Serum levels of fibrogenesis biomarkers reveal distinct endotypes predictive of response to weight loss in advanced nonalcoholic fatty liver disease

BACKGROUND

NAFLD is associated with activation of fibroblasts and hepatic fibrosis. Substantial patient heterogeneity exists, so it remains challenging to risk-stratify patients. We hypothesized that the amount of fibroblast activity, as assessed by circulating biomarkers of collagen formation, can define a "high-risk, high-fibrogenesis" patient endotype that exhibits greater fibroblast activity and potentially more progressive disease, and this endotype may be more amendable to dietary intervention.

METHODS

Patients with clinically confirmed advanced NAFLD were prescribed a very low-calorie diet (VLCD) intervention (∼800 kcal/d) to induce weight loss, achieved using total diet replacement. Serum markers of type III (PRO-C3) and IV collagen (PRO-C4) fibrogenesis were assessed at baseline every second week until the end of the VLCD, and 4 weeks post-VLCD and at 9 months follow-up.

RESULTS

Twenty-six subjects had a mean weight loss of 9.7% with VLCD. This was associated with significant improvements in liver biochemistry. When stratified by baseline PRO-C3 and PRO-C4 into distinct fibrosis endotypes, these predicted substantial differences in collagen fibrogenesis marker dynamics in response to VLCD. Patients in the high activity group (PRO-C3 >11.4 ng/mL and/or PRO-C4 >236.5 ng/mL) exhibited a marked reduction of collagen fibrogenesis, ranging from a 40%-55% decrease in PRO-C3 and PRO-C4, while fibrogenesis remained unchanged in the low activity group. The biochemical response to weight loss was substantially greater in patients a priori exhibiting a high fibroblast activity endotype in contrast to patients with low activity.

CONCLUSIONS

Thus, the likelihood of treatment response may be predicted at baseline by quantification of fibrogenesis biomarkers.

Biomarkers of Type IV Collagen Turnover Reflect Disease Activity in Patients with Early-Stage Non-Alcoholic Fatty Liver (NAFL)

BACKGROUND

Identification of progressive liver disease necessitates the finding of novel non-invasive methods to identify and monitor patients in need of early intervention. Investigating patients with early-liver injury may help identify unique biomarkers. Early-liver injury is characterized by remodeling of the hepatocyte basement membrane (BM) of the extracellular matrix. Thus, we quantified biomarkers targeting two distinct neo-epitopes of the major BM collagen, type IV collagen (PRO-C4 and C4M), in patients spanning the non-alcoholic fatty liver disease (NAFLD) spectrum.

METHODS

We evaluated PRO-C4 and C4M in a cross-sectional study with 97 patients with NAFLD confirmed on histology. Serological levels of PRO-C4 and C4M were quantified using validated competitive enzyme-linked immunosorbent assays (ELISA). Using the fatty liver inhibition of progression (FLIP) algorithm, we stratified patients into two groups: non-alcoholic fatty liver (NAFL) and non-alcoholic steatohepatitis (NASH). Biomarker levels were investigated in the two groups in patients stratified by the NAFLD activity score (NAS). In both groups, biomarker measurements were analyzed in relation to histological scorings of steatosis, inflammation, ballooning, and fibrosis.

RESULTS

Patients had a body mass index (BMI) of 30.9 ± 5.6 kg/m2, age of 53 ± 13 years and a NAS range of 1-8. Upon stratification by FLIP, the NASH patients had higher platelets, ALT, and AST levels than the NAFL group. Both PRO-C4 (p = 0.0125) and C4M (p = 0.003) increased with increasing NAS solely within the NAFL group; however, a large variability was present in the NASH group. Furthermore, both markers were significantly associated with lobular inflammation (p = 0.020 and p = 0.048) and steatosis (p = 0.004 and p = 0.015) in patients with NAFL.

CONCLUSIONS

This study found that type IV collagen turnover increased with the increase in NAS in patients with NAFL; however, this was not the case in patients with NASH. These findings support the assessments of the BM turnover using biomarkers in patients with early-disease development. These biomarkers may be used to track specific processes involved in the early pathobiology of NAFL.

Validation of scores of PRO-C3 to predict liver-related events in alcohol-related liver disease

BACKGROUND AND AIMS

Risk prediction in alcohol-related liver disease (ArLD) is an unmet need. We aimed to assess PRO-C3 models to predict liver-related events (LRE) in patients with a history of excessive alcohol use without an established diagnosis of chronic liver disease.

METHODS

A prospective cohort study of 462 patients with ArLD, split into a derivation cohort of 221 secondary care patients and a validation cohort of 241 primary care patients. Baseline variables, including fibrogenesis marker PRO-C3, were used to develop a prediction model. Prognostic accuracy was compared to enhanced liver fibrosis (ELF), fibrosis-4-index (FIB-4), transient elastography (TE) and ADAPT.

RESULTS

In the derivation and validation cohorts, 67 (30%) and 19 (8%) experienced an LRE during a median follow-up of 5.2 years (IQR: 3.2-6.8) and 4.0 years (IQR: 2.7-5.6). On top of PRO-C3 and ADAPT score, we generated a model (ALPACA) of independent predictors of LREs (PRO-C3, AST/ALT, platelets). ALPACA had high prognostic accuracy with a C-statistic of 0.85 in the derivation cohort, comparable to ELF (0.83) and TE (0.84) and significantly higher than FIB-4 (0.78), PRO-C3 (0.80) and ADAPT (0.81). In the validation cohort, all tests had comparable C-statistics. Compared to low-risk patients (ALPACA ≤11), high-risk patients (>11) had a subhazard ratio for LREs of 12.6 (95% CI 5.9-26.8, p < .001) and higher cumulative incidence (57% vs. 7%, p < .001; derivation cohort). We observed similar subhazard ratio in the validation cohort.

CONCLUSIONS

PRO-C3-based scores are reliable tools to predict LREs in ArLD patients and are suitable for risk stratification in primary and secondary care.

Effect of pegbelfermin on NASH and fibrosis-related biomarkers and correlation with histological response in the FALCON 1 trial

Background & Aims

FALCON 1 was a phase IIb study of pegbelfermin in patients with non-alcoholic steatohepatitis (NASH) and stage 3 fibrosis. This FALCON 1 post hoc analysis aimed to further assess the effect of pegbelfermin on NASH-related biomarkers, correlations between histological assessments and non-invasive biomarkers, and concordance between the week 24 histologically assessed primary endpoint response and biomarkers.

Methods

Blood-based composite fibrosis scores, blood-based biomarkers, and imaging biomarkers were evaluated for patients with available data from FALCON 1 at baseline through week 24. SomaSignal tests assessed protein signatures of NASH steatosis, inflammation, ballooning, and fibrosis in blood. Linear mixed-effect models were fit for each biomarker. Correlations and concordance were assessed between blood-based biomarkers, imaging, and histological metrics.

Results

At week 24, pegbelfermin significantly improved blood-based composite fibrosis scores (ELF, FIB-4, APRI), fibrogenesis biomarkers (PRO-C3 and PC3X), adiponectin, CK-18, hepatic fat fraction measured by MRI-proton density fat fraction, and all four SomaSignal NASH component tests. Correlation analyses between histological and non-invasive measures identified four main categories: steatosis/metabolism, tissue injury, fibrosis, and biopsy-based metrics. Concordant and discordant effects of pegbelfermin on the primary endpoint vs. biomarker responses were observed; the most clear and concordant effects were on measures of liver steatosis and metabolism. A significant association between hepatic fat measured histologically and by imaging was observed in pegbelfermin arms.

Conclusions

Pegbelfermin improved NASH-related biomarkers most consistently through improvement of liver steatosis, though biomarkers of tissue injury/inflammation and fibrosis were also improved. Concordance analysis shows that non-invasive assessments of NASH support and exceed the improvements detected by liver biopsy, suggesting that greater consideration should be given to the totality of available data when evaluating the efficacy of NASH therapeutics.

Clinical trial number

Post hoc analysis of NCT03486899.

Impact and implications

FALCON 1 was a study of pegbelfermin vs. placebo in patients with non-alcoholic steatohepatitis (NASH) without cirrhosis; in this study, patients who responded to pegbelfermin treatment were identified through examination of liver fibrosis in tissue samples collected through biopsy. In the current analysis, non-invasive blood- and imaging-based measures of fibrosis, liver fat, and liver injury were used to determine pegbelfermin treatment response to see how they compared with the biopsy-based results. We found that many of the non-invasive tests, particularly those that measured liver fat, identified patients who responded to pegbelfermin treatment, consistent with the liver biopsy findings. These results suggest that there may be additional value in using data from non-invasive tests, along with liver biopsy, to evaluate how well patients with NASH respond to treatment.

The fatal trajectory of pulmonary COVID-19 is driven by lobular ischemia and fibrotic remodelling

BACKGROUND

COVID-19 is characterized by a heterogeneous clinical presentation, ranging from mild symptoms to severe courses of disease. 9-20% of hospitalized patients with severe lung disease die from COVID-19 and a substantial number of survivors develop long-COVID. Our objective was to provide comprehensive insights into the pathophysiology of severe COVID-19 and to identify liquid biomarkers for disease severity and therapy response.

METHODS

We studied a total of 85 lungs (n = 31 COVID autopsy samples; n = 7 influenza A autopsy samples; n = 18 interstitial lung disease explants; n = 24 healthy controls) using the highest resolution Synchrotron radiation-based hierarchical phase-contrast tomography, scanning electron microscopy of microvascular corrosion casts, immunohistochemistry, matrix-assisted laser desorption ionization mass spectrometry imaging, and analysis of mRNA expression and biological pathways. Plasma samples from all disease groups were used for liquid biomarker determination using ELISA. The anatomic/molecular data were analyzed as a function of patients' hospitalization time.

