Liver collagen proportionate area predicts decompensation in patients with recurrent hepatitis C virus cirrhosis after liver transplantation

The prediction of liver decompensation using hepatic collagen deposition assessed by computer-assisted image analysis with Masson's trichrome stain

BACKGROUND & AIM

The current pathologic system classifies structural deformation caused by hepatic fibrosis semi-quantitatively, which may lead to a disagreement among pathologists. We measured hepatic fibrosis quantitatively using collagen proportionate area (CPA) in compensated cirrhotic patients and assessed its impact on predicting the development of liver decompensation.

METHOD

From January 2010 to June 2018, we assessed 101 patients who went through liver biopsy and received diagnosis as compensated cirrhosis with digital image analysis of CPA. Clinical and laboratory data were collected at the baseline and at the time of the last follow-up or progression to liver decompensation (LD).

RESULT

The mean age was 50.8 ± 10.5 years, and the most common etiology of liver disease was chronic hepatitis B (48.5%), followed by alcoholic hepatitis (18.8%). The mean CPA was 16.91 ± 9.60%. The mean CPA values were different in patients with and without LD development (21.8 ± 11.1 vs. 15.2 ± 8.5). During the median follow-up of 60.0 months, 26 out of 101 patients experienced LD. Older age (hazard ratio [HR],1.069; p = 0.015), prolonged international normalized ratio (HR, 6.449; p = 0.019) and higher CPA (HR, 1.049; p = 0.040) were independent predictors of liver decompensation on multivariate cox-regression analysis. When patients were divided according to the optimal CPA threshold (26.8%), higher CPA predicted LD better than lower CPA. (Log-rank test: p < 0.001).

CONCLUSION

CPA could be a useful quantitative prognostic value for patients with compensated cirrhosis.

Quantification of collagen fiber properties in alcoholic liver fibrosis using polarization-resolved second harmonic generation microscopy

Liver fibrosis is assessed mainly by conventional staining or second harmonic generation (SHG) microscopy, which can only provide collagen content in fibrotic area. We propose to use polarization-resolved SHG (PR-SHG) microscopy to quantify liver fibrosis in terms of collagen fiber orientation and crystallization. Liver samples obtained from autopsy cases with fibrosis stage of F0-F4 were evaluated with an SHG microscope, and 12 consecutive PR-SHG images were acquired while changing the polarization azimuth angle of the irradiated laser from 0° to 165° in 15° increments using polarizer. The fiber orientation angle (φ) and degree (ρ) of collagen were estimated from the images. The SHG-positive area increased as the fibrosis stage progressed, which was well consistent with Sirius Red staining. The value of φ was random regardless of fibrosis stage. The mean value of ρ (ρ-mean), which represents collagen fiber crystallinity, varied more as fibrosis progressed to stage F3, and converged to a significantly higher value in F4 than in other stages. Spatial dispersion of ρ (ρ-entropy) also showed increased variation in the stage F3 and decreased variation in the stage F4. It was shown that PR-SHG could provide new information on the properties of collagen fibers in human liver fibrosis.

Common variable immunodeficiency disorder (CVID)-related liver disease: assessment of the main histological aspects using novel semiquantitative scoring systems, image analysis and correlation with clinical parameters of liver stiffness and portal hypertension

AIMS

We aimed to investigate the relationship between T-cell-mediated sinusoidal injury, nodular regenerative hyperplasia like changes (NRH-LC) and fibrosis, clinical measures of fibrosis and portal hypertension, and progression rate in common variable immunodeficiency disorder (CVID)-related liver disease.

METHODS

This is a retrospective single-centre study. Liver biopsies from CVID patients with liver disease were reviewed to assess for NRH-LC, fibrosis and elastosis, including collagen and elastin proportionate areas. CD3 positive T-cells infiltration and sinusoidal endothelial changes by CD34 expression were quantified by image analysis and a semiquantitative method, respectively. These findings were correlated with liver stiffness measurements (LSM) and hepatic venous pressure gradient (HVPG).

RESULTS

NRH-LC and pericellular elastosis were present in most biopsies (32/40 and 38/40, respectively). All biopsies showed fibrosis, which was limited to pericellular in 21/40 (52.5%) and included bridging fibrous septa in 19/40 (47.5%). 28/40 liver biopsies showed enhanced sinusoidal expression of CD34. There were more CD3 positive cells in biopsies with NRH-LC compared with those without. There was no significant correlation between LSM, HVPG and fibrosis/elastosis scores. Five of seven patients with at least two biopsies showed progression in fibrosis stage.

CONCLUSIONS

NRH-LC and fibrosis in CVID patients often coexist along with the presence of sinusoidal endothelial changes and sinusoidal lymphocytic infiltration. Fibrosis progresses over time, and significant fibrosis can be observed in young patients (<30 years old), potentially reflecting a more aggressive form of CVID-related liver disease. Further studies are necessary to investigate the relationship between histological findings, clinical measures of fibrosis and portal hypertension and outcome.

Staging Liver Fibrosis by Fibroblast Activation Protein Inhibitor PET in a Human-Sized Swine Model

Current methods of staging liver fibrosis have notable limitations. We investigated the utility of PET in staging liver fibrosis by correlating liver uptake of ⁶⁸Ga-labeled fibroblast activation protein inhibitor (FAPI) with histology in a human-sized swine model. Methods: Five pigs underwent baseline ⁶⁸Ga-FAPI-46 (⁶⁸Ga-FAPI) PET/MRI and liver biopsy, followed by liver parenchymal embolization, 8 wk of oral alcohol intake, endpoint ⁶⁸Ga-FAPI PET/MRI, and necropsy. Regions of interest were drawn on baseline and endpoint PET images, and SUV_mean was recorded. At the endpoint, liver sections corresponding to regions of interest were identified and cut out. Fibrosis was histologically evaluated using a modified METAVIR score for swine liver and quantitatively using collagen proportionate area (CPA). Box-and-whisker plots and linear regression were used to correlate SUV_mean with METAVIR score and CPA, respectively. Results: Liver ⁶⁸Ga-FAPI uptake strongly correlated with CPA (r = 0.89, P < 0.001). ⁶⁸Ga-FAPI uptake was significantly and progressively higher across F2 and F3/F4 fibrosis stages, with a respective median SUV_mean of 2.9 (interquartile range [IQR], 2.7-3.8) and 7.6 (IQR, 6.7-10.2) (P < 0.001). There was no significant difference between ⁶⁸Ga-FAPI uptake of baseline liver and endpoint liver sections staged as F0/F1, with a respective median SUV_mean of 1.7 (IQR, 1.3-2.0) and 1.7 (IQR, 1.5-1.8) (P = 0.338). Conclusion: The strong correlation between liver ⁶⁸Ga-FAPI uptake and the histologic stage of liver fibrosis suggests that ⁶⁸Ga-FAPI PET can play an impactful role in noninvasive staging of liver fibrosis, pending validation in patients.

