Novel serological neo-epitope markers of extracellular matrix proteins for the detection of portal hypertension

Noninvasive assessment of hepatic decompensation

Noninvasive tests (NITs) are used in all aspects of liver disease management. Their most prominent break-through since the millennium has been in advancing early detection of liver fibrosis, but their use is not limited to this. In contrast to the symptom-driven assessment of decompensation in patients with cirrhosis, NITs provide not only opportunities for earlier diagnoses but also accurate prognostication, targeted treatment decisions, and a means of monitoring disease. NITs can inform disease management and decision-making based on validated cutoffs and standardized interpretations as a valuable supplement to clinical acumen. The Baveno VI and VII consensus meetings resulted in tangible improvements to pathways of care for patients with compensated and decompensated advanced chronic liver disease, including the combination of platelet count and transient elastography to diagnose clinically significant portal hypertension. Furthermore, circulating NITs will play increasingly important roles in assessing the response to interventions against ascites, variceal bleeding, HE, acute kidney injury, and infections. However, due to NITs' wide availability, there is a risk of inaccurate use, leading to a waste of resources and flawed decisions. In this review, we describe the uses and pitfalls of NITs for hepatic decompensation, from risk stratification in primary care to treatment decisions in outpatient clinics, as well as for the in-hospital management of patients with acute-on-chronic liver failure. We summarize which NITs to use when, for what indications, and how to maximize the potential of NITs for improved patient management.

Markers of Collagen Formation and Degradation in Serum and Pancreatic Fluid Collections in Patients With Acute and Chronic Pancreatitis

OBJECTIVES

Current knowledge on the fibro-inflammatory process underlying chronic pancreatitis originates from animal studies or human studies based on circulating biomarkers. To provide new insight into the underlying fibro-inflammatory processes, we simultaneously assessed fibrosis biomarkers in pancreatic fluid collections and the systemic circulation.

MATERIALS AND METHODS

This prospective observational cross-sectional study included patients with acute and chronic pancreatitis undergoing drainage of pancreatic fluid collections, as well as 20 healthy controls (only serum levels). PRO-C3, PRO-C11 and PRO-C19 (markers of collagen formation), and C3M and C4M (markers of collagen degradation) were evaluated for both compartments (serum and fluid collection).

RESULTS

Forty-three patients were included: 26 with walled-off necrosis and 17 with pseudocyst. Serum levels of all 5 fibrosis biomarkers were elevated in patients as compared to controls (all P < 0.001). PRO-C3 levels were significantly higher in pancreatic fluid vs serum (280.6 vs 20.8 ng/mL, P < 0.001). In contrast, levels of C3M (20.5 vs 13.1 ng/mL, P = 0.003), PRO-C19 (64.9 vs 14.3 nM, P < 0.001), and C4M (55.6 vs 20.4 ng/mL, P < 0.001) were significantly higher in serum vs pancreatic fluid.

CONCLUSIONS

The high serum levels in patients suggest increased overall fibrotic activity in pancreatitis patients as compared to healthy controls. PRO-C3 elicited higher levels in the pancreatic fluid, indicating localized fibrotic activity.

The role of noninvasive biomarkers for monitoring cell injury in advanced liver fibrosis

INTRODUCTION

Accurate and reliable diagnosis and monitoring of hepatic fibrosis is increasingly important given the variable natural history in chronic liver disease (CLD) and expanding antifibrotic therapeutic options targeting reversibility of early-stage cirrhosis. This highlights the need to develop more refined and effective noninvasive techniques for the dynamic assessment of fibrogenesis and fibrolysis.

AREAS COVERED

We conducted a literature review on PubMed, from 1 December 1970, to 1 November 2024, to evaluate and compare available blood-based and imaging-based noninvasive tools for hepatic fibrosis diagnosis and monitoring. Simple scores such as FIB-4 and NAFLD fibrosis score are suitable for excluding significant or advanced fibrosis, while tertiary centers should adopt complex scores and liver stiffness measurement as part of a secondary diagnostic and more comprehensive evaluation. Moreover, the advent of multiomics for high-resolution molecular profiling, and integration of artificial intelligence for noninvasive diagnostics holds promise for revolutionizing fibrosis monitoring and treatment through novel biomarker discovery and predictive omics-based algorithms.

EXPERT OPINION

The increased shift toward noninvasive diagnostics for liver fibrosis needs to align with personalized medicine, enabling more effective, tailored management strategies for patients with liver disease in the future.

Standard technique in Japan for measuring hepatic venous pressure gradient

BACKGROUND

Direct measurement of portal venous pressure (PVP) is invasive, so the hepatic venous pressure gradient (HVPG) is commonly measured to evaluate portal hypertension (PH). HVPG is the gold standard for estimating PVP but few reports have covered standardized measurement techniques.

METHODS

This study validated standardized techniques for PVP measurement.

RESULTS

In Western countries, electronic transducers are commonly used to measure PVP, whereas the water column method is still frequently applied in Japan. Setting a reference point for accurate PVP measurement is important but complicated. According to Japanese guidelines, the reference point for PVP measurement is 10 cm above the dorsal surface or in the midaxillary line. For simpler determination, the anterior axillary point, defined as the point of convergence between the proximal pectoralis major muscle and arm when both arms are positioned against the trunk in a supine position, can be used as the reference point. New methods, such as endoscopic ultrasound-guided portal pressure gradient, offer less invasive alternatives. Non-invasive methods like elastography measure liver and spleen stiffness, which correlate with HVPG. The Baveno VII criteria incorporate measurements of liver and splenic stiffness for risk stratification. Biomarkers such as type IV collagen, M2BPGi, and FIB-4 score also predict HVPG. The Baveno VII consensus emphasizes the status of HVPG as the gold standard while advocating for non-invasive alternative methods to improve patient care and monitor treatment efficacy.

CONCLUSIONS

Continued development of non-invasive tests is crucial for safer, more convenient PH management.

Pathophysiology and therapeutic options for cirrhotic portal hypertension

Portal hypertension represents the primary non-neoplastic complication of liver cirrhosis and has life-threatening consequences, such as oesophageal variceal bleeding, ascites, and hepatic encephalopathy. Portal hypertension occurs due to increased resistance of the cirrhotic liver vasculature to portal blood flow and is further aggravated by the hyperdynamic circulatory syndrome. Existing knowledge indicates that the profibrogenic phenotype acquired by sinusoidal cells is the initial factor leading to increased hepatic vascular tone and fibrosis, which cause increased vascular resistance and portal hypertension. Data also suggest that the phenotype of hepatic cells could be further impaired due to the altered mechanical properties of the cirrhotic liver itself, creating a deleterious cycle that worsens portal hypertension in the advanced stages of liver disease. In this Review, we discuss recent discoveries in the pathophysiology and treatment of cirrhotic portal hypertension, a condition with few pharmacological treatment options.

Non-Invasive Diagnostic Tests for Portal Hypertension in Patients with HBV- and HCV-Related Cirrhosis: A Comprehensive Review

Clinically significant portal hypertension (CSPH) in patients with compensated advanced chronic liver disease indicates an increased risk of decompensation and death. While invasive methods like hepatic venous-portal gradient measurement is considered the gold standard, non-invasive tests (NITs) have emerged as valuable tools for diagnosing and monitoring CSPH. This review comprehensively explores non-invasive diagnostic modalities for portal hypertension, focusing on NITs in the setting of hepatitis B and hepatitis C virus-related cirrhosis. Biochemical-based NITs can be represented by single serum biomarkers (e.g., platelet count) or by composite scores that combine different serum biomarkers with each other or with demographic characteristics (e.g., FIB-4). On the other hand, liver stiffness measurement and spleen stiffness measurement can be assessed using a variety of elastography techniques, and they can be used alone, in combination with, or as a second step after biochemical-based NITs. The incorporation of liver and spleen stiffness measurements, alone or combined with platelet count, into established and validated criteria, such as Baveno VI or Baveno VII criteria, provides useful tools for the prediction of CSPH and for ruling out high-risk varices, potentially avoiding invasive tests like upper endoscopy. Moreover, they have also been shown to be able to predict liver-related events (e.g., the occurrence of hepatic decompensation). When transient elastography is not available or not feasible, biochemical-based NITs (e.g., RESIST criteria, that are based on the combination of platelet count and albumin levels) are valid alternatives for predicting high-risk varices both in patients with untreated viral aetiology and after sustained virological response. Ongoing research should explore novel biomarkers and novel elastography techniques, but current evidence supports the utility of routine blood tests, LSM, and SSM as effective surrogates in diagnosing and staging portal hypertension and predicting patient outcomes.

PRO-C3 is a predictor of clinical outcomes in distinct cohorts of patients with advanced liver disease

Background & Aims

Fibroblast activity is a key feature of fibrosis progression and organ function loss, leading to liver-related complications and mortality. The fibrogenesis marker, PRO-C3, has been shown to have prognostic significance in relation to fibrosis progression and as a treatment efficacy marker. We investigated whether PRO-C3 was prognostic for clinical outcome and mortality in two distinct cohorts of compensated cirrhosis.

Methods

Cohort 1 was a rapid fibrosis progression cohort including 104 patients with HCV and biopsy-proven Ishak fibrosis stage ≥3 without prior clinical events. Cohort 2 was a prospective cohort including 172 patients with compensated cirrhosis of mixed aetiology. Patients were assessed for clinical outcomes. PRO-C3 was assessed in serum at baseline in cohorts 1 and 2, and compared with model for end-stage liver disease and albumin-bilirubin (ALBI) scores.

