Evaluation of Procalcitonin Versus Conventional Inflammatory Biomarkers for Clinical Severity Grading in Patients with Intra-Abdominal Infection

Aim We aimed to evaluate the properties of procalcitonin (PCT) as a biomarker for clinical severity grading of intra-abdominal infections (IAI) in hospital-admitted patients presenting with acute abdomen. Methods In this retrospective study, median PCT values were compared with conventional inflammatory biomarkers, including leukocyte count (LC), neutrophil count (NC), and C-reactive protein (CRP), within the patient population. Results Among the 245 patients included in the study, 58 (23.7%) were diagnosed with appendicitis, 54 (22.0%) with diverticulitis, 34 (13.9%) with calculous cholecystitis, and 21 (8.6%) with pancreatitis. Additionally, 60 (24.5%) were diagnosed with non-specific abdominal pain (NSAP), and 18 (7.3%) with gallstones without cholecystitis. Median PCT levels were significantly higher in patients with calculous cholecystitis (p < 0.0001) and pancreatitis (p < 0.0001) compared to those with NSAP. The proportion of patients with a PCT cut-off ≥ 0.04 µg/L was significantly higher across all IAI subgroups compared to the NSAP group. However, 18 (10.8%) of IAI patients exhibited PCT levels ≥ 0.5 µg/L, indicating systemic infection. Spearman’s rho analysis revealed a significant correlation between PCT and LC, NC, and CRP in patients with IAI (p < 0.0001). Moreover, median PCT levels were significantly higher in perforation/abscess vs. gangrenous appendicitis (p < 0.01), complicated vs. uncomplicated diverticulitis (p = 0.048), and severe vs. mild cholecystitis (p < 0.001). Conclusion PCT correlates strongly with conventional inflammatory biomarkers in patients with IAI. However, PCT appears to offer limited additional clinical value for guiding therapeutic decisions concerning the initial diagnosis and/or severity grading of IAI in patients admitted with acute abdomen. Further research is warranted to validate these findings.