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Šálek T, Musil P, Vermeersch P, Marrington R, Dikmen ZG, Poláchová R, Kipman U, Kouri TT, Cadamuro J. Preservation of urine specimens for metabolic evaluation of recurrent urinary stone formers. Clin Chem Lab Med 2024; 0:cclm-2024-0773. [PMID: 39072394 DOI: 10.1515/cclm-2024-0773] [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: 07/02/2024] [Accepted: 07/03/2024] [Indexed: 07/30/2024]
Abstract
OBJECTIVES Stability of concentrations of urinary stone-related metabolites was analyzed from samples of recurrent urinary stone formers to assess necessity and effectiveness of urine acidification during collection and storage. METHODS First-morning urine was collected from 20 adult calcium-stone forming patients at Tomas Bata Hospital in the Czech Republic. Urine samples were analyzed for calcium, magnesium, inorganic phosphate, uric acid, sodium, potassium, chloride, citrate, oxalate, and urine particles. The single-voided specimens were collected without acidification, after which they were divided into three groups for storage: samples without acidification ("NON"), acidification before storage ("PRE"), or acidification after storage ("POST"). The analyses were conducted on the day of arrival (day 0, "baseline"), or after storage for 2 or 7 days at room temperature. The maximum permissible difference (MPD) was defined as ±20 % from the baseline. RESULTS The urine concentrations of all stone-related metabolites remained within the 20 % MPD limits in NON and POST samples after 2 days, except for calcium in NON sample of one patient, and oxalate of three patients and citrate of one patient in POST samples. In PRE samples, stability failed in urine samples for oxalate of three patients, and for uric acid of four patients after 2 days. Failures in stability often correlated with high baseline concentrations of those metabolites in urine. CONCLUSIONS Detailed procedures are needed to collect urine specimens for analysis of urinary stone-related metabolites, considering both patient safety and stability of those metabolites. We recommend specific preservation steps.
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Affiliation(s)
- Tomáš Šálek
- Department of Clinical Biochemistry and Pharmacology, 37742 Tomas Bata Hospital Zlín , Zlín, Czech Republic
- Institute of Clinical Biochemistry and Diagnostics, Medical Faculty in Hradec Králové, Charles University, Prague, Czech Republic
| | - Pavel Musil
- Department of Clinical Biochemistry and Pharmacology, 37742 Tomas Bata Hospital Zlín , Zlín, Czech Republic
| | - Pieter Vermeersch
- Clinical Department of Laboratory Medicine, University Hospitals Leuven, Leuven, Belgium
| | - Rachel Marrington
- Birmingham Quality (UK NEQAS), University Hospitals NHS Foundation Trust, Birmingham, UK
| | - Zeliha G Dikmen
- Clinical Pathology Laboratory, Department of Medical Biochemistry and Hacettepe University Hospitals, Hacettepe University Faculty of Medicine, Ankara, Türkiye
| | - Radka Poláchová
- Department of Clinical Biochemistry and Pharmacology, 37742 Tomas Bata Hospital Zlín , Zlín, Czech Republic
| | | | - Timo T Kouri
- Department of Clinical Chemistry, University of Helsinki, Espoo, Finland
- Hospital District of Helsinki and Uusimaa, HUS Diagnostic Center, HUSLAB, Helsinki, Finland
| | - Janne Cadamuro
- Department of Laboratory Medicine, Paracelsus Medical University, Salzburg, Austria
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Vago R, Radano G, Zocco D, Zarovni N. Urine stabilization and normalization strategies favor unbiased analysis of urinary EV content. Sci Rep 2022; 12:17663. [PMID: 36271135 PMCID: PMC9587215 DOI: 10.1038/s41598-022-22577-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 10/17/2022] [Indexed: 01/18/2023] Open
Abstract
Urine features an ideal source of non-invasive diagnostic markers. Some intrinsic and methodological issues still pose barriers to its full potential as liquid biopsy substrate. Unlike blood, urine concentration varies with nutrition, hydration and environmental factors. Urine is enriched with EVs from urinary-genital tract, while its conservation, purification and normalization can introduce bias in analysis of EV subsets in inter-and intra-individual comparisons. The present study evaluated the methods that decrease such biases such as appropriate and feasible urine storage, optimal single-step EV purification method for recovery of proteins and RNAs from small urine volumes and a normalization method for quantitative analysis of urine EV RNAs. Ultracentrifugation, chemical precipitation and immuno-affinity were used to isolate EVs from healthy donors' urine that was stored frozen or at room temperature for up to 6 months. Multiple urine biochemical and EV parameters, including particle count and protein content, were compared across urine samples. To this purpose nanoparticle tracking analysis (NTA) and protein assessment by BCA, ELISA and WB assays were performed. These measurements were correlated with relative abundances of selected EV mRNAs and miRNAs assessed by RT-PCR and ranked for the ability to reflect and correct for EV content variations in longitudinal urine samples. All purification methods enabled recovery and downstream analysis of EVs from as few as 1 ml of urine. Our findings highlight long term stability of EV RNAs upon urine storage at RT as well as excellent correlation of EV content in urine with some routinely measured biochemical features, such as total urine protein and albumin, but not creatinine most conventionally used for urine normalization. Comparative evaluation of mRNA and miRNAs in EV isolates revealed specific RNAs, in particular RNY4 and small miRNA panel, levels of which well reflected the inter-sample EV variation and therefore useful as possible post-analytical normalizers of EV RNA content. We describe some realistic urine processing and normalization solutions for unbiased readout of EV biomarker studies and routine clinical sampling and diagnostics providing the input for design of larger validation studies employing urine EVs as biomarkers for particular conditions and diseases.
