fibrosis by means of the estimation of the collagen proportional area (CPA) in liver biopsies obtained from digital image analysis (DIA). In this paper, early and recent studies on this topic have been reviewed according to these research aims: the datasets used for the analysis, the employed image processing techniques, the obtained results, and the derived conclusions. The purpose is to identify the major strengths and “gray-areas” in the landscape of this topic.

Magnetic Resonance Elastography of Liver: Current Update

The first clinical application of magnetic resonance elastography (MRE) was in the evaluation of chronic liver disease (CLD) for detection and staging of liver fibrosis. In the past 10 years, MRE has been incorporated seamlessly into a standard magnetic resonance imaging (MRI) liver protocol worldwide. Liver MRE is a robust technique for evaluation of liver stiffness and is currently the most accurate noninvasive imaging technology for evaluation of liver fibrosis. Newer MRE sequences including spin-echo MRE and 3 dimensional MRE have helped in reducing the technical limitations of clinical liver MRE that is performed with 2D gradient recalled echo (GRE) MRE. Advances in MRE technology have led to understanding of newer mechanical parameters such as dispersion, attenuation, and viscoelasticity that may be useful in evaluating pathological processes in CLD and may prove useful in their management.This review article will describe the changes in CLD that cause an increase in stiffness followed by principle and technique of liver MRE. In the later part of the review, we will briefly discuss the advances in liver MRE.

Advanced septa size quantitation determines the evaluation of histological fibrosis outcome in chronic hepatitis B patients

Hepatitis B (HBV)-related fibrosis can be reversed after effective antiviral therapy. However, detailed changes of collagen characteristics during fibrosis regression remain unclear. Paired biopsy samples obtained from chronic hepatitis B patients were imaged with second harmonic generation/two photon excitation fluorescence (SHG/TPEF)-based microscopy to identify and quantify collagen features in portal, septal, and fibrillar areas. According to the changes of Ishak stage and qFibrosis score, a total of 117 patients with paired liver biopsy appeared to have four different outcomes after 78-week antiviral therapy: fast reverse (9%), reverse (63%), stable (15%), or progress (13%) on fibrosis. Among 71 collagen features identified by SHG/TPEF analysis, the most prominent fibrosis reversion occurred in the "septal" area, followed by the "fibrillar" area, but not in the "portal" area (P < 0.001). Further analysis of 1060 individual septa identified four parameters that correlated with fibrosis reversion: average width, maximum width, number of fibers, and number of cross-link fibers (P < 0.001). Average septal width was independently associated with regressive septa (odds ratio (OR) = 5.22, 95% confidence interval (CI): 4.17-6.53; P < 0.001), with an AUROC of 0.96 (95% CI: 0.95-0.97). The threshold used to discriminate reversal of fibrosis was 30 μm. In conclusion, septal collagen was determined to be the most useful histological feature for evaluation of dynamic changes in liver fibrosis. Septal width was the most predictive indicator of prognosis in liver fibrosis.

Platelets' increase is associated with improvement of liver fibrosis in entecavir-treated chronic hepatitis B patients with significant liver fibrosis

BACKGROUND AND AIM

Reduction of platelet count is often observed in chronic hepatitis B (CHB) patients with significant liver fibrosis. In this cohort study, we investigated whether platelets' increase after entecavir (ETV) therapy was associated with the improvement of liver fibrosis.

METHODS

We collected the data of a cohort 82 CHB patients with paired liver biopsies before and after 78-week ETV therapy, and assessed the platelets' change following the treatment and further investigated the associated clinical factors with platelets' change.

RESULTS

Platelet count increased after treatment, which occurred mainly in patients with low baseline level of platelet count (< 200 × 10⁹/L) or with significant fibrosis (Ishak ≥ 3). Regression analysis showed that baseline platelet count was the main factor associated with post-treatment increase of platelets (β = - 0.215, p = 0.015). In patients with significant fibrosis, correlation and linear regression analysis revealed that post-treatment platelets' increase was correlated with improvement of liver fibrosis assessed by reduction of quantitative collagen percentage area (r = 0.392, p = 0.006) (β = 2.449, p = 0.035), but no correlation between changes in platelet counts and Ishak fibrosis score. Receiver operating curve analysis showed an increase of 12.5 × 10⁹/L in platelet count could identify improvement of liver fibrosis (AUC = 0.70).

CONCLUSION

Platelets' increase after ETV therapy was associated to the improvement of liver fibrosis with reduction of collagen percentage area in CHB patients with significant fibrosis.

A methodology for automated CPA extraction using liver biopsy image analysis and machine learning techniques

BACKGROUND AND OBJECTIVE

Collagen proportional area (CPA) extraction in liver biopsy images provides the degree of fibrosis expansion in liver tissue, which is the most characteristic histological alteration in hepatitis C virus (HCV). Assessment of the fibrotic tissue is currently based on semiquantitative staging scores such as Ishak and Metavir. Since its introduction as a fibrotic tissue assessment technique, CPA calculation based on image analysis techniques has proven to be more accurate than semiquantitative scores. However, CPA has yet to reach everyday clinical practice, since the lack of standardized and robust methods for computerized image analysis for CPA assessment have proven to be a major limitation.

METHODS

The current work introduces a three-stage fully automated methodology for CPA extraction based on machine learning techniques. Specifically, clustering algorithms have been employed for background-tissue separation, as well as for fibrosis detection in liver tissue regions, in the first and the third stage of the methodology, respectively. Due to the existence of several types of tissue regions in the image (such as blood clots, muscle tissue, structural collagen, etc.), classification algorithms have been employed to identify liver tissue regions and exclude all other non-liver tissue regions from CPA computation.