FINDINGS

The observed patchy/mosaic appearance of COVID-19 in conventional lung imaging resulted from microvascular occlusion and secondary lobular ischemia. The length of hospitalization was associated with increased intussusceptive angiogenesis. This was associated with enhanced angiogenic, and fibrotic gene expression demonstrated by molecular profiling and metabolomic analysis. Increased plasma fibrosis markers correlated with their pulmonary tissue transcript levels and predicted disease severity. Plasma analysis confirmed distinct fibrosis biomarkers (TSP2, GDF15, IGFBP7, Pro-C3) that predicted the fatal trajectory in COVID-19.

INTERPRETATION

Pulmonary severe COVID-19 is a consequence of secondary lobular microischemia and fibrotic remodelling, resulting in a distinctive form of fibrotic interstitial lung disease that contributes to long-COVID.

FUNDING

This project was made possible by a number of funders. The full list can be found within the Declaration of interests / Acknowledgements section at the end of the manuscript.

Evaluation of Laboratory and Sonographic Parameters for Detection of Portal Hypertension in Patients with Common Variable Immunodeficiency

Timely detection of portal hypertension as a manifestation in a subgroup of patients with common variable immunodeficiency (CVID) represents a challenge since it is usually not associated with liver cirrhosis. To identify relevant markers for portal hypertension, we evaluated clinical history, laboratory parameters, and abdominal ultrasound including liver elastography and biomarkers of extracellular matrix formation. Twenty seven (6%) of 479 CVID patients presented with clinically significant portal hypertension as defined by either the presence of esophageal varices or ascites. This manifestation occurred late during the course of the disease (11.8 years after first diagnosis of CVID) and was typically part of a multiorgan disease and associated with a high mortality (11/27 patients died during follow up). The strongest association with portal hypertension was found for splenomegaly with a longitudinal diameter of > 16 cm. Similarly, most patients presented with a liver stiffness measurement (LSM) of above 6.5 kPa, and a LSM above 20 kPa was always indicative of manifest portal hypertension. Additionally, many laboratory parameters including Pro-C4 were significantly altered in patients with portal hypertension without clearly increasing the discriminatory power to detect non-cirrhotic portal hypertension in CVID. Our data suggest that a spleen size above 16 cm and an elevated liver stiffness above 6.5 kPa should prompt further evaluation of portal hypertension and its sequelae, but earlier and better liquid biomarkers of this serious secondary complication in CVID are needed.

An MMP-degraded and cross-linked fragment of type III collagen as a non-invasive biomarker of hepatic fibrosis resolution

BACKGROUND AND AIMS

Liver fibrosis results from a prolonged wound healing response to continued injury with excessive production of extracellular proteins. In patients with chronic liver disease, the monitoring of liver fibrosis dynamics is of high interest. Whilst markers of fibrogenesis exist, markers of hepatic fibrosis resolution remain an unmet clinical need. Thus, we sought to develop an assay quantifying a circulating proteolytic fragment of cross-linked type III collagen as a biomarker of fibrolysis, testing its utility in two clinical cohorts of liver fibrosis of distinct aetiology and regressing endotype METHODS: We used a monoclonal antibody targeting the C-telopeptide of type III collagen following C-proteinase cleavage to develop and validate a neo-epitope-specific enzyme-linked immunosorbent assay (CTX-III). A potential fibrosis resolution marker, CTX-III, was measured in two clinical cohorts of patients with obesity-associated non-alcoholic fatty liver disease undergoing bariatric surgery or hepatitis C virus infection from a clinical trial study evaluating the anti-fibrotic effect of farglitazar.

RESULTS

CTX-III was robust and specific for the targeted neo-epitope with good reproducibility in EDTA plasma. We assessed type III collagen remodelling using a panel of biomarkers, including a type III collagen formation marker (PRO-C3), degradation (C3M), and CTX-III (fibrolysis). Net fibrolysis was increased in patients with non-alcoholic fatty liver disease following bariatric surgery (p < .001). Moreover, net fibrolysis identified spontaneous fibrotic regressors from stable and progressors (p < .05 and p < .001) among hepatitis C virus infection patients.

CONCLUSION

Circulating CTX-III as a marker of fibrolysis indicates the biomarker's beneficial use in assessing hepatic fibrosis resolution.

Obesity Modifies the Performance of Fibrosis Biomarkers in Nonalcoholic Fatty Liver Disease

CONTEXT

Guidelines recommend blood-based fibrosis biomarkers to identify advanced nonalcoholic fatty liver disease (NAFLD), which is particularly prevalent in patients with obesity.

OBJECTIVE

To study whether the degree of obesity affects the performance of liver fibrosis biomarkers in NAFLD.

DESIGN

Cross-sectional cohort study comparing simple fibrosis scores [Fibrosis-4 Index (FIB-4); NAFLD Fibrosis Score (NFS); aspartate aminotransferase to platelet ratio index; BARD (body mass index, aspartate-to-alanine aminotransferase ratio, diabetes); Hepamet Fibrosis Score (HFS)] and newer scores incorporating neo-epitope biomarkers PRO-C3 (ADAPT, FIBC3) or cytokeratin 18 (MACK-3).

SETTING

Tertiary referral center.

PATIENTS

We recruited overweight/obese patients from endocrinology (n = 307) and hepatology (n = 71) clinics undergoing a liver biopsy [median body mass index (BMI) 40.3 (interquartile range 36.0-44.7) kg/m2]. Additionally, we studied 859 less obese patients with biopsy-proven NAFLD to derive BMI-adjusted cutoffs for NFS.

MAIN OUTCOME MEASURES

Biomarker area under the receiver operating characteristic (AUROC), sensitivity, specificity, and predictive values to identify histological stage ≥F3 fibrosis or nonalcoholic steatohepatitis with ≥F2 fibrosis [fibrotic nonalcoholic steatohepatitis (NASH)].

RESULTS

The scores with an AUROC ≥0.85 to identify ≥F3 fibrosis were ADAPT, FIB-4, FIBC3, and HFS. For fibrotic NASH, the best predictors were MACK-3 and ADAPT. The specificities of NFS, BARD, and FIBC3 deteriorated as a function of BMI. We derived and validated new cutoffs for NFS to rule in/out ≥F3 fibrosis in groups with BMIs <30.0, 30.0 to 39.9, and ≥40.0 kg/m2. This optimized its performance at all levels of BMI. Sequentially combining FIB-4 with ADAPT or FIBC3 increased specificity to diagnose ≥F3 fibrosis.

CONCLUSIONS

In obese patients, the best-performing fibrosis biomarkers are ADAPT and the inexpensive FIB-4, which are unaffected by BMI. The widely used NFS loses specificity in obese individuals, which may be corrected with BMI-adjusted cutoffs.

Binge drinking induces an acute burst of markers of hepatic fibrogenesis (PRO-C3)

BACKGROUND & AIMS

Binge drinking is associated with an increased risk of liver disease. Morbidity and mortality of alcohol-related liver disease (ALD) is associated with collagen deposition in the hepatic extracellular matrix (ECM). However, the acute effects of binge drinking on ECM turnover are unknown. We aimed to investigate the effects on hepatic ECM turnover following a binge drinking episode.

METHODS

We performed a pathophysiological intervention study with 15 non-alcoholic fatty liver disease (NAFLD) patients, 15 ALD patients and 10 healthy controls. We used 40% ethanol in 9 mg/mL NaCl administered through a nasogastric tube to simulate binge drinking. Hepatic vein catheterisation allowed simultaneous hepatic- and systemic vein sampling. Markers of ECM formation and degradation were measured with competitive ELISA.

RESULTS

The interstitial matrix formation marker PRO-C3 increased by 1.2 ng/mL (10%, P < .001) 24 hours after binge drinking. In participants with existing liver fibrosis determined by elevated baseline PRO-C3, hepatic levels increased by 0.09 ng/mL (95% CI: 0.03-0.15, P = .005) while systemic PRO-C3 decreased 0.11 ng/mL (95% CI: -0.15 to -0.06, P < .001) in 3 hours. PRO-C8 increased by 30% (+0.9 ng/mL, P = .014) in liver-diseased patients with F0-F1 but not in any other group. Twenty-four-hour changes in systemic C3M and PRO-C3 were not associated (P = .911).

CONCLUSIONS

Binge drinking induced an acute burst of PRO-C3 in healthy individuals and patients with liver disease. Markers of ECM degradation were not correlated to markers of ECM formation, suggesting that even a single episode of binge drinking promotes excessive hepatic fibrogenesis.

Biomarkers of extracellular matrix formation are associated with acute-on-chronic liver failure

Background & Aims

Acute-on-chronic liver failure (ACLF) is characterised by organ failure(s), high short-term mortality, and, pathophysiologically, deranged inflammatory responses. The extracellular matrix (ECM) is critically involved in regulating the inflammatory response. This study aimed to determine alterations in biomarkers of ECM turnover in ACLF and their association with inflammation, organ failures, and mortality.

Methods

We studied 283 patients with cirrhosis admitted for acute decompensation (AD) with or without ACLF, 64 patients with stable cirrhosis, and 30 healthy controls. A validation cohort (25 ACLF, 9 healthy controls) was included. Plasma PRO-C3, PRO-C4, PRO-C5, PRO-C6, and PRO-C8 (i.e. collagen type III–VI and VIII formation) and C4M and C6M (i.e. collagen type IV and VI degradation) were measured. Immunohistochemistry of PRO-C6 was performed on liver biopsies (AD [n = 7], ACLF [n = 5]). A competing-risk regression analysis was performed to explore the prognostic value of biomarkers of ECM turnover with 28- and 90-day mortality.