Collagen proportionate area predicts long-term mortality in patients with alcoholic hepatitis

BACKGROUND AND AIMS

There are several short-term prognostic scores for alcoholic hepatitis (AH) that combine demographical and biochemical parameters. The extent of liver fibrosis may also be relevant to the prognosis of AH with potential added value. We evaluated collagen proportionate area (CPA) as a predictor of short and long-term mortality in AH.

METHODS

We retrospectively included patients with biopsy-verified AH. Clinical, laboratory and outcome data were collected. CPA and five AH scores were calculated: Maddrey's DF, MELD, GAHS, ABIC, and the Lille Model. Predictors of short and long-term all-cause mortality were assessed using Cox regression analysis.

RESULTS

We included 140 patients with AH. In total, 67 (48%) patients died after a median follow-up of 66 (IQR 102) months, with 17 (12%) dying within the first 90-days. CPA was not a predictor of 90-days mortality and had no additional value to the prognostic AH scores on short-term mortality. However, CPA predicted long-term mortality independently of prognostic AH scores. Importantly, CPA and abstinence from alcohol were independent predictors of long-term mortality in patients alive 90 days after the biopsy.

CONCLUSION

CPA predicts long-term mortality in patients with AH independently of abstinence from alcohol but has no prognostic value on short-term mortality.

Collagen proportionate area correlates with histological stage and predicts clinical events in primary sclerosing cholangitis

BACKGROUND & AIMS

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease in need of accurate biomarkers for stratification and as surrogates for clinical endpoints in trials. Quantitative liver fibrosis assessment by collagen proportionate area (CPA) measurement has been demonstrated to correlate with clinical outcomes in chronic hepatitis C, alcohol-related and non-alcoholic fatty liver disease. We aimed to investigate the ability of CPA to quantify liver fibrosis and predict clinical events in PSC.

METHODS

Biopsies from 101 PSC patients from two European centres were retrospectively assessed by two expert pathologists in tandem, using grading (Ishak and Nakanuma) and staging (Ishak, Nakanuma, Ludwig) systems recently validated to predict clinical events in PSC. CPA was determined by image analysis of picro-Sirius red-stained sections following a standard protocol. We assessed the correlations between CPA, staging and grading and their associations with three outcomes: (1) time to PSC-related death, liver transplant or primary liver cancer; (2) liver transplant-free survival; (3) occurrence of cirrhosis-related clinical manifestations.

RESULTS

CPA correlated strongly with histological stage determined by each scoring system (P < .001) and was significantly associated with the three endpoints. Median time to endpoint-1, endpoint-2 and endpoint-3 was shorter in patients with higher CPA, on Kaplan-Meier analyses (P = .011, P = .034 and P = .001, respectively).

CONCLUSION

Quantitative fibrosis assessment by CPA has utility in PSC. It correlates with established histological staging systems and predicts clinical events. CPA may be a useful tool for staging fibrosis and for risk stratification in PSC and should be evaluated further within prospective clinical trials.

Portal hypertension is the main driver of liver stiffness in advanced liver cirrhosis

Liver stiffness (LS) is a novel non-invasive parameter widely used in clinical hepatology. LS correlates with liver fibrosis stage in non-cirrhotic patients. In cirrhotic patients it also shows good correlation with Hepatic Venous Pressure Gradient (HVPG). Our aim was to assess the contribution of liver fibrosis and portal hypertension to LS in patients with advanced liver cirrhosis. Eighty-one liver transplant candidates with liver cirrhosis of various aetiologies underwent direct HVPG and LS measurement by 2D shear-wave elastography (Aixplorer Multiwave, Supersonic Imagine, France). Liver collagen content was assessed in the explanted liver as collagen proportionate area (CPA) and hydroxyproline content (HP). The studied cohort included predominantly patients with Child-Pugh class B and C (63/81, 77.8%), minority of patients were Child-Pugh A (18/81, 22.2%). LS showed the best correlation with HVPG (r=0.719, p< 0.001), correlation of LS with CPA (r=0.441, p< 0.001) and HP/Amino Acids (r=0.414, p< 0.001) was weaker. Both variables expressing liver collagen content showed good correlation with each other (r=0.574, p<0.001). Multiple linear regression identified the strongest association between LS and HVPG (p < 0.0001) and weaker association of LS with CPA (p = 0.01883). Stepwise modelling showed minimal increase in r2 after addition of CPA to HVPG (0.5073 vs. 0.5513). The derived formula expressing LS value formation is: LS = 2.48 + (1.29 x HVPG) + (0.26 x CPA). We conclude that LS is determined predominantly by HVPG in patients with advanced liver cirrhosis whereas contribution of liver collagen content is relatively low.

Extension of Collagen Deposition in COVID-19 Post Mortem Lung Samples and Computed Tomography Analysis Findings

Lung fibrosis has specific computed tomography (CT) findings and represents a common finding in advanced COVID-19 pneumonia whose reversibility has been poorly investigated. The aim of this study was to quantify the extension of collagen deposition and aeration in postmortem cryobiopsies of critically ill COVID-19 patients and to describe the correlations with qualitative and quantitative analyses of lung CT. Postmortem transbronchial cryobiopsy samples were obtained, formalin fixed, paraffin embedded and stained with Sirius red to quantify collagen deposition, defining fibrotic samples as those with collagen deposition above 10%. Lung CT images were analyzed qualitatively with a radiographic score and quantitatively with computer-based analysis at the lobe level. Thirty samples from 10 patients with COVID-19 pneumonia deceased during invasive mechanical ventilation were included in this study. The median [interquartile range] percent collagen extension was 6.8% (4.6-16.2%). In fibrotic compared to nonfibrotic samples, the qualitative score was higher (260 (250-290) vs. 190 (120-270), p = 0.036) while the gas fraction was lower (0.46 (0.32-0.47) vs. 0.59 (0.37-0.68), p = 0.047). A radiographic score above 230 had 100% sensitivity (95% confidence interval, CI: 66.4% to 100%) and 66.7% specificity (95% CI: 41.0% to 92.3%) to detect fibrotic samples, while a gas fraction below 0.57 had 100% sensitivity (95% CI: 66.4% to 100%) and 57.1% specificity (95% CI: 26.3% to 88.0%). In COVID-19 pneumonia, qualitative and quantitative analyses of lung CT images have high sensitivity but moderate to low specificity to detect histopathological fibrosis. Pseudofibrotic CT findings do not always correspond to increased collagen deposition.

