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Kalaria C, Kittner S. The Therapeutic Value of Laboratory Testing for Hypercoagulable States in Secondary Stroke Prevention. Neurol Clin 2015; 33:501-13. [DOI: 10.1016/j.ncl.2015.01.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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2
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Zighetti ML, Chantarangkul V, Lombardi R, Lecchi A, Cattaneo M. Effects of some pre-analytical conditions on the measurement of homocysteine and cysteine in plasma. ACTA ACUST UNITED AC 2004; 42:204-7. [PMID: 15061362 DOI: 10.1515/cclm.2004.037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractThe association of hyperhomocysteinemia and hypercysteinemia with the risk of arterial and venous thrombosis is well documented. While it is known that standardized pre-analytical conditions are necessary for reliable measurement of plasma total homocysteine, the effects of pre-analytical conditions on cysteine measurement are less well known. The aim of this study was to evaluate the effects of pre-analytical conditions on the measurement of homocysteine and cysteine. We observed that the concentration of total homocysteine in plasma increased significantly with time (38% after 6 h), whereas total cysteine decreased (5% after 2h) when blood anticoagulated with ethylenediaminetetraacetic tripotassium salt was kept at room temperature. These changes were minimized when acidic citrate dextrose was used as an anticoagulant and were abolished when blood samples were immediately placed on crushed ice, independently of the anticoagulant. Storage of plasma for 72h at room temperature induced a small (≅6%), but significant, decrease in cysteine when blood was collected in ethylenediaminetetraacetic tripotassium salt. In contrast, homocysteine was stable in plasma for 72h, independently of the anticoagulant used. In conclusion, if blood samples for plasma total homocysteine and cysteine measurement cannot be kept on ice, they should be collected in acidic citrate dextrose to minimize the artifactual changes.
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Affiliation(s)
- Maddalena L Zighetti
- Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, IRCCS Ospedale Maggiore, Department of Internal Medicine, Milan, Italy.
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Hill DM, Johnson LJ, Burns PJ, Neale AM, Harmening DM, Kenney AC. Effects of Temperature on Stability of Blood Homocysteine in Collection Tubes Containing 3-Deazaadenosine. Clin Chem 2002. [DOI: 10.1093/clinchem/48.11.2017] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Abstract
Background: The accuracy of homocysteine (Hcy) results is currently compromised by the requirement to separate the plasma within 1 h of sample collection. We studied the effect of temperature on the stability of plasma Hcy over a 72-h time course in blood collected into evacuated tubes containing either EDTA alone or both EDTA and 3-deazaadenosine (3DA).
Methods: We recruited 100 volunteers, including both diseased and healthy individuals with a range of baseline plasma Hcy values, from two centers. Blood samples were collected into tubes containing EDTA, and EDTA plus 3DA and stored at ambient temperature (20–25 °C) or refrigerated (2–8 °C). Aliquots of blood were centrifuged at various times up to 72 h, the plasma was removed, and Hcy was measured by HPLC.
Results: Plasma Hcy measurement covering the sample collection and storage conditions during the whole time course was possible on samples from 59 of those recruited. One-way ANOVA for repeated measures within subjects revealed that only samples that were collected into tubes containing EDTA plus 3DA and stored refrigerated were stable over 72 h (P = 0.2761).
Conclusions: A combination of 3DA and storage at 2–8 °C will allow collection of samples for plasma Hcy measurement outside of the hospital setting and wider population screening.
