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Gros N, Klobučar T, Gaber K. Accuracy of Citrate Anticoagulant Amount, Volume, and Concentration in Evacuated Blood Collection Tubes Evaluated with UV Molecular Absorption Spectrometry on a Purified Water Model. Molecules 2023; 28:molecules28020486. [PMID: 36677544 PMCID: PMC9860671 DOI: 10.3390/molecules28020486] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 12/27/2022] [Accepted: 12/29/2022] [Indexed: 01/06/2023] Open
Abstract
Citrate anticoagulant concentration affects the results of coagulation tests. Until now, the end user had no direct insight into the quality of evacuated blood collection tubes. By introducing an easy-to-perform UV spectrometric method for citrate determination on a purified water model, we enabled the evaluation of (1) the accuracy of the anticoagulant amount added into the tubes by a producer, (2) the accuracy of the volume of anticoagulant solution in the tube at the instant of examination, (3) the anticoagulant concentrations at a draw volume. We examined the Vacuette®, Greiner BIO-ONE, Vacutube, LT Burnik d.o.o., and BD Vacutainer® tubes. The anticoagulant amount added into the tubes during production had a relative bias between 3.2 and 23.0%. The anticoagulant volume deficiency at the instant of examination expressed as a relative bias ranged between -11.6 and -91.1%. The anticoagulant concentration relative bias after the addition of purified water in a volume that equalled a nominal draw volume extended from 9.3 to 25.7%. Draw-volume was mostly compliant during shelf life. Only Vacutube lost water over time. Contamination with potassium, magnesium, or both was observed in all the tubes but did not exceed a 0.21 mmol/L level. This study enables medical laboratories to gain insight into the characteristics of the citrate blood collection tubes as one of the preanalytical variables. In situations that require anticoagulant adjustment for accurate results, this can help make the right decisions. The methodology gives producers additional means of controlling the quality of their production process.
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2
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Kitchen S, Adcock DM, Dauer R, Kristoffersen AH, Lippi G, Mackie I, Marlar RA, Nair S. International Council for Standardisation in Haematology (ICSH) recommendations for collection of blood samples for coagulation testing. Int J Lab Hematol 2021; 43:571-580. [PMID: 34097805 DOI: 10.1111/ijlh.13584] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 03/27/2021] [Accepted: 04/02/2021] [Indexed: 01/17/2023]
Abstract
This guidance document has been prepared on behalf of the International Council for Standardisation in Haematology (ICSH). The aim of the document is to provide guidance and recommendations for collection of blood samples for coagulation tests in clinical laboratories throughout the world. The following processes will be covered: ordering tests, sample collection tube and anticoagulant, patient preparation, sample collection device, venous stasis before sample collection, order of draw when different sample types need to be collected, sample labelling, blood-to-anticoagulant ratio (tube filling) and influence of haematocrit. The following areas are excluded from this document, but are included in an associated ICSH document addressing processing of samples for coagulation tests in clinical laboratories: sample transport and primary tube sample stability; centrifugation; interfering substances including haemolysis, icterus and lipaemia; secondary aliquots-transport and storage; and preanalytical variables for platelet function testing. The recommendations are based on published data in peer-reviewed literature and expert opinion.
