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

Serum biomarkers for liver fibrosis assessment

Liver fibrosis is the result of chronic liver injury of different etiologies produced by an imbalance between the synthesis and degeneration of the extracellular matrix and dysregulation of physiological mechanisms. Liver has a high regenerative capacity in the early stage of chronic diseases so a prompt liver fibrosis detection is important. Consequently, an easy and economic tool that could identify patients with liver fibrosis at the initial stages is needed. To achieve this, many non-invasive serum direct, such as hyaluronic acid or metalloproteases, and indirect biomarkers have been proposed to evaluate liver fibrosis. Also, there have been developed formulas that combine these biomarkers, some of them also introduce clinical and/or demographic parameters, like FIB-4, non-alcoholic fatty liver disease fibrosis score (NFS), enhance liver fibrosis (ELF) or Hepamet fibrosis score (HFS). In this manuscript we critically reviewed different serum biomarkers and formulas for their utility in the diagnosis and progression of liver fibrosis.

Biomarcadores séricos para la evaluación de la fibrosis hepática

La fibrosis hepática se desarrolla como respuesta a la presencia de daño hepático crónico de diferentes etiologías, provocando un desequilibrio entre la síntesis y degeneración de la matriz extracelular y la desregulación de diversos mecanismos fisiológicos. En los estadios iniciales de las patologías crónicas, el hígado posee una elevada capacidad de regeneración, por lo que la detección temprana de la fibrosis hepática resulta esencial. En este contexto, es preciso contar con herramientas sencillas y económicas que permitan detectar la fibrosis hepática en sus fases iniciales. Para evaluar la fibrosis hepática, se han propuesto multitud de biomarcadores séricos no invasivos, tanto directos, como el ácido hialurónico o las metaloproteasas, como indirectos. Así mismo, se han desarrollado diversas fórmulas que combinan dichos biomarcadores junto con parámetros demográficos, como el índice FIB-4, el índice de fibrosis en la enfermedad de hígado graso no alcohólico (NFS, por sus siglas en inglés), la prueba ELF o el score de fibrosis Hepamet (HFS, por sus siglas en inglés). En el presente manuscrito, realizamos una revisión crítica del valor diagnóstico y pronóstico de los diferentes biomarcadores séricos y fórmulas actualmente existentes.

Alcohol-Related Liver Disease: Is There a Safe Alcohol Consumption Limit for Liver Disease?

This review is to evaluate how much alcohol is safe in the context of alcohol-related liver disease (ALD). In patients without an established diagnosis of ALD consuming alcohol at quantities below 12 to 20 g daily with alcohol-free days is associated with a very low risk of developing disease. This risk is mediated by the presence of cofactors such as sex, medical comorbidity, obesity, and genetic factors. A threshold effect below which liver disease will not occur is not seen, instead a dose-response relationship where risk ranges from low to high. Once ALD is present, natural history studies confirm that continued alcohol consumption is clearly associated with an increased risk of ill health and premature death. In conclusion, low-level alcohol consumption in the absence of liver disease is associated with a very small risk of developing ALD, but once ALD is present patients should be supported to achieve complete abstinence from alcohol.

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

Background & Aims

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

Methods

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

Results

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

Conclusions

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

Impact and Implications

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

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.

Stratification Of LIver Disease (SOLID): protocol for a prospective observational cohort study to determine the optimum biomarker strategies for the detection of advanced liver disease at the primary-secondary care interface

INTRODUCTION

Undiagnosed fatty liver disease is prevalent in the community, due to high rates of harmful alcohol consumption and/or obesity. Fatty liver disease can progress to cirrhosis and its complications. Early identification of liver disease and treatment may prevent progression to cirrhosis. Biomarkers including FIB-4, enhanced liver fibrosis (ELF), PRO-C3 and vibration controlled transient elastography (VCTE) can stage liver fibrosis, but it is not known how well they perform in a primary care population. Moreover, no assessment of long-term prognostic ability of these biomarkers has been conducted in primary care. We aim to evaluate the performance of fibrosis biomarkers in primary care to develop a pathway to detect advanced fibrosis.