RESULTS

For the evaluation of the methodology, 79 liver biopsy images have been employed, obtaining 1.31% mean absolute CPA error, with 0.923 concordance correlation coefficient.

CONCLUSIONS

The proposed methodology is designed to (i) avoid manual threshold-based and region selection processes, widely used in similar approaches presented in the literature, and (ii) minimize CPA calculation time.

Visual morphometry and three non-invasive markers in the evaluation of liver fibrosis in chronic liver disease

OBJECTIVE

Liver fibrosis is traditionally graded into categorical stages with cirrhosis as the highest stage. However, cirrhosis stage may vary between individuals widely in terms of the amount of fibrosis which is not assessed by traditional staging systems. We aimed to utilise visual morphometry to quantify the amount of fibrosis in liver biopsy and compare how non-invasive methods of quantifying liver fibrosis correlated with histological measures.

MATERIALS AND METHODS

Liver biopsy specimens from 115 consecutive chronic liver disease patients were assessed by a single pathologist for fibrosis stage by the Clinical Research Network and METAVIR systems as well as percentage fibrosis by visual morphometry. Liver T₁ relaxation times, liver stiffness measurement (LSM) by transient elastography and enhanced liver fibrosis (ELF) score were compared between fibrosis stages. In addition, these parameters were correlated with pathologist's visual estimate of percentage fibrosis and their predictive ability for advanced fibrosis and cirrhosis assessed by area under receiver operating curve (AUROC).

RESULTS

All four parameters increased sequentially from fibrosis stage F0 to F4 (p<.001 for each). AUROCs for advanced fibrosis and cirrhosis were 0.931 and 1.000 respectively for pathologist's estimate of fibrosis, 0.707 and 0.926 for ELF score, 0.763 and 0.972 for T₁ and 0.881 and 0.989 for LSM. LSM, ELF score and T₁ correlated significantly with pathologist's estimate of percentage fibrosis.

CONCLUSION

Non-invasive markers of fibrosis LSM, ELF and T₁ relaxation time provide continuous surrogates for categorical histopathological staging of fibrosis which can be useful as markers of progression and regression of fibrosis on follow-up.

A clustering based method for collagen proportional area extraction in liver biopsy images

Collagen Proportional Area (CPA) extraction using digital image analysis (DIA) in liver biopsies provides an effective way to estimate the liver disease staging. CPA represents accurately fibrosis expansion in liver tissue. This paper presents an automated clustering-based method for fibrosis detection and CPA computation. Initially, a k-means based approach is employed to detect the liver tissue and eliminate the background. Next, the method decides about the adequacy of current biopsy, according to the size of liver tissue. Biopsies which contain small and segmented specimens must be repeated. Since the tissue has been detected, fibrosis areas are also found in the tissue. Finally, CPA is computed. For the evaluation of the proposed method 25 images are employed and the percentage errors of CPA are computed for each image. In the majority of the cases, small variation of CPA is computed, comparing to the expert's annotation.

Transient elastography compared to liver biopsy and morphometry for predicting fibrosis in pediatric chronic liver disease: Does etiology matter?

AIM: To evaluate transient elastography (TE) as a noninvasive tool in staging liver fibrosis compared with liver biopsy and morphometry in children with different chronic liver diseases.

METHODS: A total of 90 children [50 with chronic hepatitis C virus (HCV), 20 with autoimmune hepatitis (AIH) and 20 with Wilson disease] were included in the study and underwent liver stiffness measurement (LSM) using TE. Liver biopsies were evaluated for fibrosis, qualitatively, by Ishak score and quantitatively by fibrosis area fraction (FAF) using digital image analysis (morphometry). LSM was correlated with fibrosis and other studied variables using spearman correlation. A stepwise multiple regression analysis was also performed to examine independent factors associated with LSM. Different cut-off values of LSM were calculated for predicting individual fibrosis stages using receiver-operating characteristic curve. Cut-off values with optimal clinical performance (optimal sensitivity and specificity simultaneously) were selected.

RESULTS: The majority of HCV group had minimal activity (80%) and no/mild fibrosis (72%). On the other hand, the majority of AIH group had mild to moderate activity (70%) and moderate to severe fibrosis (95%) and all Wilson disease group had mild to moderate activity (100%) and moderate to severe fibrosis (100%). LSM correlated significantly with both FAF and Ishak scores and the correlation appeared better with the latter (r = 0.839 vs 0.879, P < 0.0001 for both). LSM discriminated individual stages of fibrosis with high performance. Sensitivity ranged from 81.4% to 100% and specificity ranged from 75.0% to 97.2%. When we compared LSM values for the same stage of fibrosis, they varied according to the different etiologies. Higher values were in AIH (16.15 ± 7.23 kPa) compared to Wilson disease (8.30 ± 0.84 kPa) and HCV groups (7.43 ± 1.73 kPa). Multiple regression analysis revealed that Ishak fibrosis stage was the only independent variable associated with higher LSM (P < 0.0001).

CONCLUSION: TE appears reliable in distinguishing different stages of liver fibrosis in children. However, its values vary according to the disease type. For that, a disease-specific estimation of cut-off values for fibrosis staging is worthy.

