title: Advances in Urine Microscopy.
abstract: Urine microscopy is an important tool for the diagnosis and management of several conditions affecting the kidneys and urinary tract. In this review, we describe the automated instruments, based either on flow cytometry or digitized microscopy, that are currently in use in large clinical laboratories. These tools allow the examination of large numbers of samples in short periods. We also discuss manual urinary microscopy commonly performed by nephrologists, which we encourage. After discussing the advantages of phase contrast microscopy over bright field microscopy, we describe the advancements of urine microscopy in various clinical conditions. These include persistent isolated microscopic hematuria (which can be classified as glomerular or nonglomerular on the basis of urinary erythrocyte morphology), drug- and toxin-related cystalluria (which can be a clue for the diagnosis of acute kidney injury associated with intrarenal crystal precipitation), and some inherited conditions (eg, adenine phosphoribosyltransferase deficiency, which is associated with 2,8-dihydroxyadenine crystalluria, and Fabry disease, which is characterized by unique urinary lamellated fatty particles). Finally, we describe the utility of identifying "decoy cells" and atypical malignant cells, which can be easily done with phase contrast microscopy in unfixed samples.
authors.affiliation: Department of Nephrology, The Royal Melbourne Hospital and University of Melbourne, Melbourne, Australia. Electronic address: gavin.becker@mh.org.au.
authors.forename: Gavin J
authors.initials: GJ
authors.lastname: Becker
authors.affiliation: Clinical and Research Laboratory on Urinary Sediment, UO di Nefrologia e Dialisi, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Garigali
authors.affiliation: Clinical and Research Laboratory on Urinary Sediment, UO di Nefrologia e Dialisi, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Giovanni B
authors.initials: GB
authors.lastname: Fogazzi
mesh_terms: D057205:Automation, Laboratory; D005434:Flow Cytometry; D006801:Humans; D008853:Microscopy; D016482:Urinalysis / Q000379:methods*; D014556:Urine / Q000166:cytology; D014570:Urologic Diseases / Q000473:pathology*
keywords: Urine microscopy; acute kidney injury (AKI); automation; bright-field; crystalluria; cytopathology; diagnosis; hematuria; kidney disease; nephrologist; phase-contrast; polarized light; red blood cells (RBCs); review; urinalysis; urine sediment