An assessment of digital image analysis to measure fibrosis in liver biopsy specimens of patients with chronic hepatitis C

Liver fibrosis phenotyping and severity scoring by quantitative image analysis of biopsy slides

BACKGROUND & AIMS

Digital pathology image analysis can phenotype liver fibrosis using histological traits that reflect collagen content, morphometry and architecture. Here, we aimed to calculate fibrosis severity scores to quantify these traits.

METHODS

Liver biopsy slides were categorised by Ishak stage and aetiology. We used a digital pathology technique to calculate four fibrosis severity scores: Architecture Composite Score (ACS), Collagen Composite Score (CCS), Morphometric Composite Score (MCS) and Phenotypic Fibrosis Composite Score (PH-FCS). We compared how these scores varied according to disease stage and aetiology.

RESULTS

We included 80 patients (40% female, mean age 59.0 years, mean collagen proportionate area 17.1%) with mild (F0-2, n = 28), moderate (F3-4, n = 17) or severe (F5-6, n = 35) fibrosis. All four aetiology independent scores corelated with collagen proportionate area (ACS: rp  = .512, CCS: rp  = .727, MCS: rp  = .777, PFCS: r = .772, p < .01 for all) with significant differences between moderate and severe fibrosis (p < .05). ACS increased primarily between moderate and severe fibrosis (by 95% to 226% depending on underlying aetiology), whereas MCS and CCS accumulation was more varied. We used 28 qFTs that distinguished between autoimmune- and alcohol-related liver disease to generate an MCS that significantly differed between mild and severe fibrosis for these aetiologies (p < .05).

CONCLUSIONS

We describe four aetiology-dependent and -independent severity scores that quantify fibrosis architecture, collagen content and fibre morphometry. This approach provides additional insight into how progression of architectural changes and accumulation of collagen may differ depending on underlying disease aetiology.

Loss of Krüppel-like factor-10 facilitates the development of chemical-induced liver cancer in mice

BACKGROUND

Krüppel-like factor 10 (KLF10) is involved in a positive feedback loop that regulates transforming growth factor β (TGFβ) signaling, and TGFβ plays an important role in the pathogenesis of liver disease. Here, we investigated whether KLF10 deletion affects the development of liver fibrosis and hepatocellular carcinoma (HCC).

METHODS

We induced KLF10 deletion in C57BL/6 mice. Liver fibrosis was induced by feeding a diet high in fat and sucrose (high-fat diet [HFD]), whereas HCC was produced by intraperitoneal administration of N-diethylnitrosamine (DEN). An in vitro experiment was performed to evaluate the role of KLF10 in the cancer microenvironment using Hep3B and LX2 cells. An immunohistochemical study of KLF10 expression was performed using human HCC samples from 60 patients who had undergone liver resection.

RESULTS

KLF10 deletion resulted in an increased DEN-induced HCC burden with significant upregulation of SMAD2, although loss of KLF10 did not alter HFD-induced liver fibrosis. DEN-treated mice with KLF10 deletion exhibited increased levels of mesenchymal markers (N-cadherin and SNAI2) and tumor metastasis markers (matrix metalloproteinases 2 and 9). KLF10 depletion in Hep3B and LX2 cells using siRNA was associated with increased invasiveness. Compared with co-culture of KLF10-preserved Hep3B cells and KLF10-intact LX2 cells, co-culture of KLF10-preserved Hep3B cells and KLF10-depleted LX2 cells resulted in significantly enhanced invasion. Low KLF10 expression in resected human HCC specimens was associated with poor survival.

CONCLUSION

The results of this study suggest that loss of KLF10 facilitates liver cancer development with alteration in TGFβ signaling.

Simvastatin Attenuates Areca Nut Extract-Induced Subdermal Fibrosis in Mice by Targeting TGF-β Signaling Pathways

Oral submucous fibrosis (OSMF) is a chronic inflammatory disease and a potentially malignant oral disorder, characterized by fibrosis of the oral mucosa. TGF-β signaling pathways have been implicated in the development of OSMF, with areca nut extract (ANE) contributing to the disease progression. Simvastatin, a statin drug, has demonstrated anti-fibrotic properties in various fibrotic conditions. However, its therapeutic potential in treating OSMF remains unclear. In this study, 8-week-old male BALB/c mice were randomly divided into three groups based on different time points. Each mouse was then treated with four different drug formulations. Post-treatment, specimens were collected for histopathological examination and staining to assess skin thickness, fibrosis, and collagen deposition. ANE treatment alone significantly increased skin thickness and collagen deposition compared to the control group after the 4-week time point. The combined administration of ANE and simvastatin, resulted in a notable reduction in skin thickness and collagen deposition. Western blot analysis revealed that simvastatin effectively suppressed the expression of fibrosis-related proteins, including CTGF, and α-SMA, in ANE-induced subdermal fibrosis. These results suggest that simvastatin has potential therapeutic effects on ANE-induced subdermal fibrosis, providing a foundation for future studies and possible clinical applications.

Virtual liver needle biopsy from reconstructed three-dimensional histopathological images: Quantification of sampling error

INTRODUCTION

Prevalently considered as the "gold-standard" for diagnosis of hepatic fibrosis and cirrhosis, the clinical liver needle biopsy is known to be subject to inadequate sampling and a high mis-sampling rate. However, quantifying such sampling bias has been difficult as generating a large number of needle biopsies from the same living patient is practically infeasible. We construct a three-dimension (3D) virtual liver tissue volume by spatially registered high resolution Whole Slide Images (WSIs) of serial liver tissue sections with a novel dynamic registration method. We further develop a Virtual Needle Biopsy Sampling (VNBS) method that mimics the needle biopsy sampling process. We apply the VNBS method to the reconstructed digital liver volume at different tissue locations and angles. Additionally, we quantify Collagen Proportionate Area (CPA) in all resulting virtual needle biopsies in 2D and 3D.

