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Nonkes L, Yaz Aydın G, Van't Hof M, Demir AY. Impact of different preservation methods on urinary red blood cell counts. Clin Chem Lab Med 2024; 62:e99-e101. [PMID: 37883021 DOI: 10.1515/cclm-2023-0737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 10/16/2023] [Indexed: 10/27/2023]
Affiliation(s)
- Lourens Nonkes
- Laboratory for Clinical Chemistry and Hematology, Meander Medical Centre, Amersfoort, The Netherlands
| | - Gizem Yaz Aydın
- Laboratory for Clinical Chemistry and Hematology, Meander Medical Centre, Amersfoort, The Netherlands
| | - Mirjam Van't Hof
- Laboratory for Clinical Chemistry and Hematology, Meander Medical Centre, Amersfoort, The Netherlands
| | - Ayşe Y Demir
- Laboratory for Clinical Chemistry and Hematology, Meander Medical Centre, Amersfoort, The Netherlands
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Cadamuro J, Decho C, Frans G, Auer S, von Meyer A, Kniewallner KM, Drerup M, Heinrich E, Keppel MH, Mrazek C, Felder TK, Oberkofler H, Haschke-Becher E, Kipman U, Salek T, Vermeersch P. Acidification of 24-hour urine in urolithiasis risk testing: An obsolete relic? Clin Chim Acta 2022; 532:1-9. [PMID: 35597305 DOI: 10.1016/j.cca.2022.05.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 05/09/2022] [Accepted: 05/09/2022] [Indexed: 11/15/2022]
Abstract
BACKGROUND Recommendations on the optimal preservation of 24 h urine for the metabolic work-up in urolithiasis patients are very heterogeneous. In case two such tests with different storage condition recommendations are being analysed, multiple collections would be needed, challenging especially elderly and very young patients. We therefore aimed to evaluate the stability of urine constituents under different storage conditions. MATERIAL AND METHODS We collected urine samples from ten healthy volunteers and prepared aliquots to be stored either at room temperature or 4 °C. Some aliquots were preserved using hydrochloric acid prior to storage, some thereafter, some using the BD Urine preservation tube and some were not preserved at all. Storage duration was 0, 24, 48 or 72 h. In all samples calcium, magnesium, phosphorus, creatinine, oxalate, citrate and uric acid were measured and compared to the according reference sample. RESULTS We could not find any significant deviation for any of the analytes and preanalytical treatment conditions compared to the associated reference sample. CONCLUSION Preservation of 24 h urine for the metabolic evaluation in stone formers might not be necessary for sample storage up to 72 h.
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Affiliation(s)
- Janne Cadamuro
- Department of Laboratory Medicine, Paracelsus Medical University, Salzburg, Austria.
| | - Cosima Decho
- Department of Laboratory Medicine, Paracelsus Medical University, Salzburg, Austria
| | - Glynis Frans
- Clinical Department of Laboratory Medicine, University Hospitals Leuven, Leuven, Belgium
| | - Simon Auer
- Department of Laboratory Medicine, Paracelsus Medical University, Salzburg, Austria
| | - Alexander von Meyer
- Institute for Laboratory Medicine and Medical Microbiology, Medizet, München-Klinik, Munich, Germany
| | - Kathrin M Kniewallner
- Institute of Molecular Regenerative Medicine, Paracelsus Medical University, Salzburg, Austria; Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TreCS), Paracelsus Medical University, Salzburg, Austria
| | - Martin Drerup
- Department of Urology, Barmherzige Brüder Hospital, Salzburg, Austria
| | - Elmar Heinrich
- Department of Urology, Barmherzige Brüder Hospital, Salzburg, Austria
| | - Martin H Keppel
- Department of Laboratory Medicine, Paracelsus Medical University, Salzburg, Austria
| | - Cornelia Mrazek
- Department of Laboratory Medicine, Paracelsus Medical University, Salzburg, Austria
| | - Thomas K Felder
- Department of Laboratory Medicine, Paracelsus Medical University, Salzburg, Austria
| | - Hannes Oberkofler
- Department of Laboratory Medicine, Paracelsus Medical University, Salzburg, Austria
| | | | | | - Tomas Salek
- Department of Clinical Biochemistry and Pharmacology, The Tomas Bata Hospital in Zlín, Havlíčkovo nábřeží 600, 76275 Zlín, The Czech Republic
| | - Pieter Vermeersch
- Clinical Department of Laboratory Medicine, University Hospitals Leuven, Leuven, Belgium; Department of Cardiovascular Sciences, KU Leuven, Leuven Belgium