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Affiliation(s)
- Steve Kitchen
- Sheffield Haemophilia and Thrombosis Centre, Sheffield, UK
| | | | | | - Ann-Helen Kristoffersen
- Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway.,Norwegian Organization for Quality Improvement of Laboratory Examinations (Noklus), Haraldsplass Deaconess Hospital, Bergen, Norway
| | - Giuseppe Lippi
- Section of Clinical Biochemistry, University of Verona, Verona, Italy
| | - Ian Mackie
- Research Department of Haematology, University College London, London, UK
| | - Richard A Marlar
- Department of Pathology, University of New Mexico, Albuquerque, NM, USA
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Cellular and Molecular Effects of High-Molecular-Weight Heparin on Matrix Metalloproteinase 9 Expression. Int J Mol Sci 2019; 20:ijms20071595. [PMID: 30935029 PMCID: PMC6479594 DOI: 10.3390/ijms20071595] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 03/22/2019] [Accepted: 03/28/2019] [Indexed: 12/17/2022] Open
Abstract
Blood sampling with different anticoagulants alters matrix metalloproteinase (MMP-) 9 expression, thus influencing its concentration and diagnostic validity. Here, we aimed to evaluate the effects of different anticoagulants on MMP-9 regulation. MMP-9 expression was assessed in response to ethylenediaminetetraacetic acid, citrate, and high-/low-molecular-weight heparin (HMWH, LMWH) in co-culture experiments using THP-1, Jurkat, and HT cells (representing monocytes, T, and B cells). Triple and double cell line co-culture experiments revealed that HMWH treatment of THP-1 and Jurkat led to a significant MMP-9 induction, whereas other anticoagulants and cell type combinations had no effect. Supernatant of HMWH-treated Jurkat cells also induced MMP-9 in THP-1 suggesting monocytes as MMP-9 producers. HMWH-induced cytokine/chemokine secretion was assessed in co-culture supernatant, and the influence of cytokines/chemokines on MMP-9 production was analyzed. These experiments revealed that Jurkat-derived IL-16 and soluble intercellular adhesion molecule (sICAM-) 1 are able to induce MMP-9 and IL-8 production by THP-1. As a consequence, the increased MMP-9 expression found in HMWH blood samples may be influenced by HMWH-dependent secretion of IL-16 and sICAM-1 by T cells resulting in an increased production of MMP-9 and IL-8 by monocytes. IL-8, in turn, may support MMP-9 and its own expression in a positive autocrine feedback loop.
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4
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van den Besselaar AMHP, Chantarangkul V, Angeloni F, Binder NB, Byrne M, Dauer R, Gudmundsdottir BR, Jespersen J, Kitchen S, Legnani C, Lindahl TL, Manning RA, Martinuzzo M, Panes O, Pengo V, Riddell A, Subramanian S, Szederjesi A, Tantanate C, Herbel P, Tripodi A. International collaborative study for the calibration of proposed International Standards for thromboplastin, rabbit, plain, and for thromboplastin, recombinant, human, plain. J Thromb Haemost 2018; 16:142-149. [PMID: 29065247 DOI: 10.1111/jth.13879] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Indexed: 11/28/2022]
Abstract
Essentials Two candidate International Standards for thromboplastin (coded RBT/16 and rTF/16) are proposed. International Sensitivity Index (ISI) of proposed standards was assessed in a 20-centre study. The mean ISI for RBT/16 was 1.21 with a between-centre coefficient of variation of 4.6%. The mean ISI for rTF/16 was 1.11 with a between-centre coefficient of variation of 5.7%. SUMMARY Background The availability of International Standards for thromboplastin is essential for the calibration of routine reagents and hence the calculation of the International Normalized Ratio (INR). Stocks of the current Fourth International Standards are running low. Candidate replacement materials have been prepared. This article describes the calibration of the proposed Fifth International Standards for thromboplastin, rabbit, plain (coded RBT/16) and for thromboplastin, recombinant, human, plain (coded rTF/16). Methods An international collaborative study was carried out for the assignment of International Sensitivity Indexes (ISIs) to the candidate materials, according to the World Health Organization (WHO) guidelines for thromboplastins and plasma used to control oral anticoagulant therapy with vitamin K antagonists. Results Results were obtained from 20 laboratories. In several cases, deviations from the ISI calibration model were observed, but the average INR deviation attributabled to the model was not greater than 10%. Only valid ISI assessments were used to calculate the mean ISI for each candidate. The mean ISI for RBT/16 was 1.21 (between-laboratory coefficient of variation [CV]: 4.6%), and the mean ISI for rTF/16 was 1.11 (between-laboratory CV: 5.7%). Conclusions The between-laboratory variation of the ISI for candidate material RBT/16 was similar to that of the Fourth International Standard (RBT/05), and the between-laboratory variation of the ISI for candidate material rTF/16 was slightly higher than that of the Fourth International Standard (rTF/09). The candidate materials have been accepted by WHO as the Fifth International Standards for thromboplastin, rabbit plain, and thromboplastin, recombinant, human, plain.