Results

In cohort 1, a 2-fold increase in PRO-C3 was associated with 2.7-fold increased hazard of liver-related events (95% CI 1.6-4.6), whereas a one unit increase in ALBI score was associated with a 6.5-fold increased hazard (95% CI 2.9-14.6). In cohort 2, a 2-fold increase in PRO-C3 was associated with a 2.7-fold increased hazard (95% CI 1.8-3.9), whereas a one unit increase in ALBI score was associated with a 6.3-fold increased hazard (95% CI 3.0-13.2). A multivariable Cox regression analysis identified PRO-C3 and ALBI as being independently associated with the hazard of liver-related outcomes.

Conclusions

PRO-C3 and ALBI were independent prognostic factors for predicting liver-related clinical outcomes. Understanding the dynamic range of PRO-C3 might enhance its use for both drug development and clinical practice.

Impact and Implications

We tested novel proteins of liver scarring (PRO-C3) in two groups of liver patients with advanced disease to see if they could predict clinical events. We found that this marker and an established test called ALBI were both independently associated with future liver-related clinical outcomes.

Role of elastic fiber degradation in disease pathogenesis

Elastin is a crucial extracellular matrix protein that provides structural integrity to tissues. Crosslinked elastin and associated microfibrils, named elastic fiber, contribute to biomechanics by providing the elasticity required for proper function. During aging and disease, elastic fiber can be progressively degraded and since there is little elastin synthesis in adults, degraded elastic fiber is not regenerated. There is substantial evidence linking loss or damage of elastic fibers to the clinical manifestation and pathogenesis of a variety of diseases. Disruption of elastic fiber networks by hereditary mutations, aging, or pathogenic stimuli results in systemic ailments associated with the production of elastin degradation products, inflammatory responses, and abnormal physiology. Due to its longevity, unique mechanical properties, and widespread distribution in the body, elastic fiber plays a central role in homeostasis of various physiological systems. While pathogenesis related to elastic fiber degradation has been more thoroughly studied in elastic fiber rich tissues such as the vasculature and the lungs, even tissues containing relatively small quantities of elastic fibers such as the eyes or joints may be severely impacted by elastin degradation. Elastic fiber degradation is a common observation in certain hereditary, age, and specific risk factor exposure induced diseases representing a converging point of pathological clinical phenotypes which may also help explain the appearance of co-morbidities. In this review, we will first cover the role of elastic fiber degradation in the manifestation of hereditary diseases then individually explore the structural role and degradation effects of elastic fibers in various tissues and organ systems. Overall, stabilizing elastic fiber structures and repairing lost elastin may be effective strategies to reverse the effects of these diseases.

Circulating levels of endotrophin and cross-linked type III collagen reflect liver fibrosis in people with HIV

BACKGROUND AND AIMS

Liver-associated complications still frequently lead to mortality in people with HIV (PWH), even though combined antiretroviral treatment (cART) has significantly improved overall survival. The quantification of circulating collagen fragments released during collagen formation and degradation correlate with the turnover of extracellular matrix (ECM) in liver disease. Here, we analysed the levels of ECM turnover markers PC3X, PRO-C5, and PRO-C6 in PWH and correlated these with hepatic fibrosis and steatosis.

METHODS

This monocentre, retrospective study included 141 PWH. Liver stiffness and liver fat content were determined using transient elastography (Fibroscan) with integrated CAP function. Serum levels of formation of cross-linked type III collagen (PC3X), formation of type V collagen (PRO-C5) and formation type VI collagen (PRO-C6), also known as the hormone endotrophin, were measured with ELISA.

RESULTS

Twenty-five (17.7%) of 141 PWH had clinical significant fibrosis with liver stiffness ≥ 7.1 kPa, and 62 PWH (44.0%) had steatosis with a CAP value > 238 dB/m. Study participants with fibrosis were older (p = 0.004) and had higher levels of AST (p = 0.037) and lower number of thrombocytes compared to individuals without fibrosis (p = 0.0001). PC3X and PRO-C6 were markedly elevated in PWH with fibrosis. Multivariable cox regression analysis confirmed PC3X as independently associated with hepatic fibrosis. PRO-C5 was significantly elevated in participants with presence of hepatic steatosis.

CONCLUSION

Serological levels of cross-linked type III collagen formation and endotrophin were significantly associated with liver fibrosis in PWH receiving cART and thus may be suitable as a non-invasive evaluation of liver fibrosis in HIV disease.

Systemic inflammation is linked to liver fibrogenesis in patients with advanced chronic liver disease

BACKGROUND & AIMS

Experimental evidence indicates that systemic inflammation (SI) promotes liver fibrogenesis. This study investigated the potential link between SI and fibrogenesis in patients with advanced chronic liver disease (ACLD).

METHODS

Serum biomarkers of SI (CRP, IL-6, procalcitonin [PCT]) and extracellular matrix (ECM) turnover (i.e., fibrogenesis/fibrolysis) were analysed in 215 prospectively recruited patients with ACLD (hepatic venous pressure gradient [HVPG] ≥6 mm Hg) undergoing hepatic vein catheterization. Patients with non-elective hospitalization or bacterial infection were excluded. Histological alpha-smooth muscle actin (α-SMA) area was quantified on full biopsy scans by automated morphometric quantification in a subset of 34 patients who underwent concomitant transjugular liver biopsy.

RESULTS

Histological α-SMA proportionate area correlated with enhanced liver fibrosis (ELF) score (Spearman's ρ = 0.660, p < .001), markers of collagen formation (PRO-C3, ρ = 0.717, p < .001; PRO-C6, ρ = 0.526, p = .002) and tissue inhibitor of metalloproteinases-1 (TIMP1; ρ = 0.547, p < .001), indicating that these blood biomarkers are capable of reflecting the dynamic process of ECM turnover. CRP, IL-6 and PCT levels correlated with ELF, biomarkers of collagen synthesis/degradation and TIMP1, both in compensated and decompensated patients. Multivariate linear regression models (adjusted for HVPG) confirmed that CRP, IL-6 and PCT were independently linked to markers of liver fibrogenesis and ECM turnover.

CONCLUSION

Systemic inflammation is linked to both liver fibrogenesis and ECM turnover in ACLD and this association is not confounded by the severity of liver disease, as evaluated by HVPG. Our study confirms experimental data on the detrimental impact of SI on ECM deposition and fibrosis progression in a thoroughly characterized cohort of patients with ACLD.

The Value of Liver and Spleen Stiffness for Evaluation of Portal Hypertension in Compensated Cirrhosis

Patients with compensated advanced chronic liver disease who develop clinically significant portal hypertension (CSPH) are at high risk for hepatic decompensation and mortality if left untreated. Liver biopsy and hepatic venous pressure gradient (HVPG) measurements are the current gold standard procedures for determining fibrosis severity and diagnosing CSPH, respectively; however, both are invasive, limiting their use in clinical practice and larger trials of novel agents. As such, there is an unmet clinical need for reliable, validated, noninvasive measures to detect CSPH and to further assess portal hypertension (PH) severity. Alterations in the biomechanical properties of the liver or spleen in patients with cirrhosis can be quantified by tissue elastography, which examines the elastic behavior of tissue after a force has been applied. A variety of methods are available, including magnetic resonance elastography, shear-wave elastography, and the most thoroughly investigated measure, vibration-controlled transient elastography. Liver stiffness (LS) and spleen stiffness (SS) measurements offer valuable alternatives to detect and monitor CSPH. Both LS and SS correlate well with HVPG, with thresholds of LS >20-25 kPa and SS >40-45 kPa indicating a high likelihood of CSPH. Because SS is a direct and dynamic surrogate of portal pressure, it has the potential to monitor PH severity and assess PH improvement as a surrogate marker for clinical outcomes. Importantly, SS seems to be superior to LS for monitoring treatment response in clinical trials focusing on reducing PH.

Comparison of ADAPT, FIB-4 and APRI as non-invasive predictors of liver fibrosis and NASH within the CENTAUR screening population

BACKGROUND & AIMS

The development of accurate non-invasive tests to detect and measure the extent of fibrosis and disease activity in patients with non-alcoholic steatohepatitis (NASH) - the progressive phenotype of non-alcoholic fatty liver disease (NAFLD) - is of great clinical importance. Herein, we aimed to validate the performance of PRO-C3 and ADAPT for the detection of moderate/severe fibrosis within the CENTAUR screening population.

METHODS

PRO-C3 was assessed in plasma from the screening population of the phase IIb CENTAUR study (NCT02217475) in adults with NASH and liver fibrosis. The relation between PRO-C3 and histologic features of NASH was evaluated, as well as the demographics of patients with high and low levels of PRO-C3. The diagnostic ability of PRO-C3, as a standalone marker or incorporated into ADAPT, to identify patients with F≥2 and NASH was estimated using receiver-operating characteristic analysis and logistic regression models.