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Affiliation(s)
- Riccardo Vago
- grid.18887.3e0000000417581884Urological Research Institute, Division of Experimental Oncology, IRCCS San Raffaele Scientific Institute, Milan, Italy ,grid.15496.3f0000 0001 0439 0892Università Vita-Salute San Raffaele, 20132 Milan, Italy
| | | | | | - Natasa Zarovni
- Exosomics S.p.A, 53100 Siena, Italy ,HansaBiomed Life Sciences OU, Tallinn, Estonia
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Kaya E, Usta M, Emecen Ö, Yıldırmak S. Interference of preservatives on urinary iodine measurement by Sandell–Kolthoff method. Scandinavian Journal of Clinical and Laboratory Investigation 2022; 82:498-503. [DOI: 10.1080/00365513.2022.2107566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Affiliation(s)
- Elif Kaya
- Master of Science Degree Program in Medical Biochemistry, Institute of Health Sciences, Giresun University, Giresun, Turkey
| | - Murat Usta
- Department of Medical Biochemistry, Faculty of Medicine, Giresun University, Giresun, Turkey
| | - Ömer Emecen
- Department of Medical Biochemistry, Faculty of Medicine, Giresun University, Giresun, Turkey
| | - Sembol Yıldırmak
- Department of Medical Biochemistry, Faculty of Medicine, Giresun University, Giresun, Turkey
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Bal C, Topcuoğlu C, Rıfat Balık A, Yılmaz FM, Erel Ö, Yılmaz G. The effect of acid use as a preservative on the results of biochemical tests measured in 24-h urine. Scandinavian Journal of Clinical and Laboratory Investigation 2022; 82:329-333. [PMID: 35791842 DOI: 10.1080/00365513.2022.2092899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Twenty-four-hour urine measurements play a crucial role in the diagnosis, follow-up and treatment of various diseases. There are different approaches to the collection of urine in patients who need to collect multiple urine samples at a time, especially in hospitals with heavy workloads. In this study, we compared the sodium, potassium, chloride, amylase, calcium, creatinine, phosphorus, microalbumin, protein, magnesium, urea, uric acid, adrenaline, noradrenaline, dopamine, metanephrine, normetanephrine, vanillylmandelic acid, 5-hydroxyindoleacetic acid and homovanillic acid results of 24-h urine samples analyzed immediately without acid addition, which we accepted as the reference and baseline measurement, with the results of the samples analyzed after waiting for 24 h without acid addition, analyzed immediately with acid addition and analyzed after waiting for 24 h with acid addition. Chloride, microalbumin, amylase and protein tests, which are recommended to be measured in the sample without preservatives, are affected by acid addition. Adrenaline, noradrenaline and dopamine, which are the tests recommended to be measured in acid-added urine are degraded in the samples without acid, and the levels of metanephrine and normetanephrine were not significantly degraded in the absence of preservatives.
