Abstract

Objective: The aim of this study was to evaluate the diagnostic discrimination of CRP and CBC-derived inflammatory indices for identifying concurrent culture-confirmed UTI in children with urolithiasis during early clinical assessment.

Materials and Methods: This single-center retrospective observational study included 77 children with imaging-confirmed urolithiasis and 45 healthy controls. Concurrent UTI was defined by compatible symptoms together with urine culture growth of ≥10⁵ colony-forming units/mL. Neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), monocyte-to-platelet ratio (MPR), mean platelet volume (MPV), white blood cell count, and CRP were compared across study groups. Receiver operating characteristic analyses were used to assess diagnostic discrimination for culture-confirmed UTI.

Results: Among 77 children with urolithiasis, 46 (59.7%) had concurrent culture-confirmed UTI. Compared with both healthy controls and stone/UTI-negative patients, those with concurrent UTI had significantly higher NLR, MLR, MPR, white blood cell count, and CRP levels, whereas MPV showed poor discriminatory performance. CRP demonstrated the highest diagnostic discrimination for concurrent UTI (AUC 0.996), with a cutoff of ≥5 mg/L yielding 98.0% sensitivity and 100% specificity. Among the complete blood count–derived indices, NLR performed best (AUC 0.838), followed by MLR (AUC 0.827) and MPR (AUC 0.779). Secondary exploratory analyses suggested declining inflammatory markers after infection control and stone clearance in the surgical cohort, whereas a very small subgroup with culture-negative postoperative fever showed descriptive marker re-elevation in exploratory analyses.

Conclusion: In pediatric urolithiasis, CRP demonstrated the strongest diagnostic discrimination for concurrent culture-confirmed UTI, whereas NLR was the most informative supportive complete blood count–derived index. Secondary exploratory observations should be interpreted cautiously and require confirmation in larger cohorts. Overall, the present findings remain preliminary and require prospective validation before any routine clinical application.

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Copyright © 2026 The Author(s). This is an open access article distributed under the Creative Commons Attribution License (CC BY), which permits unrestricted use, distribution, and reproduction in any medium or format, provided the original work is properly cited.

How to cite

1.
Yayla D, Tiryaki HT. Diagnostic discrimination of C-reactive protein and blood count-derived indices for concurrent urinary tract infection in pediatric urolithiasis. Turk J Pediatr Dis. 2026;Early View:1-8. https://doi.org/10.12956/TJPD.2026.1339