RESULTS

A total of 517 individuals with matched biopsy and PRO-C3 measurements were included. Patients with PRO-C3 levels ≥20.2 ng/ml showed increased levels of insulin, HOMA-IR, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase, and platelet count compared to patients with low PRO-C3 (p <0.05). PRO-C3 increased stepwise with increasing liver fibrosis, lobular inflammation, hepatocyte ballooning, steatosis, and NAFLD activity score (p <0.05), and could distinguish between NAFL and NASH (p <0.0001). PRO-C3 was independently associated with fibrosis and NASH when adjusted for clinical confounders. ADAPT outperformed Fibrosis-4, AST-to-platelet ratio index, and AST/ALT ratio as a predictor of advanced fibrosis and NASH (p <0.001).

CONCLUSION

PRO-C3 was associated with NAFLD activity score and fibrosis. ADAPT outperformed other non-invasive scores for detecting NASH. These data support the use of PRO-C3 and ADAPT as diagnostic tools to identify patients with NASH eligible for inclusion in clinical trials.

CLINICAL TRIAL NUMBER

NCT02217475 LAY SUMMARY: PRO-C3 is a serological biomarker associated with liver disease activity and fibrosis. Its performance for the detection of disease activity and fibrosis is improved when it is incorporated into the ADAPT score. Herein, we showed that ADAPT was better at selecting patients with non-alcoholic steatohepatitis for inclusion in clinical trials than other non-invasive scores.

Progressive alcohol-related liver fibrosis is characterised by imbalanced collagen formation and degradation

BACKGROUND

Liver fibrosis accumulation is considered a turnover disease, with formation exceeding degradation, although this hypothesis has never been tested in humans.

AIMS

To investigate extracellular matrix (ECM) remodelling in a biopsy-controlled study of alcohol-related liver disease (ALD) patients.

METHODS

We evaluated the relationship between formation and degradation of four collagens as a function of histological fibrosis, inflammation and steatosis in 281 patients with ALD and 50 matched healthy controls. Post hoc, we tested the findings in a cohort of patients with alcohol-related cirrhosis and assessed the collagens' prognostic accuracy. We assessed the fibrillar collagens type III (PRO-C3/C3M) and V (PRO-C5/C5M), the basement membrane collagen IV (PRO-C4/C4M), and the microfilament interface collagen VI (PRO-C6/C6M).

RESULTS

Mean age was 54 ± 6 years, 74% male, fibrosis stage F0/1/2/3/4 = 33/98/84/18/48. Compared to controls, patients with ALD had higher levels of type III collagen formation and degradation, with the highest concentrations in those with cirrhosis (PRO-C3 = 8.2 ± 1.7 ng/mL in controls, 14.6 ± 13.5 in ALD, 34.8 ± 23.1 in cirrhosis; C3M 7.4 ± 1.9 in controls, 9.3 ± 4.4 in ALD, 14.0 ± 5 in cirrhosis). ECM remodelling became increasingly imbalanced in higher stages of liver fibrosis, with formation progressively superseding degradation. This was particularly pronounced for type III collagen. We observed similar imbalance for inflammatory severity, but not steatosis.

CONCLUSIONS

ALD is characterised by both elevated collagen formation and degradation, which becomes increasingly imbalanced with more severe disease. Net increase in fibrillar collagens contributes to fibrosis progression. This has important implications for monitoring and very early identification of patients at highest risk of progressing to cirrhosis.

Extrahepatic Surgery in Cirrhosis Significantly Increases Portal Pressure in Preclinical Animal Models

Background: Liver cirrhosis is a relevant comorbidity with increasing prevalence. Postoperative decompensation and development of complications in patients with cirrhosis remains a frequent clinical problem. Surgery has been discussed as a precipitating event for decompensation and complications of cirrhosis, but the underlying pathomechanisms are still obscure. The aim of this study was to analyze the role of abdominal extrahepatic surgery in cirrhosis on portal pressure and fibrosis in a preclinical model.

Methods: Compensated liver cirrhosis was induced using tetrachlormethane (CCL4) inhalation and bile duct ligation (BDL) models in rats, non-cirrhotic portal hypertension by partial portal vein ligation (PPVL). Intestinal manipulation (IM) as a model of extrahepatic abdominal surgery was performed. 2 and 7 days after IM, portal pressure was measured in-vivo. Hydroxyproline measurements, Sirius Red staining and qPCR measurements of the liver were performed for evaluation of fibrosis development and hepatic inflammation. Laboratory parameters of liver function in serum were analyzed.

Results: Portal pressure was significantly elevated 2 and 7 days after IM in both models of cirrhosis. In the non-cirrhotic model the trend was the same, while not statistically significant. In both cirrhotic models, IM shows strong effects of decompensation, with significant weight loss, elevation of liver enzymes and hypoalbuminemia. 7 days after IM in the BDL group, Sirius red staining and hydroxyproline levels showed significant progression of fibrosis and significantly elevated mRNA levels of hepatic inflammation compared to the respective control group. A progression of fibrosis was not observed in the CCL4 model.

Conclusion: In animal models of cirrhosis with continuous liver injury (BDL), IM increases portal pressure, and development of fibrosis. Perioperative portal pressure and hence inflammation processes may be therapeutic targets to prevent post-operative decompensation in cirrhosis.

Noninvasive Detection of Clinically Significant Portal Hypertension in Compensated Advanced Chronic Liver Disease

Patients with compensated advanced chronic liver disease have different prognoses depending on the presence of portal hypertension. Current non-invasive diagnostic methods allow identification of clinically significant portal hypertension. Portosystemic collaterals on imaging or liver stiffness of more than 20 to 25 kPa by using transient elastography identifies patients with clinically significant portal hypertension. Patients with liver stiffness of less than 20 kPa and platelet count of greater than 150 g/L can avoid endoscopy. This rule could be expanded using spleen stiffness. Methods to risk stratify for portal hypertension in compensated advanced chronic liver disease and successfully treated chronic hepatitis C and B are subject of research.

Approaches to the Diagnosis of Portal Hypertension: Non-Invasive or Invasive Tests?

Portal hypertension is the main driver of complications in patients with advanced chronic liver disease (ACLD) and is defined by values of hepatic venous pressure gradient measurement (HVPG) >5 mmHg. Values of HVPG ≥10 mmHg determine the presence of clinically significant portal hypertension (CSPH), the main predictor of the risk of variceal bleeding, hepatic decompensation, and mortality. However, its measurement is invasive and requires high expertise, so its routine use outside third level centers or clinical trials is limited. In the last decades, several non-invasive tests (NITs) have been developed and validated for the diagnosis of portal hypertension. Among these, liver (LSM) and spleen stiffness measurement (SSM) are the most promising tools available, as they have been proven accurate to predict CSPH, high-risk esophageal varices, decompensation, and mortality in patients with ACLD. In the last Baveno VI Consensus proceedings, LSM evaluation was recommended for the first time for diagnosis of CSPH (LSM >20-25 kPa) and the screening of patients with a low probability of having high-risk varices (LSM <20 kPa and platelet count >150.000/mm³). In this review, we aimed to summarize the growing evidence supporting the use of non-invasive tests for the evaluation of portal hypertension in patients with chronic liver disease.

Serum C-reactive protein metabolite (CRPM) is associated with incidence of contralateral knee osteoarthritis

The heterogeneous nature of osteoarthritis (OA) and the need to subtype patients is widely accepted in the field. The biomarker CRPM, a metabolite of C-reactive protein (CRP), is released to the circulation during inflammation. Blood CRPM levels have shown to be associated with disease activity and response to treatment in rheumatoid arthritis (RA). We investigated the level of blood CRPM in OA compared to RA using data from two phase III knee OA and two RA studies (N = 1591). Moreover, the association between CRPM levels and radiographic progression was investigated. The mean CRPM levels were significantly lower in OA (8.5 [95% CI 8.3–8.8] ng/mL, n = 781) compared to the RA patients (12.8 [9.5–16.0] ng/mL, n = 60); however, a significant subset of OA patients (31%) had CRPM levels (≥ 9 ng/mL) comparable to RA. Furthermore, OA patients (n = 152) with CRPM levels ≥ 9 ng/mL were more likely to develop contra-lateral knee OA assessed by X-ray over a two-year follow-up period with an odds ratio of 2.2 [1.0–4.7]. These data suggest that CRPM is a blood-based biochemical marker for early identification OA patients with an inflammatory phenotype.

Regression of portal hypertension: underlying mechanisms and therapeutic strategies

Portal hypertension is the main non-neoplastic complication of chronic liver disease, being the cause of important life-threatening events including the development of ascites or variceal bleeding. The primary factor in the development of portal hypertension is a pathological increase in the intrahepatic vascular resistance, due to liver microcirculatory dysfunction, which is subsequently aggravated by extra-hepatic vascular disturbances including elevation of portal blood inflow. Evidence from pre-clinical models of cirrhosis has demonstrated that portal hypertension and chronic liver disease can be reversible if the injurious etiological agent is removed and can be further promoted using pharmacological therapy. These important observations have been partially demonstrated in clinical studies. This paper aims at providing an updated review of the currently available data regarding spontaneous and drug-promoted regression of portal hypertension, paying special attention to the clinical evidence. It also considers pathophysiological caveats that highlight the need for caution in establishing a new dogma that human chronic liver disease and portal hypertension is reversible.

