The value of procalcitonin and urinary NGAL in the prediction of acute pyelonephritis and kidney scarring in pediatric patients with a history of febrile urinary tract infection: a systematic review and meta-analysis

Abstract Background Children with febrile urinary tract infections (fUTI), especially those with acute pyelonephritis (APN) and vesicoureteral reflux (VUR), may face several complications, especially kidney scarring. Different biomarkers, such as urinary neutrophil gelatinase-associated lipocalin (uNGAL) and procalcitonin (PCT), have been studied for predicting kidney scarring without the need for a DMSA scan. Objectives This systematic review and meta-analysis examines the role of biomarkers in pediatric patients with a history of fUTI and their prognostic value in the diagnosis of APN and prediction of kidney scarring. Data sources A search through major databases (MEDLINE/PubMed and Scopus) was conducted from inception until January 2, 2025. The mean difference (95% CI) was applied. A p < 0.05 was considered statistically significant. Results The systematic review included 2300 participants from 28 studies. Procalcitonin and uNGAL were higher in individuals with scarring after a fUTI episode compared to those without scarring ( p = 0.035 and p < 0.0001, respectively). In addition, PCT was higher in patients with APN compared to those with lower UTI ( p < 0.0001). Finally, the good and moderate overall diagnostic accuracy (I 2 = 29.8%) of PCT in predicting APN (AUC: 0.861) and uNGAL (I 2 = 16.8%) in predicting kidney scarring after an episode of fUTI (AUC: 0.74), respectively, should be considered. Conclusions This study showed that PCT and uNGAL can detect APN and kidney scarring after fUTI. More studies should be conducted exploring the role of other biomarkers in scarring after an episode of fUTI in pediatric patients with or without VUR. Graphical abstract