Abstract
Background and aims: Metabolic dysfunction-associated steatotic liver disease (MASLD) is a leading cause of chronic liver disease, often progressing to fibrosis and up to cirrhosis. Platelet activation plays a potential role in MASLD progression, but its functional profile across disease stages remains unclear. This study aimed to characterise the platelet functional profile and phenotype in patients with MASLD ≤ F2 and F3-F4 fibrosis compared to healthy controls. Methods: We analysed biomarkers of in vivo platelet activation, including urinary 11-dehydro-thromboxane B2 (11-dh-TXB2) and plasma soluble P-selectin. Platelet phenotype was assessed via microfluidic assays and flow cytometry, evaluating adhesion and fibrinogen receptor activation and Annexin V. Patients were stratified according to liver stiffness measurement (LSM) into low fibrosis MASLD (≤ F2) and advanced fibrosis/cirrhosis (F3-F4). Results: Urinary 11-dh-TXB2 was comparable between control and the ≤ F2 patients (median difference: 7365 ng/g creatinine, 95% CI: 5257-8764); higher values were observed in F3-F4 patients, with levels significantly elevated compared to controls (6931 ng/g creatinine, 95% CI: 5290-8363). Plasma soluble P-selectin followed a similar trend. Platelet phenotype MASLD ≤ F2 patients exhibited increased adhesiveness (median difference: 289.8 a.u., 95% CI: 195.8-458.2) and displayed procoagulant activity through binding of Annexin V, whereas F3-F4 patients showed increased adhesiveness (median difference: 361.1 a.u., 95% CI: 163.4-530.4) and reduced fibrinogen receptor activation. Conclusions: Platelet activation markers correlate with fibrosis severity, highlighting their potential role in disease progression. MASLD ≤ F2 is associated with increased platelet adhesiveness, whereas F3-F4 is characterised by impaired platelet reactivity despite high activation markers. These findings support the involvement of platelets in MASLD fibrosis progression and suggest their potential as biomarkers or therapeutic targets. Impact and implications: This study provides a robust scientific rationale for further exploring platelet dynamics as both biomarkers and potential therapeutic targets in MASLD, by demonstrating distinct platelet functional profiles between early (MASLD ≤ F2) and advanced fibrosis (F3-F4). The observed increase in platelet adhesiveness and procoagulant activity in early MASLD, contrasted with a reduced reactivity in advanced stages despite elevated activation markers, is critical for clinicians and researchers aiming to refine risk stratification and optimise treatment strategies. These findings could be practically applied by guiding physicians in monitoring platelet activation markers to identify patients at higher risk of fibrosis progression and by informing the development of targeted antiplatelet interventions. However, given the cross-sectional design of the study and its inherent methodological limitations, these implications warrant cautious interpretation and further validation through longitudinal research. Trial registration: 1612CESC.