Histological sub-classification of cirrhosis using collagen proportionate area in patients with chronic hepatitis C

Collagen proportionate area (CPA, %) is used to quantify liver fibrosis. Here, we assessed CPA performance to sub-classify cirrhosis. CPA was measured in explanted livers from consecutively transplanted patients for hepatitis C virus-related cirrhosis. Model for end-stage liver disease (MELD), Child-Pugh score and decompensating events (ascites, variceal bleeding, non-obstructive jaundice and encephalopathy) were recorded at the time of liver transplant. Of the 154 patients, 24%, 12%, 35%, 24% and 5% had zero, one, two, three and four previous decompensating events. Patients with decompensation had significantly higher CPA than those without (25.1 ± 8.4 vs 15.8 ± 5.5, P < .001). Decompensation was independently associated with CPA, bilirubin and albumin or with CPA and MELD score. CPA did not differ between patients with one, two, three or four decompensating events (22.2 ± 6.3 vs 26.6 ± 8.9 vs 24.5 ± 7.7 vs 24.4 ± 10.9, P = .242). Overall, CPA correlates with the clinical severity of cirrhosis until the advent of decompensation but not with subsequent decompensating events.

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.

Enhancing the Value of Histopathological Assessment of Allograft Biopsy Monitoring

Traditional histopathological allograft biopsy evaluation provides, within hours, diagnoses, prognostic information, and mechanistic insights into disease processes. However, proponents of an array of alternative monitoring platforms, broadly classified as "invasive" or "noninvasive" depending on whether allograft tissue is needed, question the value proposition of tissue histopathology. The authors explore the pros and cons of current analytical methods relative to the value of traditional and illustrate advancements of next-generation histopathological evaluation of tissue biopsies. We describe the continuing value of traditional histopathological tissue assessment and "next-generation pathology (NGP)," broadly defined as staining/labeling techniques coupled with digital imaging and automated image analysis. Noninvasive imaging and fluid (blood and urine) analyses promote low-risk, global organ assessment, and "molecular" data output, respectively; invasive alternatives promote objective, "mechanistic" insights by creating gene lists with variably increased/decreased expression compared with steady state/baseline. Proponents of alternative approaches contrast their preferred methods with traditional histopathology and: (1) fail to cite the main value of traditional and NGP-retention of spatial and inferred temporal context available for innumerable objective analyses and (2) belie an unfamiliarity with the impact of advances in imaging and software-guided analytics on emerging histopathology practices. Illustrative NGP examples demonstrate the value of multidimensional data that preserve tissue-based spatial and temporal contexts. We outline a path forward for clinical NGP implementation where "software-assisted sign-out" will enable pathologists to conduct objective analyses that can be incorporated into their final reports and improve patient care.

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.

Comparison and correlation of fibrosis stage assessment by collagen proportionate area (CPA) and the ELF panel in patients with chronic liver disease

BACKGROUND

Fibrosis progression is the common consequence of most chronic liver diseases.

AIMS

To evaluate the performance of Collagen Proportionate Area (CPA) and ELF using Ishak's score in patients with chronic liver diseases.

METHODS

Retrospective analysis of medical data from patients on whom a liver biopsy was performed as part of the diagnostic assessment. CPA was calculated by using digital image analysis and then compared with Ishak and ELF scores.

RESULTS

143 patients (84 men (59%); mean age 48.8 ± 12.8 years) were evaluated. Patients were mainly affected by viral hepatitis (92 HCV and 8 HBV). CPA and ELF values increased with worsening Ishak stage (P < 0.001) and their median values were significantly different among Ishak stages (P < 0.001). There was a significant correlation between CPA and ELF (r = 0.5). In AUROC analysis, CPA and ELF had similar diagnostic accuracy in identifying cirrhosis, but CPA had higher diagnostic accuracy than ELF in identifying significant or absent fibrosis. High ELF scores were observed in non-cirrhotic patients who suffered non-liver related deaths.

CONCLUSIONS

This study demonstrated that CPA and ELF values successfully identified patients with advanced fibrosis or cirrhosis, thus confirming the role of ELF as a clinical method for non-invasive assessment of fibrosis stage in chronic hepatitis.

The Landscape of Digital Pathology in Transplantation: From the Beginning to the Virtual E-Slide

Background

Digital pathology has progressed over the last two decades, with many clinical and nonclinical applications. Transplantation pathology is a highly specialized field in which the majority of practicing pathologists do not have sufficient expertise to handle critical needs. In this context, digital pathology has proven to be useful as it allows for timely access to expert second-opinion teleconsultation. The aim of this study was to review the experience of the application of digital pathology to the field of transplantation.

Methods

Papers on this topic were retrieved using PubMed as a search engine. Inclusion criteria were the presence of transplantation setting and the use of any type of digital image with or without the use of image analysis tools; the search was restricted to English language papers published in the 25 years until December 31, 2018.

Results

Literature regarding digital transplant pathology is mostly about the digital interpretation of posttransplant biopsies (75 vs. 19), with 15/75 (20%) articles focusing on agreement/reproducibility. Several papers concentrated on the correlation between biopsy features assessed by digital image analysis (DIA) and clinical outcome (45/75, 60%). Whole-slide imaging (WSI) only appeared in recent publications, starting from 2011 (13/75, 17.3%). Papers dealing with preimplantation biopsy are less numerous, the majority (13/19, 68.4%) of which focus on diagnostic agreement between digital microscopy and light microscopy (LM), with WSI technology being used in only a small quota of papers (4/19, 21.1%).

Conclusions

Overall, published studies show good concordance between digital microscopy and LM modalities for diagnosis. DIA has the potential to increase diagnostic reproducibility and facilitate the identification and quantification of histological parameters. Thus, with advancing technology such as faster scanning times, better image resolution, and novel image algorithms, it is likely that WSI will eventually replace LM.

Collagen proportionate area is an independent predictor of long-term outcome in patients with non-alcoholic fatty liver disease

BACKGROUND

Collagen proportionate area (CPA) measurement is a technique that quantifies fibrous tissue in liver biopsies by measuring the amount of collagen deposition as a proportion of the total biopsy area. CPA predicts clinical outcomes in patients with HCV and can sub-classify cirrhosis.

