title: High Zn content of Randall's plaque: a μ-X-ray fluorescence investigation.
abstract: Kidney stone disease, or nephrolithiasis, is a common ailment. Among the different risk factors usually associated with nephrolithiasis are dehydration, metabolic defects (especially with regard to calcium and oxalate). The presence of a mineral deposit at the surface of the renal papilla (termed Randall's plaque) has all been recently underlined. Of note, Randall's plaque is made of the calcium phosphate, carbapatite, and serves as a nucleus for kidney stone formation. The process by which apatite nanocrystals nucleate and form Randall's plaque remains unclear. This paper deals with the possible relationship between trace elements and the formation of this mineral. The investigation has been performed on a set of Randall's plaques, extracted from human kidney stones, through μ-X-ray diffraction and μ-X-ray fluorescence analyses in order to determine the chemical composition of the plaque as well as the nature and the amount of trace elements. Our data provide evidence that Zn levels are dramatically increased in carbapatite of RP by comparison to carbapatite in kidney stones, suggesting that calcified deposits within the medullar interstitium are a pathological process involving a tissue reaction. Further studies, perhaps including the investigation of biomarkers for inflammation, are necessary for clarifying the role of Zn in Randall's plaque formation.
authors.affiliation: Laboratoire de Physique des Solides, Bat 510, Université Paris XI, 91405 Orsay, France.
authors.forename: Xavier
authors.initials: X
authors.lastname: Carpentier
authors.forename: Dominique
authors.initials: D
authors.lastname: Bazin
authors.forename: Christelle
authors.initials: C
authors.lastname: Combes
authors.forename: Aurélie
authors.initials: A
authors.lastname: Mazouyes
authors.forename: Stephan
authors.initials: S
authors.lastname: Rouzière
authors.forename: Pierre Antoine
authors.initials: PA
authors.lastname: Albouy
authors.forename: Eddy
authors.initials: E
authors.lastname: Foy
authors.forename: Michel
authors.initials: M
authors.lastname: Daudon
mesh_terms: D002138:Calibration; D006801:Humans; D007669:Kidney Calculi / Q000000981:diagnostic imaging* / Q000378:metabolism*; D007854:Lead / Q000378:metabolism / Q000652:urine; D011859:Radiography; D013052:Spectrometry, X-Ray Emission; D013324:Strontium / Q000378:metabolism / Q000652:urine; D014961:X-Ray Diffraction; D015032:Zinc / Q000378:metabolism* / Q000652:urine
chemical_list: D007854:Lead; D015032:Zinc; D013324:Strontium