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Affiliation(s)
- Ceylan Bal
- Department of Medical Biochemistry, Ankara Yıldırım Beyazıt University, Ankara, Turkey.,Department of Medical Biochemistry, Ankara City Hospital, Ankara, Turkey
| | - Canan Topcuoğlu
- Department of Medical Biochemistry, Ankara City Hospital, Ankara, Turkey
| | - Ahmet Rıfat Balık
- Department of Medical Biochemistry, Gulhane Training and Research Hospital, Ankara, Turkey
| | - Fatma Meriç Yılmaz
- Department of Medical Biochemistry, Ankara Yıldırım Beyazıt University, Ankara, Turkey.,Department of Medical Biochemistry, Ankara City Hospital, Ankara, Turkey
| | - Özcan Erel
- Department of Medical Biochemistry, Ankara Yıldırım Beyazıt University, Ankara, Turkey.,Department of Medical Biochemistry, Ankara City Hospital, Ankara, Turkey
| | - Gülsen Yılmaz
- Department of Medical Biochemistry, Ankara Yıldırım Beyazıt University, Ankara, Turkey.,Department of Medical Biochemistry, Ankara City Hospital, Ankara, Turkey
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Šálek T, Musil P, Pšenčík M, Palička V. Post-collection acidification of spot urine sample is not needed before measurement of electrolytes. Biochem Med (Zagreb) 2022; 32:020702. [PMID: 35464747 PMCID: PMC8996324 DOI: 10.11613/bm.2022.020702] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 01/18/2022] [Indexed: 11/23/2022] Open
Abstract
Introduction Kidney stone formers can have higher oxalate and phosphate salt amounts in their urine than healthy people and we hypothesized that its acidification may be useful. The study aims to compare results of urine concentrations of calcium, magnesium, and inorganic phosphorus in the midstream portion of first voided morning urine samples without (FMU) and with post-collection acidification (FMUa) in kidney stone patients. Materials and methods This is a prospective single center study. A total of 138 kidney stone patients with spot urine samples were included in the study. Urine concentrations of calcium, magnesium and inorganic phosphorus were measured with and without post-collection acidification. Acidification was performed by adding 5 µL of 6 mol/L HCl to 1 mL of urine. Results The median age (range) of all participants was 56 (18-87) years. The median paired differences between FMU and FMUa concentrations of calcium, magnesium, and inorganic phosphorus were: - 0.040 mmol/L, 0.035 mmol/L, and 0.060 mmol/L, respectively. They were statistically different: P < 0.001, P < 0.001, P = 0.004, respectively. These differences are not clinically significant because biological variations of these markers are much higher. Conclusions No clinically significant differences in urinary calcium, magnesium, and inorganic phosphorus concentrations between FMU and FMUa in patients with kidney stones were found.
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Affiliation(s)
- Tomáš Šálek
- Institute of Clinical Biochemistry and Diagnostics, Medical Faculty in Hradec Králové, Charles University, Prague, Czech Republic
- Corresponding author:
| | - Pavel Musil
- Department of Clinical biochemistry and pharmacology, The Tomas Bata Hospital in Zlín, Zlín, Czech Republic
| | - Marek Pšenčík
- Department of Clinical biochemistry and pharmacology, The Tomas Bata Hospital in Zlín, Zlín, Czech Republic
| | - Vladimír Palička
- Institute of Clinical Biochemistry and Diagnostics, Medical Faculty in Hradec Králové, Charles University, Prague, Czech Republic
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Dent A, Selvaratnam R. Measuring Magnesium – Physiological, Clinical and Analytical Perspectives. Clin Biochem 2022; 105-106:1-15. [DOI: 10.1016/j.clinbiochem.2022.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 03/23/2022] [Accepted: 04/01/2022] [Indexed: 11/03/2022]
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Abstract
PURPOSE OF REVIEW This review provides suggestions for the evaluation of patients with osteoporosis in order to assure that the diagnosis is correct, to identify potentially correctable conditions contributing to skeletal fragility and fracture risk, and to assist in individualizing management decisions. RECENT FINDINGS Some patients who appear to have osteoporosis have another skeletal disease, such as osteomalacia, that requires further evaluation and treatment that is different than for osteoporosis. Many patients with osteoporosis have contributing factors (e.g., vitamin D deficiency, high fall risk) that should be addressed before and after starting treatment to assure that treatment is effective and safe. Evaluation includes a focused medical history, skeletal-related physical examination, assessment of falls risk, appropriate laboratory tests, and rarely transiliac double-tetracycline labeled bone biopsy. Evaluation of patients with osteoporosis before starting treatment is essential for optimizing clinical outcomes.
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Affiliation(s)
- E Michael Lewiecki
- New Mexico Clinical Research & Osteoporosis Center, 300 Oak St. NE, Albuquerque, NM, 87106, USA.