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Affiliation(s)
- A M H P van den Besselaar
- Department of Thrombosis and Hemostasis, and Coagulation Reference Laboratory, Department of Clinical Chemistry and Laboratory Medicine, Leiden University Medical Center, Leiden, the Netherlands
| | | | - F Angeloni
- Hemostasis Reference Laboratory, Hamilton, Canada
| | | | - M Byrne
- National Coagulation Laboratory, St James's Hospital, Dublin, Ireland
| | - R Dauer
- Haematology Laboratory, Pathology Department, Alfred Health, Melbourne, Australia
| | - B R Gudmundsdottir
- Department of Laboratory Hematology and Hemostasis Center, Landspitali University Hospital and University of Iceland School of Medicine, Reykjavik, Iceland
| | - J Jespersen
- Department of Clinical Biochemistry, Hospital of South West Jutland and Unit for Health Promotion Research, Institute of Public Health, University of Southern Denmark, Esbjerg, Denmark
| | - S Kitchen
- Sheffield Haemophilia and Thrombosis Centre, Royal Hallamshire Hospital, Sheffield, UK
| | - C Legnani
- Department of Angiology and Blood Coagulation, University Hospital S. Orsola-Malpighi, Bologna, Italy
| | - T L Lindahl
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - R A Manning
- Department of Coagulation, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, UK
| | - M Martinuzzo
- Grupo Bioquímico, Laboratorio Central del Hospital Italiano de Buenos Aires, Buenos Aires, Argentina
| | - O Panes
- Department of Hematology-Oncology, School of Medicine, Pontifical Catholic University of Chile, Santiago, Chile
| | - V Pengo
- Clinical Cardiology, Department of Cardiac, Thoracic, and Vascular Sciences, University of Padova, Padova, Italy
| | - A Riddell
- Haemophilia Laboratory (HSL), Katharine Dormandy Haemophilia and Thrombosis Centre, Royal Free Hospital, London, UK
| | - S Subramanian
- Department of Transfusion Medicine and Immunohaematology, St John's Medical College Hospital, Bangalore, India
| | - A Szederjesi
- Hemostasis Laboratory, St István and St László Hospital, Budapest, Hungary
| | - C Tantanate
- Department of Clinical Pathology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - P Herbel
- Roche Diagnostics GmbH Mannheim, Mannheim, Germany
| | - A Tripodi
- Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Department of Clinical Sciences and Community Health, Università degli Studi di Milano and IRCCS Cà Granda Maggiore Hospital Foundation, Milano, Italy
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Abstract
Optimal management of anticoagulant therapy requires an understanding of the laboratory tests often employed to guide therapy. The activated partial thromboplastin time (aPTT) can detect abnormalities in the intrinsic and common clotting pathways. Despite numerous limitations in the aPTT test, it remains the gold standard for monitoring unfractionated heparin and direct thrombin inhibitor therapy. The aPTT can be performed in the central laboratory or at the bedside (point of care [POC] testing). The activated clotting time (ACT) is a POC test that is routinely employed to monitor high-dose heparin during invasive and surgical procedures. The ACT therapeutic range will depend on the specific procedure or surgery being performed. Heparin levels are becoming more routinely available and are used to establish the aPTT therapeutic range for heparin therapy as well as for direct monitoring of heparin and low-molecular-weight heparin therapy. The international normalized ratio (INR) is the gold standard for monitoring warfarin patients. The target INR depends on the indication for anticoagulation. POC monitoring for warfarin is becoming increasingly used. Clinicians should have a thorough understanding of the benefits as well as the limitations of warfarin POC monitoring.