Magnetic resonance elastography of abdomen

Many diseases cause substantial changes in the mechanical properties of tissue, and this provides motivation for developing methods to noninvasively assess the stiffness of tissue using imaging technology. Magnetic resonance elastography (MRE) has emerged as a versatile MRI-based technique, based on direct visualization of propagating shear waves in the tissues. The most established clinical application of MRE in the abdomen is in chronic liver disease. MRE is currently regarded as the most accurate noninvasive technique for detection and staging of liver fibrosis. Increasing experience and ongoing research is leading to exploration of applications in other abdominal organs. In this review article, the current use of MRE in liver disease and the potential future applications of this technology in other parts of the abdomen are surveyed.

Current strategies for quantitating fibrosis in liver biopsy

Objective:

The present mini-review updated the progress in methodologies based on using liver biopsy.

Data Sources:

Articles for study of liver fibrosis, liver biopsy or fibrosis assessment published on high impact peer review journals from 1980 to 2014.

Study Selection:

Key articles were selected mainly according to their levels of relevance to this topic and citations.

Results:

With the recently mounting progress in chronic liver disease therapeutics, comes by a pressing need for precise, accurate, and dynamic assessment of hepatic fibrosis and cirrhosis in individual patients. Histopathological information is recognized as the most valuable data for fibrosis assessment. Conventional histology categorical systems describe the changes of fibrosis patterns in liver tissue; but the simplified ordinal digits assigned by these systems cannot reflect the fibrosis dynamics with sufficient precision and reproducibility. Morphometric assessment by computer assist digital image analysis, such as collagen proportionate area (CPA), detects change of fibrosis amount in tissue section in a continuous variable, and has shown its independent diagnostic value for assessment of advanced or late-stage of fibrosis. Due to its evident sensitivity to sampling variances, morphometric measurement is feasible to be taken as a reliable statistical parameter for the study of a large cohort. Combining state-of-art imaging technology and fundamental principle in Tissue Engineering, structure-based quantitation was recently initiated with a novel proof-of-concept tool, qFibrosis. qFibrosis showed not only the superior performance to CPA in accurately and reproducibly differentiating adjacent stages of fibrosis, but also the possibility for facilitating analysis of fibrotic regression and cirrhosis sub-staging.

Conclusions:

With input from multidisciplinary innovation, liver biopsy assessment as a new “gold standard” is anticipated to substantially support the accelerated progress of Hepatology medicine.

Effects of ribavirin monotherapy on the viral population in patients with chronic hepatitis C genotype 1: direct sequencing and pyrosequencing of the HCV regions

Ribavirin remains essential to chronic hepatitis C treatment. This paper investigates the influence of ribavirin priming to steady state before combined pegylated-interferon/ribavirin treatment on viral kinetics, ribavirin trough concentrations, genetic variability within HCV-core, -NS5B and -NS5A, and response to antiviral therapy. A prospective cohort study was made of 27 chronic hepatitis C genotype 1 naïve patients who received four weeks of ribavirin followed by pegIFN-α-2a/ribavirin for 48 weeks (Group A). The results obtained were compared with those for a control/historical group (Group B). In addition, direct sequencing and pyrosequencing were applied to determine ribavirin monotherapy-induced sequence changes. The rapid, early, and sustained virological response values obtained were 48%, 89%, and 52%, respectively, in Group A, and 52%, 90%, and 52% in Group B (P > 0.05). In the four-week combined treatment, the Group A patients showed a greater decrease in HCV-RNA (2.3 log10  IU/ml vs. 1.2 log10  IU/ml; P = 0.04), lower alanine aminotransferase levels (23.5 ± 1.33 U/L vs. 60.11 ± 18 U/L; P < 0.001) and higher mean ribavirin trough concentrations (3.28 ± 1.26 mg/L vs. 1.74 ± 0.7 mg/L; P = 0.001). No general increase in rates of nucleotide substitutions in the ribavirin monotherapy-treated patients was observed in NS5B, ISDR, or PKRbd, but there was a decrease in silent mutations in the HCV core (P = 0.04). This result was confirmed by pyrosequencing in the NS5A region. It is concluded that the ribavirin priming combined treatment with pegIFN-α-2a does not improve sustained virological response rates in HCV genotype 1 naïve infected patients. However, the greater reductions in viral load and alanine aminotransferase levels, together with the higher ribavirin trough concentration values obtained, could reflect the greater effectiveness of the treatment. Ribavirin does not have a mutagenic effect on the virus in patients with chronic hepatitis C.

Magnetic resonance elastography of liver

Magnetic resonance elastography (MRE) assesses tissue stiffness in vivo by imaging propagating shear waves through the tissues and processing the wave information. MRE is a robust technology with excellent technical success; is applicable in almost all patients and body habitus; and has excellent reproducibility, repeatability, and interobserver agreement for assessing liver stiffness. It is currently the most accurate noninvasive technique for detection and staging of liver fibrosis and has the potential to replace liver biopsy. This article describes the principles and technique of MRE, current clinical applications, and emerging clinical indications.