Results

PRO-C3 and PRO-C6 were increased in ACLF compared to AD (p = 0.089 and p <0.001, respectively), whereas collagen degradation markers C4M and C6M were similar. Both PRO-C3 and PRO-C6 were strongly associated with liver function and inflammatory markers. Only PRO-C6 was associated with extrahepatic organ failures and 28- and 90-day mortality (hazard ratio [HR; on log-scale] 6.168, 95% CI 2.366–16.080, p <0.001, and 3.495, 95% CI 1.509–8.093, p = 0.003, respectively). These findings were consistent in the validation cohort. High PRO-C6 expression was observed in liver biopsies of patients with ACLF.

Conclusions

This study shows, for the first time, evidence of severe net interstitial collagen deposition in ACLF and makes the novel observation of the association between PRO-C6 and (extrahepatic) organ failures and mortality. Further studies are needed to define the pathogenic significance of these observations.

Lay summary

This study describes a disrupted turnover of collagen type III and VI in Acute-on-chronic liver failure (ACLF). Plasma biomarkers of these collagens (PRO-C3 and PRO-C6) are associated with the severity of liver dysfunction and inflammation. PRO-C6, also known as the hormone endotrophin, has also been found to be associated with multi-organ failure and prognosis in acute decompensation and ACLF.

•

Collagen type III and VI formation is increased in ACLF compared to AD.

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PRO-C3 and PRO-C6 correlate with the severity of liver dysfunction and inflammation in AD and ACLF.

•

High PRO-C6 levels were found to be indicative for the presence of multi-organ failure and worse survival.

Longitudinal serological assessment of type VI collagen turnover is related to progression in a real-world cohort of idiopathic pulmonary fibrosis

Background

Remodeling of the extracellular matrix (ECM) is a central mechanism in the progression of idiopathic pulmonary fibrosis (IPF), and remodeling of type VI collagen has been suggested to be associated with disease progression. Biomarkers that reflect and predict the progression of IPF would provide valuable information for clinicians when treating IPF patients.

Methods

Two serological biomarkers reflecting formation (PRO-C6) and degradation (C6M) of type VI collagen were evaluated in a real-world cohort of 178 newly diagnoses IPF patients. All patients were treatment naïve at the baseline visit. Blood samples and clinical data were collected from baseline, six months, and 12 months visit. The biomarkers were measured by competitive ELISA using monoclonal antibodies.

Results

Patients with progressive disease had higher (P = 0.0099) serum levels of PRO-C6 compared to those with stable disease over 12 months with an average difference across all timepoints of 12% (95% CI 3–22), whereas C6M levels tended (P = 0.061) to be higher in patients with progressive disease compared with stable patients over 12 months with an average difference across all timepoints of 12% (95% CI − 0.005–27). Patients who did not receive antifibrotic medicine had a greater increase of C6M (P = 0.043) compared to treated patients from baseline over 12 months with an average difference across all timepoints of 12% (95% CI − 0.07–47). There were no differences in biomarker levels between patients receiving pirfenidone or nintedanib.

Conclusions

Type VI collagen formation was related to progressive disease in patients with IPF in a real-world cohort and antifibrotic therapy seemed to affect the degradation of type VI collagen. Type VI collagen formation and degradation products might be potential biomarkers for disease progression in IPF.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01684-3.

PRO-C3, a Serological Marker of Fibrosis, During Childhood and Correlations With Fibrosis in Pediatric NAFLD

Nonalcoholic fatty liver disease (NAFLD) is a common chronic liver disease in children and may lead to cirrhosis requiring liver transplant. Thus, prompt diagnosis of advanced fibrosis is essential. Our objectives were to examine PRO-C3 (a neo-epitope pro-peptide of type III collagen formation) levels across childhood/adolescence and associations with advanced fibrosis in pediatric NAFLD. This cross-sectional study included 88 children and adolescents with biopsy-proven NAFLD (mean age: 13.9 ± 2.9 years, 71% male) and 65 healthy participants (11.8 ± 4.5 years, 38% male). PRO-C3, and the bone remodeling biomarkers C-terminal telopeptide of type I collagen (CTX-I; bone resorption) and osteocalcin (N-MID; bone formation), were measured in serum by enzyme-linked immunosorbent assay. Fibrosis was assessed by liver biopsy in participants with NAFLD, who were categorized as having advanced (Ishak score ≥ 3) or none/mild fibrosis (Ishak score ≤ 2). Overall, PRO-C3 was similar in participants with NAFLD (median [interquartile range]: 20.6 [15.8, 25.9] ng/mL) versus healthy participants (19.0 [13.8, 26.0] ng/mL), but was significantly lower in older adolescents ≥ 15 years old (16.4 [13.0, 21.2] ng/mL) compared with children ≤ 10 years old (22.9 [18.1, 28.4] ng/mL; P < 0.001) or 11-14 years old (22.4 [18.3, 31.2] ng/mL; P < 0.001). PRO-C3 was also directly correlated with levels of CTX-I and N-MID (r = 0.64 and r = 0.62, respectively; both P < 0.001). Among participants with NAFLD, PRO-C3 was higher in those with advanced fibrosis (median [IQR]: 28.5 [21.6, 37.6]) compared with none/mild fibrosis (20.3 [18.2, 22.8]; P = 0.020) in models adjusted for age, sex, and body mass index z-score. However, associations were attenuated after additionally adjusting for bone-remodeling CTX-I (P = 0.09) or N-MID (P = 0.08). Conclusion: Collectively, these findings show that PRO-C3 levels are higher in children with advanced fibrosis in NAFLD, but are also influenced by age and pubertal growth spurt, assessed by bone remodeling biomarkers, and therefore may not be a reliable biomarker for liver fibrosis in pediatric NAFLD until late adolescence.

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.

PRO-C3 and ADAPT algorithm accurately identify patients with advanced fibrosis due to alcohol-related liver disease

BACKGROUND

Alcohol is a main cause of preventable deaths and frequently leads to the development of alcohol-related liver disease. Due to the lack of diagnostics, patients are commonly diagnosed after developing clinical manifestations. Recently, the biomarker PRO-C3 was shown to accurately identify fibrosis due to non-alcoholic fatty liver disease.

AIM

To assess the diagnostic accuracy of PRO-C3, the ADAPT score and best-performing non-patented serological test to detect advanced alcohol-related liver fibrosis.

METHODS

We enrolled 426 patients with alcohol overuse in a prospective biopsy-controlled study. We evaluated the accuracy of PRO-C3 and the PRO-C3-based algorithm ADAPT to detect advanced liver fibrosis.

RESULTS

The accuracy of PRO-C3 was good with an AUROC of 0.85 (95% CI 0.79-0.90). The best-performing non-patented test was the Forns index with an AUROC of 0.83 (95% CI 0.78-0.89). The ADAPT algorithm performed better as compared to both the Forns index and PRO-C3 alone with an AUROC = 0.88 (95% CI 0.83-0.93).

CONCLUSION

PRO-C3 is a new marker with high accuracy to detect advanced alcohol-related liver fibrosis. The diagnostic accuracy of PRO-C3 can be further improved by using the ADAPT algorithm in which the test outperforms currently available non-patented serological fibrosis markers. The study is registered in the Odense Patient Data Exploratory Network (OPEN) under study identification numbers OP_040 (https://open.rsyd.dk/OpenProjects/da/openProject.jsp?openNo=40) and OP_239 (https://open.rsyd.dk/OpenProjects/openProject.jsp?openNo=239&lang=da).

Considerations for understanding protein measurements: Identification of formation, degradation and more pathological relevant epitopes

OBJECTIVES

There is a need for precision medicine and an unspoken promise of an optimal approach for identification of the right patients for value-based medicine based on big data. However, there may be a misconception that measurement of proteins is more valuable than measurement of fewer selected biomarkers. In population-based research, variation may be somewhat eliminated by quantity. However, this fascination of numbers may limit the attention to and understanding of the single. This review highlights that protein measurements (with collagens as examples) may mean different things depending on the targeted epitope - formation or degradation of tissues, and even signaling potential of proteins.

DESIGN AND METHODS

PubMed was searched for collagen, neo-epitope, biomarkers.

RESULTS

Ample examples of assays with specific epitopes, either pathological such as HbA1c, or domain specific such as pro-peptides, which total protein arrays would not have identified were evident.

CONCLUSIONS

We suggest that big data may be considered as the funnel of data points, in which most important parameters will be selected. If the technical precision is low or the biological accuracy is limited, and we include suboptimal quality of biomarkers, disguised as big data, we may not be able to fulfill the promise of helping patients searching for the optimal treatment. Alternatively, if the technical precision of the total protein quantification is high, but we miss the functional domains with the most considerable biological meaning, we miss the most important and valuable information of a given protein. This review highlights that measurements of the same protein in different ways may provide completely different meanings. We need to understand the pathological importance of each epitope quantified to maximize protein measurements.

The novel collagen matrikine, endotrophin, is associated with mortality and cardiovascular events in patients with atherosclerosis

BACKGROUND

Rupture of atherosclerotic plaques is the major cause of acute cardiovascular events. The biomarker PRO-C6 measuring Endotrophin, a matrikine of collagen type VI, may provide valuable information detecting subjects in need of intensified strategies for secondary prevention.

OBJECTIVE

In this study, we evaluate endotrophin in human atherosclerotic plaques and circulating levels of PRO-C6 in patients with atherosclerosis, to determine the predictive potential of the biomarker.

METHODS

Sections from the stenotic human carotid plaques were stained with the PRO-C6 antibody. PRO-C6 was measured in serum of patients enrolled in the Carotid Plaque Imagining Project (CPIP) (discovery cohort, n = 577) and the innovative medicines initiative surrogate markers for micro- and macrovascular hard end-points for innovative diabetes tools (IMI-SUMMIT, validation cohort, n = 1,378). Median follow-up was 43 months. Kaplan-Meier curves and log-rank tests were performed in the discovery cohort. Cox proportional hazard regression analysis (HR with 95% CI) was used in the discovery cohort and binary logistic regression (OR with 95% CI) in the validation cohort.