Endotrophin, a pro-peptide of Type VI collagen, is a biomarker of survival in cirrhotic patients with hepatocellular carcinoma

AIM

Type VI collagen, is emerging as a signaling collagen originating from different types of fibroblasts. A specific fragment of Type VI collagen, the pro-peptide, is also known as the hormone endotrophin. We hypothesized that this fibroblast hormone would be of particular relevance in cancer types with a high amount of fibrosis activity, namely for outcome in hepatocellular carcinoma (HCC) cirrhotic patients.

PATIENTS & METHODS

Plasma C6M, PRO-C6 and alphafeto-protein (AFP) were assessed in 309 patients with mixed etiologies (hepatitis C, hepatitis B, alcohol and nonalcoholic fatty liver) diagnosed as cirrhotics, cirrhotics with HCC, noncirrhotics and healthy controls. Progression-free survival and overall survival (OS) data were collected up to 6120 days after diagnosis. The ability of each marker to predict survival was investigated.

RESULTS & CONCLUSION

The level of endotrophin assessed by PRO-C6 was able to separate healthy controls, noncirrhotics and cirrhotics from HCC (p < 0.05-0.0001). Both endotrophin and C6M provided value in the prediction of OS in cirrhotic patients with HCC. In the multivariate analysis for identifying HCC, in patients with high endotrophin (highest quartile) and that were positive for AFP (≥20 IU/ml), the hazard ratio for predicting OS was increased from 3.7 (p = 0.0006) to 14.4 (p = 0.0001) when comparing with AFP positive as a stand-alone marker. In conclusion, plasma levels for markers of Type VI collagen remodeling were associated with survival in cirrhotic patients with HCC. A combination of AFP with endotrophin improved the prognostic value compared with AFP alone for predicting OS in cirrhotic patients with HCC.

Profiling and targeting connective tissue remodeling in autoimmunity - A novel paradigm for diagnosing and treating chronic diseases

Connective tissue (ConT) remodeling is an essential process in tissue regeneration, where a balanced replacement of old tissue by new tissue occurs. This balance is disturbed in chronic diseases, often autoimmune diseases, usually resulting in the buld up of fibrosis and a gradual loss of organ function. During progression of liver, lung, skin, heart, joint, skeletal and kidney diseasesboth ConT formation and degradation are elevated, which is tightly linked to immune cell activation and a loss of specific cell types and extracellular matrix (ECM) structures that are required for normal organ function. Here, we address the balance of key general and organ specific components of the ECM during homeostasis and in disease, with a focus on collagens, which are emerging as both structural and signaling molecules harbouring neoepitopes and autoantigens that are released during ConT remodeling. Specific collagen molecular signatures of ConT remodeling are linked to disease activity and stage, and to prognosis across different organs. These signatures accompany and further drive disease progression, and often become detectable before clinical disease manifestation (illness). Recent advances allow to quantify and define the nature of ConT remodeling via blood-based assays that measure the levels of well-defined collagen fragments, reflecting different facets of ConT formation and degradation, and associated immunological processes. These novel serum assays are becoming important tools of precision medicine, to detect various chronic and autoimmune diseases before their clinical manifestation, and to non-invasively monitor the efficacy of a broad range of pharmacological interventions.

Immunomodulatory Role of the Extracellular Matrix Within the Liver Disease Microenvironment

Chronic liver disease when accompanied by underlying fibrosis, is characterized by an accumulation of extracellular matrix (ECM) proteins and chronic inflammation. Although traditionally considered as a passive and largely architectural structure, the ECM is now being recognized as a source of potent damage-associated molecular pattern (DAMP)s with immune-active peptides and domains. In parallel, the ECM anchors a range of cytokines, chemokines and growth factors, all of which are capable of modulating immune responses. A growing body of evidence shows that ECM proteins themselves are capable of modulating immunity either directly via ligation with immune cell receptors including integrins and TLRs, or indirectly through release of immunoactive molecules such as cytokines which are stored within the ECM structure. Notably, ECM deposition and remodeling during injury and fibrosis can result in release or formation of ECM-DAMPs within the tissue, which can promote local inflammatory immune response and chemotactic immune cell recruitment and inflammation. It is well described that the ECM and immune response are interlinked and mutually participate in driving fibrosis, although their precise interactions in the context of chronic liver disease are poorly understood. This review aims to describe the known pro-/anti-inflammatory and fibrogenic properties of ECM proteins and DAMPs, with particular reference to the immunomodulatory properties of the ECM in the context of chronic liver disease. Finally, we discuss the importance of developing novel biotechnological platforms based on decellularized ECM-scaffolds, which provide opportunities to directly explore liver ECM-immune cell interactions in greater detail.

Cross-Linked Multimeric Pro-Peptides of Type III Collagen (PC3X) in Hepatocellular Carcinoma - A Biomarker That Provides Additional Prognostic Value in AFP Positive Patients

Purpose

Non-invasive biomarkers for diagnosing and prognosing hepatocellular carcinoma (HCC) are urgently needed. Cirrhosis is present in 80–90% of HCC patients. Cirrhosis is characterized by deposition and cross-linking of collagens that have crucial roles in HCC initiation and progression. We evaluated circulating cross-linked pro-peptides of type III collagen (PC3X) as a diagnostic and prognostic biomarker for HCC.

Patients and Methods

PC3X was measured by ELISA in plasma from patients with HCC (n=79), cirrhosis (n=86), non-cirrhotic hepatitis-B infection (n=74) and from healthy controls (n=44). PC3X was compared to the liver fibrosis marker PRO-C3 and the HCC tumor-cell derived marker alpha-fetoprotein (AFP). Diagnostic and prognostic potential was evaluated by AUROC and by calculating hazard ratios (HR) for progression-free survival (PFS) and overall survival (OS).

Results

PC3X, PRO-C3 and AFP were significantly elevated in patients with HCC compared to other liver diseases and healthy controls (p=0.0002, p<0.0001). In patients with normal AFP (<20 IU/mL), PC3X and PRO-C3 separated HCC from cirrhosis with an AUROC of 0.72 and 0.68, respectively. High PC3X and AFP predicted for poor PFS (HR_PC3X=1.80, p=0.032; HR_AFP=1.70, p=0.031) and OS (HR_PC3X=2.12, p=0.024; HR_AFP=2.55; p=0.003), whereas PRO-C3 did not (PFS: HR=1.19, p=0.059 and OS: HR=1.12, p=0.324). PC3X was independent of AFP (PFS: HR=1.74, p=0.045 and OS: HR=2.21, p=0.018) and combining the two improved prognostic value (PFS: HR=2.66, p=0.004 and OS: HR=5.86, p<0.0001).

Conclusion

PC3X is associated with HCC independent of AFP and provides diagnostic and prognostic value for HCC patients. If validated, this suggests that PC3X has biomarker potential for HCC.

Comprehensive assessment of ECM turnover using serum biomarkers establishes PBC as a high-turnover autoimmune liver disease

Background & Aims

Primary sclerosing cholangitis (PSC), primary biliary cholangitis (PBC) and autoimmune hepatitis (AIH) are phenotypically distinct autoimmune liver diseases that progress to cirrhosis and liver failure; however, their histological fibrosis distribution differs. We investigated the extracellular matrix (ECM) profiles of patients with PSC, PBC, and AIH to establish whether the diseases display differential patterns of ECM turnover.

Methods

Serum samples were retrospectively collected from the UK (test cohort; PSC n = 78; PBC n = 74; AIH n = 58) and Norway (validation cohort; PSC n = 138; PBC n = 28; AIH n = 27). Patients with ulcerative colitis without liver disease (n = 194) served as controls. We assessed specific serological biomarkers of ECM turnover: type III and V collagen formation (PRO-C3, PRO-C5), degradation of type III and IV collagen (C3M, C4M), biglycan (BGM) and citrullinated vimentin (VICM).

Results

Most of the ECM markers showed elevated serum levels in PBC compared with PSC or AIH (p <0.01). PRO-C3 correlated well with liver stiffness and showed the most striking differences between advanced and non-advanced liver disease; several of the other ECM markers were also associated with stage. PRO-C3 and other ECM markers were inversely associated with ursodeoxycholic acid treatment response in PBC and remission in AIH. All ECM remodelling markers were significantly elevated (p <0.05) in patients with PSC, PBC, or AIH compared with ulcerative colitis.

Conclusions

In this first study comparing ECM turnover in autoimmune liver diseases, we found increased ECM turnover in PBC compared with either PSC or AIH. The study indicates that ECM remodelling is different in PSC, PBC, and AIH, suggesting differing opportunities for therapeutic intervention.

Lay summary

The level of scarring is linked to prognosis in autoimmune liver diseases such as primary sclerosing cholangitis, primary biliary cholangitis, and autoimmune hepatitis; hence, the scarring process is a possible target for novel therapy. Investigating the scarring process using highly specific technology, we show that the scarring process is different between the 3 autoimmune liver diseases, and this may have important implications for the development of medical treatment.

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Serological biomarkers specifically targeting extracellular matrix remodelling enable evaluation of the dynamics of fibrosis evolution.

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ECM turnover was increased in PBC compared with PSC and AIH.

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ECM markers, particularly PRO-C3, were associated with disease stage in the autoimmune liver diseases and with clinical outcome in PSC.

Review article: the signalling and functional role of the extracellular matrix in the development of liver fibrosis

BACKGROUND

Patients with liver fibrosis show a large heterogeneity, and for that reason effective treatments are still lacking. Emerging data suggest that there is more to fibrosis than previously understood. Opposed to earlier belief of being a passive scaffold for cells to reside in, the extracellular matrix (ECM) is now known to hold both signalling and functional properties important for the development of fibrosis. The interaction between the ECM and the collagen-producing cells determines the course of the disease but is still poorly understood. Exploring the dynamics of this interplay will aid in the development of effective treatments.