RESULTS

The staging score of the center 2D longitudinal image plane from each 3D biopsy is used as the biopsy staging score, and the highest staging score of all sampled needle biopsies is the diagnostic staging score. The Mean Absolute Difference (MAD) in reference to the Scheuer and Ishak diagnostic staging scores are 0.22 and 1.00, respectively. The absolute Scheuer staging score difference in 22.22% of sampled biopsies is 1. By the Ishak staging method, 55.56% and 22.22% of sampled biopsies present score difference 1 and 2, respectively. There are 4 (Scheuer) and 6 (Ishak) out of 18 3D virtual needle biopsies with intra-needle variations. Additionally, we find a positive correlation between CPA and fibrosis stages by Scheuer but not Ishak method. Overall, CPA measures suffer large intra- and inter- needle variations.

CONCLUSIONS

The developed virtual liver needle biopsy sampling pipeline provides a computational avenue for investigating needle biopsy sampling bias with 3D virtual tissue volumes. This method can be applied to other tissue-based disease diagnoses where the needle biopsy sampling bias substantially affects the diagnostic results.

Semiautomated quantification of the fibrous tissue response to complex three-dimensional filamentous scaffolds using digital image analysis

Fibrosis represents a relevant response to the implantation of biomaterials, which occurs not only at the tissue-material interface (fibrotic encapsulation) but also within the void fraction of complex three-dimensional (3D) biomaterial constructions (fibrotic ingrowth). Usual evaluation of the biocompatibility mostly depicts fibrosis at the interface of the biomaterial using semiquantitative scores. Here, the relations between encapsulation and infiltrating fibrotic growth are poorly represented. Virtual pathology and digital image analysis provide new strategies to assess fibrosis in a more differentiated way. In this study, we adopted a method previously used to quantify fibrosis in visceral organs to the quantification of fibrosis to 3D biomaterials. In a proof-of-concept study, we transferred the "Collagen Proportionate Area" (CPA) analysis from hepatology to the field of biomaterials. As one task of an experimental animal study, we used CPA analysis to quantify the fibrotic ingrowth into a filamentous scaffold after subcutaneous implantation. We were able to demonstrate that the application of the CPA analysis is well suited as an additional fibrosis evaluation strategy for new biomaterial constructions. The CPA method can contribute to a better understanding of the fibrotic interactions between 3D scaffolds and the host tissue responses.

Liver Collagen Contents Are Closely Associated with the Severity of Cirrhosis and Posthepatectomy Liver Failure in Patients with Hepatocellular Carcinoma and Child-Pugh Grade A Liver Function

BACKGROUND

Hepatocellular carcinoma (HCC) is usually accompanied by different severities of cirrhosis, which is a risk factor for posthepatectomy liver failure (PHLF). Collagen proportional area (CPA) measurements can quantitatively determine the collagen contents of liver tissue. This study explored the impact of CPA on PHLF, and further investigated the correlation between CPA and a non-invasive method, namely cirrhotic severity scoring (CSS), previously proposed by our team.

METHODS

A total of 224 HCC patients with Child-Pugh grade A liver function undergoing hepatectomy between 2017 and 2019 were retrospectively studied. Quantitative digital image analysis of resected liver tissues was used for the CPA measurement. Risk factors for PHLF were subjected to univariate and multivariate analyses, and the correlation between CPA and CSS was analyzed.

RESULTS

Overall, 28 (12.5%) patients experienced PHLF. Patients with PHLF had higher CPA values than those without PHLF (p < 0.001). Multivariate analysis showed CPA and extent of hepatectomy to be independent risk factors for PHLF. CPA values were divided into four stages based on their quartiles (C1: < 6.6%; C2: 6.6-10.7%; C3: 10.7-18.0%; C4: ≥ 18.0%). The incidence of PHLF increased with increasing CPA stages (p < 0.001). Furthermore, CSS was significantly correlated with CPA (r = 0.720; p < 0.001). The incidence of PHLF also increased with increasing severity of cirrhosis evaluated by CSS (p < 0.001).

CONCLUSIONS

In HCC patients with Child-Pugh grade A liver function, cirrhosis could be staged by liver collagen contents, which significantly influenced PHLF. Furthermore, CSS was useful in the preoperative evaluation of cirrhotic severity.

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.

Evaluation of Peritumoral Fibrosis in Metastatic Colorectal Adenocarcinoma to the Liver Using Digital Image Analysis

Objectives

It is challenging to separate peritumoral fibrosis from fibrosis due to chronic liver disease in mass-directed liver biopsies. We evaluated the distance that peritumoral fibrosis extends from metastatic colorectal adenocarcinoma in liver.

Methods

Peritumoral and distant uninvolved liver trichrome stains from 25 cases were analyzed using digital image analysis. Fibrosis was quantitated at concentric intervals from each tumor and in uninvolved liver.

Results

There was a 3.9 fold (range 0.9-18.6) median increase in fibrosis in the first 0.5 mm of peritumoral liver compared to distant liver. Fibrosis levels returned to baseline at median 2.5 mm (interquartile range 1.5-5.0 mm) from tumor.

Conclusions

Fibrosis is markedly increased in peritumoral liver. Fibrosis levels returned to baseline by 5 mm from tumor in approximately 75% of cases. Pathologists should be cautious of fibrosis in mass-directed liver biopsies without at least 5 mm of liver tissue distal to the mass.

Selective deletion of hepatocyte platelet-derived growth factor receptor α and development of liver fibrosis in mice

BACKGROUND

Platelet-derived growth factor receptor α (PDGFRα) expression is increased in activated hepatic stellate cells (HSCs) in cirrhotic liver, while normal hepatocytes express PDGFRα at a negligible level. However, cancerous hepatocytes may show upregulation of PDGFRα, and hepatocellular carcinoma is preceded by chronic liver injury. The role of PDGFRα in non-cancerous hepatocytes and liver fibrosis is unclear. We hypothesized that upon liver injury, PDGFRα in insulted hepatocytes contributes to liver fibrosis by facilitating intercellular crosstalk between hepatocytes and HSCs.