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Affiliation(s)
- Maureen A. Smythe
- William Beaumont Hospital, Royal Oak, Michigan, Department of Pharmacy Practice, Wayne State University, Detroit, Michigan,
| | - Anne Caffee
- Shenandoah University, Winchester, Virginia, Martinsburg Veterans Affairs Medical Center, Martinsburg, West Virginia
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Toulon P, Abecassis L, Smahi M, Ternisien C. Monitoring treatments with unfractionated heparin: CTAD must be used instead of citrate as the anticoagulant solution when using partial-draw collection tubes. Results of a multicenter evaluation. Thromb Res 2010; 126:536-42. [PMID: 20950840 DOI: 10.1016/j.thromres.2010.08.029] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2010] [Revised: 08/11/2010] [Accepted: 08/22/2010] [Indexed: 11/28/2022]
Abstract
BACKGROUND Sampling small volumes of blood may be necessary, particularly in pediatric patients, or in case of difficult or recurrent venipunctures. METHODS Routine hemostasis test results evaluated in partial- and full-draw evacuated polymer tubes obtained in 4 centers were compared. RESULTS No relevant discrepancy (Bland-Altman) was found between test results measured in partial- and full-draw tubes obtained from untreated patients and from patients on vitamin K-antagonist or low molecular weight heparin. In patients on unfractionated heparin (UFH), significantly lower anti-FXa activity [median=0.29IU/mL (range:0.04-1.15) vs. 0.39 (0.05-1.25), n=89, p<0.0001] and shorter aPTT were measured in partial-draw tubes. This discrepancy was likely to be related to the release of higher amounts of PF4 after increased platelet activation in partial-draw tubes. As CTAD is known to counteract platelet activation, we then collected blood into partial-draw CTAD tube and full-draw citrate tube. Both in patients on UFH and in untreated patients, no relevant difference could be demonstrated for all studied parameters (Bland-Altman), including aPTT and anti-FXa activity, even if analytical comparison showed significantly higher anti-FXa activity in partial-draw CTAD than in full-draw citrated tubes with a mean bias of 0.02 IU/mL, identical throughout the measuring range. CONCLUSIONS These results suggest that samples collected into partial-draw citrate tubes allow accurate routine coagulation testingin all patients but those requiring UFH assessment,in which their use led to a significant underestimation ofanticoagulation. In such cases, partial-draw tubes containing CTAD could be validly used to monitor heparin therapy as well as to perform routine coagulation testing.
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Affiliation(s)
- Pierre Toulon
- Université Nice Sophia-Antipolis, Faculté de Médecine, CHU Saint Roch, Service d'Hématologie Biologique, Nice, France.
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Briggs C, Guthrie D, Hyde K, Mackie I, Parker N, Popek M, Porter N, Stephens C. Guidelines for point-of-care testing: haematology. Br J Haematol 2008; 142:904-15. [DOI: 10.1111/j.1365-2141.2008.07274.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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8
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Toulon P, Ajzenberg N, Smahi M, Guillin MC. A new plastic collection tube made of polyethylene terephtalate is suitable for monitoring traditional anticoagulant therapy (oral anticoagulant, unfractionated heparin, and low molecular weight heparin). Thromb Res 2007; 119:135-43. [PMID: 16426667 DOI: 10.1016/j.thromres.2005.11.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2005] [Revised: 10/17/2005] [Accepted: 11/05/2005] [Indexed: 12/01/2022]
Abstract
To improve the safety of blood collection, plastic tubes have been developed but various interactions with the coagulation system and/or antithrombotic drugs were reported with the first generation of such tubes. The aim of this multicentre study was to compare hemostasis test results measured in evacuated plastic tubes made of polyethylene terephtalate (VenoSafe, Terumo Europe) and in siliconized glass tubes containing the same citrate concentration (0.129 M). In addition, the impact of aging of the plastic tube was investigated by collecting blood samples in tubes at 8 months and at 1 month before expiry. Blood was drawn in 3 centres from untreated patients (n=269), patients on oral anticoagulant treatment (OAT, n=221), and patients treated with either unfractionated heparin (UFH, n=73) or a low molecular weight derivative (LMWH, n=48). Prothrombin time (PT) or INR, activated partial thromboplastin time (APTT) and anti-FXa activity were locally performed, when applicable. In untreated patients and in patients on OAT, PT and APTT values were found statistically shorter (p<0.05) when evaluated in plastic tubes than in glass tubes, except when PT was evaluated using a human thromboplastin. Surprisingly, significantly longer APTT and higher anti-FXa activities were obtained when blood from patients on UFH was drawn in plastic than in glass tubes. However, none of the differences had any clinical relevance (Bland-Altman analysis). In patients on anticoagulant treatment, there was no effect of aging of the plastic tubes. These results suggest that the plastic tube VenoSafe is suitable for coagulation testing both in untreated subjects and more interestingly in patients on traditional anticoagulant therapy during the whole shelf life indicated by the manufacturer.
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Affiliation(s)
- Pierre Toulon
- Service d'Hématologie Biologique, Hôpital Cochin, Paris, France.