RESULTS

PRO-C6 was localized in the core and shoulder of the atherosclerotic plaque. In the discovery cohort, PRO-C6 independently predicted future cardiovascular events (HR 1.089 [95% CI 1.019 -1.164], p = 0.01), cardiovascular death (HR 1.118 [95% CI 1.008 -1.241], p = 0.04) and all-cause death (HR 1.087 [95% CI 1.008 -1.172], p = 0.03). In the validation cohort, PRO-C6 predicted future cardiovascular events (OR 1.063 [95% CI 1.011 -1.117], p = 0.017).

CONCLUSION

PRO-C6 is present in the atherosclerotic plaque and associated with future cardiovascular events, cardiovascular death and all-cause mortality in two large prospective cohorts.

High turnover of types III and VI collagen in progressive idiopathic pulmonary fibrosis

BACKGROUND AND OBJECTIVE

Prediction of idiopathic pulmonary fibrosis (IPF) progression is vital for the choice and timing of treatment and patient follow-up. This could potentially be achieved by prognostic blood biomarkers of extracellular matrix (ECM) remodelling.

METHODS

Neoepitope biomarkers of types III and VI collagen turnover (C3M, C6M, PRO-C3 and PRO-C6) were measured in 185 patients with newly diagnosed IPF. Disease severity at baseline and progression over 6 months was assessed by lung function tests and 6-min walk tests. All-cause mortality was assessed over a 3-year follow-up period.

RESULTS

High baseline levels of C3M, C6M, PRO-C3 and PRO-C6 were associated with more advanced disease at the time of diagnosis. Baseline levels of C6M and PRO-C3 were also associated with mortality over 3 years of follow-up (hazard ratio [HR]: 2.3, 95% CI: 1.3-3.9, p = 0.002 and HR: 1.8, 95% CI: 1.1-3.0, p = 0.03). Patients with several increased biomarkers at baseline, representing a high ECM remodelling phenotype, had more advanced disease at baseline, higher risk of progression or death at 6 months (OR: 1.4, 95% CI: 1.1-1.8, p = 0.002) and higher mortality over 3 years of follow-up (HR: 2.4, 95% CI: 1.3-4.5, p = 0.007).

CONCLUSION

Blood biomarkers of types III and VI collagen turnover, assessed at the time of diagnosis, are associated with several indices of disease severity, short-term progression and long-term mortality. These biomarkers can help to identify patients with a high ECM remodelling phenotype at high risk of disease progression and death.

Silencing Heat Shock Protein 47 (HSP47) in Fibrogenic Precision-Cut Lung Slices: A Surprising Lack of Effects on Fibrogenesis?

Idiopathic pulmonary fibrosis (IPF) is a chronic disease that is characterized by the excessive deposition of scar tissue in the lungs. As currently available treatments are unable to restore lung function in patients, there is an urgent medical need for more effective drugs. Developing such drugs, however, is challenging because IPF has a complex pathogenesis. Emerging evidence indicates that heat shock protein 47 (HSP47), which is encoded by the gene Serpinh1, may be a suitable therapeutic target as it is required for collagen synthesis. Pharmacological inhibition or knockdown of HSP47 could therefore be a promising approach to treat fibrosis. The objective of this study was to assess the therapeutic potential of Serpinh1-targeting small interfering RNA (siRNA) in fibrogenic precision-cut lung slices prepared from murine tissue. To enhance fibrogenesis, slices were cultured for up to 144 h with transforming growth factor β1. Self-deliverable siRNA was used to knockdown mRNA and protein expression, without affecting the viability and morphology of slices. After silencing HSP47, only the secretion of fibronectin was reduced while other aspects of fibrogenesis remained unaffected (e.g., myofibroblast differentiation as well as collagen secretion and deposition). These observations are surprising as others have shown that Serpinh1-targeting siRNA suppressed collagen deposition in animals. Further studies are therefore warranted to elucidate downstream effects on fibrosis upon silencing HSP47.

Can biomarkers of extracellular matrix remodelling and wound healing be used to identify high risk patients infected with SARS-CoV-2?: lessons learned from pulmonary fibrosis

Pulmonary fibrosis has been identified as a main factor leading to pulmonary dysfunction and poor quality of life in post-recovery Severe Acute Respiratory Syndrome (SARS) survivor’s consequent to SARS-Cov-2 infection. Thus there is an urgent medical need for identification of readily available biomarkers that in patients with SARS-Cov-2 infection are able to; (1) identify patients in most need of medical care prior to admittance to an intensive care unit (ICU), and; (2) identify patients post-infection at risk of developing persistent fibrosis of lungs with subsequent impaired quality of life and increased morbidity and mortality. An intense amount of research have focused on wound healing and Extracellular Matrix (ECM) remodelling of the lungs related to lung function decline in pulmonary fibrosis (PF). A range of non-invasive serological biomarkers, reflecting tissue remodelling, and fibrosis have been shown to predict risk of acute exacerbations, lung function decline and mortality in PF and other interstitial lung diseases (Sand et al. in Respir Res 19:82, 2018). We suggest that lessons learned from such PF studies of the pathological processes leading to lung function decline could be used to better identify patients infected with SARS-Co-V2 at most risk of acute deterioration or persistent fibrotic damage of the lung and could consequently be used to guide treatment decisions.

Combining biomarkers of clot resolution and alveolar basement membrane destruction predicts mortality in the ECLIPSE COPD cohort

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is characterized by abnormal epithelial repair resulting in a hypercoagulable state with intra-alveolar accumulation of fibrin and alveolar basement membrane destruction. This study aimed to investigate if the combination of two serological biomarkers evaluating these pathological processes could improve the prediction of mortality risk compared to single biomarkers.

METHODS

Matrix metalloproteinase-mediated degradation of the type IV collagen α3 chain (C4Ma3), located in the alveolar basement membrane, and plasmin-mediated degradation of crosslinked fibrin (X-FIB), an end-product of fibrinogen, were assessed serologically in a subset of the ECLIPSE cohort (n = 982). Biomarker data were dichotomized into high versus low at the median. Cox regression and Kaplan-Meier curves were used to analyze the predictive value of having one or two high biomarkers for all-cause mortality over two years.

RESULTS

COPD participants with high levels of two biomarkers were at significantly higher risk of all-cause mortality with a hazard ratio of 7.66 (95% CI 1.75-33.48; p = 0.007) while participants with one high biomarker were not at significantly higher risk (HR 3.79 [95% CI 0.85-16.94]; p = 0.08).

CONCLUSIONS

A combination of serological biomarkers of alveolar basement membrane destruction and clot resolution was predictive of all-cause mortality in COPD. The combination of two different pathological aspects may strengthen prognostic accuracy and could be used in conjunction with clinical assessment to guide treatment decisions.

Translational pharmacology of an inhaled small molecule αvβ6 integrin inhibitor for idiopathic pulmonary fibrosis

The αvβ6 integrin plays a key role in the activation of transforming growth factor-β (TGFβ), a pro-fibrotic mediator that is pivotal to the development of idiopathic pulmonary fibrosis (IPF). We identified a selective small molecule αvβ6 RGD-mimetic, GSK3008348, and profiled it in a range of disease relevant pre-clinical systems. To understand the relationship between target engagement and inhibition of fibrosis, we measured pharmacodynamic and disease-related end points. Here, we report, GSK3008348 binds to αvβ6 with high affinity in human IPF lung and reduces downstream pro-fibrotic TGFβ signaling to normal levels. In human lung epithelial cells, GSK3008348 induces rapid internalization and lysosomal degradation of the αvβ6 integrin. In the murine bleomycin-induced lung fibrosis model, GSK3008348 engages αvβ6, induces prolonged inhibition of TGFβ signaling and reduces lung collagen deposition and serum C3M, a marker of IPF disease progression. These studies highlight the potential of inhaled GSK3008348 as an anti-fibrotic therapy.

The αvβ6 integrin is key in activating the pro-fibrotic cytokine TGFβ in idiopathic pulmonary fibrosis. Here, the authors show an inhaled small molecule αvβ6 inhibitor GSK3008348 induces prolonged inhibition of TGFβ signaling pathways in human and murine models of lung fibrosis via αvβ6 degradation.

Abstract 6484: Cross-linked multimeric pro-peptides of type III collagen (PC3X) in hepatocellular carcinoma - A biomarker that provides additional prognostic value in AFP positive patients

Background: Non-invasive biomarkers for diagnosing and prognosing hepatocellular carcinoma (HCC) are urgently needed. Cirrhosis, a consequence of deposition and cross-linking of collagens, underlies HCC in 80-90% of cases, and associates with HCC initiation and progression. We evaluated circulating cross-linked pro-peptides of type III collagen (PC3X) as a diagnostic and prognostic biomarker for HCC.

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&lt;0.0001). In patients with normal AFP (&lt;20 IU/ml), PC3X and PRO-C3 separated HCC from cirrhosis with an AUROC of 0.69 and 0.67, respectively. High PC3X and AFP predicted for poor PFS (HRPC3X=1.80, p=0.032; HRAFP=1.70, p=0.031) and OS (HRPC3X=2.12, p=0.024; HRAFP=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&lt;0.0001).

Conclusions: 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.

Citation Format: Christina Jensen, Signe H. Nielsen, Mohammed Eslam, Federica Genovese, Mette J. Nielsen, Roslyn Vongsuvanh, Raj Uchila, David van der Poorten, Jacob George, Morten A. Karsdal, Diana J. Leeming, Nicholas Willumsen. Cross-linked multimeric pro-peptides of type III collagen (PC3X) in hepatocellular carcinoma - A biomarker that provides additional prognostic value in AFP positive patients [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6484.