METHODS

Hepatocytes were isolated from normal and thioacetamide (TAA)-induced cirrhotic livers for assessment of PDGFRα expression. Conditional knock-out (KO) C57BL/6 mice, in which PDGFRα was selectively deleted in hepatocytes, were generated. Liver fibrosis was induced by injecting TAA for 8 weeks. Hep3B cells were transfected with a small interfering RNA (siRNA) (PDGFRα or control) and co-cultured with LX2 cells.

RESULTS

PDGFRα expression was increased in hepatocytes from fibrotic livers compared to normal livers. Conditional PDGFRα KO mice had attenuated TAA-induced liver fibrosis with decreased HSC activation and proliferation. Immunoblot analyses revealed decreased expression of phospho-p44/42 MAPK in TAA-treated KO mice; these mice also showed almost complete suppression of the upregulation of mouse double minute 2. Although KO mice exhibited increased expression of transforming growth factor (TGF)-β and Smad2/3, this was compensated for by increased expression of inhibitory Smad7. LX2 cells co-cultured with PDGFRα siRNA-infected Hep3B cells showed decreased PDGFRα, α smooth muscle actin, collagen α1(I), TGFβ, and Smad2/3 expression. LX2/PDGFRα-deleted hepatocyte co-culture medium showed decreased PDGF-BB and PDGF-CC levels.

CONCLUSIONS

Deletion of PDGFRα in hepatocytes attenuated the upregulation of PDGFRα in HSCs after TAA treatment, resulting in decreased liver fibrosis and HSC activation. This suggests that in the event of chronic liver injury, PDGFRα in hepatocytes plays an important role in liver fibrosis by affecting PDGFRα expression in HSCs.

Dual-photon microscopy-based quantitation of fibrosis-related parameters (q-FP) to model disease progression in steatohepatitis

There is a need for further refinement of current histological systems for assessment of hepatic fibrosis in nonalcoholic fatty liver disease (NAFLD). This study evaluated hepatic fibrosis in NAFLD using dual-photon microscopy-based quantitation of fibrosis-related parameters (q-FPs). Fifty test cohort subjects and 42 validation cohort subjects with NAFLD and the full spectrum of fibrosis were studied. q-FPs were measured in specific predefined regions of interest (general, vessel, perisinusoid, and vascular septa). Seventy q-FPs had inter- and intraobserver concordance ≥0.8 and were related to the NASH Clinical Research Network fibrosis staging. Of these, 16 q-FPs with the strongest correlations (P < 0.001 for all) were entered in a principal component analysis model (odds ratio [OR] 7.8, P < 0.001), which separated any stage of fibrosis versus no fibrosis, and cirrhosis versus earlier stages with the areas under the receiver operating characteristic curves of 0.88 and 0.93 (P ≤ 0.01 for both), respectively. In an independent multivariable analysis, four q-FPs-the number of collagen strands (OR 8.5, P = 0.004), strand length (OR 12.0, P = 0.02), strand eccentricity (OR 8.3, P = 0.004), and strand solidity (OR 8.0, P = 0.003)-were independently associated with fibrosis stages and were used to model fibrosis along a continuous linear scale using desirability functions; this linear scale of fibrosis measurement was also related to fibrosis stage (P < 0.0001). The robustness of both the multivariable model and the linear scale of measurement was confirmed in the validation cohort.

CONCLUSION

The q-FP model provides an accurate reproducible method to evaluate fibrosis in NAFLD along a quantitative and continuous scale. (Hepatology 2017;65:1891-1903).

Oncolytic adenovirus expressing relaxin (YDC002) enhances therapeutic efficacy of gemcitabine against pancreatic cancer

Pancreatic cancer is a highly lethal disease for which limited therapeutic options are available. Pancreatic cancer exhibits a pronounced collagen-rich stromal reaction, which induces chemoresistance by inhibiting drug diffusion into the tumor. Complementary treatment with oncolytic virus such as an oncolytic adenovirus expressing relaxin (YDC002) is an innovative treatment option for combating chemoresistant pancreatic cancer. Here, we examined the ability of combined treatment with gemcitabine and YDC002, which degrades extracellular matrix (ECM), to efficiently treat chemoresistant and desmoplastic pancreatic cancer. Gemcitabine alone exhibited similarly low cytotoxicity toward pancreatic cancer cells throughout the concentration range (1-50 μM) used, whereas the combination of YDC002 and a subtherapeutic dose of gemcitabine (0.01-0.05 μM) resulted in potent anticancer effects through effective induction of apoptosis. Importantly, YDC002 combined with gemcitabine significantly attenuated the expression of major ECM components including collagens, fibronectin, and elastin in tumor spheroids and xenograft tumors compared with gemcitabine alone, resulting in potent induction of apoptosis, gemcitabine-mediated cytotoxicity, and an oncolytic effect through degradation of tumor ECM. Our results demonstrate that YDC002 can selectively degrade aberrant ECM and attenuate the ECM-induced chemoresistance observed in desmoplastic pancreatic tumor, resulting in a potent antitumor effect through effective induction of apoptosis.

