CALCA and pyelonephritis: A recent prospective study comparing PCT, ESR and CRP showed superior results with PCT to assess renal parenchymal damage.37 Furthermore, a high PCT (≥0.5 ng/ml) has shown to be associated with vesicoureteral reflux in children.38 It is a non-invasive test that can help physicians make decisions regarding management and further assessment.1 Given the wide ranges in sensitivity and specificity, further study of PCT to distinguish lower UTI from pyelonephritis is warranted.