The noninvasive differentiation of acute pyelonephritis (AP) and complicated urinary tract infections (cUTI), from acute cystitis (AC), represents an important diagnostic challenge in urology and nephrology. In a study of 95 adults, urine from patients with AP (n = 17), cUTI (n = 6), AC (n = 28), and controls (n = 44) was examined using a multidisciplinary approach: enzyme-linked immunosorbent assays for quantitation of acute phase proteins ceruloplasmin (Cp), pentraxin-3 (Ptx3), and lipocalin-2 (Lcn2); inductively coupled plasma mass spectrometry for determination of total copper (Cu), zinc (Zn), and iron (Fe) concentrations; and liquid chromatography coupled to electrospray ionization MS (LC-MS) for identification and quantitation of bacterial metallophores. Markedly elevated levels of human Cp, Ptx3, and Lcn2, all normalized to urine creatinine (Cr), in AC, cUTI, and AP patients compared to controls identified ongoing urinary tract infection without further differentiation between AC and AP. On the contrary, total urine copper normalized to Cr (Cu/Cr index) significantly differentiated AP from AC (p = 0.0209), as well as from the controls. Bacterial metallophores aerobactin and yersiniabactin, but not enterobactin, were indicators of AP, cUTI, and AC caused by Enterobacteriaceae. Importantly, the newly proposed combined test based on the quantitation of Lcn2 normalized to Cr (Lcn2/Cr) and Cu/Cr could noninvasively differentiate AP and cUTIs from AC with a diagnostic accuracy of 78% sensitivity and 65% specificity. The combination of characteristic elemental and molecular biomarkers may represent a future research direction with the potential to improve diagnostics of UTIs.

Biomedicine Research Centre of the Slovak Academy of Sciences Institute of Virology Dúbravská Cesta 9 Bratislava 84505 Slovakia

Department of Analytical Chemistry Faculty of Science Palacký University 17 listopadu 12 Olomouc 771 46 Czechia

Department of Bacteriology and Mycology National Reference Laboratory for Mycological Diagnostics Public Health Institute in Ostrava Partyzánské náměstí 2633 7 Ostrava 702 00 Czechia

Department of Urology Bulovka University Hospital Budínova 67 2 Prague 180 81 Czechia

Department of Urology Thomayer University Hospital and 3rd Faculty of Medicine Charles University Vídeňská 800 Prague 140 59 Czechia

Division of Infectious Diseases and Geographic Medicine Stanford University School of Medicine Stanford California 94305 United States of America

Institute of Laboratory Medicine Faculty of Medicine University of Ostrava Syllabova 19 Ostrava 703 00 Czechia

Institute of Microbiology of the Czech Academy of Sciences Vídeňská 1083 Prague 142 00 Czechia

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