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Haugum K, Haugan MS, Skage J, Tetik M, Jakovljev A, Nilsen HJS, Afset JE. Use of Sysmex UF-5000 flow cytometry in rapid diagnosis of urinary tract infection and the importance of validating carryover rates against bacterial count cut-off. J Med Microbiol 2021; 70. [PMID: 34898416 PMCID: PMC8744275 DOI: 10.1099/jmm.0.001472] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Introduction Urinary tract infections are common bacterial infections worldwide. Urine culture is the gold standard method to identify and quantify the presence or absence of bacteria in urine. Flow cytometry, which can differentiate and quantify multiple particles (including bacteria) in the urine, presents an alternative method for rapid screening to rule out bacteriuria. Hypothesis Adding flow cytometry to identify urine samples without bacteriuria could substantially reduce the number of urine samples that need to be cultured as well as the response time for negative results. However, the level of instrument rinsing between samples could affect sample-to-sample carryover rate, a concept given little attention in previous studies. Aim We aimed to evaluate urine flow cytometry as a rapid screening method to identify urine samples without significant bacterial growth, including analyses of cross-contamination and sample-to-sample carryover rate. Methodology We analysed 3919 urine samples by quantitative urine culture and flow cytometry screening (Sysmex UF-5000). Receiver operator characteristic (ROC) curve analyses were used to test method agreement to identify: (a) positive vs. negative culture and (b) mixed vs. pure culture. In addition, we performed carryover and cross-contamination studies. Results ROC curve analyses identified bacterial count (BACT ml−1) and leucocyte count (WBC µl−1) as possible predictors of bacterial growth in the total material and subpopulations, except pregnant women (n=451). This subgroup was excluded from further analyses, leaving a final 3468 urine samples. Area under the ROC curve was 0.94 (95 % CI 0.93–0.95) and 0.81 (95 % CI 0.79–0.82) for bacterial and leucocyte count, respectively. A bacterial count cut-off of 30 BACT ml−1 resulted in 95.2 % sensitivity and 91.2 % negative predictive value, resulting in approximately 30 % of urine samples that could be reported as negative without culture. Use of high-level rinse modes was necessary to ensure carryover rates <0.05 %. Conclusion Flow cytometry is a suitable and rapid method to rule out urine samples without significant bacterial growth. Rinses between samples should be adjusted, depending on the cut-off used, to prevent sample-to-sample carryover, whereas cross-contamination can be eliminated by the use of separate urine aliquots for flow cytometry analysis and urine culturing respectively.
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Affiliation(s)
- Kjersti Haugum
- Department of Medical Microbiology, St. Olavs Hospital, Trondheim, Norway.,Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway
| | - Maria Schei Haugan
- Department of Medical Microbiology, St. Olavs Hospital, Trondheim, Norway
| | - Jannicke Skage
- Department of Medical Microbiology, St. Olavs Hospital, Trondheim, Norway
| | - Mariann Tetik
- Department of Medical Microbiology, St. Olavs Hospital, Trondheim, Norway
| | | | | | - Jan Egil Afset
- Department of Medical Microbiology, St. Olavs Hospital, Trondheim, Norway.,Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway
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Diagnostic accuracy of semiquantitative point of care urine albumin to creatinine ratio and urine dipstick analysis in a primary care resource limited setting in South Africa. BMC Nephrol 2021; 22:103. [PMID: 33743616 PMCID: PMC7981803 DOI: 10.1186/s12882-021-02290-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 03/02/2021] [Indexed: 11/21/2022] Open
Abstract
Background The prevalence of chronic kidney disease (CKD) is predicted to rise over the next few decades. In resource-limited settings access to central laboratory services is limited. Point-of-care (POC) urine dipstick testing offers the potential to detect markers of kidney damage (albuminuria) as well as markers of other disease processes. We evaluated the diagnostic accuracy of the semi-quantitative albumin-creatinine ratio (ACR) Sysmex UC-1000 POC urine dipstick system as well as the extent of other abnormal dipstick findings in urine. Methods 700 participants from a rural area in South Africa were screened for albuminuria. A spot urine sample was used to measure POC and central laboratory ACR. We determined the sensitivity, specificity, positive predictive value and negative predictive value of the POC ACR, and recorded dipstick parameters. Results The prevalence of albuminuria was 11.6% (95%CI; 9.3–14.2). Those with albuminuria had higher mean diastolic (82 vs 79 mmHg, p = 0.019) and systolic (133 vs 128 mmHg, p = 0.002) blood pressures and a higher proportion of diabetes mellitus (17.6 vs 4.9%, p < 0.001). The sensitivity of the POC ACR system was 0.79, specificity 0.84, positive predictive