Asian-Pacific Association for the Study of the Liver (APASL) consensus guidelines on invasive and non-invasive assessment of hepatic fibrosis: a 2016 update

Hepatic fibrosis is a common pathway leading to liver cirrhosis, which is the end result of any injury to the liver. Accurate assessment of the degree of fibrosis is important clinically, especially when treatments aimed at reversing fibrosis are being evolved. Despite the fact that liver biopsy (LB) has been considered the "gold standard" of assessment of hepatic fibrosis, LB is not favored by patients or physicians owing to its invasiveness, limitations, sampling errors, etc. Therefore, many alternative approaches to assess liver fibrosis are gaining more popularity and have assumed great importance, and many data on such approaches are being generated. The Asian Pacific Association for the Study of the Liver (APASL) set up a working party on liver fibrosis in 2007, with a mandate to develop consensus guidelines on various aspects of liver fibrosis relevant to disease patterns and clinical practice in the Asia-Pacific region. The first consensus guidelines of the APASL recommendations on hepatic fibrosis were published in 2009. Due to advances in the field, we present herein the APASL 2016 updated version on invasive and non-invasive assessment of hepatic fibrosis. The process for the development of these consensus guidelines involved review of all available published literature by a core group of experts who subsequently proposed consensus statements followed by discussion of the contentious issues and unanimous approval of the consensus statements. The Oxford System of the evidence-based approach was adopted for developing the consensus statements using the level of evidence from one (highest) to five (lowest) and grade of recommendation from A (strongest) to D (weakest). The topics covered in the guidelines include invasive methods (LB and hepatic venous pressure gradient measurements), blood tests, conventional radiological methods, elastography techniques and cost-effectiveness of hepatic fibrosis assessment methods, in addition to fibrosis assessment in special and rare situations.

Simvastatin Reduces Capsular Fibrosis around Silicone Implants

Capsular fibrosis and contracture occurs in most breast reconstruction patients who undergo radiotherapy, and there is no definitive solution for its prevention. Simvastatin was effective at reducing fibrosis in various models. Peri-implant capsular formation is the result of tissue fibrosis development in irradiated breasts. The purpose of this study was to examine the effect of simvastatin on peri-implant fibrosis in rats. Eighteen male Sprague-Dawley rats were allocated to an experimental group (9 rats, 18 implants) or a control group (9 rats, 18 implants). Two hemispherical silicone implants, 10 mm in diameter, were inserted in subpanniculus pockets in each rat. The next day, 10-Gy of radiation from a clinical accelerator was targeted at the implants. Simvastatin (15 mg/kg/day) was administered by oral gavage in the experimental group, while animals in the control group received water. At 12 weeks post-implantation, peri-implant capsules were harvested and examined histologically and by real-time polymerase chain reaction. The average capsular thickness was 371.2 μm in the simvastatin group and 491.2 μm in the control group. The fibrosis ratio was significantly different, with 32.33% in the simvastatin group and 58.44% in the control group (P < 0.001). Connective tissue growth factor (CTGF) and transforming growth factor (TGF)-β1 gene expression decreased significantly in the simvastatin group compared to the control group (P < 0.001). This study shows that simvastatin reduces radiation-induced capsular fibrosis around silicone implants in rats. This finding offers an alternative therapeutic strategy for reducing capsular fibrosis and contracture after implant-based breast reconstruction.

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.

Longitudinal assessment of hepatitis C fibrosis progression by collagen and smooth muscle actin morphometry in comparison to serum markers

BACKGROUND

Assessment of fibrosis progression in chronic liver disease relies upon non-invasive tools and changes in semi-quantitative histopathology scores that may not be reliable.

AIM

To assess the diagnostic performance of the FibroSURE (FS) index and collagen/alpha smooth muscle actin (α-SMA) morphometry in relation to longitudinal changes in fibrosis on paired biopsies.

METHODS

The study cohort included 201 chronic hepatitis C (CHC) nonresponders enrolled in a prior phase II anti-fibrotic study. Serum FS and paired biopsies, with both collagen and α-SMA morphometry, were evaluated at baseline and week 52.

RESULTS

Study patients were mostly male (67%) and Caucasian (77%), with Ishak stages 2 (n = 79), 3 (n = 88) and 4 (n = 30), excluded (n = 4 stage 1 or 5). Mean biopsy length was 22.9 mm. For baseline Ishak 2/3 vs. 4, there were no significant differences in AUROCs for collagen (0.71), SMA (0.66) or FS (0.70). At week 52, 62% of patients had no change in Ishak stage, but collagen/α-SMA increased by 34-51% (P < 0.0001), and FS decreased by 5% (P = 0.008). Among the 33% of patients with +/-1 Ishak stage change, FS changes were not significant, but α-SMA increased 29-72%, and collagen increased by 12-38% (P = 0.01 for +1 only).

CONCLUSIONS

Longitudinal changes in collagen and α-SMA morphometry are apparent prior to change in histological stage or FibroSURE in CHC nonresponders with intermediate fibrosis. This likely reflects quantitative morphological differences that are not detected by routine histological staging or serum markers such as FibroSURE.

Magnetic resonance elastography of abdomen. ACTA ACUST UNITED AC. 2015;40:745-759. [PMID: 25488346 DOI: 10.1007/s00261-014-0315-6]

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.

Evaluation of Liver Fibrosis Using Texture Analysis on Combined-Contrast-Enhanced Magnetic Resonance Images at 3.0T

Purpose. To noninvasively assess liver fibrosis using combined-contrast-enhanced (CCE) magnetic resonance imaging (MRI) and texture analysis. Materials and Methods. In this IRB-approved, HIPAA-compliant prospective study, 46 adults with newly diagnosed HCV infection and recent liver biopsy underwent CCE liver MRI following intravenous administration of superparamagnetic iron oxides (ferumoxides) and gadolinium DTPA (gadopentetate dimeglumine). The image texture of the liver was quantified in regions-of-interest by calculating 165 texture features. Liver biopsy specimens were stained with Masson trichrome and assessed qualitatively (METAVIR fibrosis score) and quantitatively (% collagen stained area). Using L₁ regularization path algorithm, two texture-based multivariate linear models were constructed, one for quantitative and the other for quantitative histology prediction. The prediction performance of each model was assessed using receiver operating characteristics (ROC) and correlation analyses. Results. The texture-based predicted fibrosis score significantly correlated with qualitative (r = 0.698, P < 0.001) and quantitative (r = 0.757, P < 0.001) histology. The prediction model for qualitative histology had 0.814–0.976 areas under the curve (AUC), 0.659–1.000 sensitivity, 0.778–0.930 specificity, and 0.674–0.935 accuracy, depending on the binary classification threshold. The prediction model for quantitative histology had 0.742–0.950 AUC, 0.688–1.000 sensitivity, 0.679–0.857 specificity, and 0.696–0.848 accuracy, depending on the binary classification threshold. Conclusion. CCE MRI and texture analysis may permit noninvasive assessment of liver fibrosis.