Quantification of portal-bridging fibrosis area more accurately reflects fibrosis stage and liver stiffness than whole fibrosis or perisinusoidal fibrosis areas in chronic hepatitis C

Morphometry provides an objective evaluation of fibrosis in liver diseases. We developed an image analysis algorithm using automated thresholding and segmentation to separately quantify the areas and the fractal dimensions of portal-bridging fibrosis and perisinusoidal fibrosis in chronic hepatitis C liver biopsies. We studied 427 digitized liver biopsies and compared the automated measures of the different fibrosis compartments with (1) the Metavir F (fibrosis) and A (activity) histological scores, (2) the digitally assessed area of steatosis, and (3) the liver stiffness measured by elastography (Fibroscan). The perisinusoidal fibrosis area was higher than that of portal fibrosis in stages ≤F2; it reached its highest value in F2 stage and stabilized thereafter. The F3 stage was characterized by equal proportions of portal-bridging and perisinusoidal fibrosis, whereas portal-bridging area was predominant in cirrhosis. Measurement of portal-bridging fibrosis showed highly significantly different values between contiguous F stages; the ratio of portal-bridging fibrosis/perisinusoidal fibrosis displayed less overlap between Metavir stages than did the whole fibrosis area values. Fractal dimension showed that portal-bridging fibrosis tended to display a homogeneous surface-like spatial organization, whereas perisinusoidal fibrosis appeared more heterogeneous according to stage and curvilinear. The portal-bridging fibrosis area was low in cases with low Metavir activity and little steatosis, and became predominant with increasing activity and steatosis. Using stepwise multiple linear regression analysis, the liver stiffness was independently correlated to the portal-bridging fibrosis area (first step, P<0.001), the steatosis area (second step, P<0.001), and the Metavir A grade (third step, P=0.001), but not to the perisinusoidal fibrosis area. Automated quantification in a large cohort of chronic hepatitis C showed that perisinusoidal fibrosis progressively grew in early fibrosis stages but did not increase in septal or cirrhotic stages and that the portal-bridging fibrosis area appeared as a more accurate tool to assess fibrosis progression than the whole fibrosis area.

Quantification of myocardial fibrosis by digital image analysis and interactive stereology

BACKGROUND

Cardiac fibrosis disrupts the normal myocardial structure and has a direct impact on heart function and survival. Despite already available digital methods, the pathologist's visual score is still widely considered as ground truth and used as a primary method in histomorphometric evaluations. The aim of this study was to compare the accuracy of digital image analysis tools and the pathologist's visual scoring for evaluating fibrosis in human myocardial biopsies, based on reference data obtained by point counting performed on the same images.

METHODS

Endomyocardial biopsy material from 38 patients diagnosed with inflammatory dilated cardiomyopathy was used. The extent of total cardiac fibrosis was assessed by image analysis on Masson's trichrome-stained tissue specimens using automated Colocalization and Genie software, by Stereology grid count and manually by Pathologist's visual score.

RESULTS

A total of 116 slides were analyzed. The mean results obtained by the Colocalization software (13.72 ± 12.24%) were closest to the reference value of stereology (RVS), while the Genie software and Pathologist score gave a slight underestimation. RVS values correlated strongly with values obtained using the Colocalization and Genie (r>0.9, p<0.001) software as well as the pathologist visual score. Differences in fibrosis quantification by Colocalization and RVS were statistically insignificant. However, significant bias was found in the results obtained by using Genie versus RVS and pathologist score versus RVS with mean difference values of: -1.61% and 2.24%. Bland-Altman plots showed a bidirectional bias dependent on the magnitude of the measurement: Colocalization software overestimated the area fraction of fibrosis in the lower end, and underestimated in the higher end of the RVS values. Meanwhile, Genie software as well as the pathologist score showed more uniform results throughout the values, with a slight underestimation in the mid-range for both.

CONCLUSION

Both applied digital image analysis methods revealed almost perfect correlation with the criterion standard obtained by stereology grid count and, in terms of accuracy, outperformed the pathologist's visual score. Genie algorithm proved to be the method of choice with the only drawback of a slight underestimation bias, which is considered acceptable for both clinical and research evaluations.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/9857909611227193.

Hydrogels with differential and patterned mechanics to study stiffness-mediated myofibroblastic differentiation of hepatic stellate cells

The differentiation of hepatic stellate cells (HSCs) into myofibroblasts is a key event in liver fibrosis. Due to the local stiffening of the extracellular matrix (ECM) during fibrosis, it is of great interest to develop mimics that can be used to investigate the cellular response to changes in mechanics. Here, we used a step-wise hydrogel crosslinking technique, where macromolecules are crosslinked using a sequence of addition then UV light-mediated radical crosslinking, to generate hydrogels with tunable stiffness. Freshly isolated HSCs remained rounded with lipid droplets and high levels of PPARγ expression on soft substrates (E~2kPa); however, HSCs spread, lost their lipid droplets, and expressed high levels of α-smooth muscle actin (α-SMA) and type I collagen on stiff substrates (E~24kPa). Similarly, fully differentiated cells reverted to a quiescent state when plated on soft substrates. Stiffness-induced differentiation of HSCs was enhanced in the presence of exogenous TGF-β1, a dominant signal in fibrosis. When the UV-induced secondary crosslinking was restricted with a photomask to spatially control mechanics, HSCs responded based on the local hydrogel stiffness, although they remained quiescent on stiff substrates if the stiff feature size was not sufficient to allow cell spreading. This hydrogel system permits the investigation of HSC response to materials with diverse levels and spatially heterogeneous mechanical properties.

Correlation of MR elastography with morphometric quantification of liver fibrosis (Fibro-C-Index) in chronic hepatitis B

PURPOSE

We evaluated the correlation of MR Elastography (MRE) with morphometric assessment of liver fibrosis in chronic hepatitis B (CHB).