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9
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Toulon P, Aillaud MF, Arnoux D, Boissier E, Borg JY, Gourmel C. Multicenter evaluation of a bilayer polymer blood collection tube for coagulation testing: effect on routine hemostasis test results and on plasma levels of coagulation activation markers. Blood Coagul Fibrinolysis 2006; 17:625-31. [PMID: 17102648 DOI: 10.1097/01.mbc.0000252595.79282.86] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We compared the results of different hemostasis tests obtained in an evacuated bilayer polymer tubes (Vacuette, Greiner Bio-One) and in a siliconized glass tubes containing the same citrate concentrations (0.109 M and 0.129 M). For that purpose, blood was collected in five centers from 60 untreated patients and from patients on oral anticoagulant (n = 168), unfractionated heparin (n = 111) or a low molecular weight derivative (n = 108). Test results obtained in polymer tubes were not significantly different from those in glass tubes, except for INR when a high ISI thromboplastin was used (p < 0.0001 for tubes containing 0.129 M sodium citrate) and for APTT (p < 0.05 for both citrate concentrations). However, these differences had no clinical relevance (Bland-Altman analysis). In addition, no effect of aging of the polymer tubes on the test results could be demonstrated. The plasma levels of F1+2 and TAT, measured in a subset of 30 untreated patients, were significantly lower when blood was collected in polymer than in glass tubes, for both citrate concentrations. These results suggest that samples collected into the Vacuette polymer tubes allow accurate routine hemostasis testing both in untreated patients and in patients on traditional anticoagulant treatment during the whole shelf-life indicated by the manufacturer.
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Affiliation(s)
- Pierre Toulon
- Laboratoire d'Hématologie, Hôpital Cochin, Paris, France.
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10
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Lippi G, Salvagno GL, Montagnana M, Guidi GC. Influence of two different buffered sodium citrate concentrations on coagulation testing. Blood Coagul Fibrinolysis 2005; 16:381-3. [PMID: 15970724 DOI: 10.1097/01.mbc.0000172097.15458.c5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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11
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van den Besselaar AMHP, Rutten WPF, Witteveen E. Effect of magnesium contamination in evacuated blood collection tubes on the prothrombin time test and ISI calibration using recombinant human thromboplastin and different types of coagulometer. Thromb Res 2005; 115:239-44. [PMID: 15617747 DOI: 10.1016/j.thromres.2004.08.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2004] [Revised: 08/13/2004] [Accepted: 08/13/2004] [Indexed: 11/16/2022]
Abstract
UNLABELLED The purpose of the present study was to assess the effect of two types of evacuated blood collection tube on the prothrombin time and international sensitivity index (ISI) of Recombiplastin, a recombinant human thromboplastin. Vacutainer tubes were compared with Venoject II tubes. Magnesium contamination was detected in the sodium citrate solutions contained in the Vacutainer tubes with concentrations ranging from 1.1 to 1.5 mmol/l. In contrast, magnesium ions could not be detected in the Venoject II tubes. The prothrombin ratio was decreased by contamination with magnesium ions and, hence, the ISI was increased. The magnitude of the effect of magnesium contamination on the ISI was influenced by the type of coagulometer and increased in the order: ACL Advance (3%), ACL-300 (4%), Electra-1000 (6%). The ISI bias is transmitted to the international normalized ratio (INR). In the case of the Electra-1000, the INR bias would be approximately 6% at INR 3.0 if the two types of blood collection tubes would be used without distinction. In a secondary study, the effect of magnesium contamination on the prothrombin time was assessed with the current World Health Organization international reference preparation for recombinant human thromboplastin (rTF/95). Magnesium chloride added to patients' blood (0.2 mmol/l) induced 2.3% reduction of the INR determined with rTF/95 and the manual technique. CONCLUSION The magnitude of the influence of blood collection tubes contaminated with magnesium on ISI and INR determined with recombinant human thromboplastin depends on the coagulometer.
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Affiliation(s)
- A M H P van den Besselaar
- Hemostasis and Thrombosis Research Center, Department of Hematology, Leiden University Medical Center, C2-R, P.O. Box 9600, Leiden 2300 RC, The Netherlands.