Automated biphasic morphological assessment of hepatitis B-related liver fibrosis using second harmonic generation microscopy. Sci Rep. 2015;5:12962. [PMID: 26260921 PMCID: PMC4531344 DOI: 10.1038/srep12962]

Liver fibrosis assessment by biopsy and conventional staining scores is based on histopathological criteria. Variations in sample preparation and the use of semi-quantitative histopathological methods commonly result in discrepancies between medical centers. Thus, minor changes in liver fibrosis might be overlooked in multi-center clinical trials, leading to statistically non-significant data. Here, we developed a computer-assisted, fully automated, staining-free method for hepatitis B-related liver fibrosis assessment. In total, 175 liver biopsies were divided into training (n = 105) and verification (n = 70) cohorts. Collagen was observed using second harmonic generation (SHG) microscopy without prior staining, and hepatocyte morphology was recorded using two-photon excitation fluorescence (TPEF) microscopy. The training cohort was utilized to establish a quantification algorithm. Eleven of 19 computer-recognizable SHG/TPEF microscopic morphological features were significantly correlated with the ISHAK fibrosis stages (P < 0.001). A biphasic scoring method was applied, combining support vector machine and multivariate generalized linear models to assess the early and late stages of fibrosis, respectively, based on these parameters. The verification cohort was used to verify the scoring method, and the area under the receiver operating characteristic curve was >0.82 for liver cirrhosis detection. Since no subjective gradings are needed, interobserver discrepancies could be avoided using this fully automated method.

Evaluation of Histological and non-Invasive Methods for the Detection of Liver Fibrosis: The Values of Histological and Digital Morphometric Analysis, Liver Stiffness Measurement and APRI Score

Prognosis and treatment of liver diseases mainly depend on the precise evaluation of the fibrosis. Comparisons were made between the results of Metavir fibrosis scores and digital morphometric analyses (DMA), liver stiffness (LS) values and aminotransferase-platelet ratio (APRI) scores, respectively. Liver biopsy specimens stained with Sirius red and analysed by morphometry, LS and APRI measurements were taken from 96 patients with chronic liver diseases (56 cases of viral hepatitis, 22 cases of autoimmune- and 18 of mixed origin). The strongest correlation was observed between Metavir score and DMA (r = 0.75 p < 0.05), followed in decreasing order by LS and Metavir (r = 0.61), LS and DMA (r = 0.47) LS and APRI (r = 0.35) and Metavir and APRI (r = 0.24), respectively. DMA is a helpful additional tool for the histopathological evaluation of fibrosis, even when the sample size is small and especially in case of advanced fibrosis. The non-invasive methods showed good correlation with the histopathological methods; LS proved to be more accurate than APRI. The stronger correlation between LS values and Metavir scores, as well as the results of DMA in case of appropriate sample size were remarkable.

Quantitative assessment of liver fibrosis by digital image analysis: Relationship to Ishak staging and elasticity by shear-wave elastography

OBJECTIVE

To analyze the relationship between fibrosis staged by Ishak stage and quantified by digital image analysis (DIA), and to reveal the optimum performance of shear-wave elastography (SWE) using quantitative DIA measurements as a comparative histological standard.

METHODS

The proportionate area (PA) of fibrosis was measured by DIA from images of the PA of trichrome-stain (TPA) of 168 chronic hepatitis patients. SWE was performed in 105 patients. The accuracy of SWE for predicting the fibrosis defined by quantitative PA thresholds (≥ 2.5%, ≥ 5%, ≥ 10% and ≥ 20%, respectively) and by Ishak stages was measured using the area under the receiver operating characteristic curve (AUROC).

RESULTS

DIA was proven to be highly reproducible (interclass correlation coefficient  0.926). The TPA range corresponding to each Ishak stage was large, widened as stages progressed, and reached its greatest extent in cirrhosis. TPA magnified at ×50 ranges 11.9-56% for Ishak stage F5-6. A good correlation between TPA and elasticity was presented for more advanced fibrosis (TPA ≥10%, rs  = 0.732, P = 0.000) than milder fibrosis (TPA <10%, rs  = 0.308, P = 0.006). With the advance of fibrosis either by stages or PA thresholds the discriminative accuracy of SWE gradually increased, but was less satisfactory for milder fibrosis.

CONCLUSIONS

DIA may serve as a reproducible and reliable quantitative standard for surrogate tests for liver fibrosis. The performance and correlation of SWE with the fibrotic extent were better for advanced fibrosis, but less satisfactory for milder fibrosis.

Quantification of collagen and elastic fibers using whole-slide images of liver biopsy specimens

Histological evaluation of fibrosis after a liver biopsy is crucial for evaluating the pathology of patients with chronic liver disease. Previous studies have reported quantitative analyses of fibrosis using images of collagen-stained sections. However, analysis of these studies requires manual selection of the region of interest. In addition, the quantification of elastic fibers is not considered. The present study was conducted in order to measure both the collagen and elastic fiber area ratios using Elastica van Gieson-stained whole-slide images (WSIs) of liver biopsy specimens. High-resolution WSIs provide precise color classification, enabling accurate detection of even fine collagen and elastic fibers. To minimize the influence of pre-existing fibrous tissue, median area ratios of the collagen and elastic fibers were independently calculated from the image tiles of the WSIs. These median area ratios were highly concordant with area ratios after the pre-existing fibrous tissues were manually trimmed from the WSI. Further, these median area ratios were correlated with liver stiffness as measured by transient elastography (collagen: r = 0.73 [P < 0.01], elastic: r = 0.53 [P < 0.01]). Our approach to quantifying liver fibrosis will serve as an effective tool to evaluate liver diseases in routine practice.