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Khodadadi M, Pourfarzam M. A review of strategies for untargeted urinary metabolomic analysis using gas chromatography-mass spectrometry. Metabolomics 2020; 16:66. [PMID: 32419109 DOI: 10.1007/s11306-020-01687-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Accepted: 04/30/2020] [Indexed: 02/06/2023]
Abstract
BACKGROUND Human urine gives evidence of the metabolism in the body and contains different metabolites at various concentrations. A number of analytical techniques including mass spectrometry (MS) and nuclear magnetic resonance (NMR) have been used to obtain metabolites levels in urine samples. However, gas chromatography-mass spectrometry (GC-MS) is one of the most widely used techniques for urinary metabolomics studies due to its higher sensitivity, resolution, reproducibility, reliability, relatively low cost and ease of operation compared to liquid chromatography-mass spectrometry and NMR. AIM OF REVIEW This review looks at various aspects of urine preparation prior to analysis by GC-MS including sample storage, urease pretreatment, derivatization, use of internal standard and quality control samples for data correction. In addition, most common types of inlet liners, ionization techniques and columns are discussed and a summary of mass analyzers are also highlighted. Lastly, the role of retention index in metabolite identification and data normalization methods are presented. KEY SCIENTIFIC CONCEPTS OF REVIEW The purpose of this review is summarizing methods of sample storage, pretreatment, and GC-MS analysis that are mostly used in urine metabolomics studies. Specific emphasis is given to the critical steps within the GC-MS urine metabolomics that those new to this field need to be aware of and the remaining challenges that require further attention and studies.
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Affiliation(s)
- Mohammad Khodadadi
- Department of Clinical Biochemistry, School of Pharmacy & Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Morteza Pourfarzam
- Department of Clinical Biochemistry, School of Pharmacy & Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran.
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Solving a myth: Does boric acid stabilize aldosterone in urine at typical clinical laboratory storage conditions? Clin Biochem 2019; 73:112-114. [DOI: 10.1016/j.clinbiochem.2019.07.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 07/26/2019] [Accepted: 07/30/2019] [Indexed: 11/21/2022]
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10
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Redmond EJ, Murphy CF, Leonard J, Faulds K, Abdelfadil S, Crowley VE, Lynch TH, Manecksha RP. The influence of dietary supplementation with cranberry tablets on the urinary risk factors for nephrolithiasis. World J Urol 2018; 37:561-566. [DOI: 10.1007/s00345-018-2344-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 05/17/2018] [Indexed: 10/28/2022] Open
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Ellervik C, Vaught J. Preanalytical Variables Affecting the Integrity of Human Biospecimens in Biobanking. Clin Chem 2015; 61:914-34. [DOI: 10.1373/clinchem.2014.228783] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 04/13/2015] [Indexed: 12/20/2022]
Abstract
Abstract
BACKGROUND
Most errors in a clinical chemistry laboratory are due to preanalytical errors. Preanalytical variability of biospecimens can have significant effects on downstream analyses, and controlling such variables is therefore fundamental for the future use of biospecimens in personalized medicine for diagnostic or prognostic purposes.
CONTENT
The focus of this review is to examine the preanalytical variables that affect human biospecimen integrity in biobanking, with a special focus on blood, saliva, and urine. Cost efficiency is discussed in relation to these issues.
SUMMARY
The quality of a study will depend on the integrity of the biospecimens. Preanalytical preparations should be planned with consideration of the effect on downstream analyses. Currently such preanalytical variables are not routinely documented in the biospecimen research literature. Future studies using biobanked biospecimens should describe in detail the preanalytical handling of biospecimens and analyze and interpret the results with regard to the effects of these variables.