value 0.39 and negative predictive value 0.97. The sensitivity improved to 0.80, 0.85, 0.85 and 0.89 in those with elevated blood pressure, diabetes mellitus, HIV positive status, and those 65 years and older, respectively. Abnormalities other than albuminuria were detected in 240 (34.3%) of the samples; 88 (12.6%) were positive for haematuria, 113 (16.1%) for leucocytes, 66 (9.4%) for nitrites and 27 (3.9%) for glycosuria. Conclusion Our study shows that POC ACR has good negative predictive value and could be used to rule out albuminuria when screening for CKD. Additionally, a high proportion of participants had other urine abnormalities detected with dipsticks which may reflect kidney disease or co-morbid untreated genitourinary pathology such as urinary tract infections or endemic schistosomiasis with important implications for CKD. Supplementary Information The online version contains supplementary material available at 10.1186/s12882-021-02290-5.
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Aulakh HK, Aulakh KS, Ryan KA, Liu CC, Acierno MJ. Investigation of the effects of storage with preservatives at room temperature or refrigeration without preservatives on urinalysis results for samples from healthy dogs. J Am Vet Med Assoc 2021; 257:726-733. [PMID: 32955395 DOI: 10.2460/javma.257.7.726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To compare urinalysis results for canine urine samples stored in preservative-containing tubes at room temperature (20°C to 25°C [68°F to 77°F]) or refrigerated at 4°C (39.2°F) in plain glass tubes with results for the same samples immediately after collection. SAMPLES Urine samples from 20 healthy dogs. PROCEDURES Urine samples (1/dog) were divided into 6 aliquots (3 in preservative-containing tubes and 3 in plain glass tubes). Preservative-containing tubes were stored at room temperature and plain glass tubes were refrigerated. Urinalysis was performed 0, 24, and 72 hours after collection. Results for both storage conditions were compared with results for a reference sample (the 0-hour [immediate post-collection] aliquot in a plain glass tube) by Spearman correlation analysis with pairwise tests for selected variables. RESULTS Physical variables (urine color and turbidity with and without centrifugation) for both storage conditions had high (rs = 0.7 to 0.9) or very high (rs = 0.9 to 1.0) degrees of positive correlation with reference sample results at all time points, except for color at 24 hours. Similar results were found for all biochemical variables with storage up to 72 hours. For microscopic characteristics, correlation with reference sample results ranged from low or nonsignificant to very high under both storage conditions. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that if a delay in urinalysis is expected, use of the preservative-containing tubes evaluated in this study may be a viable option for sample storage. Further research is warranted to assess direct comparability of results to those of freshly collected samples and use of these tubes to store samples from dogs with conditions affecting the urinary tract.
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Salazar-García S, Lares-Villaseñor E, Bárcenas-Morales A, Vargas-Morales Juan M. Impact of chemical preservative in urine samples. EJIFCC 2020; 31:56-64. [PMID: 32256289 PMCID: PMC7109501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Urinalysis is one of the most important tests in the clinical laboratory. In this study we assessed the use of chemical preservative in urinalysis during preanalytical phase. Fifty first morning urine samples from medical laboratory patients were collected and stored with and without chemical preservative. Difference between medians were analyzed using Wilcoxon signed rank test for glucose, bilirubin, ketones, specific gravity, erythrocytes, pH, proteins, nitrites, leukocytes using urine strips; and on leukocytes, erythrocytes, epithelial cells, and bacteria in the urinary sediment, at 90 minutes after sampling. Our results showed that the specific gravity and the pH values increased in samples with chemical preservative in urine strip tests. Concerning urinary sediment analysis no differences were observed in the studied parameters between samples with and without chemical preservative. We suggest that the effect on urine pH is due to the chemical nature of the substances in the preservative. Thus, we caution about the use of chemical preservatives in samples to be analyzed within short time (i.e. less than 1.5 - 2 hours) after sample collection. Avoid chemical preservatives, in this situation, could help avoid changes in the pH and specific gravity, which could eventually help in maintaining quality in the preanalytical phase of urinalysis.