Omega-3 polyunsaturated fatty acid and ursodeoxycholic acid have an additive effect in attenuating diet-induced nonalcoholic steatohepatitis in mice

Nonalcoholic steatohepatitis (NASH) can progress into liver cirrhosis; however, no definite treatment is available. Omega-3 polyunsaturated fatty acid (omega-3) has been reported to alleviate experimental NASH, although its beneficial effect was not evident when tested clinically. Thus, this study aimed to investigate the additive effect of omega-3 and ursodeoxycholic acid (UDCA) on diet-induced NASH in mice. C57BL/6 mice were given a high-fat diet (HFD) for 24 weeks, at which point the mice were divided into three groups and fed HFD alone, HFD with omega-3 or HFD with omega-3 in combination with UDCA for another 24 weeks. Feeding mice an HFD and administering omega-3 improved histologically assessed liver fibrosis, and UDCA in combination with omega-3 further attenuated this disease. The assessment of collagen α1(I) expression agreed with the histological evaluation. Omega-3 in combination with UDCA resulted in a significant attenuation of inflammation whereas administering omega-3 alone failed to improve histologically assessed liver inflammation. Quantitative analysis of tumor necrosis factor α showed an additive effect of omega-3 and UDCA on liver inflammation. HFD-induced hepatic triglyceride accumulation was attenuated by omega-3 and adding UDCA accentuated this effect. In accordance with this result, the expression of sterol regulatory binding protein-1c decreased after omega-3 administration and adding UDCA further diminished SREBP-1c expression. The expression of inducible nitric oxide synthase (iNOS), which may reflect oxidative stress-induced tissue damage, was suppressed by omega-3 administration and adding UDCA further attenuated iNOS expression. These results demonstrated an additive effect of omega-3 and UDCA for alleviating fibrosis, inflammation and steatosis in diet-induced NASH.

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.

Liver collagen in cirrhosis correlates with portal hypertension and liver dysfunction

Liver collagen proportionate area (CPA) assessed by computer-assisted digital image analysis has been proposed as an accurate and objective histological variable for subclassifying cirrhosis. The study aimed to examine the relationship between CPA and relevant clinical parameters in cirrhotic patients and to evaluate the sampling variability for CPA. The study included 48 consecutive liver transplantation patients with established cirrhosis. Hepatic venous pressure gradient (HVPG) and serum markers of liver failure were determined prior to transplantation. CPA was assessed in the explanted livers. In 20 of the livers, CPA was measured in more than one tissue sample. CPA showed significant correlations with HVPG and with various surrogate markers of hepatic dysfunction including albumin, bilirubin, INR, MELD score and Child-Pugh score. CPA reliably discriminated HVPG ≥10 mmHg, termed 'clinically significant portal hypertension' (area under receiver operator curve: 0.923, p < 0.001; odds ratio: 1.209, p = 0.003). CPA measured on tissue blocks showed no significant sampling variability (p > 0.5). In conclusion, the study correlated portal hypertension and hepatic dysfunction with the amount of collagen in cirrhotic livers. The findings support the presumption of CPA as a useful histological marker for subclassifying cirrhosis and as a helpful supplement to the qualitative description of hepatic architectural changes in routine pathology.

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.

An inexpensive and worldwide available digital image analysis technique for histological fibrosis quantification in chronic hepatitis C

Hepatic fibrosis staging is based on semiquantitative scores. Digital imaging analysis (DIA) appears more accurate because fibrosis is quantified in a continuous scale. However, high cost, lack of standardization and worldwide unavailability restrict its use in clinical practice. We developed an inexpensive and widely available DIA technique for fibrosis quantification in hepatitis C, and here, we evaluate its reproducibility and correlation with semiquantitative scores, and determine the fibrosis percentage associated with septal fibrosis and cirrhosis. 282 needle biopsies staged by Ishak and METAVIR scores were included. Images of trichrome-stained sections were captured and processed using Adobe(®) Photoshop(®) CS3 and Adobe(®) Bridge(®) softwares. The percentage of fibrosis (fibrosis index) was determined by the ratio between the fibrosis area and the total sample area, expressed in pixels calculated in an automated way. An excellent correlation between DIA fibrosis index and Ishak and METAVIR scores was observed (Spearman's r = 0.95 and 0.92; P < 0.001, respectively). Excellent intra-observer reproducibility was observed in a randomly chosen subset of 39 biopsies with an intraclass correlation index of 0.99 (95% CI, 0.95-0.99). The best cut-offs associated with septal fibrosis and cirrhosis were 6% (AUROC 0.97, 95% CI, 0.95-0.99) and 27% (AUROC 1.0, 95% CI, 0.99-1), respectively. This new DIA technique had high correlation with semiquantitative scores in hepatitis C. This method is reproducible, inexpensive and available worldwide allowing its use in clinical practice. The incorporation of DIA technique provides a more complete evaluation of fibrosis adding the quantification to architectural patterns.

Magnetic resonance elastography of liver: clinical applications. J Comput Assist Tomogr. 2013;37:887-896. [PMID: 24270110 DOI: 10.1097/rct.0000000000000032]

Magnetic resonance elastography (MRE) has been successfully implemented in the assessment of diffuse liver diseases. Currently, MRE is the most accurate noninvasive technique for detection and staging of liver fibrosis with a potential to replace liver biopsy. Magnetic resonance elastography is able to differentiate isolated fatty liver disease from steatohepatitis with or without fibrosis. Potential clinical applications include the differentiation of benign and malignant focal liver masses and the assessment of treatment response in diffuse liver diseases.

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.

Image analysis of liver collagen using sirius red is more accurate and correlates better with serum fibrosis markers than trichrome

BACKGROUND

Collagen proportional area (CPA) determined by quantitative digital image analysis better quantifies liver fibrosis than histological stage; however, its clinical use has been limited by non-standardized methods.