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Affiliation(s)
- Diane M Hill
- Research and Development Department, Drew Scientific Ltd., Sowerby Woods Business Park, Barrow-in-Furness LA14 4QR, United Kingdom
| | - Lisa J Johnson
- University of Maryland School of Medicine, Department of Medical and Research Technology, 100 Penn St., Room 340, Baltimore, MD 21201
| | - Paul J Burns
- Lincoln House, Department of Vascular Surgery, Birmingham Heartlands Hospital, Bordesley Green East, Birmingham B9 5SS, United Kingdom
| | - Angela M Neale
- University of Maryland School of Medicine, Department of Medical and Research Technology, 100 Penn St., Room 340, Baltimore, MD 21201
| | - Denise M Harmening
- University of Maryland School of Medicine, Department of Medical and Research Technology, 100 Penn St., Room 340, Baltimore, MD 21201
| | - Andrew C Kenney
- Research and Development Department, Drew Scientific Ltd., Sowerby Woods Business Park, Barrow-in-Furness LA14 4QR, United Kingdom
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Théorêt Y, Rivard GE, Infante-Rivard C, Yotov WV. Stability of total plasma homocysteine in perinatology. Clin Chim Acta 2002; 319:63-6. [PMID: 11922925 DOI: 10.1016/s0009-8981(02)00010-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND Typical assay methods for total homocysteine in human plasma involve EDTA-containing whole blood. Unfortunately, rapid increases of the plasma homocysteine concentrations due to cellular export are observed when the EDTA-containing samples are not stored on ice and processed shortly after collection. This is a cumbersome procedure in perinatal settings, whereby delivery usually takes place at unpredictable times. METHODS The stability of homocysteine was assessed from six placental and neonatal blood samples collected in citrate buffer. Samples were stored at 4 degrees C and tested at regular intervals for the first 24 h. RESULTS There was no statistical difference in homocysteine concentrations as observed over the study storage period (mean coefficient of variation [CV] 4.9%). CONCLUSIONS Citrated samples can be left in a refrigerator for at least 24 h with no effect on the plasma homocysteine concentrations.
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Affiliation(s)
- Yves Théorêt
- Département de Pharmacologie, Université de Montreal, Quebec, Canada
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Nauck M, Bisse E, Nauck M, Wieland H. Pre-analytical conditions affecting the determination of the plasma homocysteine concentration. Clin Chem Lab Med 2001; 39:675-80. [PMID: 11592432 DOI: 10.1515/cclm.2001.111] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In the past decade, moderately elevated homocysteine concentration has achieved wide-spread recognition as an independent risk factor for vascular diseases, such as stroke and peripheral vascular disease, as well as for an impaired nutritional status. In general, EDTA plasma is used for the determination of homocysteine. However, from the pre-analytical point of view it is important, that, when plasma is not separated from blood cells within 30 minutes, homocysteine levels increase in samples significantly by about 10% per hour. This 10% increase is very important, because the normal range is between 5 and 15 micromol/l and moderately elevated homocysteine concentrations above 15 micromol/l may signify an increased risk of vascular disease. These preliminary cut-off points show that there is only a small difference between normal and moderately elevated homocysteine concentrations. Most blood samples are obtained outside the hospital, and in these cases homocysteine concentrations will be falsely elevated, if no precautions are taken, such as immediate centrifugation and separation of plasma and cells. This aspect is critical both for clinical studies and in patient care outside the hospital. But even in the hospital it is difficult to separate plasma and cells within 30 minutes. In the past, different approaches were adopted to solve this problem. Potential stabilisers were sodium fluoride (4 g/l) and 3-deazaadenosine (100 micromol/l). Sodium fluoride initially increased the homocysteine concentration, which dropped below the initial values after 72 h. On the other hand, 3-deazaadenosine stabilised homocysteine concentrations for 24 h, but increased it within 72 h by roughly 10%. However, this stabiliser is restricted to HPLC technology but does not work reliably with immunoassays. Lysis of blood stabilised homocysteine, but homocysteine concentrations were systematically lower requiring totally new reference ranges. In addition, acidic citrate (0.5 mol/l) was evaluated, which seems to stabilise plasma homocysteine concentrations at ambient temperatures for several hours. However, small but systematic deviations at baseline are observed. This stabilisation procedure does not interfere with immunoassays. Because immunoassays will be the future method of choice for robust and easy to perform homocysteine measurements, because they easily allow the analyses of high sample numbers, homocysteine stabilisation in whole blood is still an important matter. It must be solved before homocysteine determinations are introduced as a general screening for vascular risk factors in non-specialist laboratories.
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Affiliation(s)
- M Nauck
- Department of Clinical Chemistry, University Hospital Freiburg, Germany.