AIM

To summarise and discuss the latest advances in the pathogenesis of liver fibrosis as well as key mediators of early disease progression.

METHODS

Through literature search using databases including PubMed and Google Scholar, manuscripts published between 1961 and 2019 were included to assess both well-established and recent theories of fibrosis development. Both pre-clinical and clinical studies were included.

RESULTS

Fibrosis alters the structure of the ECM releasing signalling fragments with the potential to escalate disease severity. In a diseased liver, hepatic stellate cells and other fibroblasts, together with hepatocytes and sinusoidal cells, produce an excessive amount of collagens. The cell-to-collagen interactions are unique in the different liver aetiologies, generating ECM profiles with considerable patient-monitoring potential.

CONCLUSIONS

The local milieu in the injured area affects the course of fibrosis development in a site-specific manner. Future research should focus on the dissimilarities in the ECM profile between different aetiologies of liver fibrosis.

Applying Non-Invasive Fibrosis Measurements in NAFLD/NASH: Progress to Date

Nonalcoholic fatty liver disease (NAFLD) has now become a worldwide health issue due to the obesity epidemic, affecting approximately 90% of the obese population and 15-40% of the general population. It is the most common form of chronic liver disease in the United States. NAFLD constitutes a spectrum of diseases ranging in severity from mild, such as fatty liver, progressing into nonalcoholic steatohepatitis (NASH), then fibrosis, and ending with cirrhosis. NASH and increasing fibrosis stage are associated with increased morbidity and mortality; the fibrosis stage is therefore a critical element of risk stratification needed to determine therapeutic approach and also the response to treatment. Liver biopsy is considered the 'gold standard' in the diagnosis of NAFLD. However, it is not practical for widespread clinical use because it is invasive, costly, and associated with complications including occasional death. These limitations have driven the development of noninvasive tests that can accurately predict the fibrosis stage in those with NAFLD. In this review, we provide a concise overview of different non-invasive measurements used for NAFLD/NASH.

Recent advances in the non-invasive assessment of fibrosis using biomarkers

Fibrosis can occur in most organs and is characterised by excessive and progressive extracellular matrix deposition and destruction of normal tissue architecture and function. In many cases treatment options are limited. Fibrotic diseases are therefore associated with high morbidity and mortality. Tissue biopsies remain a key part of diagnosing fibrosis; however, due to their invasive nature, tissue biopsies are unsuitable for monitoring disease progression. In some cases, tissue biopsies carry an unacceptable risk of mortality to the patient. Furthermore, assessing fibrosis via tissue biopsy is severely limited by the heterogenetic nature of fibrotic diseases and suffers from both sampling bias and observer variation/bias. The search for less invasive methods of diagnosing and monitoring fibrosis has led to the identification of many new biomarkers, many of which can be measured in serum in a so-called 'liquid biopsy' or can be imaged using state-of-the-art imaging modalities. These approaches have the potential to dramatically improve the diagnosis and monitoring of disease, and improve the design of clinical trials in to novel fibrotic therapies. This review summarises some of the recent advances in identifying novel biomarkers to diagnose and monitor fibrosis non-invasively.

Diagnostic accuracy of non-invasive methods detecting clinically significant portal hypertension in liver cirrhosis: a systematic review and meta-analysis

INTRODUCTION

We attempted to investigate non-invasive techniques and their diagnostic performances for evaluating clinically significant portal hypertension.

EVIDENCE ACQUISITION

The systematic search was performed on PubMed, Embase, Scopus, and Web of Science TM core index databases before 13 December 2018 restricted to English language and human studies.

EVIDENCE SYNTHESIS

Thirty-two studies were included, with total populations of 3,987. The overall pooled analysis was performed by bivariate random effect model, which revealed significantly higher sensitivity and specificity of 77.1% (95% confidence interval, 76.8-78.5%) and 80.1% (95% confidence interval, 78.2-81.9%), respectively; positive likelihood ratio (3.67), negative likelihood ratio (0.26); and diagnostic odd ratio (16.24). Additionally, the area under curve exhibited significant diagnostic accuracy of 0.871. However, notable heterogeneity existed in between studies (I2=87.1%), therefore, further subgroup analysis was performed. It demonstrated ultrasonography, elastography, biomarker, and computed tomography scan had a significant overall summary sensitivity (specificity) of 89.6% (78.9%), 81.7% (83.2%), 72.2% (76.8%), and 77.2% (81.2%), respectively. Moreover, the areas under curve values were significantly higher in elastography (0.906), followed by computed tomography scan (0.847), biomarker (0.825), and ultrasonography (0.803).

CONCLUSIONS

In future, non-invasive techniques could be the future choice of investigations for screening and diagnosis of clinically significant portal hypertension in cirrhosis. However, standardization of diagnostic indices and their cut-off values in each non-invasive method needs to be addressed.

Enhanced processing of von Willebrand factor reflects disease severity and discriminates severe portal hypertension in cirrhosis

OBJECTIVES

Portal hypertension in cirrhosis is associated with endothelial dysfunction, impaired wound healing, and decreased platelet count. Increased von Willebrand factor (VWF) formation has been suggested as a compensatory mechanism, but the role of VWF processing has not been directly assessed. The aim was to measure the processing of activated VWF (VWF-A) in addition to VWF release (VWF-N) to investigate the association of primary hemostasis with disease activity and portal hypertension in liver cirrhosis.

PARTICIPANTS AND METHODS

Plasma samples from 105 participants undergoing liver vein catheterization and with liver cirrhosis of varying severity were included in the study together with 20 controls without liver disease. Competitive enzyme-linked immunosorbent assay format was used to estimate biomarkers of VWF turnover using neo-epitope-specific monoclonal antibodies.

RESULTS

VWF-N levels and VWF-A levels were significantly elevated in cirrhotic patients compared with controls (P<0.0001), and both markers could discriminate mild from severe cirrhosis (VWF-N, P<0.0001; VWF-A, P<0.05). Both markers correlated well with increasing portal hypertension and could identify patients with clinically significant portal hypertension (VWF-N, area under the curve: 0.78; VWF-A, area under the curve: 0.67). Only VWF-A significantly separated compensated from decompensated patients (P<0.05).

CONCLUSION

The data indicate that both VWF release and processing of active VWF are increased in cirrhosis, reflecting ongoing wound healing initiation. VWF-N and VWF-A may specifically contain information to assess the presence and severity of PHT as an early indicator of cirrhosis, and for acute damage in decompensated cirrhosis. Whether the increased wound healing affects long-term outcome needs to be addressed in future studies.

Performance of the PRO-C3 collagen neo-epitope biomarker in non-alcoholic fatty liver disease

There is an unmet need for non-invasive biomarkers in non-alcoholic fatty liver disease (NAFLD) that can diagnose advanced disease and identify patients suitable for clinical trials. The PRO-C3 collagen neo-epitope is a putative direct marker of fibrogenesis. We assessed the performance of PRO-C3 in a large, well-characterised international NAFLD cohort and report the development and validation of 2 novel panels for the diagnosis of advanced fibrosis (F≥3) in NAFLD, including a simplified clinical score which eliminates the need for online calculators.

Methods

Plasma PRO-C3 levels were determined in a prospectively recruited international cohort of 449 patients with biopsy diagnosed NAFLD across the full disease spectrum (F0: n = 90; F1: 100; F2: 92; F3: 101; F4: 66). The cohort was divided into a discovery group (n = 151) and a validation group (n = 298). Logistic regression was performed to establish complex (FIBC3) and simplified (ABC3D) diagnostic scores that accurately identify advanced fibrosis. Performance for each was compared to established non-invasive fibrosis scoring systems.

Results

Plasma PRO-C3 levels correlated with grade of histological steatohepatitis (r_s = 0.367, p ≪0.0001) and stage of fibrosis (r_s = 0.462, p ≪0.0001), exhibiting similar performance to current fibrosis scores such as FIB4 for the detection of F≥3 fibrosis. FIBC3 exhibited substantially improved accuracy (AUROC 0.89 and 0.83 in the discovery and validation sets, respectively) and outperformed FIB4 and other similar diagnostic panels. The simplified version, ABC3D, was concurrently developed and had comparable diagnostic accuracy (AUROC 0.88 and 0.81 in the discovery and validation sets, respectively).

Conclusion

Plasma PRO-C3 levels correlate with severity of steatohepatitis and fibrosis stage. The FIBC3 panel is an accurate tool with a single threshold value that maintains both sensitivity and specificity for the identification of F≥3 fibrosis in NAFLD, eliminating indeterminate results and outperforming commonly used non-invasive tools. A greatly simplified version (ABC3D) that is readily amenable to use in the clinic has been validated and shown to perform with similar accuracy, and may prove a useful tool in routine clinical practice.

Lay summary

We performed a comprehensive, independent evaluation of a collagen biomarker (PRO-C3) to detect and quantify liver fibrosis in patients with non-alcoholic fatty liver disease (NAFLD). We report the development of 2 diagnostic panels using PRO-C3 to identify patients with advanced fibrosis, one optimal but more complex to calculate (FIBC3), the other easier to use (ABC3D) whilst still performing well.

