Serum Procalcitonin as a Prognostic Biomarker in Acute Liver Failure: A Retrospective Cohort Study

Background: Acute liver failure (ALF) carries high mortality, and early prognostication remains challenging. We evaluated the prognostic value of serum procalcitonin (PCT) in ALF and its association with transplant‑free survival. Objectives: To investigate serum procalcitonin (PCT) as a prognostic marker for transplant‑free survival in patients with acute liver failure. Methods: We retrospectively analyzed 83 ICU patients (41 ALF; 42 major hepatectomy controls) between January 2021 and June 2025. All ALF patients received combined extracorporeal therapy—therapeutic plasma exchange (TPE) plus continuous venovenous hemodiafiltration (CVVHDF). Serum PCT was measured within 24 hours of admission and monitored throughout treatment. Results: Peak PCT (PCTmax) was associated with poor prognosis (liver transplantation or mortality): Area Under the Curve (AUC) 0.693 (P = 0.035); optimal cutoff 1.625 ng/mL (sensitivity 84.2%, specificity 63.6%). The transplant‑free survival rate following combined extracorporeal therapy was 53.7%. Conclusions: Serum PCT may serve as an adjunctive prognostic biomarker in ALF, interpreted alongside established scores (MELD, King’s College Criteria) rather than alone. Due to limited transplant events, the findings are hypothesis‑generating and require validation in independent cohorts.