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6
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Homocysteine as a Risk Factor for Coronary Artery Disease. HOMOCYSTEINE AND VASCULAR DISEASE 2000. [DOI: 10.1007/978-94-017-1789-2_11] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Abstract
Recent data have shown that an elevated plasma level of the amino acid homocysteine (Hcy) is a common, independent, easily modifiable and possibly causal risk factor for cardiovascular disease (CVD) which may be of equal importance to hypercholesterolemia, hypertension and smoking. This paper reviews the biochemical, clinical, epidemiological and experimental data underlying this conclusion and is critically questioning whether elevated tHcy is a causal factor.
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Affiliation(s)
- O Nygård
- Division for Medical Statistics, Department of Public Health, University of Bergen, Norway, Sweden.
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Kittner SJ, Giles WH, Macko RF, Hebel JR, Wozniak MA, Wityk RJ, Stolley PD, Stern BJ, Sloan MA, Sherwin R, Price TR, McCarter RJ, Johnson CJ, Earley CJ, Buchholz DW, Malinow MR. Homocyst(e)ine and risk of cerebral infarction in a biracial population : the stroke prevention in young women study. Stroke 1999; 30:1554-60. [PMID: 10436100 DOI: 10.1161/01.str.30.8.1554] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Genetic enzyme variation and vitamin intake are important determinants of blood homocyst(e)ine levels. The prevalence of common genetic polymorphisms influencing homocyst(e)ine levels varies by race, and vitamin intake varies by socioeconomic status. Therefore, we examined the effect of vitamin intake, race, and socioeconomic status on the association of homocyst(e)ine with stroke risk. METHODS All 59 hospitals in the greater Baltimore-Washington area participated in a population-based case-control study of stroke in young women. One hundred sixty-seven cases of first ischemic stroke among women aged 15 to 44 years were compared with 328 controls identified by random-digit dialing from the same region. Risk factor data were collected by standardized interview and nonfasting phlebotomy. Plasma homocyst(e)ine was measured by high-performance liquid chromatography and electrochemical detection. RESULTS Blacks and whites did not differ in median homocyst(e)ine levels, nor did race modify the association between homocyst(e)ine and stroke. After adjustment for cigarettes per day, poverty status, and regular vitamin use, a plasma homocyst(e)ine level of >/=7.3 micromol/L was associated with an odds ratio for stroke of 1.6 (95% CI, 1.1 to 2.5). CONCLUSIONS The association between elevated homocyst(e)ine and stroke was independent not only of traditional vascular risk factors but also of vitamin use and poverty status. The degree of homocyst(e)ine elevation associated with an increased stroke risk in young women is lower than that previously reported for middle-aged men and the elderly and was highly prevalent, being present in one third of the control group.
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Affiliation(s)
- S J Kittner
- Department of Neurology, University of Maryland at Baltimore, USA.
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Giles WH, Kittner SJ, Croft JB, Wozniak MA, Wityk RJ, Stern BJ, Sloan MA, Price TR, McCarter RJ, Macko RF, Johnson CJ, Feeser BR, Earley CJ, Buchholz DW, Stolley PD. Distribution and correlates of elevated total homocyst(e)ine: the Stroke Prevention in Young Women Study. Ann Epidemiol 1999; 9:307-13. [PMID: 10976857 DOI: 10.1016/s1047-2797(99)00006-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE To determine the distribution and correlates of elevated total homocyst(e)ine (tHcy) concentration in a population of premenopausal black and white women. METHODS Data from the Stroke Prevention in Young Women Study (N = 304), a population-based study of risk factors for stroke in women aged 15-44 years of age, were used to determine the distribution and correlates of elevated tHcy in black (N = 103) and white women (N = 201). RESULTS The mean tHcy level for the population was 6.58 micromol/L (range 2.89-26.5 micromol/L). Mean tHcy levels increased with age, cholesterol level, alcohol intake, and number of cigarettes smoked (all: p < 0.05). There were no race differences (mean tHcy 6.72 micromol/L among blacks and 6.51 micromol/L among whites; p = 0.4346). Regular use of multivitamins and increasing education was associated with significant reductions in tHcy concentration. Approximately 13% of the sample had elevated tHcy levels, defined as a tHcy concentration > or = 10.0 micromol/L. Multivariate-adjusted correlates of elevated tHcy included education > 12 vs. < or = 12 (odds ratio [OR] = 0.4, 95% confidence interval [CI] = 0.2-0.8); smoking > or = 20 cigarettes/day vs. nonsmokers (OR = 2.8, 95% CI = 1.1-7.3); and the regular use of multivitamins (OR = 0.4, 95% CI = 0.2-0.9). CONCLUSIONS These results suggest that a substantial proportion of healthy young premenopausal women have tHcy levels that increase their risk for vascular disease. A number of potentially modifiable behavioral and environmental factors appear to be significantly related to elevated tHcy levels in young women.