Collagen type IV remodelling gender-specifically predicts mortality in decompensated cirrhosis

BACKGROUND & AIMS

Remodelling of extracellular matrix is crucial in progressive liver fibrosis. Collagen type III desposition has been shown in acute decompensation. Extratracellular matrix is compiled of deposition of various components. The role of basement membrane collagen type IV in advanced cirrhosis and acute decompensation is unclear and investigated in this study.

METHODS

Patients with decompensated cirrhosis from the prospective NEPTUN cohort (ClinicalTrials.gov Identifier: NCT03628807), who underwent transjugular intrahepatic portosystemic shunt procedure were included. Clinical and laboratory parameters, PRO-C4 and C4M levels were measured in blood samples from portal and hepatic veins just before transjugular intrahepatic portosystemic shunt placement.

RESULTS

Levels of C4M and PRO-C4 are significantly lower in patients with massive ascites and impaired renal sodium excretion. C4M and PRO-C4 show gender-specific profiles with significantly lower levels in females compared to males. Females with higher C4M levels show higher mortality. By contrast, males with higher C4M levels show lower mortality. In multivariate Cox regression analysis, C4M is an independent predictor of survival in female patients.

CONCLUSION

This study shows that markers of collagen type IV remodelling do not accumulate in severe renal dysfunction. Although collagen type IV degradation markers derive from the liver, portal venous C4M levels are relevant for survival. Moreover, it demonstrates that circulating C4M shows gender-specific profiles, which can independently predict survival in female patients with decompensated cirrhosis.

Alterations in non-type I collagen biomarkers in osteogenesis imperfecta

Osteogenesis imperfecta [1] is a rare disorder of connective tissue caused by abnormalities in the synthesis or processing of type I collagen. Type I collagen is the most abundant type of collagen and is expressed in almost all connective tissues. Given that type I collagen interacts with other collagens based in the extracellular matrix (ECM), we hypothesized changes in type I collagen in OI would result in perturbations in the homeostasis of other collagen types. We measured serum biomarkers of several non-type I collagens in patients with mild (type I) and moderate-to-severe (type III/IV) OI. Compared to controls, those with moderate-to severe OI had a higher mean level of the synthesis markers of collagen III (ProC3) (P = 0.02), and levels of collagen V (ProC5) (P = 0.07) were slightly, but not significantly, higher. Degradation markers of collage type IV (C4M2) (P = 0.04) and type VI (C6M) (P = 0.003) were also higher. In each case, a test for trend suggested levels were higher in moderate-to-severe OI, intermediate in mild OI, and lowest in controls (P = 0.06-0.002). These changes supports the hypothesis that mutations in type I collagen induce a widespread alteration in the ECM, and that the diverse clinical manifestations of OI reflect an extensive disruption in ECM biology.

Non-invasive liver fibrosis assessment correlates with collagen and elastic fiber quantity in patients with hepatitis C virus infection

AIM

Elastic fiber deposition is a cause of irreversibility of liver fibrosis. However, to date, its relevance to clinical features has not yet been clarified. This study aimed to clarify the correlation between non-invasive markers of fibrosis and fiber quantity, including elastic fiber, obtained from computational analysis.

METHODS

This retrospective study included 270 patients evaluated by non-invasive liver fibrosis assessment prior to liver biopsy. Of these patients, 95 underwent magnetic resonance elastography (MRE) and 244 were assessed with Wisteria floribunda agglutinin-positive Mac-2 binding protein (WFA⁺ -M2BP). Using whole-slide imaging of Elastica van Gieson-stained liver biopsy sections, the quantity of collagen, elastin, and total fiber (elastin + collagen) was determined.

RESULTS

The total fiber quantity showed significant linear correlation with fibrosis stage F0-F4. Collagen fiber quantity increased from stage F0 to F4, whereas elastic fiber quantity increased significantly only from stage F2 to F3. Spearman's rank correlation test revealed that non-invasive liver fibrosis assessment significantly correlates with each fiber quantity, including correlation between total fiber quantity and the Fibrosis-4 (FIB-4) index (r = 0.361, P < 0.001), WFA⁺ -M2BP values (r = 0.404, P < 0.001), and liver stiffness value by MRE (r = 0.615, P < 0.001). Receiver operating characteristic (ROC) curve analyses revealed that the area under ROC for predicting higher elastic fiber (>3.6%) is 0.731 by FIB-4 index, 0.716 by WFA⁺ -M2BP, and 0.822 by liver stiffness by MRE.

CONCLUSION

Liver fibrosis correlates with fiber quantity through non-invasive assessment regardless of fiber type, including elastic fiber. Moreover, MRE is useful for predicting high amounts of elastic fiber.

Assessment of liver fibrosis progression and regression by a serological collagen turnover profile

There is a need for noninvasive biomarkers that can identify patients with progressive liver fibrosis and monitor response to antifibrotic therapy. An equally important need is identification of patients with spontaneous fibrosis regression, since they may not need treatment nor be included in clinical studies with fibrosis as end point. Circulating biomarkers, originating from defined fragments of the scar tissue itself, may serve as valuable tools for this aspect of precision medicine. We investigated a panel of serological collagen formation and degradation markers to identify patients likely to regress or progress in absence of a therapeutic intervention. Plasma samples from patients with moderate-stage hepatitis C receiving placebo treatment in a phase II trial of the peroxisome proliferator-activated receptor agonist farglitazar were included. The patients had matched liver biopsies at baseline and 52 wk of follow-up. Serological biomarkers of collagen formation (PRO-C3, PRO-C4, PRO-C5) and collagen degradation (C3M, C4M, and C6M) were analyzed. Logistic regression analysis including PRO-C3 and C6M identified subjects with progressive liver fibrosis with an AUROC of 0.91 ( P < 0.0001) and positive and negative predictive values (PPV/NPV) of 75.0%/88.6%. Low levels of PRO-C5 predicted a spontaneous regression phenotype, with an odds ratio of 33.8 times higher compared with patients with high levels ( P < 0.0025) with an AUROC of 0.78 ( P < 0.0001) and PPV/NPV of 60.0%/95.7%. Two collagen fragments (PRO-C3 and C6M) identified liver fibrosis progressors, and one collagen fragment (PRO-C5) identified liver fibrosis regressors. These biomarkers may improve patient stratification and monitor treatment efficacy in studies with fibrosis as clinical end point. NEW & NOTEWORTHY In this study we report two biomarkers of collagen fragments (PRO-C3 and C6M) that are able to identify liver fibrosis progressors while one biomarker (PRO-C5) identified liver fibrosis regressors. In particular, we present three noninvasive biomarkers that can be used to identify patients with progressive liver fibrosis, monitor response to antifibrotic therapy, and also identify the spontaneous liver fibrosis regression phenotype.

Protective effects of combined Losartan and Nilotinib on carbon tetrachloride (CCl4)-induced liver fibrosis in rats

Tyrosine kinase inhibitors (TKIs) have been developed as therapeutic compounds for inhibiting the progression of liver fibrosis. In the present study, the simultaneous treatment of Nilotinib (TKIs) and Losartan was studied. Forty rats were divided into eight groups of fibrosis induced by carbon tetrachloride (CCl₄) and therapeutics (Nilotinib, Losartan, and combination therapy). In the end, serum parameters of the liver and gene expression analysis of transforming growth factor-β₁, its receptors (TβRII), platelet-derived growth factor, its receptors (PDGFR_β), matrix metalloproteinases (MMP-2 and MMP-9), tumor necrosis factor-α, cytochrome P450 2E1, and collagen1 type 1 were performed. The oxidant/antioxidant factors were also analyzed. Histopathology analysis along with α-SMA immunohistochemistry and hydroxyproline evaluation was also conducted for a more in-depth study. The overall results indicated a better therapeutic effect of co-treatment of Nilotinib-Losartan in comparison with the treatment of each of them alone. Interestingly, some gene and protein factors and fibrotic indices were reduced even to the normal levels of the control group. The results of this study suggest that co-administration of these two combinations, strengthens their anti-fibrotic properties and, due to the routine use of these compounds against AML and blood pressure, these compounds can be used with caution against human liver fibrosis.

No effect of rifaximin on soluble CD163, mannose receptor or type III and IV neoepitope collagen markers in decompensated cirrhosis: Results from a randomized, placebo controlled trial

BACKGROUND AND AIMS

Macrophages play a significant role in chronic liver disease as reflected by elevated soluble (s)CD163 and mannose receptor (sMR) levels and associated with liver disease severity and prognosis. Extracellular matrix remodelling associated with fibrogenesis may be affected by systemic inflammation induced by bacterial translocation. Therefore, we aimed to investigate the effect of rifaximin-α, an antibiotic with effect on gut bacteria, on sCD163, sMR, and collagen metabolites.

METHODS

Fifty-four clinically stable patients with decompensated cirrhosis were randomized to 4 weeks treatment with rifaximin-α (n = 36) or placebo (n = 18). Macrophage markers sCD163, sMR and markers of collagen fibrogenesis (C3M and C4M) and formation (PRO-C3 and P4NPS7) were analysed in plasma before and after treatment.

