title: Occasional urinary tract infections and urinary depletion effect mask RTA and carbonate-apatite formation in a strong urinary stone former.
abstract: We report on a female patient with severe bilateral urolithiasis. A once-off stone analysis performed in the past revealed Mg-phosphate. Occasional UTIs were considered to be the sole cause of stone formation. To date, this assumption had not been checked thoroughly, while stone formation in the patient steadily increased. An inpatient metabolic and analytical work up was performed and stone-growth related urinary alteration was taken into account in urinalysis interpretation. No UTI. NH4Cl-loading test indicated RTA. CT revealed calculi in both kidneys. Carbonate-apatite (CAP) dominates stone composition. Computed urinary composition proximal to stones indicates hypercalciuria. In this patient, occasional UTIs (pH) masked the causes of urolithiasis. Lack of updated stone analysis (CAP), metabolic work up (RTA) and improved urinalysis interpretation (hypercalciuria) concealed the true causes of stone formation.
authors.affiliation: Division of Experimental Urology, Department of Urology, University of Bonn, Sigmund-Freud-Strasse 25, D-53125 Bonn, Germany. norbert.laube@ukb.uni-bonn.de
authors.forename: N
authors.initials: N
authors.lastname: Laube
authors.forename: E
authors.initials: E
authors.lastname: Thomas
authors.forename: A
authors.initials: A
authors.lastname: Kovács
authors.forename: A
authors.initials: A
authors.lastname: Meissner
mesh_terms: D000141:Acidosis, Renal Tubular / Q000150:complications* / Q000652:urine; D000328:Adult; D001031:Apatites / Q000652:urine*; D005260:Female; D006801:Humans; D012307:Risk Factors; D014057:Tomography, X-Ray Computed; D016482:Urinalysis; D014545:Urinary Calculi / Q000000981:diagnostic imaging / Q000209:etiology* / Q000652:urine; D014552:Urinary Tract Infections / Q000150:complications* / Q000652:urine
chemical_list: D001031:Apatites; C030782:carboapatite