Diagnostic Accuracy of Serum Procalcitonin, C-Reactive Protein and White Blood Cell Count in Differentiating Uncomplicated versus Complicated Acute Appendicitis

Abstract

Background: Acute appendicitis is a common surgical emergency. The ability to differentiate between uncomplicated and complicated appendicitis early in the disease process is important as complicated appendicitis is associated with perforation, abscess, peritonitis, longer hospital stay, and higher post-operative complications. Preoperative assessment of the severity of appendicitis may be aided by inflammatory markers such as serum procalcitonin, C-reactive protein, and white blood cell count.

Objective: To assess and compare the diagnostic value of serum procalcitonin, C-reactive protein and white blood cell count in distinguishing uncomplicated acute appendicitis from complicated acute appendicitis.

Methods: This cross-sectional analytical study was performed in the Department of General Surgery, Pir Abdul Qadir Shah Jeelani Institute of Medical Sciences, Gambat, Sindh from 1^st August 2025 to 31^st January 2026. One hundred patients between 15 and 60 years of age with a clinical diagnosis of acute appendicitis who were operated on by consecutive sampling were enrolled. Serum procalcitonin, C-reactive protein and white blood cell count were determined preoperatively. Uncomplicated and complicated appendicitis were defined by surgery and histopathology. SPSS version 26.0 was used for the statistical analysis.

Results: Among the 100 patients, 58 (58.0%) had uncomplicated appendicitis and 42 (42.0%) had complicated appendicitis. Patients with complicated appendicitis were older, had longer duration of symptoms, and had more fever, guarding, and rebound tenderness. The average white blood cell count, C-reactive protein and procalcitonin were significantly elevated in complicated appendicitis (p<0.001). Serum procalcitonin had the best diagnostic performance (sensitivity, 85.7%; specificity, 87.9%; positive predictive value, 83.7%; negative predictive value, 89.5%; and accuracy, 87.0%). C-reactive protein had intermediate diagnostic performance, while white blood cell count was the least accurate.

Conclusion: Procalcitonin was the most accurate marker to distinguish complicated from uncomplicated acute appendicitis, followed by C-reactive protein and white blood cell count. This can be used in the preoperative period for early risk assessment and surgical planning.