METHODS

Thirty-two patients with CHB underwent both MRE and a liver biopsy within a 6-month interval. MRE was performed using standard MRE sequence on a 1.5 Tesla clinical scanner. The liver stiffness (LS) was measured on automatically generated stiffness maps. Morphometric quantification of fibrosis of liver biopsies was performed using a semi-automated image analysis program and expressed as percentage area (Fibro-C-Index). Correlations between MRE, Fibro-C-Index, and histologic fibrosis stages were evaluated. Receiver operating curve (ROC) analysis of MRE and Fibro-C-index for differentiating fibrosis (≥F1), significant fibrosis (≥F2), advanced fibrosis (≥F3), and cirrhosis (F4) was performed.

RESULTS

MRE showed excellent correlation with both Fibro-C-Index (r = 0.78, 95% confidence interval [CI], 0.59-0.88, P < 0.001) and histologic staging (rho = 0.87, 95% CI, 0.72-0.94, P < 0.0001). Significant differences in MRE (P = 0.0001) and Fibro-C-Index (P = 0.003) among different stages of liver fibrosis was found. MRE and Fibro-C-Index had similar accuracies for differentiating fibrosis stages: ≥F1 (0.87 versus 0.81, P = 0.6), ≥F2 (0.95 versus 0.94, P = 0.78), ≥F3 (0.98 versus 0.96, P = 0.76), and F4 (1.00 versus 0.92, P = 0.10).

CONCLUSION

MRE is an excellent noninvasive indicator of liver fibrosis burden in CHB.

Comparative assessment of liver fibrosis by computerized morphometry in naïve patients with chronic hepatitis B and C

BACKGROUND

Liver fibrosis, now assessed by liver biopsy or using non-invasive methods, might be different in chronic hepatitis B (CHB) and chronic hepatitis C (CHC).

AIM

To compare histological amount and pattern of fibrosis in CHB and CHC.

METHODS

Sixty CHB and sixty CHC biopsies from naïve patients, standardized for the spectrum of Metavir fibrosis stages, were analysed for (1) semi-quantitative Metavir activity, steatosis, perisinusoidal fibrosis, alpha-smooth muscle actin immunoreactivity, (2) quantitative morphometry of total and perisinusoidal fibrosis ratio (FR and PFR).

RESULTS

Biopsy quality, activity, steatosis, Fibrotest(®) values were not different between the two groups. Correlation between FR and fibrosis stage was stronger in CHB (r = 0.90) than CHC (r = 0.81). Mean FR was 1.5-fold higher in CHC than CHB for early fibrosis stages (F ≤ 2, P = 0.001), with higher PFR in CHC for F0 (P = 0.001), F1 (P = 0.08) and F2 (P = 0.004). Hepatic stellate cell activation index was also higher in CHC than in CHB (P = 0.007). Diagnosis performance of FR for significant fibrosis was not statistically different in CHB than CHC (AUROC 0.92 and 0.87 respectively), but cut-offs optimizing sensitivity and specificity were higher in CHC and their extrapolation to CHB led to 10% decrease in sensitivity. In F ≤ 2 patients, correlation between FR and Fibrotest(®) was only significant in CHC.

CONCLUSIONS

As compared to CHB, amount of fibrosis is greater in CHC for F ≤ 2 patients, mainly because of higher perisinusoidal fibrosis. These data illustrate difficulty to assess early fibrosis stages by non-invasive methods, and support the need for specific cut-offs in CHB.

Advanced characterization of microscopic kidney biopsies utilizing image analysis techniques

Correct annotation and identification of salient regions in Kidney biopsy images can provide an estimation of pathogenesis in obstructive nephropathy. This paper presents a tool for the automatic or manual segmentation of such regions along with methodology for their characterization in terms of the exhibited pathology. The proposed implementation is based on custom code written in Java and the utilization of open source tools (i.e. RapidMiner, ImageJ). The corresponding implementation details along with the initial evaluation of the proposed integrated system are also presented in the paper.

Importance of IL-10 and IL-6 during chronic hepatitis C genotype-1 treatment and their relation with IL28B

This paper investigates serum levels of interleukin 10 (IL-10) and interleukin 6 (IL-6) in patients with chronic hepatitis C genotype 1 (CHC-GT1), the relation of each with clinical and virological characteristics, how they affect the response to combined therapy and their relation with the IL28B polymorphisms rs12979860. Serum level expression and the polymorphism of IL-10, IL-6 and IL28B were determined in 138 CHC-GT1 patients, treated with pegylated interferon/ribavirin (pegIFN-α/RBV) for 48 weeks, in the following samples: baseline, week-12 (during treatment) and week-72 (post-treatment). 77 patients (56%) presented Sustained Virological Response (SVR) and 61 (44%) were non-SVR. Multivariate logistic regression showed that age ≤ 40 years (aOR=3.7, 95%CI=1.5-8.9, P=0.004), low activity of gamma glutamyl transferase (GGT) (aOR=0.9, 95%CI=0.98-0.99, P=0.028), CC genotype of IL28B polymorphism (aOR=2.7, 95%CI=1.0-7.2, P=0.044) and low IL-6 (aOR=0.5, 95%CI=0.3-1.0, P=0.038) were predictor factors of virological response. In all patients, following treatment, IL-6 decreased at week-12 (P=0.004) from baseline and had returned to basal values at week-72. Serum IL-10 concentration was significantly decreased at week-72 only in SVR patients (P ≤ 0.001). When patients were stratified by IL28B polymorphisms rs12979860 CC vs non-CC patients, a statistically significant decrease in IL-10 at week-72 in both groups was observed (P=0.003 and P ≤ 0.001, respectively). None of the polymorphisms of IL-10 or IL-6 studied were associated with SVR.