AIM

This study aimed to compare CPA obtained using different staining methods, magnifications and biopsy sizes.

METHODS

Two hundred and forty-nine patients with chronic hepatitis C who had a liver biopsy and serum fibrosis markers performed were included. CPA was measured either using a sirius red (CPAs) or a trichrome (CPAt) stain.

RESULTS

CPAs measured at 20× and 40× magnifications generated similar outcomes with interclass correlation (ICC) coefficient of 0.98. Compared with trichrome, sirius red staining had much less variation with an ICC coefficient of 0.99 for slides stained in the same batch and 0.92 in different batches. Mean CPAs was higher than mean CPAt by 3.53%, P < 0.001. Morphological analysis found that sirius red detected delicate fibrous septa and spurs better than trichrome. Both CPAs and CPAt correlated well with Metavir stage, whereas CPAs had better ability to detect cirrhosis with the area under ROC curve of 0.95. Overall CPA had superior correlation with serum markers of fibrosis in Metavir F2-F4 than that in F0-F1 and CPAs correlated better with serum fibrosis markers than CPAt in Metavir F0-F1. Multivairate analysis found that HA, α2-macroglobulin, platelet count and albumin were independently correlated with CPAs and only HA was independently correlated with CPAt.

CONCLUSIONS

Sirius red staining for CPA determination was more accurate and reliable for quantifying hepatic collagen compared with trichrome staining.

Magnetic resonance elastography in the diagnosis of hepatic fibrosis

Liver fibrosis is a common feature of many chronic liver diseases, and can ultimately progress to cirrhosis. Conventional imaging is insensitive to liver fibrosis, necessitating a liver biopsy for diagnosis and monitoring of progression. However, liver biopsy risks complications, and is an imperfect gold standard in view of sampling error and intraobserver or interobserver variation. Magnetic resonance elastography (MRE) is a noninvasive method for assessing the mechanical properties of tissues and is gaining credence as a method of assessment for hepatic fibrosis. The aim of this review is to describe how MRE is performed, to review the present literature on the subject, to compare MRE with other noninvasive techniques used to assess for liver fibrosis, and to highlight areas of future research.

Preexisting epithelial diversity in normal human livers: a tissue-tethered cytometric analysis in portal/periportal epithelial cells

Routine light microscopy identifies two distinct epithelial cell populations in normal human livers: hepatocytes and biliary epithelial cells (BECs). Considerable epithelial diversity, however, arises during disease states when a variety of hepatocyte-BEC hybrid cells appear. This has been attributed to activation and differentiation of putative hepatic progenitor cells (HPC) residing in the canals of Hering and/or metaplasia of preexisting mature epithelial cells. A novel analytic approach consisting of multiplex labeling, high-resolution whole-slide imaging (WSI), and automated image analysis was used to determine if more complex epithelial cell phenotypes preexist in normal adult human livers, which might provide an alternative explanation for disease-induced epithelial diversity. "Virtually digested" WSI enabled quantitative cytometric analyses of individual cells displayed in a variety of formats (e.g., scatterplots) while still tethered to the WSI and tissue structure. We employed biomarkers specifically associated with mature epithelial forms (HNF4α for hepatocytes, CK19 and HNF1β for BEC) and explored for the presence of cells with hybrid biomarker phenotypes. The results showed abundant hybrid cells in portal bile duct BEC, canals of Hering, and immediate periportal hepatocytes. These bipotential cells likely serve as a reservoir for the epithelial diversity of ductular reactions, appearance of hepatocytes in bile ducts, and the rapid and fluid transition of BEC to hepatocytes, and vice versa.

CONCLUSION

Novel imaging and computational tools enable increased information extraction from tissue samples and quantify the considerable preexistent hybrid epithelial diversity in normal human liver. This computationally enabled tissue analysis approach offers much broader potential beyond the results presented here.

Translating an understanding of the pathogenesis of hepatic fibrosis to novel therapies

The response to injury is one of wound healing and fibrogenesis, which ultimately leads to fibrosis. The fibrogenic response to injury is a generalized one across virtually all organ systems. In the liver, the injury response, typically occurring over a prolonged period of time, leads to cirrhosis (although it should be pointed out that not all patients with liver injury develop cirrhosis). The fact that many different diseases result in cirrhosis suggests a common pathogenesis. The study of hepatic fibrogenesis over the past 2 decades has been remarkably active, leading to a considerable understanding of this process. It clearly has been shown that the hepatic stellate cell is a central component in the fibrogenic process. It also has been recognized that other effector cells are important in the fibrogenic process, including resident fibroblasts, bone marrow-derived cells, fibrocytes, and even perhaps cells derived from epithelial cells (ie, through epithelial to mesenchymal transition). A key aspect of the biology of fibrogenesis is that the fibrogenic process is dynamic; thus, even advanced fibrosis (or cirrhosis) is reversible. Together, an understanding of the cellular basis for liver fibrogenesis, along with multiple aspects of the basic pathogenesis of fibrosis, have highlighted many exciting potential therapeutic opportunities. Thus, although the most effective antifibrotic therapy is simply treatment of the underlying disease, in situations in which this is not possible, specific antifibrotic therapy is likely not only to become feasible, but will soon become a reality. This review highlights the mechanisms underlying fibrogenesis that may be translated into future antifibrotic therapies and to review the current state of clinical development.

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.

Hepatocellular necrosis, fibrosis and microsomal activity determine the hepatic pharmacokinetics of basic drugs in right-heart-failure-induced liver damage

PURPOSE

To explore how liver damage arising from cardio-hepatic syndromes in RHF affect the hepatic pharmacokinetics of basic drugs.