AIM

To test the ability of CPA to quantify fibrosis and predict clinical outcomes in patients with NAFLD.

METHODS

We assessed consecutive patients with biopsy-proven NAFLD from three European centres. Clinical and laboratory data were collected at baseline and at the time of the last clinical follow-up or death. CPA was performed at two different objective magnifications, whole biopsy macro and ×4 objective magnification, named standard (SM) and high (HM) magnification respectively. The correlation between CPA and liver stiffness was assessed in a sub-group of patients.

RESULTS

Of 437 patients, 32 (7.3%) decompensated and/or died from liver-related causes during a median follow-up of 103 months. CPA correlated with liver stiffness and liver fibrosis stage across the whole spectrum of fibrosis. HM CPA was significantly higher than SM CPA in stages F0-F3 but similar in cirrhosis, reflecting a higher ability to capture pericellular/perisinusoidal fibrosis at early stages. Age at baseline (HR: 1.04, 95% CI: 1.01-1.08), HM CPA (HR: 1.04 per 1% increase, 95% CI: 1.01-1.08) and presence of advanced fibrosis (HR: 15.4, 95% CI: 5.02-47.84) were independent predictors of liver-related clinical outcomes at standard and competing risk multivariate Cox-regression analysis.

CONCLUSIONS

CPA accurately measures fibrosis and is an independent predictor of clinical outcomes in NAFLD; hence it merits further evaluation as a surrogate endpoint in clinical trials.

Systematic quantification of histological patterns shows accuracy in reflecting cirrhotic remodeling

BACKGROUND AND AIM

There still lacks a tool for precisely evaluating cirrhotic remodeling. Histologic distortion characterized in cirrhosis (i.e. cirrhotic patterns) has a validated pathophysiological meaning and potential relevance to clinical complications. We aimed to establish a new tool to quantify the cirrhotic patterns and test it for reflecting the cirrhotic remodeling.

METHODS

We designed a computerized algorithm, named qCP, dedicated for the analysis of liver images acquired by second harmonic microscopy. We evaluated its measurement by using a cohort of 95 biopsies (Ishak staging F4/5/6 = 33/35/27) of chronic hepatitis B and a carbon tetrachloride-intoxicated rat model for simulating the bidirectional cirrhotic change.

RESULTS

QCP can characterize 14 histological cirrhosis parameters involving the nodules, septa, sinusoid, and vessels. For chronic hepatitis B biopsies, the mean overall intra-observer and inter-observer agreement was 0.94 ± 0.08 and 0.93 ± 0.09, respectively. The robustness in resisting sample adequacy-related scoring error was demonstrated. The proportionate areas of total (collagen proportionate area), septal (septal collagen proportionate area [SPA]), sinusoidal, and vessel collagen, nodule area, and nodule density (ND) were associated with Ishak staging (P < 0.01 for all). But only ND and SPA were independently associated (P ≤ 0.001 for both). A histological cirrhosis parameters-composed qCP-index demonstrated an excellent accuracy in quantitatively diagnosing evolving cirrhosis (areas under receiver operating characteristic curves 0.95-0.92; sensitivity 0.93-0.82; specificity 0.94-0.85). In the rat model, changes in collagen proportionate area, SPA, and ND had strong correlations with both cirrhosis progression and regression and faithfully characterized the histological evolution.

CONCLUSIONS

QCP preliminarily demonstrates potential for quantitating cirrhotic remodeling with high resolution and accuracy. Further validation with in-study cohorts and multiple-etiologies is warranted.

Current and future treatment options in non-alcoholic steatohepatitis (NASH)

Non-alcoholic steatohepatitis (NASH) is a chronic liver disease that can progress to cirrhosis and hepatocellular carcinoma. Diagnosis of NASH requires a liver biopsy and is defined as presence of hepatic steatosis, ballooning and lobular inflammation with or without fibrosis. Although NASH is the most common cause of liver disease in the west world and among the top three indications for liver transplantation, there are no universally accepted pharmacological therapies and therapeutic advances have been slow. Areas covered: Current evidence about lifestyle interventions, bariatric surgery and pharmacotherapy is reviewed. Dietary recommendations and lifestyle interventions have shown promising results but are difficult to maintain. At the moment, there is no universally approved medical treatment for NASH. Pioglitazone and vitamin E are recommended by guidelines in selected patients. An increasing number of phase II and III trials in non-cirrhotic NASH are currently recruiting and their preliminary results discussed. Expert commentary: As NASH is classified as a medical condition of an unmet therapeutic need, it has gained an accelerated access pathway for drug approval based on surrogate endpoints. It is therefore expected that within the next five years, there will be at least one approved agent for the pharmacological treatment of pre-cirrhotic NASH.

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.

Fibrosis assessment in patients with chronic hepatitis B virus (HBV) infection

Chronic hepatitis B virus (HBV) infection is a major cause of liver morbidity and mortality worldwide. While a proportion of the 250 million individuals chronically infected with HBV will not come to significant harm or require therapy, many others risk developing complications of the end-stage liver disease such as decompensated cirrhosis and hepatocellular carcinoma (HCC), without intervention. Due to the complex natural history of HBV infection, patients require an expert assessment to interpret biochemistry, viral serology and appropriately stage the disease, and to initiate monitoring and/or therapy where indicated. The detection and quantification of liver fibrosis is a key factor for disease management and prognostication for an individual with HBV. The reliance on invasive liver biopsy to stage disease is diminishing with the advent of robust non-invasive blood- and imaging-based algorithms which can reliably stage disease in many cases. These tests are now incorporated into International guidelines for HBV management and relied upon daily to inform clinical judgement. Both blood- and imaging-based approaches have advantages over liver biopsy, including minimal risks, lower cost, better patient acceptance and speed of results, while disadvantages include lower diagnostic accuracy in intermediate disease stages and variability with co-existing hepatic inflammation or steatosis. This review outlines the methods of fibrosis assessment in chronic HBV infection and focuses on the most commonly used blood- and imaging-based non-invasive tests, reviewing their diagnostic performance and applicability to patient care.

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.

Early non-invasive selection of patients at high risk of severe hepatitis C recurrence after liver transplantation

BACKGROUND

The early identification of patients at high risk of severe post liver transplant hepatitis C recurrence is relevant, as these patients may be treated using interferon (IFN)-free regimens.

