Abstract:The morphological analysis of urine sediment is an essential part of urinalysis and casts are important elements of urinary sediment. Their shape is typically cylindrical, with extremities often rounded. Casts form within the renal tubules and are made of Tamm-Horsfall glycoprotein (THG). Under some physiological or pathological conditions THG fibrils aggregate giving rise to casts, whose formation is favoured by a number of factors including high urine osmolality and/or low pH. Casts can be found in normal subjects, in non-renal conditions, such as fever, dehydration, and acute heart failure as well as in virtually all renal diseases. Casts can be classified on the basis of their morphology as hyaline, granular, waxy, fatty, cellular (leukocytic, erythrocytic, epithelial), containing crystals or microorganisms, pigmented and mixed. As the correct identification of casts is crucial for an accurate and timely diagnosis of renal disorders, laboratory professionals should be trained to identify and classify casts properly.
AbstractIn analogy with other areas of laboratory diagnostics, the pre-analytical phase is the leading source of variability also in urinalysis. We carried out a multicentric study for comparing results obtained from first-voided and mid-stream urine samples.Each of the six hospital-based clinical laboratories participating to this study recruited 50 healthy subjects among laboratory staff and/or their relatives. Two consecutive samples of the first morning micturition were collected by vacuum system, the first from the first-void and the second from the mid-stream. Routine urinalysis was performed using dip-stick automated analyzers for chemical examination and automated analyzers for formed particle examination (Sysmex UF-100, Sysmex UF-1000i and Iris iQ-200).Counts of epithelial cells (EC), erythrocytes (ERY) and leukocytes (LEU) but not for cylinders (CAS) were significantly higher in the first-voided samples. A significantly higher count of EC, ERY and LEU was also observed between females and males in first-voided samples, whereas no significant difference could be found in mid-stream samples. Health related analyzer specific upper reference limits (URL) were CAS≤1, EC≤5, ERY≤19, Leu≤13 for UF-100; CAS≤1, EC≤4, ERY≤15, Leu≤11 for UF-1000i; CAS≤1, EC≤4, ERY≤18, Leu≤10 for iQ200. The overall prevalence of subjects with cellular elements count exceeding URL was also higher in first-voided than in mid-stream samples.Mid-stream urine was confirmed as the most appropriate sample, since the presence of contaminating elements, such as bacteria, analytes and formed particles are minimized.
The che mi cal, physi cal and mor pho lo gic uri ne exa mi na tion has un der go ne ra di cal chan ges over the la st few yea rs, so that the ti me has co me for intro du ci ng fur ther chan ges and mo di ca tio ns in va rious ste ps of this im por ta nt te st. The break throug hs of new tec hno lo gies ha ve al lowed ma ki ng the la bo ra to ry re po rt mu ch mo re in for ma ti ve for the sta ke hol de rs. Ne ver the le ss, im por ta nt con si de ra tio ns for im pro vi ng the qua li ty throug hout the tes ti ng pro ce ss we re al so rai sed, es pe cial ly in the prea na lyti cal pha se. Cur ren tly, it mig ht be ad vi sab le to pur sue con so li da tion and stan dar di za tion of the ana lyti cal pha se, as we ll as re de ni tion of cli ni cal tar ge ts throu gh con struc tion of a com ple te, in teg ra ted and mu ch mo re cli ni cal ly mea nin gful re po rt. This ar tic le ai ms to re view the sta te of the art in uri na lysis, as we ll as pro vi di ng use ful in for ma tion for ac hie vi ng mo re stan dar di za tion and qua li ty of this use ful diag nos tic te st.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.