RESULTS

sCD163 and sMR levels were associated with liver disease severity (MELD score, sCD163 rho = 0.47, p<0.001 and sMR rho = 0.37, p = 0.005). There was no effect of Rifaximin-α on sCD163 levels (median (range) sCD163 5.64(2.02 to 10.8) at baseline versus 4.42(1.98 to 8.92) at follow-up in the rifaximin-α group and 4.85 (2.29 to 12.1) at baseline versus 4.32 (1.98 to 12.4) at follow-up in the placebo-group), p = 0.34); nor sMR levels, p = 0.34. Also in patients with elevated lipopolysaccharide binding protein (> 5.9 μg/ml, 38 patients) there was no effect of rifaximin-α on sCD163 (p = 0.49) or sMR levels (p = 0.32).

CONCLUSION

We confirmed that macrophage activation markers sCD163 and sMR are directly associated to liver disease severity (MELD score). However, rifaximin-α has no effect on sCD163, sMR or collagen markers in decompensated cirrhosis and does therefore not seem to interfere with macrophage activation or fibrogenesis.

An Evaluation of the Collagen Fragments Related to Fibrogenesis and Fibrolysis in Nonalcoholic Steatohepatitis

Fibrosis, resulted from the imbalance of fibrogenesis and fibrolysis, is a key readout of disease progression in nonalcoholic steatohepatitis (NASH) and reflects mortality risk. Non-invasive biomarkers capable of diagnosing fibrosis stages and monitoring fibrosis changes in NASH patients are urgently needed. This study is to evaluate collagen formation and degradation biomarkers, reflective of fibrogenesis or fibrolysis, in patients with biopsy proven NASH. Collagen formation biomarker PRO-C3 and PRO-C6 levels were significantly higher in patients with advanced fibrosis stage 3–4 than those with fibrosis stage 0–2. Elevated PRO-C3 levels were also associated with severe lobular inflammation and ballooning, but not with steatosis. Multivariate logistic regression analysis identified PRO-C3 and PRO-C6 to be independently related to fibrosis stage. PRO-C3 showed similar performance to identify patients with advanced fibrosis in discovery and validation cohorts. Furthermore, in a longitudinal study cohort with paired biopsies, mean PRO-C3 increased with worsening of fibrosis and decreased with fibrosis improvement. The results suggest that PRO-C3 may be a potentially useful biomarker in identifying patients with advanced fibrosis and active fibrogenesis, as well as in assessing changes in fibrosis over time. It is worthy of further evaluation to confirm its diagnostic value and clinical utility.

Serological markers of extracellular matrix remodeling predict transplant-free survival in primary sclerosing cholangitis

BACKGROUND

Primary sclerosing cholangitis is a progressive liver disease with a remarkably variable course. Biomarkers of disease activity or prognostic models predicting outcome at an individual level are currently not established.

AIM

To evaluate the prognostic utility of four biomarkers of basement membrane and interstitial extracellular matrix remodeling in patients with primary sclerosing cholangitis.

METHODS

Serum samples were available from 138 large-duct primary sclerosing cholangitis patients (of which 102 [74%] with IBD) recruited 2008-2012 and 52 ulcerative colitis patients (controls). The median follow-up time was 2.2 (range 0-4.3) years. Specific biomarkers of type III and V collagen formation (PRO-C3 and PRO-C5, respectively) and type III and IV collagen degradation (C3M and C4M, respectively) were assessed. The Enhanced Liver Fibrosis test, including procollagen type III N-terminal peptide, tissue inhibitor of metalloproteinase-1 and hyaluronic acid was assessed for comparison.

RESULTS

All markers were elevated in primary sclerosing cholangitis compared to ulcerative colitis patients (P < 0.001). PRO-C3 showed the largest difference between the two groups with a threefold increase in primary sclerosing cholangitis compared to ulcerative colitis patients. Patients with high baseline serum levels of all markers, except C3M, had shorter survival compared to patients with low baseline serum levels (P < 0.001). Combining PRO-C3 and PRO-C5 the odds ratio for predicting transplant-free survival was 47 compared to the Enhanced Liver Fibrosis test's odds ratio of 11.

CONCLUSIONS

Extracellular matrix remodeling is elevated in primary sclerosing cholangitis patients compared to ulcerative colitis patients. Furthermore, the interstitial matrix marker PRO-C3 was identified as a potent prognostic marker and an independent predictor of transplant-free survival in primary sclerosing cholangitis.

Hepatic elastin content is predictive of adverse outcome in advanced fibrotic liver disease

AIMS

The aim of this study was to determine if elastin content in needle core native liver biopsies was predictive of clinical outcome in patients with chronic hepatitis C virus-related chronic liver disease.

METHODS AND RESULTS

Elastin contents in liver biopsies were determined by image analysis, technically validated in an independent centre, and correlated with outcome in patients with advanced (Ishak stage ≥5) chronic hepatitis C virus-related chronic liver disease. Elastin was robustly quantified in an operator-independent and laboratory-independent manner, with very strong correlation of elastin staining measured with two methods of image classification (rs = 0.873, P < 0.00001). Elastin content (but not absolute scar content or Ishak stage) was predictive for future clinical outcomes. In a cohort of patients without sustained virological response, the median hepatic elastin content was 3.4%, and 17 patients (57%) progressed to a liver-related clinical outcome; 11 of the 15 patients (73%) with a hepatic elastin content of >3.4% progressed to a clinical outcome, as compared with only six of 15 (40%) with an elastin content of <3.4%. The difference in time to outcome was significant.

CONCLUSIONS

We describe a simple and reproducible method for elastin quantification in liver biopsies that provides potentially valuable prognostic information to inform clinical management.

Noninvasive Assessment of Portal Hypertension in Advanced Chronic Liver Disease: An Update

The assessment of portal hypertension is a relevant step in the evaluation of newly diagnosed advanced chronic liver disease (ACLD). The current gold standard includes the invasive evaluation of hepatic venous pressure gradient (HVPG) and endoscopy. However, noninvasive or minimally invasive techniques to assess portal hypertension have been proposed and well established. In the present manuscript, we review clinical studies on the use of noninvasive or minimally invasive techniques to assess portal hypertension in ACLD patients.

Non-invasive Markers of Portal Hypertension: Appraisal of Adult Experience and Potential Utilisation in Children

Portal hypertension (PHT) is a significant cause of morbidity and mortality in children with chronic liver disease and portal vein obstruction. Increased portal pressure results in variceal formation along the gastrointestinal (GI) tract resulting in major bleeding. Identifying children with significant PHT who are more likely to suffer GI bleeding has been challenging and the role of surveillance upper GI endoscopy has been debated. This review analyses research done on serum biomarkers and imaging techniques as possible predictors of significant PHT. We evaluated the research performed on adult population, as well as the limited work done on children, to identify promising areas for future research. A literature search was conducted on "PubMed." Several search terms were used including "portal hypertension," "paediatric portal hypertension," "non-invasive markers of portal hypertension," "spleen stiffness," "liver stiffness," "elastography," and "endothelial damage." The articles included were selected based on their relevance to the purpose of our review. The research suggests a combination of several biomarkers, in addition to an imaging technique such as transient elastography or magnetic resonance elastography, would allow for the best prediction of significant varices. The most promising indicators would be those that are applicable in both intra- and extra-hepatic causes of PHT. Further research on these predictors in children with PHT is required to determine their potential role as selection criteria for PHT and stratification of surveillance GI endoscopies.

Age-related collagen turnover of the interstitial matrix and basement membrane: Implications of age- and sex-dependent remodeling of the extracellular matrix

The extracellular matrix (ECM) plays a vital role in maintaining normal tissue function. Collagens are major components of the ECM and there is a tight equilibrium between degradation and formation of these proteins ensuring tissue health and homeostasis. As a consequence of tissue turnover, small collagen fragments are released into the circulation, which act as important biomarkers in the study of certain tissue-related remodeling factors in health and disease. The aim of this study was to establish an age-related collagen turnover profile of the main collagens of the interstitial matrix (type I and III collagen) and basement membrane (type IV collagen) in healthy men and women. By using well-characterized competitive ELISA-assays, we assessed specific fragments of degraded (C1M, C3M, C4M) and formed (PINP, Pro-C3, P4NP7S) type I, III and IV collagen in serum from 617 healthy men and women ranging in ages from 22 to 86. Subjects were divided into 5-year age groups according to their sex and age. Groups were compared using Kruskal-Wallis adjusted for Dunn's multiple comparisons test and Mann-Whitney t-test. Age-specific changes in collagen turnover was most profound for type I collagen. PINP levels decreased in men with advancing age, whereas in women, the level decreased in early adulthood followed by an increase around the age of menopause (age 40-60). Sex-specific changes in type I, III and IV collagen turnover was present at the age around menopause (age 40-60) with women having an increased turnover. In summary, collagen turnover is affected by age and sex with the interstitial matrix and the basement membrane being differently regulated. The observed changes needs to be accounted for when measuring ECM related biomarkers in clinical studies.