CONCLUSIONS

CC genotype of IL28B and low IL-6 serum concentration are factors associated independently with SVR. Moreover, decreased IL-10 at week-72 is associated with SVR in both CC and non-CC patients, and both factors are important to determine the effectiveness of treatment.

A collaborative biomedical image mining framework: application on the image analysis of microscopic kidney biopsies

The analysis and characterization of biomedical image data is a complex procedure involving several processing phases, like data acquisition, preprocessing, segmentation, feature extraction and classification. The proper combination and parameterization of the utilized methods are heavily relying on the given image data set and experiment type. They may thus necessitate advanced image processing and classification knowledge and skills from the side of the biomedical expert. In this work, an application, exploiting web services and applying ontological modeling, is presented, to enable the intelligent creation of image mining workflows. The described tool can be directly integrated to the RapidMiner, Taverna or similar workflow management platforms. A case study dealing with the creation of a sample workflow for the analysis of kidney biopsy microscopy images is presented to demonstrate the functionality of the proposed framework.

Quantitative histological-hemodynamic correlations in cirrhosis

We have previously shown, in a semiquantitative analysis of liver biopsies showing cirrhosis, that thickness of fibrous septa separating cirrhotic nodules and small size of cirrhotic nodules correlated independently with portal pressure (as determined by the hepatic venous pressure gradient; HVPG) and were independent predictors of the presence of clinically significant portal hypertension (PH). This study aimed to confirm these results using quantitative analysis of these biopsies using digital image analysis. Biopsies of 42 patients with cirrhosis and HVPG measurements within 6 months of the biopsy were included in the study. The following parameters were scored quantitatively and without knowledge of HVPG results: total fibrosis area, septal thickness, nodule size, and number of nodules per millimeter of length of liver biopsy. Fibrosis area was the only parameter that independently correlated with HVPG (r = 0.606; P < 0.0001). Correlation was significant, even among patients with clinically significant PH (r = 0.636; P < 0.005). Fibrosis area and nodule size were both independently predictive of the presence of clinically significant PH (r = 0.57; P = 0.003).

CONCLUSIONS

On quantitative analysis, fibrosis area was the parameter that correlated best with HVPG and the presence of clinically significant PH. Beyond pathophysiological implications, this also has methodological implications that are discussed in this article.

Plasma ribavirin trough concentrations during treatment of chronic hepatitis C in genotype-1 patients

GOALS

To investigate the correlation between virological response and plasma ribavirin trough concentrations (RBV Ctrough) during the full period of chronic hepatitis C (CHC) treatment.

STUDY

Multicenter prospective cohort study. Total 119 patients with CHC genotype-1 were treated with peginterferon alfa-2a (pegIFN) and RBV for 48 weeks. RBV quantification was carried out at week 4 (W4), W8, W12, W16, W24, W32, and W40 of treatment.

RESULTS

The mean RBV Ctrough value during treatment was 2.5±0.9 mg/L in total patients. At no time point of treatment were patients with RBV Ctrough average correlated with early and sustained virological response (SVR), but those with RBV Ctrough ≥5 mg/L (95th percentile) at any time point (22/119, 18%) were correlated with SVR (P=0.02). Such high RBV Ctrough values were found from the second to the fourth months of treatment in 73% of these patients (16/22), and this was independently associated with SVR (odds ratio=3.6, 95% confidence interval:1.02-13.2, P=0.04).

CONCLUSION

Our data do not support RBV plasma monitoring as a tool to optimize treatment in patients with CHC genotype-1, but show that a high RBV plasma concentration could improve SVR rates.

Collagen proportionate area of liver tissue determined by digital image analysis in patients with HBV-related decompensated cirrhosis

BACKGROUND

The accurate assessment of the degree of hepatic fibrosis plays a critical role in guiding the diagnosis, treatment and prognostic assessment of chronic liver diseases. Liver biopsy is currently the most reliable method to evaluate the severity of hepatic fibrosis. However, liver biopsy is an invasive procedure associated with morbidity and mortality, and has several limitations in patients with decompensated cirrhosis. There is no report on the collagen proportionate area (CPA) of liver tissue in the decompensated stage of cirrhosis. This study aimed to determine the CPA of resected liver tissue samples from patients with HBV-related decompensated cirrhosis using digital image analysis, and to analyze the relationship between the CPA and liver functional reserve.

METHODS

Fifty-three resected liver tissue samples from liver transplant patients with chronic hepatitis B-induced decompensated cirrhosis were stained with Masson's trichrome, and the CPA in these samples was quantitatively determined using digital image analysis. The values of relevant liver function just before liver transplantation, the CPA in liver tissue, and their correlation were analyzed.

RESULTS

The mean CPA at the decompensated stage of cirrhosis was 35.93+/-14.42% (11.24%-63.41%). The correlation coefficients of the CPA with a model for end-stage liver disease score, serum total bilirubin and international standard ratio of prothrombin B were 0.553, 0.519 and 0.533, respectively (P<0.001). With increasing CPA values, the three indices reflecting liver functional reserve also changed significantly.

CONCLUSIONS

The degree of fibrosis may be correlated with the functional reserve. With the advancement of fibrosis, the liver functional reserve is attenuated accordingly.