METHODS

The hepatic pharmacokinetics of five selected basic drugs with different physicochemical properties were studied in IPRL from control rats and rats with RHF. Hepatic pharmacokinetic modelling was performed with a two-phase physiologically-based organ pharmacokinetic model with the vascular space and dispersion evaluated with the MID technique. The liver damage arising from RHF was assessed by changes in liver biochemistry and histopathology. The expression of various CYP isoforms was evaluated by real-time RT-PCR analysis.

RESULTS

Four of the five basic drugs had a significantly lower E in RHF rat livers compared to the control rat livers. Hepatic pharmacokinetic analysis showed that both the CL int and PS were significantly decreased in the RHF rat livers. Stepwise regression analysis showed that the alterations in the pharmacokinetic parameters (E, CL int and PS) can be correlated to the observed histopathological changes (NI, CYP concentration and FI) as well as to the lipophilicity of the basic drugs (logP app).

CONCLUSIONS

Serious hepatocellular necrosis and fibrosis induced by RHF affects both hepatic microsomal activity and hepatocyte wall permeability, leading to significant impairment in the hepatic pharmacokinetics of basic drugs.

Fibrosis distribution in explanted cirrhotic livers

AIMS

Little information is available regarding the distribution of fibrosis within cirrhotic livers. We measured collagen in cirrhotic explants to determine if fibrosis differs (i) between left (L) and right (R) lobes, and (ii) between different aetiologies.

METHODS AND RESULTS

Ten cases each of common aetiologies of cirrhosis were studied: alcoholic liver disease (ALD), primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC), autoimmune hepatitis (AIH), hepatitis C virus (HCV) and hepatitis B virus (HBV). A total of 120 tissue blocks (one block each from L and R lobes) were studied. Collagen was measured as collagen proportionate area (CPA), i.e. the proportion of the tissue sections stained by picro-Sirius red. L and R lobes contained similar amounts of fibrosis (r = 0.788; P < 0.0001) with good agreement between L and R lobes (Bland-Altman analysis, R lobe bias = 1.35%). Median CPA across all aetiologies (R plus L lobes) was 21.5%, (L = 8-40%, R = 10-47%). There was more fibrosis in ALD (30%, 15-47%) than PBC (23.5%, 16-34%) and PSC (22.5%, 8-33%), which in turn showed more than AIH (18.5%, 10-40%), HCV (17%, 13-31%) and HBV (16.5%, 8-30%).

CONCLUSIONS

At the time of transplantation cirrhotic livers have different ranges of collagen proportionate area, according to aetiology. R lobe fibrosis corresponds with L lobe fibrosis. The range of fibrosis within each aetiological group could be useful for prognostic subclassification.

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.

Hepatic pharmacokinetics of cationic drugs in a high-fat emulsion-induced rat model of nonalcoholic steatohepatitis

The hepatic pharmacokinetics of five selected cationic drugs (propranolol, labetalol, metoprolol, antipyrine, and atenolol) was studied in the liver from control rats and from those with high-fat emulsion-induced nonalcoholic steatohepatitis (NASH). Studies were undertaken using an in situ-perfused rat liver and multiple indicator dilution, and outflow data were analyzed with a physiologically based organ pharmacokinetic model. Hepatic extraction (E) was significantly lower in the NASH model, and lipophilicity was the main solute structural determinant of the observed differences in intrinsic elimination clearance (CL(int)) and permeability-surface area product (PS) with pK(a) defining the extent of sequestration in the liver [apparent distribution ratio (K(v))]. The main pathophysiological determinants were liver fibrosis, leading to a decreased PS, liver fat causing an increase in K(v), and an increase in both total liver cytochrome P450 (P450) concentration and P450 isoform expression for Cyp3a2 and Cyp2d2, causing an increase CL(int) in NASH rat livers compared with control livers. Changes in hepatic pharmacokinetics (PS, K(v), CL(int), and E ratio) as a result of NASH were related to the physicochemical properties of drugs (lipophilicity or pK(a)) and hepatic histopathological changes (fibrosis index, steatosis index, and P450 concentration) by stepwise regression analysis. Thus, it appears that in NASH, counteracting mechanisms to facilitate hepatic removal are created in NASH-induced P450 expression, whereas NASH-induced fibrosis and steatohepatitis inhibit E by decreasing hepatocyte permeability through fibrosis and hepatic sequestration.

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.

Digital quantification is more precise than traditional semiquantitation of hepatic steatosis: correlation with fibrosis in 220 treatment-naïve patients with chronic hepatitis C

BACKGROUND

Steatosis, as associated with chronic hepatitis C (CHC) and non-alcoholic fatty liver disease (NAFLD), has been considered a risk factor for development of fibrosis.

AIMS

Our aims were to determine if correlations existed between the degree of steatosis and fibrosis in treatment-naïve CHC patients, and to compare the accuracy of digital image analysis with semiquantification (manual assessment) to quantify hepatic steatosis.

METHODS

We studied 220 treatment-naïve, liver biopsy-proven CHC patients, including a serial biopsy sub-cohort of 37 patients with a mean interval of 3.82 years. Steatosis and fibrosis % were evaluated using digital quantification of steatosis (DQS) and fibrosis contrasted with manual assessment.

RESULTS

Most patients had <6% steatosis measured manually and digitally. Overall, manual assessment of steatosis was 3.78 times greater than DQS. Increasing steatosis % was associated with advancing fibrosis stage, both manually and digitally. Intraobserver reliability for DQS showed higher intraclass correlation reproducibility (r = 0.98, P < 0.001) than the manual method (r = 0.81, P < 0.01). Interobserver concordance for DQS had an average measure intraclass correlation of r = 0.99. Cirrhotics were more likely than non-cirrhotics to have grade 2 steatosis.

CONCLUSIONS

Increased steatosis was associated with increased fibrosis. DQS was consistently more precise and reproducible than manual assessment of steatosis in grades 1 (1 to <6%) and 2 (6 to <34%), and may prove to be especially preferable in clinical trials of pharmacotherapeutic agents.