METHODS

In a retrospective study with prospectively collected data, we investigated whether the use of several non-invasive methods (fibrosis 4 index [FIB-4], AST-to-platelets ratio index [APRI], enhanced liver fibrosis test [ELF], IFN-γ-inducible protein 10 [IP-10], and transient elastography by Fibroscan) and their combinations 6 months after transplantation could identify those recipients at higher risk of severe recurrence, defined by the presence of significant fibrosis (F ≥2) and/or portal hypertension (hepatic venous pressure gradient ≥6 mmHg) 12 months after transplant. Seventy-two hepatitis C virus (HCV)-infected liver transplant patients and 10 recipients in whom HCV was eradicated before transplantation were included in the study.

RESULTS

The levels of all biomarkers were significantly higher in HCV-infected recipients than in controls. Among HCV recipients, levels of biomarkers were significantly higher in patients with severe recurrence. Although there were no statistically significant differences between biomarkers, APRI, ELF, and FIB-4 obtained the highest area under the ROC curve values. The combination of serum biomarkers with Fibroscan increased the negative and positive predictive values, although diagnostic accuracy of individual tests was not significantly improved.

CONCLUSIONS

Patients at higher risk of severe HCV recurrence can be identified early, 6 months after transplantation, using readily available non-invasive methods.

Evaluation of liver fibrosis: "Something old, something new…"

Hepatic fibrogenesis may gradually result to cirrhosis due to the accumulation of extracellular matrix components as a response to liver injury. Thus, therapeutic decisions in chronic liver disease, regardless of the cause, should first and foremost be guided by an accurate quantification of hepatic fibrosis. Detection and assessment of the extent of hepatic fibrosis represent a challenge in modern Hepatology. Although traditional histological staging systems remain the “best standard”, they are not able to quantify liver fibrosis as a dynamic process and may not accurately substage cirrhosis. This review aims to compare the currently used non-invasive methods of measuring liver fibrosis and provide an update in current tissue-based digital techniques developed for this purpose, that may prove of value in daily clinical practice.

Quantitative fibrosis estimation by image analysis predicts development of decompensation, composite events and defines event-free survival in chronic hepatitis B patients

The extent of fibrosis is a major determinant of the clinical outcome in patients with chronic liver diseases. We undertook this study to explore the degree of fibrosis in baseline liver biopsies to predict clinical outcomes in chronic hepatitis B (CHB) patients. Fibrosis quantification was done by image analysis on Masson's trichrome-stained sections and correlated with clinical and biochemical parameters, liver stiffness and hepatic vein pressure gradient (n = 96). Follow-up information collected related to clinical outcome. A total of 964 cases was analyzed. Median quantitative fibrosis (QF) was 3.7% (interquartile range, 1.6%-9.7%) with substantial variation in various stages. Median QF was F0, 1% (0.7%-1.65%); F1, 3.03% (2.07%-4.0%); F2, 7.1% (5.6%-8.7%); F3, 12.7% (10.15%-16.7%); F4, 26.9% (20.3%-36.4%). QF positively correlated with METAVIR staging, liver stiffness measurement, and hepatic vein pressure gradient. Eighty-nine cases developed liver-related events: decompensation, hepatocellular carcinoma, liver transplantation and death. Cox regression analysis after adjusting for METAVIR staging-QF, albumin, and AST for composite events; QF and albumin for decompensation; and only QF for hepatocellular carcinoma-were found to be significant predictors of clinical outcomes. QF categorized into five stages: QF1, 0%-5%; QF2, 5.1%-10%; QF3, 10.1%-15%; QF4, 15.1%-20%; QF5, >20.1%. In patients with advanced stages of QF, probability of event-free survival found to be low. Quantitative fibrosis in baseline liver biopsy predicts progression of the disease and disease outcome in CHB patients. QF defines the probability of event-free survival in CHB cases.

Assessment of liver fibrosis in primary biliary cholangitis: Comparison between indirect serum markers and fibrosis morphometry

BACKGROUND

The accuracy of non-invasive methods for the quantification of liver fibrosis in primary biliary cholangitis (PBC) is still debated.

AIMS

To determine the histo-morphometric measurement of fibrotic tissue and to explore the possible association between indirect markers (APRI, FORNS, FIB-4, and Lok) and morphometry.

METHODS

Retrospective analysis of medical data from patients with PBC, on whom needle liver biopsy was performed as part of the diagnostic assessment. One section of each biopsy stained with Sirius red was used for calculating the percentage of collagen. Quantitative measure of fibrotic tissue (fibrosis morphometry) was calculated as a percentage of collagen content by digital image analysis. Morphometry results were divided into four groups reflecting Ludwig's staging and compared with values for indirect serum markers.

RESULTS

50 PBC patients were enrolled (86% females, mean age 57 ± 12.30 years), 19 were Ludwig's stage I (38%), 14 stage II (28%), 12 stage III (24%), and five stage IV (10%). Morphometry results were significantly different among Ludwig stages (p<0.05). No significant differences were found for indirect serum markers. A significant correlation was found between morphometry results and indirect serum markers tested (p<0.05).

CONCLUSION

In our cohort, the histo-morphometric values of fibrotic tissue increased progressively with Ludwig's stages of PBC, while non-invasive markers did not.

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

BACKGROUND

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

OBJECTIVE

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

DATA SOURCES

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

METHODS

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

RESULTS

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

LIMITATIONS

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

CONCLUSIONS

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

STUDY REGISTRATION

This study is registered as PROSPERO CRD42011001561.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Comparison of Histochemical Stainings in Evaluation of Liver Fibrosis and Correlation with Transient Elastography in Chronic Hepatitis

Background and Aim. The best staining to evaluate liver fibrosis in liver hepatitis is still a debated topic. This study aimed to compare Masson's trichrome (MT), Sirius Red (SR), and orcein stainings in evaluating liver fibrosis in chronic HCV hepatitis (CHC) with semiquantitative and quantitative methods (Collagen Proportionate Area (CPA) by Digital Image Analysis (DIA)) and correlate them with transient elastography (TE). Methods. Liver stiffness evaluation of 111 consecutive patients with CHC was performed by TE. Semiquantitative staging by Metavir score system and CPA by DIA were assessed on liver biopsy stained with MT, SR, and orcein. Results. MT, SR, and orcein staining showed concordant results in 89.6% of cases in staging CHC, without significant difference in both semiquantitative and quantitative evaluations of fibrosis. TE values were concordant with orcein levels in 86.5% of the cases and with MT/RS in 77.5% (P < 0.001). No significant correlation between the grade of necroinflammatory activity and TE values was found. Conclusion. In CHC, SR/MT and orcein stainings are almost concordant and when discordant, orcein staining is better related to TE values than MT/RS. This suggests that elastic fibers play a more important role than reticular or collagenous ones in determining stiffness values in CHC.