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12
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van den Besselaar AMHP, Barrowcliffe TW, Houbouyan-Réveillard LL, Jespersen J, Johnston M, Poller L, Tripodi A. Guidelines on preparation, certification, and use of certified plasmas for ISI calibration and INR determination. J Thromb Haemost 2004; 2:1946-53. [PMID: 15550026 DOI: 10.1111/j.1538-7836.2004.00970.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Reliable international normalized ratio (INR) determination depends on accurate values for international sensitivity index (ISI) and mean normal prothrombin time (MNPT). Local ISI calibration can be performed to obtain reliable INR. Alternatively, the laboratory may determine INR directly from a line relating local log(prothrombin time [PT]) to log(INR). This can be done by means of lyophilized or frozen plasmas to which certified values of PT or INR have been assigned. Currently there is one procedure for local calibration with certified plasmas which is a modification of the WHO method of ISI determination. In the other procedure, named 'direct' INR determination, certified plasmas are used to calculate a line relating log(PT) to log(INR). The number of certified plasmas for each procedure depends on the method of preparation and type of plasma. Lyophilization of plasma may induce variable effects on the INR, the magnitude of which depends on the type of thromboplastin used. Consequently, the manufacturer or supplier of certified plasmas must assign the values for different (reference) thromboplastins and validate the procedure for reliable ISI calibration or 'direct' INR determination. Certification of plasmas should be performed by at least three laboratories. Multiple values should be assigned if the differences between thromboplastin systems are greater than 10%. Testing of certified plasmas for ISI calibration may be performed in quadruplicate in the same working session. It is recommended to repeat the measurements on three sessions or days to control day-to-day variation. Testing of certified plasmas for 'direct' INR determination should be performed in at least three sessions or days. Correlation lines for ISI calibration and for 'direct' INR determination should be calculated by means of orthogonal regression. Quality assessment of the INR with certified plasmas should be performed regularly and should be repeated whenever there is a change in reagent batch or in instrument. Discrepant results obtained by users of certified plasmas should be reported to manufacturers or suppliers.
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Affiliation(s)
- A M H P van den Besselaar
- Hemostasis and Thrombosis Research Center, Department of Hematology, Leiden University Medical Center, The Netherlands.
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13
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Yang DT, Robetorye RS, Rodgers GM. Home prothrombin time monitoring: a literature analysis. Am J Hematol 2004; 77:177-86. [PMID: 15389909 DOI: 10.1002/ajh.20161] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The anticoagulant activity of warfarin sodium is monitored by the prothrombin time (PT) using the international normalized ratio (INR). Standard oral anticoagulant therapy monitoring requires frequent patient visits to physicians' offices and/or laboratories to optimize warfarin dosage. Home PT monitoring by patients can increase testing frequency and may thus decrease complications associated with oral anticoagulant therapy. Clinical studies suggest that home PT monitoring is more effective than uncoordinated management and is as effective as care through specialized anticoagulation clinics for keeping INRs within a therapeutic range. There are accurate and reliable instruments available, but paramount to the success of home PT monitoring is sound patient selection, appropriate patient training, and consistent quality control.
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Affiliation(s)
- David T Yang
- Department of Pathology, University of Utah Health Sciences Center, Salt Lake City, Utah 84132, USA
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14
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Houdijk WPM, Van Den Besselaar AMHP. International multicenter international sensitivity index (ISI) calibration of a new human tissue factor thromboplastin reagent derived from cultured human cells. J Thromb Haemost 2004; 2:266-70. [PMID: 14995988 DOI: 10.1111/j.1538-7836.2004.00434.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The international sensitivity index (ISI) of the first working standard of Simplastin HTF, a new human tissue factor thromboplastin derived from cultured human cells, has been assessed in a calibration exercise in two Canadian and five European laboratories. Calibrations against international reference preparations (IRP) were performed for the manual method and six types of automated coagulometers that cover the majority of clotting endpoint principles in routine use. The ISI was method-dependent and varied between 1.03 and 1.29 when calibrated against rTF/95 (human IRP). The ISI was also dependent on the route of calibration. Compared with calibration against rTF/95, the ISIs obtained by calibration against RBT/90 (rabbit IRP) were on average 4.4% higher (P < 0.005). Considering the principle of 'like vs. like', the ISIs obtained by calibration against rTF/95 should be preferred.
