Meiqian Hu, Maria Pilar Ballester, Anindro Bhattacharya, Ferran Aguilar, François Fenaille, Cristina Sánchez-Garrido, Richard Moreau, Vicente Arroyo, Victor Vargas Blasco, Wim Laleman, Joan Clària, Jonel Trebicka, Juan Antonio Carbonell-Asins, Christopher F. Rose, Rajiv Jalan.
Background and aims: Overt hepatic encephalopathy (OHE) is a severe neuropsychiatric complication of decompensated cirrhosis. Beyond hyperammonemia, increasing evidence suggests that systemic immune dysregulation and metabolic alterations contribute to its pathogenesis. We aimed to characterize the immune-metabolic landscape associated with OHE using integrative multi-omics analyses. Method: Transcriptomic profiling was performed in 78-patients with decompensated cirrhosis from the PREDICT cohort, comparing patients with OHE and age- and sex-matched non-OHE controls (1:2). Differential expression, pathway enrichment (GO and KEGG), and gene set enrichment analyses were conducted. In a subset of 37-patients with paired transcriptomic and metabolomic data, integrative analyses were used to explore immune-metabolic interactions. Transcriptomic data from microglia and astrocytes isolated from bile duct ligation (BDL) and sham-operated mice were analyzed for supportive validation. Results: Whole blood transcriptomics revealed that OHE was characterized by robust activation of type I interferon signaling and innate antiviral responses, including upregulation of interferon-stimulated genes, RIG-I-like receptor signaling components, and chemokines involved in immune cell recruitment. Genes related to tryptophan metabolism (IDO1, IL4I1) were significantly upregulated. Gene set enrichment analysis further confirmed enhanced innate immune and interferon responses, accompanied by downregulation of pathways related to glial and astrocyte differentiation. Metabolomic profiling identified distinct metabolic alterations in OHE, with prominent enrichment of pathways related to carnitine synthesis, ammonia recycling, amino-acid and purine metabolism. Integrative correlation analysis demonstrated significant associations between interferon-related genes and metabolites involved in carnitine metabolism and the tryptophan-kynurenine pathway. In keeping with the systemic data, interferon-stimulated genes, including Mx1, were markedly upregulated in microglia and astrocytes from BDL mice. Conclusion: OHE is associated with a systemic type I interferon-driven immune activation coupled with metabolic reprogramming. These alterations may contribute to impaired glial homeostasis and neuroinflammation, providing important mechanistic insights into the pathogenesis of OHE and potential therapeutic targets related to type 1 interferon and tryptophan metabolism pathways.
