Metabolic Dysfunction-Associated Fibrosis 5 (MAF-5) Score Predicts Liver Fibrosis Risk and Outcome in the General Population With Metabolic Dysfunction.

BACKGROUND & AIMS: There is an unmet need for noninvasive tests to improve case-finding and aid primary care professionals in referring patients at high risk of liver disease. METHODS: A metabolic dysfunction-associated fibrosis (MAF-5) score was developed and externally validated in a total of 21,797 individuals with metabolic dysfunction in population-based (National Health and Nutrition Examination Survey 2017-2020, National Health and Nutrition Examination Survey III, and Rotterdam Study) and hospital-based (from Antwerp and Bogota) cohorts. Fibrosis was defined as liver stiffness ≥8.0 kPa. Diagnostic accuracy was compared with FIB-4, nonalcoholic fatty liver disease fibrosis score (NFS), LiverRisk score and steatosis-associated fibrosis estimator (SAFE). MAF-5 was externally validated with liver stiffness measurement ≥8.0 kPa, with shear-wave elastography ≥7.5 kPa, and biopsy-proven steatotic liver disease according to Metavir and Nonalcoholic Steatohepatitis Clinical Research Network scores, and was tested for prognostic performance (all-cause mortality). RESULTS: The MAF-5 score comprised waist circumference, body mass index (calculated as kg / m2), diabetes, aspartate aminotransferase, and platelets. With this score, 60.9% was predicted at low, 14.1% at intermediate, and 24.9% at high risk of fibrosis. The observed prevalence was 3.3%, 7.9%, and 28.1%, respectively. The area under the receiver operator curve of MAF-5 (0.81) was significantly higher than FIB-4 (0.61), and outperformed the FIB-4 among young people (negative predictive value [NPV], 99%; area under the curve [AUC], 0.86 vs NPV, 94%; AUC, 0.51) and older adults (NPV, 94%; AUC, 0.75 vs NPV, 88%; AUC, 0.55). MAF-5 showed excellent performance to detect liver stiffness measurement ≥12 kPa (AUC, 0.86 training; AUC, 0.85 validation) and good performance in detecting liver stiffness and biopsy-proven liver fibrosis among the external validation cohorts. MAF-5 score >1 was associated with increased risk of all-cause mortality in (un)adjusted models (adjusted hazard ratio, 1.59; 95% CI, 1.47-1.73). CONCLUSIONS: The MAF-5 score is a validated, age-independent, inexpensive referral tool to identify individuals at high risk of liver fibrosis and all-cause mortality in primary care populations, using simple variables.

Bariatric surgery post-liver transplantation: A Belgian nationwide study.

Weight gain poses a rising concern post-liver transplantation (LT), and metabolic dysfunction-associated steatotic liver disease might impair graft health. The timing is crucial when considering bariatric surgery (BS) in a population with liver disease or transplantation. BS can be considered for post-LT weight gain, although the evidence is limited and the long-term outcome still uncertain. We conducted a national retrospective analysis in 5 Belgian transplant centers and included 25 patients with an LT followed by a bariatric procedure. A total of 187 LT patients without BS were included for comparison. Clinical, biochemical, and outcome data were retrospectively retrieved. In our nationwide cohort, 25 patients had undergone BS post-LT, at a median 3.5 years after LT. Twenty-one (84.0%) patients received a sleeve gastrectomy (SG). Patients were predominantly male (72.0%), with a lower age at time of transplantation compared with the non-BS population (54.5 vs. 60.6, p <0.001). Weight loss was significant and sustained, with a decrease in body mass index from 41.0±4.5 pre-BS to 32.6±5.8 1-3 years post-BS ( p <0.001) and 31.1±5.8 3-5 years post-BS ( p <0.001). Three pre-BS (12.0%) patients presented with recurrent and one (4.0%) de novo metabolic dysfunction-associated steatotic liver disease after LT, with 100% resolution post-BS ( p =0.016). Notable reductions were observed in alanine transaminase levels (40.5±28.5 U/L to 27.1±25.1 U/L post-BS, p =0.05) and HbA1c levels (6.9±1.6 to 6.0±1.4 post-BS, p <0.001). Three patients were re-transplanted, and eight patients died, of which five (20.0%) due to a nonhepatic malignancy and one (4.0%) due to liver failure. SG is the favored BS post-LT and has proven to be safe and feasible in a post-LT setting with favorable metabolic consequences. SG post-LT is a valid treatment for de novo and recurrent metabolic dysfunction-associated steatotic liver disease post-LT. Although we report on the largest cohort to date, there is still a need for larger cohorts to examine the effect of BS on patient and graft survival.