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Tripodi A, Chantarangkul V, Bressi C, Mannucci PM. How to evaluate the influence of blood collection systems on the international sensitivity index. Protocol applied to two new evacuated tubes and eight coagulometer/thromboplastin combinations. Thromb Res 2002; 108:85-9. [PMID: 12586137 DOI: 10.1016/s0049-3848(02)00383-3] [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: 11/27/2022]
Abstract
Previous reports indicate that the international sensitivity index (ISI) of coagulometer/thromboplastin combinations (measuring systems) may be influenced by blood collection systems. We applied a new protocol to assess the extent with which two new blood collection systems (evaluation tubes) influence the ISI of eight widely used measuring systems. The evaluation tubes were made of plastic and had draw volumes of 1.8 and 2.7 ml; citrate concentration was 0.109 M. Well-established collection tubes (from the same manufacturer)-which were made of siliconized glass with draw volume and citrate concentration of 4.5 ml and 0.105 M, respectively-served as control. Plasmas from 20 healthy subjects and 60 patients on oral anticoagulants, collected with the evaluation and control tubes, were tested for prothrombin time (PT) with the eight measuring systems. Plasmas collected with the control tubes were also tested with an international standard for thromboplastin. Results were used to calculate the ISIs of the measuring systems. These were then used to calculate the differences of the crossover international normalized ratio (INR) (i.e., the INR obtained with PT ratios of plasmas collected into the evaluation tubes and the ISI determined with plasmas collected into the control tubes). Overall, the differences were small but measurable, especially for the 2.7-ml draw evaluation tubes and with some of the measuring systems (mean difference, </=5.50%; mean relative deviation (MRD), </=5.82%). Although statistically significant, these differences are not clinically relevant as they are unlikely to affect decision making in drug prescription. In conclusion, the study shows that the evaluation tubes compare well with the control tubes from the same manufacturer. The protocol described here should be adopted for the evaluation of other blood collection systems.
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Affiliation(s)
- Armando Tripodi
- Angelo Bianchi Bonomi, Hemophilia and Thrombosis Center, Department of Internal Medicine, University and IRCCS Maggiore Hospital, Via Pace 9, Milan 20122, Italy.
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Lottin L, Woodhams BJ, Saureau M, Robert A, Aillaud MF, Arnaud E, Martinoli J. The clinical relevance of the citrate effect on International Normalized Ratio determinations depends on the reagent and instrument combination used. Blood Coagul Fibrinolysis 2001; 12:399-404. [PMID: 11505084 DOI: 10.1097/00001721-200107000-00010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Multiple studies have shown that the two different citrate concentrations in common use as the anticoagulant in blood collection for haemostasis assays can affect the results obtained with the prothrombin time assay. It is clear from the literature that there is considerable variability in the results obtained using different instrument-reagents combinations, but the clinical relevance of these differences is unclear. Most of the studies have used an optical system for end-point detection. This study reports on the citrate sensitivity using mechanical end-point detection. Using two different reagents, one previously shown to be citrate sensitive on optical systems (Neoplastin CI plus) and a citrate-insensitive reagent (Neoplastin CI), we demonstrate that the effect of using different citrate concentrations (0.105 or 0.129 mol/l) has statistically significant but clinically irrelevant effects on the International Normalized Ratio using a mechanical instrument (STA)-reagent combination (mean percentage difference in results, 1.9 and 3.8% respectively). This demonstrates that the citrate effect is both instrument type and reagent dependent. Every reagent and instrument combination needs to be tested to see whether any citrate effect exists. In a secondary study, it was shown that the international reference rabbit thromboplastin (CRM 149(s)) was not citrate-concentration sensitive.
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Affiliation(s)
- L Lottin
- Diagnostica Stago, Franconville, France
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Tripodi A, Chantarangkul V, Mannucci P. Near-patient testing devices to monitor oral anticoagulant therapy. Br J Haematol 2001; 113:847-52. [PMID: 11442473 DOI: 10.1046/j.1365-2141.2001.02753.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- A Tripodi
- Angelo Bianchi Bonomi Haemophilia and Thrombosis Centre, Department of Internal Medicine, University and IRCCS Maggiore Hospital, Milan, Italy.
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