Introduction
Patients with acute-on-chronic liver failure (ACLF) have traditionally been considered with a tendecy for bleeding however, they frequently display a paradoxical prothrombotic state. ACLF is characterized systemic inflammation and an increased risk of both bleeding and thrombosis. Bleeding arises from decreased pro-coagulation factors and platelet sequestration due to portal hypertension, while thrombosis is exacerbated by endothelial dysfunction and elevated heparinoids, thrombomodulin, or von Willebrand factor.
Aims & Methods
The aim of this study was to evaluate platelet aggregation pattern in patients with ACLF compared to acute decompensated (AD) liver cirrhosis.
The study took place in between the 1st of July 2024- 31st of January 2025 and we prospectively included cirrhotic patients, divided in two groups: ACLF group and AD group. The exclusion criteria were people with compensated liver cirrhosis, antiaggregant or anticoagulant treatment and patients with hepatocellular carcinoma or other malignancies. We investigated platelet aggregability in whole blood, by using multiplate aggregometry. For analysis, platelet aggregometry was performed induced by: adenosine diphosphate (ADP), arachidonic acid (ASPI), prostaglandin E2 (PGE2) and thrombin receptor-activated peptide (TRAP-6) as agonist were determined. TRAP‑6 is a peptide that stimulates protease-activated receptor 1 (PAR1) on platelet membrane.
Results
In this study we included 52 patients – 25 patients with ACLF and 27 patients with AD. There were no differences regarding demographic parameters and liver disease etiology between the two study groups. Compared to AD group, patients with ACLF showed an enhanced maximal platelet aggregation with TRAP-6 (AUC 85±12 U vs 45±10 U, p<0.0001). In contrast, we did not detect any differences in platelet aggregation between the two groups after ADP, ASPI or PGE2 activations. We observe that PAR-1 stimulation induces the highest aggregation curve and area under the curve in patients with ACLF and AD, but ACLF patients show the strongest response, highlighting that the degree of liver decompensation influences aggregation results. Severe decompensation correlates with a stronger TRAP response, suggesting that there are more PAR-1 receptors on platelets of this patients.
Conclusion
Our results indirectly indicate that platelet reactivity is higher in patients with ACLF likely due to enhanced PAR-1 receptor activity. Severe decompensation correlates with a stronger TRAP response, suggesting that there are more PAR-1 receptors on platelets of this patients.
References
1. EASL Clinical Practice Guidelines on acute on liver failure; J. Hepatol. 2023
2. Napolitano et al. European Journal of Internal Medicine 2017
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5. Nassar et al. BIOMEDICINES 2023
6. Rogalski et al. Scandinavian Journal of Gastroenterology 2019
7. Zanetto et al. Liver International 2022
8. Vecerzan et al. Cureus 2024
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