MASLD/MASH and type 2 diabetes: Two sides of the same coin? From single PPAR to pan-PPAR agonists.

Type 2 diabetes (T2D) and metabolic dysfunction-associated steatotic liver disease (MASLD), mainly related to nutrition and lack of physical activity, are both very common conditions, share several disease pathways and clinical manifestations, and increasingly co-occur with disease progression. Insulin resistance is an upstream node in the biology of both conditions and triggers liver parenchymal injury, inflammation and fibrosis. Peroxisome proliferator-activated receptor (PPAR) nuclear transcription factors are master regulators of energy homeostasis - insulin signaling in liver, adipose and skeletal muscle tissue - and affect immune and fibrogenesis pathways. Among distinct yet overlapping effects, PPARα regulates lipid metabolism and energy expenditure, PPARß/δ has anti-inflammatory effects and increases glucose uptake by skeletal muscle, while PPARγ improves insulin sensitivity and exerts direct antifibrotic effects on hepatic stellate cells. Together PPARs thus represent pharmacological targets across the entire biology of MASH. Single PPAR agonists are approved for hypertriglyceridemia (PPARα) and T2D (PPARγ), but these, as well as dual PPAR agonists, have shown mixed results as anti-MASH treatments in clinical trials. Agonists of all three PPAR isoforms have the potential to improve the full disease spectrum from insulin resistance to fibrosis, and correspondingly to improve cardiometabolic and hepatic health, as has been shown (phase II data) with the pan-PPAR agonist lanifibranor.

Ferroptosis is a targetable detrimental factor in metabolic dysfunction-associated steatotic liver disease.

There is an unmet clinical need for pharmacologic treatment for metabolic dysfunction-associated steatotic liver disease (MASLD). Hepatocyte cell death is a hallmark of this highly prevalent chronic liver disease, but the dominant type of cell death remains uncertain. Here we report that ferroptosis, an iron-catalyzed mode of regulated cell death, contributes to MASLD. Unsupervised clustering in a cohort of biopsy-proven MASLD patients revealed a subgroup with hepatic ferroptosis signature and lower glutathione peroxidase 4 (GPX4) levels. Likewise, a subgroup with reduced ferroptosis defenses was discerned in public transcriptomics datasets. Four weeks of choline-deficient L-amino acid-defined high-fat diet (CDAHFD) induced MASLD with ferroptosis in mice. Gpx4 overexpression did not affect steatohepatitis, instead CDAHFD protected from morbidity due to hepatocyte-specific Gpx4 knockout. The ferroptosis inhibitor UAMC-3203 attenuated steatosis and alanine aminotransferase in CDAHFD and a second model, i.e., the high-fat high-fructose diet (HFHFD). The effect of monounsaturated and saturated fatty acids supplementation on ferroptosis susceptibility was assessed in human HepG2 cells. Fat-laden HepG2 showed a drop in ferroptosis defenses, increased phosphatidylglycerol with two polyunsaturated fatty acid (PUFA) lipid tails, and sustained ferroptosis sensitivity. In conclusion, this study identified hepatic ferroptosis as a detrimental factor in MASLD patients. Unexpectedly, non-PUFA supplementation to hepatocytes altered lipid bilayer composition to maintain ferroptosis sensitivity. Based on findings in in vivo models, ferroptosis inhibition represents a promising therapeutic target in MASLD.