METHODS AND ANALYSIS

This prospective, observational cohort study will recruit 3000 individuals with fatty liver disease risk factors (obesity, type 2 diabetes or hazardous alcohol consumption) at their primary care 'annual chronic disease review'. Participants will have a 'liver health check'. Two pathways will be evaluated: (1) all have FIB-4, ELF and VCTE performed, and (2) patients have an initial assessment with FIB-4 and ELF, followed by VCTE in only those with increased FIB-4 and/or ELF. Individuals with suspected significant/advanced liver fibrosis (liver stiffness measurement>8 kPa), will be reviewed in secondary care to confirm their fibrosis stage and institute treatment. The performance of FIB-4, ELF, PRO-C3, VCTE and novel biomarkers alone or in combination for advanced fibrosis/cirrhosis will be evaluated. Participants will be followed longitudinally via their electronic health records to assess long-term clinical outcomes.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the London-Chelsea Research Ethics Committee (22/PR/0535; 27 June 2022). Recruitment began on 31 October 2022. Outcomes of this study will be published in peer-reviewed journals and presented at scientific meetings. A lay summary of the results will be available for study participants and will be disseminated widely by LIVErNORTH.

Cross-Sectional and Longitudinal Performance of Non-Invasive Tests of Liver Fibrosis in Patients with Non-Alcoholic Fatty Liver Disease

Background and aims: Non-invasive tests (NITs) are needed in clinical practice to replace histology for the identification of liver fibrosis and prognostication in Non-Alcoholic Fatty Liver Disease (NAFLD). Novel collagen-derived fibrogenesis markers including N-terminal type III collagen pro-peptide (PRO-C3) are among the most promising tools in this field. The aim of this study was to assess the diagnostic accuracy of PRO-C3, the derivative ADAPT score, and other NITs for the identification of advanced fibrosis (stages 3-4) and changes over 12 months of follow-up. Methods: In this longitudinal study, 96 patients with biopsy-proven NAFLD were evaluated at baseline, of which 50 underwent a follow-up visit after 12 months. Clinical-biochemical parameters, liver stiffness (LS) by transient elastography, PRO-C3, and other NITs (ADAPT, FIB-4, NFS, APRI) were collected at baseline and follow-up. Results: LS showed the best accuracy for the identification of advanced fibrosis, with Area under the Receiving Operator Curve (AUROC) 0.82 (0.73-0.89) for a cut-off value of 9.4 kPa. Among the other NITs, the ADAPT score showed the best accuracy, with AUROC 0.80 (0.71-0.88) for a cut-off of 5.02 (Se 62%, Sp 89%, PPV 74%, NPV 83%). The comparison between the AUROC of LS with that of ADAPT was not statistically different (DeLong test p value 0.348). At follow-up, LS was slightly reduced, whilst PRO-C3 displayed a significant increase from baseline median 11.2 ng/mL to 13.9 ng/mL at follow-up (p = 0.017). Accordingly, ADAPT score increased from median 5.3 to 6.1 (p = 0.019). The other NITs did not significantly change over 12 months. Conclusions: The ADAPT score shows the best performance among non-invasive scores for the identification of advanced fibrosis, not different from LS. Collagen-derived biomarker PRO-C3 and the derivative score ADAPT display significant changes over time, and may be useful tools for monitoring the progression of liver disease or assessing responses to treatments.

Noninvasive proteomic biomarkers for alcohol-related liver disease

Alcohol-related liver disease (ALD) is a major cause of liver-related death worldwide, yet understanding of the three key pathological features of the disease-fibrosis, inflammation and steatosis-remains incomplete. Here, we present a paired liver-plasma proteomics approach to infer molecular pathophysiology and to explore the diagnostic and prognostic capability of plasma proteomics in 596 individuals (137 controls and 459 individuals with ALD), 360 of whom had biopsy-based histological assessment. We analyzed all plasma samples and 79 liver biopsies using a mass spectrometry (MS)-based proteomics workflow with short gradient times and an enhanced, data-independent acquisition scheme in only 3 weeks of measurement time. In plasma and liver biopsy tissues, metabolic functions were downregulated whereas fibrosis-associated signaling and immune responses were upregulated. Machine learning models identified proteomics biomarker panels that detected significant fibrosis (receiver operating characteristic-area under the curve (ROC-AUC), 0.92, accuracy, 0.82) and mild inflammation (ROC-AUC, 0.87, accuracy, 0.79) more accurately than existing clinical assays (DeLong's test, P < 0.05). These biomarker panels were found to be accurate in prediction of future liver-related events and all-cause mortality, with a Harrell's C-index of 0.90 and 0.79, respectively. An independent validation cohort reproduced the diagnostic model performance, laying the foundation for routine MS-based liver disease testing.