Endotrophin, an extracellular hormone, in combination with neoepitope markers of von Willebrand factor improves prediction of mortality in the ECLIPSE COPD cohort

BACKGROUND

Lung epithelial damage, activation of the wound healing cascade, and remodeling of the extracellular matrix (ECM) play a major role in chronic obstructive pulmonary disease (COPD). The pro-peptide of type VI collagen has been identified as the hormone endotrophin. Endotrophin has been shown to promote fibrosis and inflammation, whereas von Willebrand factor (VWF) is a crucial part of wound healing initiation. Here, we assessed the released and activated form of VWF and endotrophin, the pro-peptide of type VI collagen, serologically to investigate their association with mortality in COPD subjects alone or in combination.

METHODS

One thousand COPD patients with 3 years of clinical follow-up from the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE) cohort were included. Serum and heparin plasma were collected at 6 months and 1 year, respectively. Competitive ELISA utilizing specific monoclonal antibodies assessed endotrophin/type VI collagen formation (PRO-C6), VWF release (VWF-N), and activated VWF (VWF-A). Biomarker levels were dichotomized into high and low as defined by receiver operating characteristic (ROC) curves based on mortality data. Kaplan-Meier analysis was used to determine hazard ratios for all-cause mortality for biomarkers alone or in combination.

RESULTS

High levels of PRO-C6, VWF-A, and VWF-N have previously been shown to be individually associated with a higher risk of mortality with hazard ratios of 5.6 (95% CI 2.4-13.1), 3.7 (1.8-7.6), and 4.6 (2.2-9.6), respectively. The hazard ratios increased when combining the biomarkers: PRO-C6*VWFA 8.8 (2.8-27.7) and PRO-C6*VWFN 13.3 (5.6-32.0). Notably, PRO-C6*VWF-N increased more than 2-fold.

CONCLUSION

We demonstrated that by combining two pathological relevant aspects of COPD, tissue remodeling, and wound healing, the predictive value of biomarkers for mortality increased notably.

Collagen biology and non-invasive biomarkers of liver fibrosis

There is an unmet need for high-quality liquid biomarkers that can safely and reproducibly predict the stage of fibrosis and the outcomes of chronic liver disease (CLD). The requirement for such markers has intensified because of the high global prevalence of diseases such as non-alcoholic fatty liver disease (NAFLD). In particular, there is a need for diagnostic and prognostic tools, as well as predictive biomarkers that reflect the efficacy of interventions, as described by the BEST criteria (Biomarkers, EndpointS, and other Tools Resource). This review covers the various liver collagens, their functional role in tissue homeostasis and delineates the common nomenclature for biomarkers based on BEST criteria. It addresses the common confounders affecting serological biomarkers, and describes defined collagen epitope biomarkers that originate from the dynamic processes of extracellular matrix (ECM) remodelling during liver injury.

Addition of trans fat and alcohol has divergent effects on atherogenic diet-induced liver injury in rodent models of steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD) are common causes of chronic liver disease. The overlap between ALD and NAFLD suggests the existence of metabolic steatohepatitis. Development of in vivo models that reflect various aspects of human steatohepatitis is essential for drug discovery. We aimed to characterize several models of steatohepatitis (SH) and to investigate whether the pathology could be modulated. Sprague-Dawley rats were fed a high-fat diet (HFD) for 9 wk, followed by either a high-fat, high-cholesterol and cholate diet (HFC) or a HFC diet containing 13% trans fat (HFC-TF). A subset received 15% ethanol-water twice a week for 12 wk. Serum triglycerides, cholesterol, LDL, HDL, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and rodent NH₂-terminal propeptide of type III collagen (rPRO-C3) were assessed. The liver was weighed and evaluated using modified Nonalcoholic Steatohepatitis Clinical Research Network histological score system criteria. All diets induced hepatomegaly, but only HFC-TF increased the size of visceral adipose tissue. Trans fat augmented HFC-induced dyslipidemia, and cholesterol was higher and HDL was lower in the HFC-TF groups. Alcohol lowered triglycerides in both dietary groups. HFC elevated ALT and AST, which were lowered by trans fat. All diets induced histological SH, addition of trans fat induced more steatosis but less inflammation. Inclusion of alcohol augmented the HFC-induced inflammation. All diets induced mild fibrosis. Inclusion of trans fat and alcohol significantly increased rPRO-C3. The addition of trans fat reduced the HFC-induced inflammation but augmented steatosis and dyslipidemia. Inclusion of alcohol induced a more inflammatory and fibrogenic phenotype.NEW & NOTEWORTHY Alcoholic liver disease and nonalcoholic liver disease share significant overlap, which suggests the existence of metabolic steatohepatitis. Trans fat has been implicated in steatohepatitis development. Here, we show that the addition of trans fat to an atherogenic diet results in a more steatotic but less inflammatory phenotype, whereas the addition of alcohol to an atherogenic diet augments the inflammatory and fibrogenic properties of the diet.

Markers of Basement Membrane Remodeling Are Associated With Higher Mortality in Patients With Known Atherosclerosis

Background Patients with atherosclerosis have a high risk of cardiovascular events and death. Atherosclerosis is characterized by accumulation of lipids, cells and extracellular matrix proteins in the intima. We hypothesized that dysregulated remodeling of the basement membrane proteins may be associated with clinical outcomes in patients with atherosclerosis. Methods and Results Neoepitope fragments of collagen type IV (C4M) and laminin ( LG 1M) were assessed by ELISA s in serum from 787 endarterectomy patients. Matrix metalloproteinase s were measured using proximity extension assay and correlated to C4M and LG 1M levels using Spearman correlations. A total of 473 patients were followed up for 6 years using national registers, medical charts, and telephone interviews. The incidence of cardiovascular events, cardiovascular mortality, and all-cause mortality were associated to levels of C4M and LG 1M using Kaplan-Meier curves and Cox regression analyses. A total of 101 patients had cardiovascular events, 39 died of cardiovascular mortality, and 64 patients died from all-cause mortality. C4M levels were increased in patients with symptomatic carotid atherosclerotic disease before surgery ( P=0.048). High C4M and LG 1M levels were associated with increased risk of all-cause mortality ( P=0.020 and 0.031, respectively) and predicted all-cause death together with glomerular filtration rate and diabetes mellitus. Conclusions High LG 1M and C4M levels were associated with all-cause mortality, together with glomerular filtration rate and diabetes mellitus. These novel biomarkers need further evaluation but might be tools to identify high-risk patients.

3046High levels of MMP-cleaved mimecan is associated to carotid plaque stability and less future cardiovascular events

Introduction

The clinical consequences of atherosclerosis, myocardial infarction and stroke are the most common causes of death globally. Mimecan, a small leucine rich-repeat proteoglycan (SLRP), is cleaved by matrix metalloproteinases (MMPs) and known to be involved in collagen fibrillogenesis and angiogenesis. Circulating levels of MMP-cleaved mimecan (cMIM) has previously been identified as a marker of extracellular matrix remodelling in ApoE−/− knockout mice. The role of mimecan and its degradation in human atherosclerotic plaques has not been explored.

Purpose

We explored whether full-length mimecan and cleaved mimecan (cMIM) are associated to plaque composition and evaluated if they can predict future cardiovascular events.

Methods

Two hundred and eighteen human atherosclerotic plaques were stained for mimecan using immunohistochemistry. cMIM was measured in 202 plaque tissue homogenates using a competitive ELISA assay. Histological components (α-actin, CD68 and glycophorin A) were assessed using immunohistochemistry, neutral lipids were measured using Oil Red O and visible areas of calcium deposits were quantified. Matrix metalloproteinases (MMP-1, -2, -3, -9, -10 and -12), tissue inhibitors of matrix metalloproteinases (TIMP-1 and -2) were analysed in plaque tissue homogenates using ELISA assays and a proximity extension assay. ECM components (glycosaminoglycans, collagen and elastin) were detected with colorimetric assays and the TGF-β1, β2 and β3 were measured by a multiplex assay. Cardiovascular events were registered using national registers, patient records and telephone calls during a follow-up period of 59 months IQR (34–73).

Results

Mimecan was expressed in human atherosclerotic plaques. The expression correlated positively with neutral lipids and intraplaque hemorrhage and inversely with α-actin. In contrast cMIM correlated with α-actin and inversely with neutral lipids. cMIM correlated also with stabilizing extracellular matrix proteins elastin, collagen as well as TGF-β1, β2 and β3. Mimecan correlated to MMP-9 and cMIM correlated to MMP-2 and TIMP-2. Patient with high levels of cMIM had a lower risk of future cardiovascular events which remained significant after adjusting for risk factors (age, gender, diabetes and symptoms) in a multivariate Cox regression

Conclusion(s)

Mimecan was associated with vulnerable plaque features, whereas cMIM was related to stable plaque features. Low levels of cMIM predicted future cardiovascular events, independently of known risk factors. Taken together this suggests a possible role for mimecan and its cleavage in atherosclerosis that needs to be further explored.

Acknowledgement/Funding

Danish Research Foundation, Swedish Research Council, Swedish Heart and Lung Foundation, Skåne University Hospital and more.

Improvement of non-invasive markers of NAFLD from an individualised, web-based exercise program

BACKGROUND

Lifestyle modifications remain the cornerstone of treatment in non-alcoholic fatty liver disease (NAFLD). However, they requently fail related to the inability of patients to implement lasting changes.

AIMS

To evaluate the effects of a short, web-based, individualised exercise program on non-invasive markers of hepatic steatosis, inflammation and fibrosis.

METHODS

Patients with histologically confirmed NAFLD underwent an 8-week, web-based, individualised exercise program that contained bidirectional feedback.

