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Manning JE, Arachchillage DJ. Dilemmas in the diagnosis and management of antiphospholipid syndrome. J Thromb Haemost 2024; 22:2156-2170. [PMID: 38705387 DOI: 10.1016/j.jtha.2024.03.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 02/27/2024] [Accepted: 03/20/2024] [Indexed: 05/07/2024]
Abstract
Antiphospholipid syndrome (APS) is characterized by thrombosis (which may be venous, arterial, or microvascular) and/or pregnancy morbidity in association with persistently positive antiphospholipid antibodies. Although thrombosis and pregnancy morbidity are the main clinical criteria for a diagnosis of APS in the revised Sapporo (Sydney) criteria, recently published American College of Rheumatology/European Alliance of Associations for Rheumatology classification criteria for APS have significantly refined the diagnostic algorithm to include a scoring system clustered into 6 clinical domains (macrovascular venous thromboembolism, macrovascular arterial thrombosis, microvascular thrombosis, obstetric, cardiac valve, and hematologic). Diagnosis of APS is complicated by the fact that significant heterogeneity exists in patients' clinical presentation, underlying vascular risk factors, and methods of detecting antiphospholipid antibodies. Despite the autoimmune nature of APS, anticoagulation remains the main strategy for secondary prevention of thrombosis. Furthermore, optimal antithrombotic treatment in APS patients with arterial thrombosis remains controversial due to a paucity of data from randomized controlled studies. In this paper, we present 2 cases and highlight the diagnostic and therapeutic challenges they pose and how we approach them in the light of current evidence.
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Affiliation(s)
- James E Manning
- Centre for Haematology, Department of Immunology and Inflammation, Imperial College London, London, United Kingdom; Department of Haematology, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Deepa J Arachchillage
- Centre for Haematology, Department of Immunology and Inflammation, Imperial College London, London, United Kingdom; Department of Haematology, Imperial College Healthcare NHS Trust, London, United Kingdom.
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2
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Moore GW, Platton S, Yartey N, Foxton E, White D, MacDonald SG. Taipan snake venom time has high sensitivity for lupus anticoagulants in non-anticoagulated, triple positive antiphospholipid syndrome patients. Int J Lab Hematol 2024; 46:538-545. [PMID: 38303489 DOI: 10.1111/ijlh.14240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 01/05/2024] [Indexed: 02/03/2024]
Abstract
INTRODUCTION Dilute Russell's viper venom time (dRVVT) and activated partial thromboplastin time (APTT) are the mainstay assays in lupus anticoagulant (LA) detection yet they have limitations, particularly in relation to interferences and specificity. The recently validated Taipan snake venom time (TSVT) screening with ecarin time (ET) confirmatory assays overcome many of those limitations due to the innate specificity engendered from direct prothrombin activation, and insensitivity to the effects of vitamin K antagonists (VKA). The present study aimed to further evidence diagnostic utility of TSVT/ET by performing them in samples from 116 nonanticoagulated patients with established triple-positive antiphospholipid syndrome (APS). METHODS Samples were identified in three expert centres who performed dRVVT, APTT and solid phase antiphospholipid antibody assays with reagents from a variety of manufacturers. All samples additionally received TSVT/ET analysis using standardised reagents. RESULTS Ninety seven of 116 (83.6%) were dRVVT- and APTT-positive, 85/97 (87.6%) of which were TSVT/ET-positive, 9/116 (7.8%) were dRVVT-positive only, 6 of which were TSVT/ET-positive, and 10/116 (8.6%) were APTT-positive only, 5 of which were TSVT/ET-positive. 96/116 TSVT/ET-positivity returned a high sensitivity for LA of 82.8%. Low coefficients of determination revealed weak relationships between LA potency and anticardiolipin and anti-β2-glycoprotein I antibody titres for all three LA assays. CONCLUSIONS TSVT/ET has high sensitivity for the clinically significant LA found in triple positive APS patients. TSVT/ET can establish multiple LA assay positivity in nonanticoagulated patients negative for one of dRVVT or APTT, and is the only assay pairing insensitive to VKAs, the recommended anticoagulation for APS.
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Affiliation(s)
- Gary W Moore
- Department of Haematology, Specialist Haemostasis Unit, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
- Department of Natural Sciences, Faculty of Science and Technology, Middlesex University, London, UK
| | - Sean Platton
- The Royal London Hospital Haemophilia Centre, Barts Health NHS Trust, London, UK
| | - Nada Yartey
- East and South East London NHS Pathology Partnership, Barts Health NHS Trust, London, UK
| | - Eleanor Foxton
- Synnovis Haemostasis and Thrombosis Laboratory, St. Thomas' Hospital, London, UK
| | - Danielle White
- Department of Haematology, Specialist Haemostasis Unit, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Stephen G MacDonald
- Department of Haematology, Specialist Haemostasis Unit, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
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Efthymiou M, Bertolaccini ML, Cohen H. Viewpoint: Lupus anticoagulant detection and interpretation in antiphospholipid syndrome. Rheumatology (Oxford) 2024; 63:SI54-SI63. [PMID: 38320587 DOI: 10.1093/rheumatology/kead623] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 11/08/2023] [Accepted: 11/19/2023] [Indexed: 02/08/2024] Open
Abstract
Lupus anticoagulant (LA) is a well-established risk factor for the clinical manifestations of antiphospholipid syndrome (APS). Accurate LA detection is an essential prerequisite for optimal diagnosis and management of patients with APS or aPL carriers. Variability remains a challenge in LA testing, with reliable detection influenced by multiple factors, including pre-analytical conditions, anticoagulation treatment, choice of tests and procedures performed, as well as interpretation of results, that can lead to false-positives or negatives. A standardised approach to LA testing, following current guidance, based on published data and international consensus, and with attention to detail, is required to underpin accurate detection of LA. Future work should focus on better characterisation of the nature of LA, which may ultimately lead to improved diagnosis and management of patients with APS and aPL carriers. This article reviews current practice and challenges, providing an overview on detection of LA.