Molecular prognostic prediction in liver cirrhosis

The natural history of cirrhosis varies and therefore prognostic prediction is critical given the sizable patient population. A variety of clinical prognostic indicators have been developed and enable patient risk stratification although their performance is somewhat limited especially within relatively earlier stage of disease. Molecular prognostic indicators are expected to refine the prediction, and potentially link a subset of patients with molecular targeted interventions that counteract poor prognosis. Here we overview clinical and molecular prognostic indicators in the literature, and discuss critical issues to successfully define, evaluate, and deploy prognostic indicators as clinical scores or tests. The use of liver biopsy has been diminishing due to sampling variability on fibrosis assessment and emergence of imaging- or lab test-based fibrosis assessment methods. However, recent rapid developments of genomics technologies and selective molecular targeted agents has highlighted the need for biopsy tissue specimen to explore and establish molecular information-guided personalized/stratified clinical care, and eventually achieve “precision medicine”.

Automated morphometry provides accurate and reproducible virtual staging of liver fibrosis in chronic hepatitis C

Background:

Liver fibrosis staging provides prognostic value, although hampered by observer variability. We used digital analysis to develop diagnostic morphometric scores for significant fibrosis, cirrhosis and fibrosis staging in chronic hepatitis C.

Materials and Methods:

We automated the measurement of 44 classical and new morphometric descriptors. The reference was histological METAVIR fibrosis (F) staging (F0 to F4) on liver biopsies. The derivation population included 416 patients and liver biopsies ≥20 mm-length. Two validation population included 438 patients.

Results:

In the derivation population, the area under the receiver operating characteristic (AUROC) for clinically significant fibrosis (F stage ≥2) of a logistic score combining 5 new descriptors (stellar fibrosis area, edge linearity, bridge thickness, bridge number, nodularity) was 0.957. The AUROC for cirrhosis of 6 new descriptors (edge linearity, nodularity, portal stellar fibrosis area, portal distance, granularity, fragmentation) was 0.994. Predicted METAVIR F staging combining 8 morphometric descriptors agreed well with METAVIR F staging by pathologists: κ = 0.868. Morphometric score of clinically significant fibrosis had a higher correlation with porto-septal fibrosis area (r_s = 0.835) than METAVIR F staging (r_s = 0.756, P < 0.001) and the same correlations with fibrosis biomarkers, e.g., serum hyaluronate: r_s = 0.484 versus r_s = 0.476 for METAVIR F (P = 0.862). In the validation population, the AUROCs of clinically significant fibrosis and cirrhosis scores were, respectively: 0.893 and 0.993 in 153 patients (biopsy < 20 mm); 0.955 and 0.994 in 285 patients (biopsy ≥ 20 mm). The three morphometric diagnoses agreed with consensus expert reference as well as or better than diagnoses by first-line pathologists in 285 patients, respectively: significant fibrosis: 0.733 versus 0.733 (κ), cirrhosis: 0.900 versus 0.827, METAVIR F: 0.881 versus 0.865.

Conclusion:

The new automated morphometric scores provide reproducible and accurate diagnoses of fibrosis stages via “virtual expert pathologist.”

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.

Comparison of Histochemical Staining Methods and Correlation with Transient Elastography in Acute Hepatitis

OBJECTIVE

To compare Masson's trichrome (MT), Sirius red (SR) and orcein staining in acute hepatitis (AH) and to correlate them with transient elastography (TE), a noninvasive method to assess hepatic fibrosis.

METHODS

We evaluated liver stiffness by TE in a cohort of 34 consecutive patients and assessed MT-, SR- and orcein-stained biopsies using the METAVIR scoring system and digital image analysis (DIA).

RESULTS

MT and SR both showed severe fibrosis (stage III-IV, DIA = 12.7%). Orcein showed absent or mild fibrosis (stage 0-II, DIA = 4.4%; p < 0.05). In 29/34 cases (85%), stiffness values were >12.5 kPa, in keeping with SR/MT but not with orcein results.

CONCLUSIONS

Even though in AH true elastic fibrosis is typically absent or mild, TE shows elevated stiffness values, in keeping with SR/MT evaluations. If not properly evaluated in the clinical context, these results would lead to an overestimation of fibrosis. Orcein is the only staining able to evidence the absence of true elastic fibrosis, which is a typical feature of AH. This is the first study comparing different staining procedures performed on AH biopsies by DIA versus TE. © 2015 S. Karger AG, Basel.

Assessment of liver fibrosis: the relationship between point shear wave elastography and quantitative histological analysis

BACKGROUND AND AIM

Traditional pathological scoring systems for liver fibrosis progression are predominantly based on the description of architectural changes with no consideration of the amount of collagen fiber deposition. Our purpose was to explore a true histological standard in accordance with the liver stiffness measured by point shear wave elastography (PSWE) in patients with chronic hepatitis B.

METHODS

A total of 78 patients with liver neoplasms underwent liver stiffness measurements with PSWE as well as biochemical investigations within 3 days before partial hepatectomy. One tissue section of the liver specimens was stained with HE trichrome and evaluated traditionally with the Scheuer scoring system. The other tissue section was stained with picroSirius red and was evaluated according to the semiquantitative Chevallier et al. scoring system. In addition, this second tissue section was evaluated for the collagen proportionate area (CPA) with computer-assisted digital image analysis. The reproducibility of PSWE technology was explored through the intra-class correlation coefficient of a reliability analysis.

RESULTS

The PSWE technology revealed good reproducibility in liver stiffness measurements, and the PSWE values increased with the pathological severity of liver fibrosis on both the Scheuer scoring system and the semiquantitative Chevallier et al. scoring system. PSWE values exhibited more reasonable relationships with CPA (r = 0.628, P = 0.00 < 0.05) than with the Scheuer scoring system (r = 0.473, P = 0.00 < 0.05) or the Chevallier et al. semiquantitative scoring system (r = 0.487, P = 0.00 < 0.05).

CONCLUSION

CPA is a better pathological parameter than traditional semiquantitative scoring systems in accordance with liver stiffness measured by PSWE technology.

Quantification of fibrosis by collagen proportionate area predicts hepatic decompensation in hepatitis C cirrhosis

BACKGROUND

It is unclear whether the course of cirrhosis and its prognosis are related to the amount of collagen in the liver.

AIM

To determine whether fibrosis, assessed by collagen proportionate area (CPA) in patients with compensated cirrhosis, is associated with the presence of oesophageal varices, and predict disease decompensation during the follow-up period.