RESULTS

Forty-four patients entered the study and 41 completed the assigned training goal (93.2%). In the completer population, 8 weeks of individualised exercise increased the VO_2peak by 12.2% compared to baseline (P < .001). ALT and AST decreased by 14.3% (P = .002) and 18.2% (P < .001) and remained at this level until follow-up 12 weeks after the intervention. Markers of inflammation including hsCRP, ferritin, and M30 decreased. In parallel, gut microbiota exhibited increased metagenomic richness (P < .05) and at the taxonomic levels Bacteroidetes and Euryarchaeota increased whereas Actinobacteria phylum decreased. Surrogate scores of steatosis and fibrosis including the fatty liver index (FLI), FiB-4, APRI and transient elastography showed significant reductions. In parallel, a marker of procollagen-3 turnover (PRO-C3) decreased while C4M2, reflecting type IV collagen, degradation increased suggesting beneficial hepatic fibrosis remodelling from exercise. Also, an enhancement in health-related quality of life was reported.

CONCLUSION

The current study underlines the plausibility and potential of an 8 week individualised web-based exercise program in NAFLD. Clinical trial number: NCT02526732.

Safety profile of autologous macrophage therapy for liver cirrhosis

Therapies to reduce liver fibrosis and stimulate organ regeneration are urgently needed. We conducted a first-in-human, phase 1 dose-escalation trial of autologous macrophage therapy in nine adults with cirrhosis and a Model for End-Stage Liver Disease (MELD) score of 10-16 (ISRCTN 10368050). Groups of three participants received a single peripheral infusion of 10⁷, 10⁸ or up to 10⁹ cells. Leukapheresis and macrophage infusion were well tolerated with no transfusion reactions, dose-limiting toxicities or macrophage activation syndrome. All participants were alive and transplant-free at one year, with only one clinical event recorded, the occurrence of minimal ascites. The primary outcomes of safety and feasibility were met. This study informs and provides a rationale for efficacy studies in cirrhosis and other fibrotic diseases.

Biomarkers of collagen synthesis predict progression in the PROFILE idiopathic pulmonary fibrosis cohort

Idiopathic pulmonary fibrosis (IPF) is characterised by excessive extracellular matrix (ECM) deposition and remodelling. Measuring this activity provides an opportunity to develop tools capable of identifying individuals at-risk of progression. Longitudinal change in markers of ECM synthesis was assessed in 145 newly-diagnosed individuals with IPF.Serum levels of collagen synthesis neoepitopes, PRO-C3 and PRO-C6 (collagen type 3 and 6), were elevated in IPF compared with controls at baseline, and progressive disease versus stable disease during follow up, (PRO-C3 p < 0.001; PRO-C6 p = 0.029). Assessment of rate of change in neoepitope levels from baseline to 3 months (defined as 'slope to month 3': HIGH slope, slope > 0 vs. LOW slope, slope < =0) demonstrated no relationship with mortality for these markers (PRO-C3 (HR 1.62, p = 0.080); PINP (HR 0.76, p = 0.309); PRO-C6 (HR 1.14, p = 0.628)). As previously reported, rising concentrations of collagen degradation markers C1M, C3M, C6M and CRPM were associated with an increased risk of overall mortality (HR = 1.84, CI 1.03-3.27, p = 0.038, HR = 2.44, CI 1.39-4.31, p = 0.002; HR = 2.19, CI 1.25-3.82, p = 0.006; HR = 2.13 CI 1.21-3.75, p = 0.009 respectively).Elevated levels of PRO-C3 and PRO-C6 associate with IPF disease progression. Collagen synthesis and degradation biomarkers have the potential to enhance clinical trials in IPF and may inform prognostic assessment and therapeutic decision making in the clinic.

Circulating levels of PRO-C3 reflect liver fibrosis and liver function in HIV positive patients receiving modern cART

Background and aims

Although combined antiretroviral treatment (cART) has improved overall survival of HIV infected patients, liver fibrosis and liver related-mortality still constitute major challenges in HIV positive patients. Collagen accumulates in the liver during fibrogenesis. Recent studies showed that circulating levels of extracellular matrix (ECM) fragments might reflect degree of portal hypertension and fibrosis stage in liver disease. In this study, we analyzed the correlation between liver fibrosis assessed by Fibroscan and levels of the formation and degradation markers of type III and IV collagen in HIV positive patients receiving cART.

Methods

116 HIV positive patients (82.7% male, median age 47 years) were enrolled into the study. Liver stiffness and liver fat content were determined using a Fibroscan with integrated CAP function. We quantified ECM formation and degradation fragments of collagen III and IV: PRO-C3, PRO-C4, C3M and C4M. These fragments were measured in peripheral serum by using specific ELISAs.

Results

Fifteen (12.9%) out of the 116 HIV positive patients had relevant fibrosis with a liver stiffness ≥ 7.1 kPa, and 79 patients had relevant steatosis with a CAP value > 248 dB/m. Circulating PRO-C3 levels significantly correlated with increasing degree of liver fibrosis assessed by Fibroscan (p = 0.0005), as well as with APRI score (p = 0.015). Interestingly, circulating PRO-C3 levels were significantly correlated with bilirubin (p = 0.022), reduced platelet count (p = 0.0008) and low albumin levels (p = 0.001), suggesting the association of type III collagen deposition with impaired liver function. None of the other measured ECM components significantly correlated with fibrosis or steatosis.

Conclusion

The formation marker of type III collagen, PRO-C3 not only reflects liver fibrosis, but might also mirror liver dysfunction in HIV positive patients receiving cART. Therefore, the circulating levels of PRO-C3 might be suitable to monitor progression of liver fibrosis and deterioration of liver function in HIV positive patients receiving cART.

Collagen Formation Assessed by N-Terminal Propeptide of Type 3 Procollagen Is a Heritable Trait and Is Associated With Liver Fibrosis Assessed by Magnetic Resonance Elastography

N-terminal propeptide of type 3 procollagen (PRO-C3) is a biomarker of liver fibrosis in nonalcoholic fatty liver disease (NAFLD). This study examines the association between PRO-C3 concentration and liver fibrosis assessed by magnetic resonance elastography (MRE)-measured stiffness (MRE-stiffness) and the heritability of PRO-C3 concentration in a cohort of twins and families with and without NAFLD. We performed a cross-sectional analysis of a well-characterized prospective cohort of 306 participants, including 44 probands with NAFLD-cirrhosis and their 72 first-degree relatives, 24 probands with NAFLD without advanced fibrosis and their 24 first-degree relatives, and 72 controls without NAFLD and their 72 first-degree relatives. Liver steatosis was assessed by magnetic resonance imaging proton density fat fraction, and liver fibrosis was assessed by MRE-stiffness. Serum PRO-C3 was assessed by competitive, enzyme-linked immunosorbent assay. We assessed the familial correlation of PRO-C3 concentration, the shared gene effects between PRO-C3 concentration and liver steatosis and fibrosis, and the association between PRO-C3 concentration and genetic variants in the patatin-like phospholipase domain-containing 3 (PNPLA3), transmembrane 6 superfamily member 2 (TM6SF2), membrane-bound O-acyltransferase domain-containing (MBOAT), and glucokinase regulator (CGKR) genes. In multivariable-adjusted models including age, sex, body mass index, and ethnicity, serum PRO-C3 correlated strongly with liver fibrosis (r²  = 0.50, P < 0.001) and demonstrated robust heritability (h² , 0.36; 95% confidence interval [CI], 0.07, 0.59; P = 0.016). PRO-C3 concentration and steatosis had a strong genetic correlation (shared genetic determination: 0.62; 95% CI, 0.236, 1.001; P = 0.002), whereas PRO-C3 concentration and fibrosis had a strong environmental correlation (shared environmental determination: 0.55; 95% CI, 0.317, 0.717; P < 0.001). PRO-C3 concentrations were higher in carriers of the TM6SF2 rs58542926-T allele compared with noncarriers: 15.7 (± 10.5) versus 10.8 (± 5.7) ng/L (P = 0.047). Conclusion: Serum PRO-C3 correlates with MRE-assessed fibrosis, is heritable, shares genetic correlation with liver steatosis and shares environmental correlation with liver fibrosis. PRO-C3 concentration appears to be linked to both fibrosis and steatosis and increased in carriers of the TM6SF2 rs58542926 risk allele.

ADAPT: An Algorithm Incorporating PRO-C3 Accurately Identifies Patients With NAFLD and Advanced Fibrosis

Given the high global prevalence of nonalcoholic fatty liver disease (NAFLD), the need for relevant noninvasive biomarkers and algorithms to accurately stage disease severity is a critical unmet medical need. Identifying those with advanced fibrosis (≥ F3) is the most crucial, as these individuals have the greatest risk of adverse, long-term, liver-related outcomes. We aimed to investigate the role of PRO-C3 (a marker of type III collagen formation) as a biomarker for advanced fibrosis in NAFLD. We measured PRO-C3 by enzyme-linked immunosorbent assay in two large independent cohorts with extensive clinical phenotyping and liver biopsy: 150 in the derivation and 281 in the validation cohort. A PRO-C3-based fibrosis algorithm that included age, presence of diabetes, PRO-C3, and platelet count (ADAPT) was developed. PRO-C3 increased with fibrosis stage (Rho 0.50; P < 0.0001) and was independently associated with advanced fibrosis (odds ratio = 1.05; 95% confidence interval [CI] 1.02-1.08; P = 0.003). ADAPT showed areas under the receiver operating characteristics curve of 0.86 (95% CI 0.79-0.91) in the derivation and 0.87 in the validation cohort (95% CI 0.83-0.91) for advanced fibrosis. This was superior to the existing fibrosis scores, aspartate aminotransferase to platelet ratio index (APRI), FIB-4, and NAFLD fibrosis score (NFS) in most comparisons. Conclusion: PRO-C3 is an independent predictor of fibrosis stage in NAFLD. A PRO-C3-based score (ADAPT) accurately identifies patients with NAFLD and advanced fibrosis and is superior to APRI, FIB-4, and NFS.

