The diagnostic value of interleukin-6, procalcitonin, and C-reactive protein in the severity of acute appendicitis in children.

BACKGROUND: Our aim was to explore the diagnostic potential of IL-6, PCT, and CRP for the severity of acute appendicitis (AA) in children. METHODS: We carried out a retrospective study on 412 children (≤ 18 years) with surgically - confirmed AA and 160 children with non-AA abdominal pain as controls (October 2024-September 2025). AA cases were divided into mild (simple/suppurative) and severe(gangrenous/perforated) types based on pathology. We compared the biomarkers (IL-6, PCT, CRP, WBC, N%) among groups and used ROC curves to evaluate their diagnostic performance. RESULTS: There were no significant differences in all indicators between the mild and the control group (all P > 0.05); all indicators in the severe group were higher than those in the control group (all P < 0.001); IL-6, PCT, and CRP in the severe group were higher than those in the mild group (all P < 0.001). IL-6 showed the best sensitivity (83.6%) with ROC AUC 0.776. CRP showed the best specificity (80.4%) with ROC AUC (0.774). An IL - 6 level > 21.7 pg/ml could independently predict severe AA. Combining the three biomarkers didn't improve diagnostic accuracy. CONCLUSION: IL-6, PCT, and CRP are useful for assessing AA severity in children, The diagnostic performance of IL-6 is comparable to that of CRP, but superior to PCT.