Identification and validation of RIPK3 as a novel biomarker to predict outcomes in patients with acutely decompensated cirrhosis.

Background: In cirrhosis patients with acute decompensation (AD) and acute-on-chronic liver failure (ACLF) non-apoptotic forms of cell death predominate with increasing severity, which are potential targets of therapy. This study evaluated contribution of cell death markers in predicting organ dysfunctions, course, and outcomes in AD/ACLF.

Methods: A derivation cohort of AD patients (n=200, 153 with ACLF) was recruited. Plasma Cytokeratin-18 (M30: apoptosis, M65: total cell death), Receptor-Interacting Protein Kinase 3 (RIPK3), Mixed-Lineage Kinase-Like Protein (necroptosis), and Gasdermin-D (pyroptosis); were assessed at baseline and day-7. A mortality prediction model was developed and validated in three independent cohorts (n=106, 150, and 100). Liver biopsies from a fourth AD/ACLF cohort (n=21) were stained for cell death markers.

Results: The cell death markers increased with disease severity but RIPK3 levels showed the strongest link with it and multi-organ failures, particularly hepatic and renal (p<0.05, each). Higher baseline RIPK3 was independently associated with worsening disease course [adjusted OR: 4.85 (95%CI: 2.36-9.94), p<0.001] and mortality [adjusted OR: 4.74; (95%CI: 2.38-9.44), p<0.001]. Rising RIPK3 correlated with worsening course and mortality. A reduction was observed in those that improved and survived (p<0.001). A mortality prediction model, including RIPK3-ULN>2.261, CLIF-C OF, and leucocytosis/leucopoenia demonstrated high accuracy (AUC: 0.839) in the derivation cohort that was validated in two distinct cohorts (AUC: 0.752 and 0.794 respectively). Temporal evolution was validated in the third cohort (AUC: 0.796). Hepatic-RIPK1-expression was increased in patients with ACLF, and was associated with mortality in fourth cohort.

Conclusions: RIPK3-associated cell death is an important driver of organ failure and mortality in AD/ACLF. Integrating plasma RIPK3 into prognostic models would enhance risk stratification and may guide personalised cell death inhibitor therapy in AD/ACLF patients.

Impact And Implications: Our study underscores the pivotal role of Receptor-Interacting Protein Kinase 3 (RIPK3) as a biomarker in acute decompensation (AD) and acute-on-chronic liver failure (ACLF), linking its elevated levels with disease progression, organ dysfunction, and mortality. In liver biopsies, hepatic RIPK1 expression was significantly higher in ACLF than AD and correlated with disease severity and non-survival, supporting their hepatic origin. Through the integration of RIPK3 into predictive models, we provide a path towards personalized therapeutic strategies for AD by targeting necroptosis. This approach has the potential to revolutionize risk stratification, enhance clinical decision-making, and improve outcomes for these high-risk patients.

Lay Summary: Patients with cirrhosis can experience rapid and severe complications, leading to organ failure and death. This study identifies blood-based marker of cell death, especially, Receptor-Interacting Protein Kinase 3 (RIPK3), as a key factor driving disease progression and poor outcomes in these patients. Elevated levels of RIPK3 were linked to worsening organ dysfunction, especially liver and kidney failure, and higher mortality risk. Sicker patients had more RIPK in their liver, linking it to disease severity and poor outcomes. We developed and validated a prediction model incorporating plasma RIPK3 to improve risk assessment and guide treatment strategies. Our findings pave the way for personalized therapies targeting RIPK3-related cell death, offering hope for better outcomes in these critically ill patients.