Effect of NGM282, an FGF19 analogue, in primary sclerosing cholangitis: A multicenter, randomized, double-blind, placebo-controlled phase II trial

BACKGROUND & AIMS

Primary sclerosing cholangitis (PSC) is an inflammatory, cholestatic and progressively fibrotic liver disease devoid of effective medical intervention. NGM282, an engineered, non-tumorigenic FGF19 analogue, potently regulates CYP7A1-mediated bile acid homeostasis. We assessed the activity and safety of NGM282 in patients with PSC.

METHODS

In this double-blind, placebo-controlled phase II trial, 62 patients who had PSC confirmed by cholangiography or biopsy and an elevated alkaline phosphatase (ALP) >1.5 × the upper limit of normal were randomly assigned 1:1:1 to receive NGM282 1 mg, 3 mg or placebo once daily for 12 weeks. The primary outcome was the change in ALP from baseline to week 12. Secondary and exploratory outcomes included changes in serum biomarkers of bile acid metabolism and fibrosis. Efficacy analysis was by intention-to-treat.

RESULTS

At 12 weeks, there were no significant differences in the mean change from baseline in ALP between the NGM282 and placebo groups, and therefore, the primary endpoint was not met. However, NGM282 significantly reduced levels of 7alpha-hydroxy-4-cholesten-3-one (a marker of hepatic CYP7A1 activity, LS mean differences -6.2 ng/ml (95% CI -10.7 to -1.7; p = 0.008) and -9.4 ng/ml (-14.0 to -4.9; p <0.001) in the NGM282 1 mg and 3 mg groups, respectively, compared with placebo) and bile acids. Importantly, fibrosis biomarkers that predict transplant-free survival, including Enhanced Liver Fibrosis score and Pro-C3, were significantly improved following NGM282 treatment. Most adverse events were mild to moderate in severity, with gastrointestinal symptoms more frequent in the NGM282 treatment groups.

CONCLUSIONS

In patients with PSC, NGM282 potently inhibited bile acid synthesis and decreased fibrosis markers, without significantly affecting ALP levels.

LAY SUMMARY

We present for the first time, the clinical and laboratory effects of a first-in-class, engineered analogue of the endocrine hormone FGF19 in patients with primary sclerosing cholangitis (PSC). By incorporating non-invasive markers of fibrosis, beyond standard liver injury markers, we show that NGM282 impacted on fibrosis turnover and hepatic inflammation without changing alkaline phosphatase. Our findings demonstrate the complexities of using highly potent rational agents in PSC, and furthermore challenge the dogma about what the appropriate endpoints should be for trials in PSC.

A biomarker of collagen type I degradation is associated with cardiovascular events and mortality in patients with atherosclerosis

OBJECTIVE

Atherosclerosis is characterized by accumulation of lipids, cells and extracellular matrix (ECM) proteins in the arterial wall. Collagen type I (COL1), a component of the arterial ECM, is cleaved by matrix metalloproteinases (MMPs) and known to be remodelled in atherosclerosis. We explored whether the MMP-mediated COL1 biomarker, C1M, was associated with cardiovascular events, cardiovascular mortality and all-cause mortality in a large prospective cohort of patients with known atherosclerosis.

METHODS

Serum from 787 patients who underwent a carotid endarterectomy was included. Circulating levels of C1M were measured in serum. A total of 473 patients were followed for 6 years after surgery. Associations between C1M and incidence of cardiovascular events, cardiovascular mortality and all-cause mortality were assessed by Kaplan-Meier curves and Cox regression analysis.

RESULTS

A total of 101 (21.4%) patients suffered from nonfatal cardiovascular events during the follow-up period, and 64 (13.5%) patients died. Of these, 39 (60.9%) died from cardiovascular diseases. Patients with C1M levels above the median were significantly associated with cardiovascular events, cardiovascular mortality and all-cause mortality (P < 0.001, P = 0.004 and P < 0.001, respectively). C1M was included in the final model for prediction of cardiovascular events (HR 2.15, 95% CI 1.40-3.32, P = 0.001), cardiovascular mortality (HR 2.20, 95% CI 1.07-4.51, P = 0.031) and all-cause mortality (HR 2.98 95% CI 1.67-5.33, P = < 0.001).

CONCLUSIONS

In patients with atherosclerotic carotid lesions, high levels of C1M predicted cardiovascular events, cardiovascular mortality and all-cause mortality. These findings emphasize the importance of remodelling mechanisms in atherosclerosis that are now becoming more and more explored.

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.

A serological marker of the N-terminal neoepitope generated during LOXL2 maturation is elevated in patients with cancer or idiopathic pulmonary fibrosis

Objectives

Lysyl oxidase like 2 (LOXL2) is associated with poor prognosis in idiopathic pulmonary disease (IPF) and cancer. We developed an Enzyme-linked immunosorbent assay (ELISA) targeting the LOXL2 neo-epitope generated through the release of the signal peptide during LOXL2 maturation.

Design and methods

An ELISA targeting the N-terminal site of the human LOXL2 was developed including technical optimization and validation steps. Serum LOXL2 was measured in patients with breast, colorectal, lung, ovarian, pancreatic and prostate cancer, melanoma, IPF and in healthy controls (n = 16).

Results

A technically robust and specific assay was developed. LOXL2 was detectable in serum from healthy controls and showed reactivity towards recombinant LOXL2. Compared to controls, LOXL2 levels were significantly (p < 0.001–0.05) elevated in serum from patients with breast, colerectal, lung, ovarian and pancreatic cancer (mean range: 49–84 ng/mL), but not in prostate cancer (mean: 36 ng/mL) and malignant melanoma patients (41 ng/mL). Serum LOXL2 was elevated in IPF patients compared to healthy controls (mean: 76.5 vs 46.8 ng/mL; p > 0.001)

Conclusions

A specific ELISA towards the N-terminal neo-epitope site in LOXL2 was developed which detected significantly elevated serum levels from patients with above-mentioned cancer types or IPF compared to healthy controls.

High turnover of extracellular matrix reflected by specific protein fragments measured in serum is associated with poor outcomes in two metastatic breast cancer cohorts

Increased extracellular matrix (ECM) formation and matrix metalloprotease (MMP)-mediated ECM degradation are parts of tumorgenesis and generates collagen fragments that are released into circulation. We evaluated the association of specific collagen fragments measured in serum with outcomes in two independent metastatic breast cancer (MBC) cohorts. ELISAs were used to measure C1M (MMP-generated type I collagen fragment), C3M (MMP-generated type III collagen fragment), C4M (MMP-generated type IV collagen fragment), and PRO-C3 (pro-peptide of type III collagen) in pretreatment serum from a phase 3 randomized clinical trial of second-line hormone therapy (HR+, n = 148), and a first-line trastuzumab-treated cohort (HER2+, n = 55). All sites of metastases were included. The collagen fragments were evaluated by Cox-regression analysis for their association with time-to-progression (TTP) and overall survival (OS). In the HR+ cohort, higher C1M and C3M levels (75th percentile cut-off) were associated with shorter TTP; all fragments were associated with shorter OS. In the HER2+ cohort, higher levels of all fragments were associated with shorter TTP; higher PRO-C3 was associated with shorter OS. In multivariate analysis of the HR+ trial for OS, higher levels of all fragments were significant for reduced OS when added separately (C1M HR = 2.1, p < 0.001; C3M HR = 1.8, p = 0.028; C4M HR = 1.8, p = 0.018; PRO-C3 HR = 1.8, p = 0.017); none other clinical covariates were significant. In conclusion, collagen fragments quantified in pretreatment serum was associated with shorter TTP and OS in two independent MBC cohorts receiving systemic therapy. If validated, quantification of ECM remodeling in serum has potential as prognostic and/or predictive biomarkers in MBC.

A STAT4 variant increases liver fibrosis risk in Caucasian patients with chronic hepatitis B

BACKGROUND

Host genetic modifiers of the natural history of chronic hepatitis B (CHB) remain poorly understood. Recently, a genome-wide association study (GWAS)-identified polymorphism in the STAT4 gene that contributes to the risk for hepatocellular carcinoma (HCC) was shown to be associated with the full spectrum of hepatitis B virus (HBV) outcomes in Asian patients. However, the functional mechanisms for this effect are unknown and the role of the variant in modulating HBV disease in Caucasians has not been investigated.

AIMS

To determine whether STAT4 genetic variation is associated with liver injury in Caucasian patients with CHB and to investigate potential mechanisms mediating this effect.

METHODS

STAT4 rs7574865 was genotyped in 1085 subjects (830 with CHB and 255 healthy controls). STAT4 expression in liver, PBMCs and NK cells, STAT4 phosphorylation and secretion of interferon-gamma (IFN-γ) according to STAT4 genetic variation was examined.

RESULTS

STAT4 rs7574865 genotype was independently associated with hepatic inflammation (OR: 1.42, 95% CI: 1.07-2.06, P = 0.02) and advanced fibrosis (OR: 1.83, 95% CI: 1.19-2.83, P = 0.006). The minor allele frequency of rs7574865 was significantly lower than that in healthy controls. rs7574865 GG risk carriers expressed lower levels of STAT4 in liver, PBMCs and in NK cells, while NK cells from patients with the risk genotype had impaired STAT4 phosphorylation following stimulation with IL-12/IL-18 and a reduction in secretion of IFN-γ.

CONCLUSION

Genetic susceptibility to HBV persistence, hepatic inflammation and fibrosis in Caucasians associates with STAT4 rs7574865 variant. Downstream effects on NK cell function through STAT4 phosphorylation-dependent IFN-γ production likely contribute to these effects.