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Affiliation(s)
- Samuel Salazar-García
- Laboratorio de Análisis Clínicos, Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí, México
| | - Eunice Lares-Villaseñor
- Laboratorio de Análisis Clínicos, Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí, México
| | - Abraham Bárcenas-Morales
- Laboratorio de Química Clínica, Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí, México
| | - Manuel Vargas-Morales Juan
- Laboratorio de Análisis Clínicos, Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí, México
- Laboratorio de Química Clínica, Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí, México
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Yun BH, Bellamri M, Rosenquist TA, Turesky RJ. Method for Biomonitoring DNA Adducts in Exfoliated Urinary Cells by Mass Spectrometry. Anal Chem 2018; 90:9943-9950. [PMID: 30001485 PMCID: PMC6237078 DOI: 10.1021/acs.analchem.8b02170] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Tobacco smoking contributes to about 50% of the bladder-cancer (BC) cases in the United States. Some aromatic amines in tobacco smoke are bladder carcinogens; however, other causal agents of BC are uncertain. Exfoliated urinary cells (EUCs) are a promising noninvasive biospecimen to screen for DNA adducts of chemicals that damage the bladder genome, although the analysis of DNA adducts in EUCs is technically challenging because of the low number of EUCs and limiting quantity of cellular DNA. Moreover, EUCs and their DNA adducts must remain viable during the time of collection and storage of urine to develop robust screening methods. We employed RT4 cells, a well-differentiated transitional epithelial bladder cell line, as a cell-model system in urine to investigate cell viability and the chemical stability of DNA adducts of two prototypical bladder carcinogens: 4-aminobiphenyl (4-ABP), an aromatic amine found in tobacco smoke, and aristolochic acid I (AA-I), a nitrophenanthrene found in Aristolochia herbaceous plants used for medicinal purposes worldwide. The cell viability of RT4 cells pretreated with 4-ABP or AA-I in urine exceeded 80%, and the major DNA adducts of 4-ABP and AA-I, quantified by liquid chromatography-mass spectrometry, were stable for 24 h. Thereafter, we successfully screened EUCs of mice treated with AA-I to measure DNA adducts of AA-I, which were still detected 25 days following treatment with the carcinogen. EUCs are promising biospecimens that can be employed for the screening of DNA adducts of environmental and dietary genotoxicants that may contribute to the development of BC.
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Affiliation(s)
- Byeong Hwa Yun
- Masonic Cancer Center and Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455
| | - Medjda Bellamri
- Masonic Cancer Center and Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455
| | - Thomas A. Rosenquist
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794
| | - Robert J. Turesky
- Masonic Cancer Center and Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455
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Cho SS, Kim MS, Shin KA. Chemical Preservation Methods of Urine Sediment for Quality Control. KOREAN JOURNAL OF CLINICAL LABORATORY SCIENCE 2017. [DOI: 10.15324/kjcls.2017.49.4.359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Affiliation(s)
- Soung Suck Cho
- Department of Clinical Laboratory Science, Shinsung University, Dangjin, Korea
| | - Myong Soo Kim
- Department of Laboratory Medicine, Samsung Medical Center, Seoul, Korea
| | - Kyung-A Shin
- Department of Clinical Laboratory Science, Shinsung University, Dangjin, Korea
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Delanghe JR, Speeckaert MM. Preanalytics in urinalysis. Clin Biochem 2016; 49:1346-1350. [DOI: 10.1016/j.clinbiochem.2016.10.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 09/05/2016] [Accepted: 10/18/2016] [Indexed: 02/07/2023]
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