Early Biomarker Signatures in Acute Pancreatitis: Predicting Severity Using Interleukin-6, Procalcitonin, High-Sensitivity C-reactive Protein, and D-Dimer

Background and Objectives: Acute pancreatitis (AP) is a pancreatic inflammatory disorder that may present as a mild, self-limiting illness or progress to severe systemic disease. Early recognition of severe forms is essential to reduce morbidity and mortality. This study evaluated the performance of serum interleukin-6 (IL-6), procalcitonin (PCT), high-sensitivity C-reactive protein (hs-CRP), and D-dimer in predicting disease severity and compared these biomarkers with established clinical scoring systems. Materials and Methods: In this prospective and observational study, 164 patients with AP were enrolled within 48 h of hospital admission. Biomarker levels were measured on admission and disease severity was classified according to the Revised Atlanta Classification. Ranson’s score, Acute Physiology and Chronic Health Evaluation II (APACHE II), bedside index for severity in AP (BISAP), and modified computed tomography severity index (MCTSI) were calculated. Receiver operating characteristic (ROC) curves were used to assess predictive performance. Results: All four biomarkers and scoring systems demonstrated excellent accuracy in predicting moderately severe AP (SAP) and SAP. IL-6 had the highest biomarker performance (area under the ROC curve [AUC] 0.986), closely matching MCTSI (AUC 0.993), the best-performing scoring system. D-dimer (AUC 0.955) and hs-CRP (AUC 0.971) outperformed BISAP (AUC 0.908) and APACHE II (AUC 0.940), while PCT (AUC 0.932) achieved perfect specificity (100%). Overall, IL-6 provided the most balanced accuracy. Conclusions: Serum IL-6, PCT, hs-CRP, and D-dimer, particularly IL-6, can accurately predict severe disease early in the course of AP and perform comparably to standard scoring systems. Integrating these biomarkers into early evaluation protocols could improve risk stratification in clinical practice.