Fluorescence Profiling of Urine in Non-Invasive Diagnostics of Obstructive and Reflux Uropathies in Children

Background: Rapid screening methods reflecting the metabolic profile of urine are promising for assessing the risk of decreased renal function in children with obstructive uropathies. The aim of this pilot study was to evaluate the applicability of a reaction-based fingerprinting strategy for this purpose, which has previously demonstrated its effectiveness in recognizing samples with similar composition. Methods: The study included 28 children with hydronephrosis (HN, 5 patients) and vesicoureteral reflux (VUR, 15 patients), as well as healthy children without urinary pathology who comprised the control group (8 patients). Using the kinetic variant of optical fingerprinting, six indicator reactions of different natures involving dyes were investigated, with absorbance and fluorescence of the reaction products monitored photographically throughout the reaction. Results: Supervised chemometric analysis demonstrated that standard clinical and laboratory indicators enabled discrimination of urine samples from children with HN and VUR from the control group; however, the recognition accuracy was only satisfactory, ranging from 79% to 86%. The introduction of urine samples into the indicator reactions enabled discrimination of both diagnoses (VUR and HN) from the control group and from each other, with recognition accuracy reaching 100%. Furthermore, no correlation was observed between the results obtained using kinetic-based methods and standard clinical and laboratory indicators, which may reflect different levels of the pathological process, namely functional and molecular. Conclusions: The reaction-based optical fingerprinting strategy can be considered a promising approach for in-depth non-invasive diagnostics in pediatric urology. The reported diagnostic performance is limited to the analyzed cohort and should not be extrapolated to general clinical use without independent validation in a larger, age-matched population. If validated, kinetic optical fingerprinting could serve as an adjunct to conventional imaging and clinical assessment to inform risk stratification and guide further investigations, rather than functioning as a stand-alone decision-maker.