METHODS

We prospectively evaluated 118 consecutive patients with compensated cirrhosis to correlate fibrosis, assessed by CPA in liver biopsies, with the presence of oesophageal varices (OV) and with the rate of liver decompensation (LD) development during a median follow-up of 72 months.

RESULTS

At baseline 38 (32.2%) patients had OV and during the follow-up (median 72 months, IQR 47-91), 17 patients (14.4%) developed LD. The mean CPA value was different in patients with and without OV (14.8 ± 5.9% vs. 21.6 ± 9.5%, P < 0.001). The best CPA cut-off for OV by area under the receiver operating characteristic (AUROC) was ≥14% and with multivariate logistic analysis CPA was the only variable associated with OV (OR: 28.32, 95% CI: 6.30-127.28; P < 0.001). By AUROC analysis the best CPA cut-off to predict LD was 18.0%. By Cox regression multivariate analysis CPA ≥18% (HR: 3.99, 95% CI: 1.04-11.45; P = 0.036), albumin (HR: 0.12, 95% CI: 0.04-0.43; P = 0.001) and presence of OV (HR: 8.15, 95% CI: 2.31-28.78; P = 0.001) were independently associated with LD.

CONCLUSION

Quantification of fibrosis by collagen proportionate area allows identification of patients with compensated HCV cirrhosis with a higher likelihood of clinically relevant portal hypertension and a higher risk of decompensation.

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.

Image analysis of liver biopsy samples measures fibrosis and predicts clinical outcome

BACKGROUND & AIMS

Histopathological scoring of liver fibrosis mainly measures architectural abnormalities and requires a minimum biopsy size (⩾ 10 mm). Liver collagen quantification may allow use of small size biopsies and improve the prediction of clinical outcomes. This study evaluated the ability of the collagen proportional area (CPA) measurement to predict clinical outcomes.

METHODS

Clinical outcomes were determined using population based data-linkage for chronic hepatitis C (CHC) patients from 1992 to 2012. Quantitative digital image analysis of liver biopsies was used for CPA measurement.

RESULTS

533 patients with a biopsy size ⩾ 5 mm were included. Median follow up was 10.5 years. 26 developed hepatocellular carcinoma (HCC), 39 developed liver decompensation and 33 had liver related death. 453 had Metavir F0-F2 and 80 had F3-F4. CPA ranged from 1.3% to 44.6%. CPA and Metavir stage were independently associated with liver related death. Metavir stage, CPA stage and age were independently associated with HCC. CPA stage (C1: 0%-5%, C2: 5%-10%, C3: 10%-20%, C4: >20%) stratified risk and a significant difference in outcomes was present between all CPA stages for HCC and between C2-C3 and C3-C4 for decompensation and liver related death. The 15 year composite endpoint-free survival was 97% for C1, 89% for C2, 60% for C3, 7% for C4. C4 had significantly worse survival than ⩽ C3 (p<0.001) in cirrhotic patients.

CONCLUSIONS

CPA stage gave additional information regarding risk stratification for adverse clinical outcomes independent of Metavir stage.

Collagen proportionate area is superior to other histological methods for sub-classifying cirrhosis and determining prognosis

BACKGROUND & AIMS

One-year survival in cirrhosis ranges from 1 to 57% depending on the clinical stage. Accurate sub-classification has important prognostic implications but there is no stage beyond cirrhosis using current qualitative histological systems. We compared the performance of all histological semi-quantitative and quantitative methods specifically developed for sub-classifying cirrhosis that have been described to date, with collagen proportionate area (CPA), to evaluate how well they distinguish patients with and without hepatic clinical decompensation at presentation, and in predicting future decompensating events.

METHODS

We included consecutive patients with a histological diagnosis of cirrhosis that had a suitable liver biopsy between 2003 and 2007. We used semi-quantitative histological scoring systems proposed by Laennec, Kumar, and Nagula. We also measured quantitatively nodule size, septal width and fibrous tissue expressed in CPA.

RESULTS

Sixty-nine patients, mean age 52.3±11years, mean MELD 11.8±5.8, median follow-up 56months. Main aetiologies were alcohol (38%) and hepatitis C (27.5%). Twenty-four patients (34.8%) had had a previous episode of clinical decompensation. Amongst the 45 patients who were compensated, 11 (24%) decompensated on follow-up. In Cox regression, amongst all histological parameters, CPA was the only variable independently associated with clinical decompensation up to the time of biopsy, with an odds ratio that ranged from 1.245 to 1.292. Furthermore, only CPA was significantly associated with future decompensation (OR: 1.117, 95% CI 1.020-1.223; p=0.017).

CONCLUSIONS

Cirrhosis can be accurately sub-classified using quantification of fibrosis with CPA, and furthermore CPA is the only independent predictor of clinical decompensation amongst all other histological sub-classification systems described to date.

Histopathological evaluation of recurrent hepatitis C after liver transplantation: A review

Although the morphological features of hepatitis C virus (HCV) recurrence after orthotopic liver transplantation (OLT) have been well established in the last decades, the differential diagnosis still represents a challenge for the pathologist, especially early recurrent hepatitis C vs mild acute cellular rejection. The present review focuses on the role of the pathologist and the pathology laboratory in the management of recipients with recurrent hepatitis C, the usefulness of early and late post-OLT liver biopsies, and the potential role of ancillary techniques (immunohistochemistry and reverse transcription-polymerase chain reaction, RT-PCR). The English literature on the topic is reviewed, focusing on the histopathology, the immunohistochemistry and the use of RT-PCR on HCV-positive post-OLT biopsies. The different histopathological illustrations of early and chronic recurrent hepatitis C are presented, with special focus on the main differential diagnoses and those features with prognostic relevance (cholestasis above all). The usefulness of ancillary techniques are discussed, especially HCV RNA quantitation by RT-PCR. Finally, the usefulness of long-term protocol biopsies is addressed: their usefulness for the study of allograft disease progression is clear, but their meaning in the long term is still debated. The significance of plasma cell infiltrate in HCV-positive allografts, the prognostic weight of graft steatosis, and the impact of donor age in recurrent hepatitis C also represent additional open issues.

The relationship between transient elastography and histological collagen proportionate area for assessing fibrosis in chronic viral hepatitis

BACKGROUND

Collagen proportionate area (CPA) has a better correlation with hepatic venous pressure gradient (HVPG) than with Ishak stage. Liver stiffness measurement (LSM) is proposed as non invasive marker of portal hypertension/disease progression. Our aim was to compare LSM and CPA with Ishak staging in chronic viral hepatitis, and HVPG in HCV hepatitis after transplantation.