Deconstruction of a Metastatic Tumor Microenvironment Reveals a Common Matrix Response in Human Cancers

We have profiled, for the first time, an evolving human metastatic microenvironment by measuring gene expression, matrisome proteomics, cytokine and chemokine levels, cellularity, extracellular matrix organization, and biomechanical properties, all on the same sample. Using biopsies of high-grade serous ovarian cancer metastases that ranged from minimal to extensive disease, we show how nonmalignant cell densities and cytokine networks evolve with disease progression. Multivariate integration of the different components allowed us to define, for the first time, gene and protein profiles that predict extent of disease and tissue stiffness, while also revealing the complexity and dynamic nature of matrisome remodeling during development of metastases. Although we studied a single metastatic site from one human malignancy, a pattern of expression of 22 matrisome genes distinguished patients with a shorter overall survival in ovarian and 12 other primary solid cancers, suggesting that there may be a common matrix response to human cancer.Significance: Conducting multilevel analysis with data integration on biopsies with a range of disease involvement identifies important features of the evolving tumor microenvironment. The data suggest that despite the large spectrum of genomic alterations, some human malignancies may have a common and potentially targetable matrix response that influences the course of disease. Cancer Discov; 8(3); 304-19. ©2017 AACR.This article is highlighted in the In This Issue feature, p. 253.

Acute decompensation boosts hepatic collagen type III deposition and deteriorates experimental and human cirrhosis

Patients with end-stage liver disease develop acute decompensation (AD) episodes, which become more frequent and might develop into acute-on-chronic liver failure (ACLF). However, it remains unknown how AD induces acceleration of liver disease. We hypothesized that remodeling of collagen type III plays a role in the acceleration of liver cirrhosis after AD and analyzed its formation (Pro-C3) and degradation (matrix metalloproteinase-degraded type III collagen [C3M]) markers in animal models and human disease. Bile duct ligation induced different stages of liver fibrosis in rats. Fibrosis development (hydroxyprolin content, sirius red staining, α-smooth muscle actin immunohistochemistry, messenger RNA of profibrotic cytokines), necroinflammation (aminotransferases levels), fibrolysis (matrix metalloproteinase 2 expression and activity, C1M, C4M), and Pro-C3 and C3M were analyzed 2, 3, 4, 5, and 6 weeks after bile duct ligation (n = 5 each group). In 110 patients with decompensated liver cirrhosis who underwent a transjugular intrahepatic portosystemic shunt procedure for AD, clinical and laboratory parameters as well as Pro-C3 and C3M were measured in blood samples from portal and hepatic veins and were collected just before the transjugular intrahepatic portosystemic shunt placement and 1-3 weeks later. Animal studies showed increased markers of collagen type III deposition with fibrosis, necroinflammation, and decompensation of liver cirrhosis, defined as ascites development. Higher Pro-C3 levels were associated with injury, disease severity scores (Model for End-Stage Liver Disease, Child-Pugh, chronic liver failure-C AD), ACLF development, and mortality. C3M decreased with AD and the chronic liver failure-C AD score. Collagen type III deposition ratio increased with the risk of ACLF development and mortality. Conclusion: We show for the first time that AD boosts collagen type III deposition in experimental and human cirrhosis, possibly contributing to the worsened outcome in patients with decompensated cirrhosis. (Hepatology Communications 2018;2:211-222).

Fragments generated upon extracellular matrix remodeling: Biological regulators and potential drugs

The remodeling of the extracellular matrix (ECM) by several protease families releases a number of bioactive fragments, which regulate numerous biological processes such as autophagy, angiogenesis, adipogenesis, fibrosis, tumor growth, metastasis and wound healing. We review here the proteases which generate bioactive ECM fragments, their ECM substrates, the major bioactive ECM fragments, together with their biological properties and their receptors. The translation of ECM fragments into drugs is challenging and would take advantage of an integrative approach to optimize the design of pre-clinical and clinical studies. This could be done by building the contextualized interaction network of the ECM fragment repertoire including their parent proteins, remodeling proteinases, and their receptors, and by using mathematical disease models.

Non-invasive quantification of collagen turnover in renal transplant recipients

Kidney allograft failure due to chronic injury/rejection remains the main cause of graft loss in renal transplant recipients (RTR). Here, we investigated whether specific biomarkers of extracellular matrix (ECM) turnover are associated with allograft function and chronic kidney disease (CKD) stage in RTR. Seventy-eight patients who attended the University Medical Center Groningen for a routine check-up after kidney transplantation were enrolled in the study. Plasma and/or 24h-urine samples were collected and specific matrix-metalloproteinase-generated neo-epitope fragments of collagens were measured by enzyme-linked immunosorbent assay. Our results demonstrated that urinary levels of C3M, a marker for collagen type III degradation, correlated with estimated glomerular filtration rate (eGFR; r = 0.58, p<0.0001), with lower levels detected in the urine of patients with advanced CKD. In addition, plasma levels of Pro-C6, a marker for collagen type VI formation, significantly increased with disease progression and correlated with eGFR (r = -0.72, p<0.0001). Conversely, plasma C3M and urinary Pro-C6 levels showed no correlation with renal function. We identified two neo-epitope biomarkers of tissue turnover associated with ECM remodeling and fibrosis that can stratify patients by CKD stage. This is as promising first step towards non-invasive monitoring of ECM turnover in the kidneys.

Serum endotrophin identifies optimal responders to PPARγ agonists in type 2 diabetes

AIMS/HYPOTHESIS

The treatment of type 2 diabetes with full peroxisome proliferator-activated receptor gamma (PPARγ) agonists improves insulin sensitivity, but is associated with weight gain, heart failure, peripheral oedema and bone loss. Endotrophin, the C-terminal fragment of the α3 chain of procollagen type VI (also called Pro-C6), is involved in both adipose tissue matrix remodelling and metabolic control. We established a serum assay for endotrophin to assess if this novel adipokine could identify type 2 diabetic patients who respond optimally to PPARγ agonists, improving the risk-to-benefit ratio.

METHODS

The BALLET trial (NCT00515632) compared the glucose-lowering effects and safety of the partial PPARγ agonist balaglitazone with those of pioglitazone in individuals with type 2 diabetes on stable insulin therapy. The per protocol population (n = 297) was stratified into tertiles based on baseline endotrophin levels. Participants were followed-up after 26 weeks, after which correlational analysis was carried out between endotrophin levels and measures of glucose control. This is a secondary post hoc analysis.

RESULTS

Endotrophin was significantly associated with therapeutic response to balaglitazone and pioglitazone. At week 26, only individuals in the upper two tertiles showed significant reductions in HbA_1c and fasting serum glucose compared with baseline. The OR for a 1% and a 0.5% reduction in HbA_1c for individuals in the upper two tertiles were 3.83 (95% CI 1.62, 9.04) p < 0.01, and 3.85 (95% CI 1.94, 7.61) p < 0.001, respectively. Endotrophin levels correlated with adipose tissue mass, insulin resistance and fatty liver index. Notably, PPARγ-associated adverse effects, such as moderate-to-severe lower extremity oedema, only occurred in the lower tertile.

CONCLUSIONS/INTERPRETATION

Elevated endotrophin serum levels predict response to two insulin sensitisers and reduce the risk of associated adverse effects, thereby, identifying patients with type 2 diabetes who may profit from PPARγ agonist treatment.

The importance of serum biglycan levels as a fibrosis marker in patients with chronic hepatitis B

BACKGROUND

Liver biopsy is recommended in the majority of patients with chronic viral hepatitis for fibrosis evaluation. Because of the potential risks of liver biopsy, many studies related to non-invasive biomarkers of hepatic fibrosis have been performed. We aimed to assess the diagnostic value of serum biglycan as a non-invasive fibrosis marker in chronic hepatitis B patients.

METHODS

This study included 120 patients with biopsy-proven hepatitis B patients and 60 healthy controls. Fibrosis stage and necroinflammatory activity were assessed in liver biopsy specimens. Biglycan level was measured using an ELISA assay.

RESULTS

Serum biglycan levels of chronic hepatitis B patients were found to be significantly higher than those of healthy controls (337.3±363.0 pg/mL vs 189.1±61.9 pg/mL, respectively, P<.001). There was a statistically significant positive correlation between serum biglycan level and fibrosis stage (P=.004; r=.213). Besides, a statistically significant positive correlation was found between serum biglycan level and necroinflammatory activity (P<.001; r=.271). The AUROC of BGN levels was 0.702 for fibrosis stage, differentiating patients from healthy controls with statistical significance (P<.001). The AUROC of BGN levels was 0.632 for necroinflammatory activity score, differentiating patients from healthy controls with statistical significance (P=.004).

CONCLUSIONS

Serum biglycan might be used as a non-invasive marker of liver fibrosis. Further studies are needed to evaluate the usefulness of this marker.

Antifibrotics in chronic liver disease: tractable targets and translational challenges

Chronic liver disease prevalence is increasing globally. Iterative liver damage, secondary to any cause of liver injury, results in progressive fibrosis, disrupted hepatic architecture, and aberrant regeneration, which are defining characteristics of liver cirrhosis. Liver transplantation is an effective treatment for end-stage liver disease; however, demand greatly outweighs donor organ supply, and in many parts of the world liver transplantation is unavailable. Hence, effective antifibrotic therapies are urgently required. In the past decade, rapid progress has been made in our understanding of the pathophysiology of liver fibrosis and a large number of potential cellular and molecular antifibrotic targets have been identified. This has led to numerous clinical trials of antifibrotic agents in patients with chronic liver disease. However, none of these have resulted in a robust and reproducible effect on fibrosis. It is therefore imperative that the ongoing translational challenges are addressed, to convert scientific discoveries into potent antifibrotics and enable bridging of the translational gap between putative therapeutic targets and effective treatments for patients with chronic liver disease.