A fragment of SPARC reflecting increased collagen affinity shows pathological relevance in lung cancer - implications of a new collagen chaperone function of SPARC

The matricellular protein SPARC (secreted proteome acidic and rich in cysteine) is known to bind collagens and regulate fibrillogenesis. Cleavage of SPARC at a single peptide bond, increases the affinity for collagens up to 20-fold. To investigate if this specific cleavage has pathological relevance in fibrotic disorders, we developed a competitive ELISA targeting the generated neo-epitope on the released fragment and quantified it in serum from patients with lung cancer, idiopathic pulmonary fibrosis (IPF), chronic obstructive pulmonary disease (COPD) and healthy subjects. Furthermore, the ability of SPARC to protect fibrillar collagens from proteolytic degradation was investigated in vitro, potentially adding a new collagen chaperone function to SPARC. The fragment was significantly elevated in lung cancer patients when compared to healthy subjects measured in a discovery cohort (p = 0.0005) and a validation cohort (p < 0.0001). No significant difference was observed for IPF and COPD patients compared to healthy subjects. When recombinant SPARC was incubated with type I or type III collagen and matrix metalloproteinase-9, collagen degradation was completely inhibited. Together, these data suggest that cleavage of SPARC at a specific site, which modulates collagen binding, is a physiological mechanism increased during pathogenesis of lung cancer. Furthermore, inhibition of fibrillar collagen degradation by SPARC adds a new chaperone function to SPARC which may play additional roles in the contribution to increased collagen deposition leading to a pro-fibrotic and tumorigenic environment.

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.

Development of a Neo-Epitope Specific Assay for Serological Assessment of Type VII Collagen Turnover and Its Relevance in Fibroproliferative Disorders

Type VII collagen is the main component of the anchoring fibrils connecting the basement membrane to the underlying interstitial matrix. Mutations in the type VII collagen gene cause dystrophic epidermolysis bullosa. Increased levels of type VII collagen in the skin have been reported in patients with systemic sclerosis (SSc), whereas reduced levels in the airways have been related to asthma. This indicates that type VII collagen plays an important part in upholding tissue integrity and that its remodeling may lead to pathological states. The aim of this study was to investigate the role of type VII collagen remodeling in fibroproliferative disorders. We produced monoclonal antibody targeting a specific fragment of type VII collagen (C7M) released to the systemic circulation and developed a neo-epitope specific competitive enzyme-linked immunosorbent assay (ELISA). Biological relevance was evaluated in serum from patients with SSc or chronic obstructive pulmonary disease (COPD). The C7M ELISA was technically robust and specific for the C7M neo-epitope. Serum C7M levels were significantly elevated in two cohorts of patients with SSc and in patients with COPD as compared with healthy individuals (P < 0.0001). The C7M ELISA enabled quantification of type VII collagen turnover in serum. Elevated serum C7M levels indicated that the turnover rate of type VII collagen was significantly increased in patients with SSc or COPD, suggesting a pathological role. Thus, the C7M ELISA may become useful in future investigations of type VII collagen turnover in fibroproliferative disorders, and it may prove a valuable tool for evaluating novel anti-fibrotic drugs.

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).

Biomarkers of collagen turnover are related to annual change in FEV1 in patients with chronic obstructive pulmonary disease within the ECLIPSE study

Background

Change in forced expiratory volume in one second (FEV₁) is important for defining severity of chronic obstructive pulmonary disease (COPD). Serological neoepitope markers of collagen turnover may predict rate of change in FEV₁.

Methods

One thousand COPD subjects from the observational, multicentre, three-year ECLIPSE (Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints) study (NCT00292552, trial registration in February 2006) were included. Matrix metalloproteinase (MMP)-generated fragments of collagen type I, and type VI (C1M and C6M) were assessed in month six serum samples. A random-coefficient model with both a random intercept and a random slope was used to test the ability of the markers to predict post-dose bronchodilator FEV₁ (PD-FEV₁) change over two years adjusting for sex, age, BMI, smoking, bronchodilator reversibility, prior exacerbations, emphysema and chronic bronchitis status at baseline.

Results

Annual change of PD-FEV₁ was estimated from a linear model for the two-year study period. Serum C1M and C6M were independent predictors of lung function change (p = 0.007/0.005). Smoking, bronchodilator reversibility, plasma hsCRP and emphysema were also significant predictors. The effect estimate between annual change in PD-FEV₁ per one standard deviation (1SD) increase of C1M and C6M was +10.4 mL/yr. and +8.6 mL/yr. C1M, and C6M, had a significant association with baseline FEV₁.

Conclusion

We demonstrated that markers of tissue turnover were significantly associated with lung function change. These markers may function as prognostic biomarkers and possibly as efficacy biomarkers in clinical trials focusing on lung function change in COPD.

Trial registration

NCT00292552, Retrospectively registered, trial registration in February 2006.

Electronic supplementary material

The online version of this article (10.1186/s12890-017-0505-4) contains supplementary material, which is available to authorized users.

The good and the bad collagens of fibrosis - Their role in signaling and organ function

Usually the dense extracellular structure in fibrotic tissues is described as extracellular matrix (ECM) or simply as collagen. However, fibrosis is not just fibrosis, which is already exemplified by the variant morphological characteristics of fibrosis due to viral versus cholestatic, autoimmune or toxic liver injury, with reticular, chicken wire and bridging fibrosis. Importantly, the overall composition of the ECM, especially the relative amounts of the many types of collagens, which represent the most abundant ECM molecules and which centrally modulate cellular functions and physiological processes, changes dramatically during fibrosis progression. We hypothesize that there are good and bad collagens in fibrosis and that a change of location alone may change the function from good to bad. Whereas basement membrane collagen type IV anchors epithelial and other cells in a polarized manner, the interstitial fibroblast collagens type I and III do not provide directional information. In addition, feedback loops from biologically active degradation products of some collagens are examples of the importance of having the right collagen at the right place and at the right time controlling cell function, proliferation, matrix production and fate. Examples are the interstitial collagen type VI and basement membrane collagen type XVIII. Their carboxyterminal propeptides serve as an adipose tissue hormone, endotrophin, and as a regulator of angiogenesis, endostatin, respectively. We provide an overview of the 28 known collagen types and propose that the molecular composition of the ECM in fibrosis needs careful attention to assess its impact on organ function and its potential to progress or reverse. Consequently, to adequately assess fibrosis and to design optimal antifibrotic therapies, we need to dissect the molecular entity of fibrosis for the molecular composition and spatial distribution of collagens and the associated ECM.

Cathepsin-S degraded decorin are elevated in fibrotic lung disorders - development and biological validation of a new serum biomarker

Background

Decorin is one of the most abundant proteoglycans of the extracellular matrix and is mainly secreted and deposited in the interstitial matrix by fibroblasts where it plays an important role in collagen turnover and tissue homeostasis. Degradation of decorin might disturb normal tissue homeostasis contributing to extracellular matrix remodeling diseases. Here, we present the development and validation of a competitive enzyme-linked immunosorbent assay (ELISA) quantifying a specific fragment of degraded decorin, which has potential as a novel non-invasive serum biomarker for fibrotic lung disorders.

Methods

A fragment of decorin cleaved in vitro using human articular cartilage was identified by mass-spectrometry (MS/MS). Monoclonal antibodies were raised against the neo-epitope of the cleaved decorin fragment and a competitive ELISA assay (DCN-CS) was developed. The assay was evaluated by determining the inter- and intra-assay precision, dilution recovery, accuracy, analyte stability and interference. Serum levels were assessed in lung cancer patients, patients with idiopathic pulmonary fibrosis (IPF), patients with chronic obstructive pulmonary disease (COPD) and healthy controls.

Results

The DCN-CS ELISA was technically robust and was specific for decorin cleaved by cathepsin-S. DCN-CS was elevated in lung cancer patients (p < 0.0001) and IPF patients (p < 0.001) when compared to healthy controls. The diagnostic power for differentiating lung cancer patients and IPF patients from healthy controls was 0.96 and 0.77, respectively.

Conclusion

Cathepsin-S degraded decorin could be quantified in serum using the DCN-CS competitive ELISA. The clinical data indicated that degradation of decorin by cathepsin-S is an important part of the pathology of lung cancer and IPF.

Nidogen-1 Degraded by Cathepsin S can be Quantified in Serum and is Associated with Non-Small Cell Lung Cancer

Loss of basement membrane (BM) integrity is typically associated with cancer. Nidogen-1 is an essential component of the BM. Nidogen-1 is a substrate for cathepsin-S (CatS) which is released into the tumor microenvironment. Measuring nidogen-1 degraded by CatS may therefore have biomarker potential in cancer. The aim of this study was to investigate if CatS-degraded nidogen-1 was detectable in serum and a possible biomarker for cancer, a pathology associated with disruption of the BM. A competitive enzyme-linked immunosorbent assay (NIC) was developed with a monoclonal mouse antibody specific for a CatS cleavage site on human nidogen-1. Dilution and spiking recovery, inter- and intravariation, as well as accuracy were evaluated. Serum levels were evaluated in patients with breast cancer, small cell lung cancer (SCLC), and non-SCLC (NSCLC) and in healthy controls. The results indicated that the NIC assay was specific for nidogen-1 cleaved by CatS. Inter- and intraassay variations were 9% and 14%, respectively. NIC was elevated in NSCLC as compared to healthy controls (P<.001), breast cancer (P<.01), and SCLC (P<.5). The diagnostic power (area under the receiver operating characteristics) of NIC for NSCLC as compared to all other samples combined was 0.83 (95% confidence interval: 0.71-0.95), P<.0001. In conclusion, nidogen-1 degraded by CatS can be quantified in serum by the NIC assay. The current data strongly suggest that cathepsin-S degradation of nidogen-1 is strongly associated with NSCLC, which needs validation in larger clinical cohorts.

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.