Increase in Serum MMP-9 and TIMP-1 Concentrations during Alcohol Intoxication in Adolescents-A Preliminary Study

Background: Alcohol consumption by adolescents is responsible for a number of adverse health and social outcomes. Despite the well-established effect of alcohol use on the development of alcoholic liver disease, the relationship between the pattern of alcohol consumption and liver fibrosis is still unclear. This study is a follow-up to work on liver damage from alcohol intoxication. The aim of our study was to explore the early effects of alcohol intoxication on liver fibrosis in adolescents. Methods: The prospective study included 57 adolescents aged 14−17 years admitted to the emergency department (ED) from February 2017 to June 2018 due to acute alcohol intoxication. Serum levels of amino terminal propeptide of type III procollagen (PIIINP), type IV collagen, matrix metallopeptidase 9 (MMP-9) and tissue inhibitor of metalloproteinase 1 (TIMP-1) were determined by enzyme-linked immunosorbent assays. Results: There were significant differences in MMP-9 (p = 0.02) and TIMP-1 (p = 0.007) levels between the study and control groups. Liver parameters and selected markers of fibrosis were similar in groups in terms of blood alcohol concentrations (BAC). MMP-9 was positively correlated with alanine aminotransferase (ALT) (r = 0.38; p = 0.004) and total bilirubin (r = 0.39; p = 0.004). Positive significant correlations were also found between TIMP-1 and ALT (r = 0.47; p < 0.001), AST (r = 0.29; p = 0.03) and total bilirubin (r = 0.32; p = 0.02). In receiver operating characteristic (ROC) analysis, MMP-9 (AUC = 0.67, p = 0.02) and TIMP-1 (AUC = 0.69, p = 0.003) allowed for the differentiation of patients with and without alcohol intoxication. Conclusion: Our results show that even a single episode of alcohol intoxication in adolescents can lead to imbalance in markers of fibrosis.

Principles of diagnosis and treatment of alcohol-induced liver fibrosis

Alcohol-related liver diseases are one of the leading causes of death worldwide, primarily due to complications of liver cirrhosis (LC). Early detection of alcohol-induced liver fibrosis (LF) is a difficult task, since often  alcoholic liver disease (ALD) is clinically manifested only at late stages. Given that not all alcoholic suffer from ALD, the widespread use of liver biopsy to verify the diagnosis is not advisable. Despite the variety of proposed non-invasive methods for assessing the severity of LF in patients with ALD, none of them has sufficient validation and therefore cannot be recommended for widespread use in clinical practice. The most well-studied transient elastography, due to its suboptimal specificity, can be effectively used only to exclude clinically significant LF or LC. The only proven approach to treat ALD is persistent and total alcohol abstinence. While the therapeutic options for patients with severe forms of acute hepatitis remain unchanged since the 70s of the last century and are based mainly on the use of corticosteroids, currently, there are no approaches to antifibrotic therapy of ALD approved by the guidelines. At the same time, modern achievements in understanding the pathophysiological mechanisms  of this disease  have served  as an impetus  for  the development  of ways to solve  the problem. In particular, providing intestinal eubiosis may be an important goal for the prevention and treatment of alcohol-induced LF. Randomized controlled multicenter trials involving a large number of patients are needed to confirm this and other hypotheses related to antifibrotic therapy of ALD and to accept them as a standard of medical care.

Diagnostic challenges in patients with alcohol-related liver disease

Alcohol is globally the leading risk factor for cirrhosis and is subsumed under the term alcohol-related liver disease (ALD). However, only ca. 10% of people with harmful alcohol consumption (>40 gram alcohol per day) develop cirrhosis, while 15% have normal liver histology. Unfortunately, laboratory parameters and ultrasound hold little value to neither rule-in nor rule out alcohol related liver fibrosis. While several indices with combinations of liver associated markers such as FIB4 seem to be promising, non-invasive test strategies are urgently needed with cut-off's that can be applied to guide clinical decision making. The aims of this review article are to highlight novel developments for the diagnosis of ALD and to identify topics of controversy and potential future directions. In the last 15 years, elastography to measure liver stiffness (LS) has significantly improved our screening strategies for cirrhosis. LS values below 6 kPa are considered as normal and exclude ALD. LS of 8 and 12.5 kPa represent generally accepted cut-off values for F3 and F4 fibrosis. Especially, transient elastography (TE) has been assessed in numerous studies, but similar performance can be obtained with point shear wave elastography, 2 SD shear wave elastography or MR elastography. Important confounders of elevated LS such as inflammation should also be considered and alcohol withdrawal not only improves liver inflammation but also LS. Liver stiffness measurement has signficiantly improved early diagnosis and follow-up of fibrosis in patients with ALD and patients with diagnosed manifest but clinically compensated cirrhosis should undergo further clinical examinations to rule out complications of portal hypertension. In addition, surveillance for the occurrence of hepatocellular carcinoma is recommended in all cirrhotic patients.

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.