Öz

Objective: Extreme leukocytosis is often considered a warning sign of serious bacterial infection (SBI) in febrile children. However, its diagnostic value remains controversial, particularly in the post-vaccination era. This study aimed to evaluate whether extreme leukocytosis is associated with an increased risk of SBI compared with moderate leukocytosis in pediatric emergency patients.

Materials and Methods: This single-center, retrospective comparative study included children aged 1 month to 18 years who presented to a tertiary pediatric emergency department in Ankara, Türkiye, with a white blood cell (WBC) count ≥15.000/mm³. Patients were classified into moderate (15.000–24.999/mm³) and extreme (≥25.000/mm³) leukocytosis groups. SBI frequency, C-reactive protein (CRP) levels, and multivariable predictors of SBI were analyzed.

Results: A total of 955 patients were included (423 extreme, 532 moderate leukocytosis). SBI was identified in 26.0% of extreme and 22.7% of moderate leukocytosis patients (p=0.243). In multivariable analysis, extreme leukocytosis was not independently associated with SBI (OR 1.18, 95% CI 0.86–1.61, p=0.308), whereas CRP (OR 1.05, 95% CI 1.02–1.07, p=0.001) and fever (OR 2.21, 95% CI 1.54–3.16, p<0.001) were significant predictors. CRP showed moderate discriminatory ability (AUC 0.649), with improved performance in the extreme leukocytosis subgroup (AUC 0.705).

Conclusion: Extreme leukocytosis was not associated with increased SBI risk compared with moderate leukocytosis. CRP provided independent predictive value and may serve as a more useful biomarker for SBI risk stratification in pediatric emergency patients with leukocytosis.

Kaynakça

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Nasıl atıf yapılır

1.
Birbilen AZ, Taşar Karabulut S, Hürmüzlü Közler S, Kurt F, Yakut Hİ, Dibek Mısırlıoğlu E. Extreme leukocytosis is not associated with increased risk of serious bacterial infection in pediatric emergency patients. Turk J Pediatr Dis. 2026;Early View:1-6. https://doi.org/10.12956/TJPD.2026.1335