Value of C-reactive protein, white blood cells and neutrophils to distinguish appendicitis in pediatric patients

Abstract The value for ordering laboratory tests like CRP for appendicitis in children is debatable. The objective of this study was to determine the diagnostic utility of CRP, WBC, and NP to differentiate acute and perforated appendicitis. A retrospective cohort study of pediatric patients referred for appendicitis at CHEO from January 2016 to January 2019 was conducted. Comparisons of laboratory test results were made using the Wilcoxon rank sum test. ROC curves were used to examine diagnostic utility. One hundred and eighty (101 male) of 899 children with appendicitis had CRP, WBC, and NP levels available with a median age of 11.1 (8.1, 13.7) years. There were 93 (51.7%) patients with acute appendicitis and 87 (48.3%) were perforated. The median CRP level for patients with acute appendicitis was 20.3 (6.9, 38.3) versus 65.3 (48.7, 180.8) for perforated appendicitis (p <0.001). The area under the ROC curve for CRP was 85.1 % (95% C.I. 79.5-90.7), higher than that of WBC’s 68.1 % (95% C.I. 60.1- 76.1). Our study demonstrates that CRP can achieve good sensitivity without compromising specificity. These findings suggest that CRP performs better than WBC and NP in terms of discriminating between acute versus perforated appendicitis.