Diagnostic Performance of Inflammatory Biomarkers in Pediatric Acute Appendicitis

Objectives: The diagnosis of pediatric acute appendicitis remains challenging due to clinical findings that overlap with nonspecific abdominal pain (NSAP). In this study, the value of fibrinogen in the diagnosis of pediatric acute appendicitis and in the classification of disease severity was investigated. Methods: In a single-center, retrospective cohort study, 145 patients aged 1 month to 18 years who underwent contrast-enhanced abdominal computed tomography were divided into three groups: NSAP (n = 62), uncomplicated appendicitis (n = 44), and complicated appendicitis (n = 39). Hemogram parameters, CRP, procalcitonin, albumin, and fibrinogen levels were compared. Diagnostic performance was assessed using ROC analysis, and independent predictors were evaluated via multivariate logistic regression. Results: Fibrinogen levels showed a gradual and statistically significant increase from NSAP to uncomplicated appendicitis and then to complicated appendicitis (p < 0.001 for all pairwise comparisons). In distinguishing appendicitis from NSAP, fibrinogen achieved the highest diagnostic accuracy among the biomarkers examined (AUC = 0.95); CRP, WBC, ANC, and NLR demonstrated lower discriminatory performance. In multivariate logistic regression analysis, fibrinogen was validated as an independent predictor of appendicitis (p < 0.001). Conclusions: Fibrinogen demonstrates high discriminatory performance in the diagnosis of pediatric acute appendicitis and shows a graded relationship with disease severity. These findings suggest that fibrinogen may be a promising biomarker for the evaluation of pediatric acute appendicitis. However, larger prospective multicenter studies are required before its routine integration into diagnostic algorithms can be recommended.