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Affiliation(s)
- Christina Ellervik
- Department of Research, Nykoebing Falster Hospital, Nykoebing Falster, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Laboratory Medicine, Boston Children's Hospital, Boston, MA
| | - Jim Vaught
- International Society for Biological and Environmental Repositories, Vancouver, Canada
- Editor-in-Chief, Biopreservation and Biobanking, Vancouver, Canada
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Yaroshenko IS, Kartsova LA. Determination of markers of the urinary stone disease. JOURNAL OF ANALYTICAL CHEMISTRY 2015. [DOI: 10.1134/s1061934815030223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Feres MC, Cintra FD, Rizzi CF, Mello-Fujita L, Lino de Souza AA, Tufik S, Poyares D. Evaluation and validation of a method for determining platelet catecholamine in patients with obstructive sleep apnea and arterial hypertension. PLoS One 2014; 9:e98407. [PMID: 24911183 PMCID: PMC4049580 DOI: 10.1371/journal.pone.0098407] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Accepted: 05/02/2014] [Indexed: 11/23/2022] Open
Abstract
Background Measurements of plasma and urinary catecholamine are susceptible to confounding factors that influence the results, complicating the interpretation of sympathetic nervous system (SNS) activity in the Obstructive sleep apnea (OSA) and arterial hypertension (HYP) conditions. Objective In this study, we validated a test for platelet catecholamine and compared the catecholamine levels (adrenaline and noradrenaline) in urine, plasma and platelets in patients with OSA and HYP compared with controls. Methods In the validation, 30 healthy, nonsmoking volunteers who were not currently undergoing treatment or medication were selected as the control group. One hundred fifty-four individuals (114 OSA, 40 non-OSA) were consecutively selected from the outpatient clinic of the Sleep Institute and underwent clinical, polysomnographic and laboratory evaluation, including the urinary, plasma and platelet levels of adrenaline (AD) and noradrenaline (NA). Patients were then allocated to groups according to the presence of OSA and/or hypertension. Results A logistic regression model, controlled for age and BMI, showed that urinary AD and urinary NA were risk factors in the OSA+HYP group and the HYP group; however, the model showed higher levels of platelet NA for OSA without HYP. After 1 year of CPAP (continuous upper airway pressure) treatment, patients (n = 9) presented lower levels of urinary NA (p = 0.04) and platelet NA (p = 0.05). Conclusion Urinary NA and AD levels were significantly associated with the condition of hypertension with and without OSA, whereas platelet NA with OSA without comorbidity. These findings suggest that platelet catecholamine levels might reflect nocturnal sympathetic activation in OSA patients without hypertension.
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Affiliation(s)
- Marcia C. Feres
- Psychobiology Department of Universidade Federal de São Paulo, Sao Paulo, SP, Brazil
- * E-mail:
| | - Fatima D. Cintra
- Cardiology Department of Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Camila F. Rizzi
- Psychobiology Department of Universidade Federal de São Paulo, Sao Paulo, SP, Brazil
| | - Luciane Mello-Fujita
- Psychobiology Department of Universidade Federal de São Paulo, Sao Paulo, SP, Brazil
| | | | - Sergio Tufik
- Psychobiology Department of Universidade Federal de São Paulo, Sao Paulo, SP, Brazil
- Associação Fundo de Incentivo a Pesquisa – AFIP- São Paulo, São Paulo, SP, Brazil
| | - Dalva Poyares
- Psychobiology Department of Universidade Federal de São Paulo, Sao Paulo, SP, Brazil
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Pratumvinit B, Reesukumal K, Wongkrajang P, Khejonnit V, Klinbua C, Dangneawnoi W. Should acidification of urine be performed before the analysis of calcium, phosphate and magnesium in the presence of crystals? Clin Chim Acta 2013; 426:46-50. [PMID: 24012827 DOI: 10.1016/j.cca.2013.08.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Revised: 08/21/2013] [Accepted: 08/29/2013] [Indexed: 11/29/2022]
Abstract
BACKGROUND Acidification of urine has been recommended before testing for calcium, phosphate, and magnesium. We investigated the necessity of pre-analytical acidification in both crystallized and non-crystallized urine samples. METHODS From 130 urine samples obtained via routine urine analysis, 65 (50%) samples were classified as non-crystallized. All samples were divided into three groups: untreated samples, acidified samples with HCl, and acidified samples after 1h room-temperature incubation. Urine samples were measured for calcium, phosphate, magnesium, and creatinine using Modular P800 and were examined for crystals using light microscopy. RESULTS In crystallized samples, acidified samples with 1h incubation had significantly higher Ca/Cr, P/Cr, and Mg/Cr than did untreated samples with mean differences of 0.04, 0.03, and 0.01 mg/mg, respectively (P<0.001). In acidified samples that were analyzed immediately, crystallized samples had lower calcium concentrations than those of acidified samples with 1h incubation and a mean difference of 0.21 mg/dl (P = 0.025). None of the sample differences which exceeded the critical difference of urinary Ca, P and Mg was observed. CONCLUSIONS Acidification of urine should be performed before the measurement of Ca, P, and Mg in the presence of urinary crystals. However, the lack of an acidification process does not result in a clinically significant change.
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Affiliation(s)
- Busadee Pratumvinit
- Department of Clinical Pathology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
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