Dynamic Procalcitonin Trajectories Predict Adverse Outcomes in Acute-on-Chronic Pancreatitis

Background and objective Acute-on-chronic pancreatitis (ACP) is an increasingly recognized clinical entity associated with significant morbidity, prolonged hospitalization, and increased intensive care utilization. Early identification of high-risk patients remains challenging because conventional prognostic scoring systems are often time-consuming, complex, or insufficiently validated in ACP. Procalcitonin (PCT), a rapid inflammatory biomarker, has demonstrated prognostic utility in acute pancreatitis. However, evidence regarding its role in ACP remains limited. This study aimed to evaluate serial serum PCT levels in hospitalized patients with ACP from Northeast India. Methods This prospective observational study was conducted over one year at a tertiary care center and included 58 adult patients diagnosed with ACP based on the revised Atlanta classification criteria and imaging evidence of chronic pancreatitis (CP). Serial serum PCT levels were measured at admission and 48 hours later. Clinical outcomes, including mortality, ICU admission, organ dysfunction, local complications, and duration of hospitalization, were analyzed. Receiver operating characteristic (ROC) curve analysis was performed to assess the prognostic accuracy of PCT. Results Severe clinical outcomes were common, with mortality observed in 12.1% (n = 7) of patients, ICU admission in 60.3% (n = 35), and local pancreatic complications noted among 82.8% (n = 48) of the cases. Admission PCT demonstrated poor prognostic performance for mortality prediction (area under the curve (AUC): 0.555), with a sensitivity of 46.9% at a cutoff of 3.46 ng/mL. In contrast, 48-hour PCT showed excellent predictive accuracy, yielding an AUC of 0.992. A threshold value of 4.04 ng/mL achieved 100% sensitivity and 100% negative predictive value (NPV) for mortality prediction. Elevated PCT levels were significantly associated with ICU admission (p = 0.034), organ dysfunction (p = 0.021), local complications (p = 0.041), and prolonged hospitalization (r > 0.95). Conclusions Serial serum PCT assessment, particularly at 48 hours, is a reliable prognostic biomarker in ACP and may facilitate early risk stratification, optimized critical care allocation, and individualized clinical management.