In the diagnostic evaluation of urinary tract infection (UTI) in children, dipstick urinalysis and urine microscopy/culture are the
initial steps. Although these investigations are not without their drawbacks, urine culture remains the gold standard. Biomarkers
may also be used as diagnostic tools, predictors of complications, and renal parenchymal injury. This paper aims to review the
studies reporting the utility of biomarkers in the diagnosis and prognostication of UTI. Using the key words- ‘urinary tract infection’,
‘children’, and ‘biomarkers’- the PubMed database was searched for systematic reviews/meta-analyses and original studies, which
were published within the past 25 years. Information was also gathered from relevant textbooks published within the same period.
Serum procalcitonin, urine/serum interleukin 6 (IL-6) and 8 (IL-8), as well as urine neutrophil gelatinase-associated lipocalin (NGAL)
are the major biomarkers of febrile UTI. In addition, procalcitonin and these cytokines are reported to be early predictors of vesicoureteric
reflux (VUR) and renal parenchymal injury, while procalcitonin and IL-6 can also help to differentiate between lower UTI and
upper UTI (pyelonephritis). Despite the wide range in the sensitivity and specificity of these biomarkers reported in the reviewed
studies, the values are still acceptable. Some of these biomarkers may, in the future, obviate the need for invasive radiological tests,
although their utility still require validation by further research. However, given the ability of imaging studies to detect structural
abnormalities of the urinary tract, their use still remains relevant in the investigation of UTI despite the radiation risks associated
with majority of them.