Distinct immunometabolic signatures in circulating immune cells define disease outcome in acute-on-chronic liver failure.

Abstract

Acute-on-chronic liver failure (ACLF) is a complication of cirrhosis characterized by multiple organ failure and high short-term mortality. The pathophysiology of ACLF involves elevated systemic inflammation leading to organ failure, along with immune dysfunction that heightens susceptibility to bacterial infections. However, it is unclear how these aspects are associated with recovery and non-recovery in ACLF. Here we mapped the single-cell transcriptome of circulating immune cells from ACLF-, acute decompensated (AD) cirrhosis patients and healthy individuals. We further interrogate how these findings as well as immunometabolic- and functional profiles associate with ACLF recovery (ACLF-R) or non-recovery (ACLF-NR). Our analysis unveiled two distinct states of classical monocytes (cMon). Hereto, ACLF-R cMons were characterized by transcripts associated with immune- and stress tolerance, including anti-inflammatory genes such as RETN and LGALS1. Additional metabolomic- and functional validation experiments implicated an elevated oxidative phosphorylation metabolic program as well as an impaired ACLF-R cMon functionality. Interestingly, we observed a common stress-induced tolerant state, oxidative phosphorylation program and blunted activation among lymphoid populations in ACLF-R patients. Conversely, ACLF-NR cMon featured elevated expression of inflammatory- and stress response genes such as VIM, LGALS2, and TREM1 along with blunted metabolic activity and increased functionality. This study identifies distinct immuno-metabolic cellular states that contribute to disease outcome in ACLF patients. Our findings provide valuable insights into the pathogenesis of ACLF, shedding light on factors driving either recovery or non-recovery phenotypes which may be harnessed as potential therapeutic targets in the future.