METHODS

One hundred and sixty-nine consecutive patients with chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) infections pre/post liver transplantation (LT), had a liver biopsy combined with LSM (transient elastography), CPA (biopsies stained with Sirius Red and evaluated by digital image analysis and expressed as CPA) and HVPG (measured contemporaneously with transjugular biopsies in LT HCV patients).

RESULTS

LSM was dependent on CPA in HBV (r (2) = 0.61, p < 0.0001), HCV (r (2) = 0.59, p < 0.0001) and LT groups (r (2) = 0.64, p < 0.0001). In all three groups, CPA and Ishak were predictors of LSM, but multivariately CPA was better related to LSM (HBV: r (2) = 0.61, p < 0.0001; HCV: r (2) = 0.59, p < 0.0001; post-LT: r (2) = 0.68, p < 0.0001) than Ishak stage. In the LT group, multiple regression analysis including HVPG, LSM, aspartate aminotransferase to platelet ratio index (APRI) and Ishak stage/grade, showed that only CPA was related to HVPG (r (2) = 0.41, p = 0.01), both for HVPG ≥6 mmHg (OR 1.34, 95 % CI 1.14-1.58; p < 0.0001) or ≥10 mmHg (OR 1.25, 95 % CI 1.06-1.47; p = 0.007).

CONCLUSION

CPA was related to LSM in HBV or HCV hepatitis pre/post-LT. CPA was better related to LSM than Ishak stage. In the LT HCV group, CPA was better related to HVPG than Ishak stage/grade, LSM or APRI. CPA may represent a better comparative histological index for LSM, rather than histological stages.

Histopathology of post-transplant liver biopsies, the first report from iran

BACKGROUND

Evaluation of a transplanted liver by Imaging techniques and enzyme changes is sensitive to hepatocellular or biliary problems, but in most instances liver allograft biopsies are performed in order to find out the final reason for these changes.

OBJECTIVES

It's been about 17 years (with more than 1326 cases) since the first liver transplantation in the Namazi Hospital of Shiraz University of Medical Sciences while during the last five years the number of post liver transplant biopsies have increased. Until now there has been no report of the pathological results of post liver transplant needle biopsies from Iran.

MATERIALS AND METHODS

During the last 5 years, there have been 382 post liver transplant biopsies. We studied the clinical charts and pathological results of all needle biopsies.

RESULTS

A total of 382 needle biopsies were performed on 287 patients aged between 1 and 64 years old. The earliest specimen was obtained within the first few hours following transplantation, and the last was gathered 3209 days (261 ± 523) post-transplantation. Acute rejection was the most common diagnosis, which occurred in 180 (47%) of specimens. Among other complications were vascular problems (8.6%), preservation/reperfusion (I/R) injury (7%), chronic rejection (5.2%), biliary injury/obstruction (3.4%), recurrence of primary disease (2.6%), drug-induced hepatic injury (1.8%), cirrhosis (1.6%), sepsis (1.4%), cytomegalovirus hepatitis (1.4%), post-transplantation lymphoproliferative disease (1%) and Venous outflow obstruction (0.5%).

CONCLUSIONS

The most common pathological diagnosis of post-transplant liver needle biopsies has been acute rejection, followed by ischemia due to hepatic artery thrombosis, preservation/reperfusion injury, and chronic rejection.

Digital image analysis of collagen assessment of progression of fibrosis in recurrent HCV after liver transplantation

BACKGROUND & AIMS

Histological assessment of fibrosis progression is currently performed by staging systems which are not continuous quantitative measurements. We aimed at assessing a quantitative measurement of fibrosis collagen proportionate area (CPA), to evaluate fibrosis progression and compare it to Ishak stage progression.

METHODS

We studied a consecutive cohort of 155 patients with recurrent HCV hepatitis after liver transplantation (LT), who had liver biopsies at one year and were subsequently evaluated for progression of fibrosis using CPA and Ishak staging, and correlated with clinical decompensation. The upper quartile of distribution of fibrosis rates (difference in CPA or Ishak stage between paired biopsies) defined fast fibrosers.

RESULTS

Patients had 610 biopsies and a median follow-up of 116 (18-252) months. Decompensation occurred in 29 (18%) patients. Median Ishak stage progression rate was 0.42 units/year: (24 (15%) fast fibrosers). Median CPA fibrosis progression rate was 0.71%/year (36 (23%) fast fibrosers). Clinical decompensation was independently associated by Cox regression only with CPA (p=0.007), with AUROCs of 0.81 (95% CI 0.71-0.91) compared to 0.68 (95% CI 0.56-0.81) for Ishak stage. Fast fibrosis defined by CPA progression was independently associated with histological de novo hepatitis (OR: 3.77), older donor age (OR: 1.03) and non-use/discontinuation of azathioprine before 1 year post-LT (OR: 3.85), whereas when defined by Ishak progression, fast fibrosers was only associated with histological de novo hepatitis.

CONCLUSIONS

CPA fibrosis progression rate is a better predictor of clinical outcome than progression by Ishak stage. Histological de novo hepatitis, older donor age and non-use/discontinuation of azathioprine are associated with rapid fibrosis progression in recurrent HCV chronic hepatitis after liver transplantation.

Sample size requirement for digital image analysis of collagen proportionate area in cirrhotic livers

AIMS

   The requirements for adequate cirrhotic liver biopsy size have not been established for quantitative fibrosis measurements (collagen proportionate area: CPA). We evaluated the CPA of virtual biopsies in cirrhosis to elucidate (i) the amount of tissue required to achieve reliable CPA measurements and (ii) the effect of aetiology on sample size requirements.

METHOD AND RESULTS

   A total of 120 cirrhotic tissue blocks (six aetiologies) were studied. A representative 100 mm(2) region was selected from each block and a reference CPA measured. Each image (n = 120) was divided into 100 × 1 mm(2) images; CPA was measured for each 1 mm(2) and virtual biopsies of different sizes were created from the 1 mm(2) components. For each virtual biopsy size the probability that the virtual biopsy CPA would be within 5% of the reference CPA was calculated. There were 441 000 virtual biopsies. Biopsy size versus probability plots indicated that, for 90% probability that the virtual biopsy CPA can be expected to be within 5% of the reference CPA, 22-28 mm(2) of analysable tissue is required depending on liver disease aetiology; and that a 75% probability level requires a biopsy with 12-15 mm(2) of analysable tissue.

CONCLUSION

   The sample size required for a given probability level depends on the aetiology of cirrhosis, and this should be taken into account when judging the reliability of cirrhotic liver biopsy CPA.