Comparison of Procalcitonin and C-Reactive Protein Tests in Children with Urinary tract infection

Objective: Urinary tract infection (UTI) is a common disease in children. The distinction between upper and lower UTI in children is associated with some ambiguities. The objective of this study was to determine the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of procalcitonin (PCT) compared to C-reactive protein (CRP) in predicting renal involvement.
Methods: Serum concentrations of PCT and CRP in blood samples of 111 children with UTI were measured. Renal parenchymal involvement was evaluated with 99mTc-dimercaptosuccinic acid (DMSA) scintigraphy. Sensitivity, specificity, PPV and NPV were determined.
Findings: Out of 111 children, 52 (46.8%) were shown to have acute renal involvement, 23 (20.7%) lower UTI, and 36 (32.5%) refused to be examined by DMSA renal scan. PCT was positive in 36 (69.2%) patients with upper UTI and 12 (52.2%) with lower UTI. The sensitivity, specificity, PPV and NPV obtained for PCT and CRP were 70.6, 45.5, 75, 40% and 96.2, 4.3, 69.4, and 33.3%, respectively.
Conclusion: No significant correlation was found between renal parenchymal involvement and serum levels of PCT and CRP. However, the results demonstrated that the PCT was a better diagnostic test compared to CRP.

Keywords
Pyelonephritis; UTI; Procalcitonin; Serum marker; Children; C-reactive protein