Soluble factors and suppressive monocytes can predict early development of sepsis in acute-on-chronic liver failure

Patients with acute-on-chronic liver failure (ACLF) have a high probability of developing systemic inflammation and sepsis due to immune dysregulation. Fifty-nine patients with ACLF (12 without and 19 with systemic inflammation, and 28 with sepsis) were serially monitored for clinical and immunological changes at baseline, 6 hours, 24 hours, day 3, and day 7 following hospitalization. Ten healthy controls were also included. At all time points, soluble plasma factors and monocyte functions were studied. Patients with ACLF and systemic inflammation showed higher interleukin (IL)-6, vascular endothelial growth factor-a, monocyte chemoattractant protein 1, and macrophage inflammatory protein 1β than patients with no systemic inflammation. Patients with ACLF with sepsis had raised (p < 0.001) levels of IL-1Ra, IL-18, and triggering receptor expressed on myeloid cells 1 (TREM1) compared to patients with ACLF-systemic inflammation. Five of the 19 (26.3%) patients with systemic inflammation developed sepsis within 48-72 hours with a rapid rise in plasma levels of IL-1Ra (1203-35,000 pg/ml), IL-18 (48-114 pg/ml), and TREM1 (1273-4865 pg/ml). Monocytes of patients with ACLF with systemic inflammation and sepsis showed reduced human leukocyte antigen-DR but increased programmed death ligand 1 (PD-L1) and T-cell immunoglobulin and mucin domain-containing protein 3 (TIM3) (p < 0.04) expression with increased ETosis by monocytes at baseline and until day 7. Conclusion: High and rising levels of plasma IL-1Ra, IL-18, TREM1 soluble factors, and increased suppressive monocytes (PDL1^+ve , TIM3^+ve ) at baseline can stratify patients with ACLF at high risk of developing sepsis within 48-72 hours of hospitalization.