Importance of host genetic factors HLA and IL28B as predictors of response to pegylated interferon and ribavirin

OBJECTIVES

Viral factors are considered the best predictors of response to treatment for chronic hepatitis C (CHC), but genetic factors are known to have an important role in this respect. This paper investigates the relationships among the host genetic factors HLA and IL28B, viral factors, and the outcome of combination therapy.

METHODS

A multicenter retrospective cohort of 428 previously untreated CHC patients was treated with pegylated interferon/ribavirin (pegIFN/RBV) for 48 weeks. In all, 378 (88%) of these patients were genotype 1 or 4, and 50 (12%) were genotype 2 or 3.

RESULTS

Multivariate logistic regression showed the rs12979860 CC genotype (adjusted odds ratio (aOR)=4.3, 95% confidence interval (95% CI): 2.6-7), the HLA-DQB1*0301 allele (aOR=2.08, 95% CI: 1.2-3.5) and age, viral genotype, and viral load levels to be significantly associated with sustained virological response (SVR). When the variable rs12979860 was eliminated, the area under the receiver operating characteristic (ROC) curve (AUC) decreased significantly (0.76 vs. 0.69; P=0.03). AUC values derived from viral factors were lower than those corresponding to host genetic factors (0.67 vs. 0.72, respectively; P=0.04). The HLA-DQB1*0301 and A*0201 alleles were associated with rs12979860 CC genotype and SVR (P<0.0001).

CONCLUSIONS

The HLA-DQB1*0301 allele and IL28B genotype are factors that are associated independently with SVR. There is a synergism between the HLA-DQB1*0301 and HLA-A*0201 alleles with polymorphism rs12979860 CC, which increases the SVR rate. IL28B genotype is the best predictor of SVR.

The relationship between liver disease stage and liver fibrosis: a tangled web

The structural consequences of chronic liver disease are described as a series of liver disease 'stages' with scarring and architectural change that eventually destroys and replaces the normal lobular structure of the liver. Fibrosis ('excess collagen') and stage have been confused in histological staging systems. Fibrosis is part of increasing liver disease stage, but fibrosis and stage are different. Staging liver disease is important in routine histopathological assessment. Measurement of liver fibrosis is another process. The collagenous proportion of a liver biopsy [collagen proportionate area (CPA)] correlates with hepatic venous pressure gradient (HVPG), which is of recognized prognostic value. CPA at 1 year post-transplantation in hepatitis C virus-infected patients predicts subsequent clinical decompensation. CPA in cirrhotic patients predicts decompensation more accurately than staging or HVPG. The 'cirrhosis' stage category has poor prognostic power, and CPA effectively substages cirrhosis. CPA improves the description of liver disease stage. Proper validation of antifibrotic treatments and 'non-invasive markers of liver fibrosis' requires measurement of liver fibrosis (and not liver biopsy stage scores). It is unacceptable for the words 'fibrosis' and 'score' to remain next to each other. There are benefits to properly understanding liver fibrosis and liver disease stage and properly assessing each of them.

Non-invasive assessment of liver fibrosis progression in hepatitis C patients retreated for 96 weeks with antiviral therapy: a randomized study

BACKGROUND

The efficacy of a maintenance therapy in non-responder patients with chronic hepatitis C has been essentially evaluated by histological semiquantitative scores.

AIM

The aim was to evaluate the efficiency of 2 years of treatment with peginterferon alpha-2a vs alpha-tocopherol in these patients by histology, morphometry and blood markers of fibrosis.

METHOD

Hundred and five HCV patients with a Metavir fibrosis score > or = 2 were randomized to receive peginterferon alpha-2a 180 microg/week (PEG) (n=55) or alpha-tocopherol (TOCO) 1000 mg/day (n=50) for 96 weeks. The primary endpoint was improvement or stabilization of the Metavir fibrosis score by biopsy performed at week 96. Secondary endpoints included a quantitative assessment of fibrosis by morphometry and changes in blood markers of fibrosis.

RESULTS

There was no difference at baseline between PEG and TOCO according to the metavir (83.3 vs 86.8%, P=0.751) stage. The median fibrosis rate, measured with morphometry was 2.72 and 2.86% at day 0, and 3.66 and 2.82% at week 96, in the PEG and TOCO groups (P=0.90) respectively. However, the percentage of patients with metavir activity grade improvement was significantly higher in the PEG group vs the TOCO group (52.8 vs 23.7%, P=0.016). Non-invasive markers analysis did not show any significant change in both groups.

CONCLUSION

Long-term therapy with peginterferon alpha-2a did not reduce liver fibrosis degree assessed by morphometry and blood tests as compared with alpha-tocopherol. Blood tests could be useful to assess liver fibrosis changes in clinical trials.

Development and evaluation of an open source Delphi-based software for morphometric quantification of liver fibrosis

Background

Computer-based morphometry can minimize subjectivity in the assessment of liver fibrosis. An image processing program was developed with Delphi for the quantification of fibrosis in liver tissue samples stained with Sirius Red. Bile duct ligated and sham operated wild type C57BL/6 mice served as a model of time-dependent induction of liver fibrosis. Formation of fibrosis was determined with the developed software at day 0, 3, 7, 10, 14, 20, 30 and 60. The results were compared to a semi-quantitative scoring system.

Results

Quantitative accumulation of collagen fibres was observed from day 3 to day 14, with a slight further increase thereafter. During ongoing fibrogenesis, there was a significant elevation of alanine aminotransferase (ALT), aspartate transaminase (AST) and bilirubin. The results from our computer-based morphometric analysis were highly correlated with the results that were obtained in a standardized pathology semi-quantitative scoring system (R ² = 0.89, n = 38).

