BACKGROUND: In 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. METHODS: 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). RESULTS: 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. CONCLUSIONS: 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.
BACKGROUND: In 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. METHODS: 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). RESULTS: 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. CONCLUSIONS: 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.
Authors: Anne Russcher; Elske Kusters; Ron Wolterbeek; Ed J Kuijper; Christa M Cobbaert; Martha T van der Beek Journal: J Clin Microbiol Date: 2015-10-21 Impact factor: 5.948
Authors: Uta Erdbrügger; Charles J Blijdorp; Irene V Bijnsdorp; Francesc E Borràs; Dylan Burger; Benedetta Bussolati; James Brian Byrd; Aled Clayton; James W Dear; Juan M Falcón-Pérez; Cristina Grange; Andrew F Hill; Harry Holthöfer; Ewout J Hoorn; Guido Jenster; Connie R Jimenez; Kerstin Junker; John Klein; Mark A Knepper; Erik H Koritzinsky; James M Luther; Metka Lenassi; Janne Leivo; Inge Mertens; Luca Musante; Eline Oeyen; Maija Puhka; Martin E van Royen; Catherine Sánchez; Carolina Soekmadji; Visith Thongboonkerd; Volkert van Steijn; Gerald Verhaegh; Jason P Webber; Kenneth Witwer; Peter S T Yuen; Lei Zheng; Alicia Llorente; Elena S Martens-Uzunova Journal: J Extracell Vesicles Date: 2021-05-21
Authors: K Perslev; O A Msemo; D T R Minja; S L Møller; T G Theander; J P A Lusingu; I C Bygbjerg; B B Nielsen; C Schmiegelow Journal: PLoS One Date: 2019-01-10 Impact factor: 3.240
Authors: Suchitra K Hourigan; Wei Zhu; Wendy S W Wong; Nicole C Clemency; Marina Provenzano; Thierry Vilboux; John E Niederhuber; John Deeken; Simon Chung; Kim McDaniel-Wiley; Donald Trump Journal: BMC Urol Date: 2020-01-28 Impact factor: 2.264