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Affiliation(s)
- W H Giles
- Cardiovascular Health Branch, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
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Hughes MP, Carlson TH, McLaughlin MK, Bankson DD. Addition of Sodium Fluoride to Whole Blood Does Not Stabilize Plasma Homocysteine But Produces Dilution Effects on Plasma Constituents and Hematocrit. Clin Chem 1998. [DOI: 10.1093/clinchem/44.10.2204] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
| | - Timothy H Carlson
- Department of Laboratory Medicine, University of Washington, Seattle, WA 98195
| | | | - Daniel D Bankson
- Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108
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11
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Willems HPJ, Bos GMJ, Gerrits WBJ, den Heijer M, Vloet S, Blom HJ. Acidic Citrate Stabilizes Blood Samples for Assay of Total Homocysteine. Clin Chem 1998. [DOI: 10.1093/clinchem/44.2.342] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Huub P J Willems
- Dept. of Hematol., Leyenburg Hosp., PO Box 40551, 2504 LN Den Haag; Dept. of Hematol., Dr. Daniel den Hoed Clinic, Rotterdam; Dept. of Intern. Med., TweeSteden Hosp., Tilburg; Lab. of Pediatrics and Neurol., Univ. Hosp. Radboud, Nijmegen, The Netherlands
| | - Gerard M J Bos
- Dept. of Hematol., Leyenburg Hosp., PO Box 40551, 2504 LN Den Haag; Dept. of Hematol., Dr. Daniel den Hoed Clinic, Rotterdam; Dept. of Intern. Med., TweeSteden Hosp., Tilburg; Lab. of Pediatrics and Neurol., Univ. Hosp. Radboud, Nijmegen, The Netherlands
| | - Wim B J Gerrits
- Dept. of Hematol., Leyenburg Hosp., PO Box 40551, 2504 LN Den Haag; Dept. of Hematol., Dr. Daniel den Hoed Clinic, Rotterdam; Dept. of Intern. Med., TweeSteden Hosp., Tilburg; Lab. of Pediatrics and Neurol., Univ. Hosp. Radboud, Nijmegen, The Netherlands
| | - Martin den Heijer
- Dept. of Hematol., Leyenburg Hosp., PO Box 40551, 2504 LN Den Haag; Dept. of Hematol., Dr. Daniel den Hoed Clinic, Rotterdam; Dept. of Intern. Med., TweeSteden Hosp., Tilburg; Lab. of Pediatrics and Neurol., Univ. Hosp. Radboud, Nijmegen, The Netherlands
| | - Stephanie Vloet
- Dept. of Hematol., Leyenburg Hosp., PO Box 40551, 2504 LN Den Haag; Dept. of Hematol., Dr. Daniel den Hoed Clinic, Rotterdam; Dept. of Intern. Med., TweeSteden Hosp., Tilburg; Lab. of Pediatrics and Neurol., Univ. Hosp. Radboud, Nijmegen, The Netherlands
| | - Henk J Blom
- Dept. of Hematol., Leyenburg Hosp., PO Box 40551, 2504 LN Den Haag; Dept. of Hematol., Dr. Daniel den Hoed Clinic, Rotterdam; Dept. of Intern. Med., TweeSteden Hosp., Tilburg; Lab. of Pediatrics and Neurol., Univ. Hosp. Radboud, Nijmegen, The Netherlands
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