Conclusions

Using our Delphi-based image analysing software, the morphometric assessment of fibrosis is as precise as semi-quantitative scoring by an experienced pathologist. This program can be a valuable tool in any kind of experimental or clinical setting for standardized quantitative assessment of fibrosis.

Farglitazar lacks antifibrotic activity in patients with chronic hepatitis C infection

BACKGROUND & AIMS

Farglitazar (GI262570), an insulin-sensitizing agent, selectively binds and activates peroxisome proliferator-activated receptor gamma (PPARgamma) and inhibits stellate cell activation. We evaluated its antifibrotic effect in patients with chronic hepatitis C that did not respond to standard-of-care therapy.

METHODS

Patients with fibrosis of Ishak stages 2-4 (n = 265), based on analysis of liver biopsy samples, were randomly assigned to groups given once-daily doses of 0.5 mg farglitazar, 1.0 mg farglitazar, or placebo for 52 weeks; repeat liver biopsy samples were then obtained. The primary end points were changes in levels of alpha-smooth muscle actin (SMA) expression and collagen, based on morphometry and ranked histologic assessments.

RESULTS

Two hundred nine patients had paired biopsy specimens adequate for analysis (81.5% with pretreatment Ishak scores of stage 2 or 3). There was no overall difference in SMA (P = .58) or collagen (P = .99) levels at week 52. SMA levels increased by a median of 49% in samples from patients given placebo, 58% in patients given 0.5 mg farglitizar and 52% in patients given 1.0 mg farglitizar, respectively. Collagen increased by 27% in placebo samples and 31% in samples from patients given either dose of farglitizar. There were no significant differences between treatment groups in the ranked assessment of paired biopsy specimens or in the proportion of patients with a change in fibrosis score > or = Ishak stage.

CONCLUSIONS

In patients with chronic hepatitis C and moderate fibrosis, 52 weeks of treatment with farglitazar does not affect stellate cell activation or fibrosis (measured by morphometry or comparison of paired biopsy specimens).

Relationships between fibrosis amounts assessed by morphometry and liver stiffness measurements in chronic hepatitis or steatohepatitis

OBJECTIVES

To examine the relationships between fibrosis amounts evaluated by morphometric analysis and liver stiffness measurement (LSM) as well as the influence of steatosis, of activity grade and of the type of chronic liver injury.

METHODS

One hundred and fifty-two consecutive patients were selected from a prospective cohort of patients with concurrent liver biopsy and LSM on the basis of a more than 25 mm long liver biopsy. Morphometric quantification of collagen deposition was expressed as fibrosis area fraction (FAF). Steatosis, activity grade, and predominant type of liver injury (chronic hepatitis or steatohepatitis) were assessed.

RESULTS

In the whole population (chronic viral hepatitis n = 96, alcoholic or nonalcoholic steatohepatitis n = 56), FAF was significantly correlated to LSM (rho = 0.6, P<0.0001). Steatosis independently influenced LSM in patients without cirrhosis, but not activity grade. In the absence of cirrhosis, LSM and FAF were correlated in patients with chronic hepatitis (rho = 0.49, P<0.0001) but not in those with steatohepatitis (rho = 0.22, P = 0.16). In cirrhotic patients, LSM was correlated with fibrosis amount. (rho = 0.43, P = 0.006). The area under the receiver operating characteristics curve of LSM was 0.75 for separating no or minor fibrosis from significant fibrosis and 0.9 for the diagnosis of cirrhosis.

CONCLUSION

LSM was significantly correlated with collagen deposition. However, the relationships between LSM and fibrosis amount seems to differ according to steatosis and to the pattern of liver fibrosis below the cirrhotic stage. Its performances are fair for segregating patients with no or minor fibrosis from those with significant fibrosis and high for the diagnosis of cirrhosis.

Adiponectin knockout mice on high fat diet develop fibrosing steatohepatitis

BACKGROUND AND AIM

Low levels of serum adiponectin have been reported to be associated with obesity, diabetes, and non-alcoholic steatohepatitis (NASH), as well as several malignancies. Adiponectin knockout (KO) mice have been reported to cause insulin resistance and neointimal formation of the artery. We used adiponectin KO mice fed a high fat (HF) diet, and investigated the effect of adiponectin on the progression of steatohepatitis and carcinogenesis in vivo.

METHODS

Adiponectin KO mice and wild type (WT) mice were fed a HF diet or normal chow for the periods of 24 and 48 weeks. The HF diet contained 60% of calories from fat.

RESULTS

The adiponectin KO mice on the HF diet showed obesity, marked elevation of serum transaminase levels, and hyperlipidemia. At 24 weeks, hepatic expression of tumor necrosis factor-alpha and procollagen alpha (I) was higher in KO mice as compared with WT mice. At 48 weeks, liver triglyceride contents in KO mice on normal chow were significantly higher than those in WT mice. Hepatocyte ballooning, spotty necrosis, and pericellular fibrosis around central veins were observed in KO mice on the HF diet. The pericellular fibrosis was more severe in KO mice on the HF diet than that in WT mice (1.62% vs 1.16%, P = 0.033). Liver adenoma and hyperplastic nodules developed in a KO mouse on the HF diet at 48 weeks (12.5%, n = 1/8), whereas no tumor was detected in WT mice (n = 10).

CONCLUSIONS

Adiponectin may play a protective role in the progression of NASH in the early stages by suppressing tumor necrosis factor-alpha expression and liver fibrosis.