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Affiliation(s)
- Maria Efthymiou
- Department of Haematology, Cancer Institute, University College London, London, UK
- Department of Haematology, University College London Hospitals NHS Foundation Trust, London, UK
| | - Maria Laura Bertolaccini
- Academic Department of Vascular Surgery, School of Cardiovascular and Metabolic Medicine & Sciences, King's College London, London, UK
| | - Hannah Cohen
- Department of Haematology, Cancer Institute, University College London, London, UK
- Department of Haematology, University College London Hospitals NHS Foundation Trust, London, UK
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Tripodi A, Scalambrino E, Clerici M, Peyvandi F. Laboratory Diagnosis of Antiphospholipid Syndrome in Anticoagulated Patients. Biomedicines 2023; 11:1760. [PMID: 37371855 DOI: 10.3390/biomedicines11061760] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 06/06/2023] [Accepted: 06/12/2023] [Indexed: 06/29/2023] Open
Abstract
The laboratory diagnosis of antiphospholipid syndrome (APS) requires the measurement of solid-phase antibodies to cardiolipin or β2-Glycoprotein-I and the search for lupus anticoagulant (LA). The diagnosis of patients whilst on anticoagulation is impaired by the difficult interpretation of results, at least for LA, owing to the fact that prolongations of clotting times induced by LA superimpose those induced by anticoagulants. This is a matter of concern as treating physicians very often need to know the APS status of their patients to make a decision on secondary antithrombotic prophylaxis. This article aims to review the effect brought about by anticoagulants on APS diagnosis and discuss the options that can be used to overcome such an effect.
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Affiliation(s)
- Armando Tripodi
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, 20122 Milan, Italy
- Fondazione Luigi Villa, 20122 Milano, Italy
| | - Erica Scalambrino
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, 20122 Milan, Italy
| | - Marigrazia Clerici
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, 20122 Milan, Italy
| | - Flora Peyvandi
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, 20122 Milan, Italy
- Department of Pathophysiology and Transplantation, Università Degli Studi di Milano, 20122 Milano, Italy
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Moore GW. Lupus Anticoagulant Testing: Taipan Snake Venom Time with Ecarin Time as Confirmatory Test. Methods Mol Biol 2023; 2663:263-274. [PMID: 37204716 DOI: 10.1007/978-1-0716-3175-1_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Testing for lupus anticoagulants (LA) in the presence of therapeutic anticoagulation is largely discouraged because of the risk of false-positive and false-negative results, although the ability to detect LA in this setting can be clinically valuable. Strategies such as mixing tests and anticoagulant neutralization can be effective, but have their own limitations. The prothrombin activators in venoms from Coastal Taipan and Indian saw-scaled viper snakes provide an additional analytical avenue in that they are insensitive to the effects of vitamin K antagonists and inevitably bypass the effects of direct factor Xa inhibitors. Oscutarin C in Coastal Taipan venom is phospholipid- and Ca2+-dependent, so the venom is used in a dilute phospholipid design as an LA screening test called the Taipan snake venom time (TSVT). The ecarin fraction of Indian saw-scaled viper venom is cofactor-independent and operates as a prothrombin-activated confirmatory test, the ecarin time, because the absent phospholipid precludes inhibition by LAs. Bypassing all coagulation factors except prothrombin and fibrinogen renders the assays innately more specific than other LA assays, while TSVT as a screening test has good sensitivity to LAs detected in other assays, as well as occasional antibodies unreactive in other assays.
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Affiliation(s)
- Gary W Moore
- Research and Development, Technoclone Herstellung von Diagnostika und Arzneimitteln GmbH, Vienna, Austria.
- Specialist Haemostasis Unit, Department of Haematology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK.
- Department of Natural Sciences, Faculty of Science and Technology, Middlesex University London, London, UK.
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Abstract
Lupus anticoagulant (LA) is one of the three criteria antiphospholipid antibodies (aPLs) employed in classification, and by default diagnosis, of antiphospholipid syndrome (APS). Detection of LA is not via calibrated assays but is based on functional behavior of the antibodies in a medley of coagulation assays. A prolonged clotting time in a screening test is followed by demonstration of phospholipid dependence and inhibitory properties in confirmatory and mixing tests, respectively, which are modifications of the parent screening test. Complications arise because no single screening test is sensitive to every LA, and no test is specific for LA, because they are prone to interference by other causes of elevated clotting times. Several screening tests are available but the pairing of dilute Russell's viper venom time (dRVVT) with LA-sensitive activated partial thromboplastin time (aPTT) is widely used and recommended because it is proven to have good detection rates. Nonetheless, judicious use of other assays can improve diagnostic performance, such as dilute prothrombin time to find LA unreactive with dRVVT and aPTT, and the recently validated Taipan snake venom time with ecarin time confirmatory test that are unaffected by vitamin K antagonist and direct factor Xa inhibitor anticoagulation. Expert body guidelines and their updates have improved harmonization of laboratory practices, although some issues continue to attract debate, such as the place of mixing tests in the medley hierarchy, and areas of data manipulation such as assay cut-offs and ratio generation. This article reviews current practices and challenges in the laboratory detection of LA.
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Affiliation(s)
- Gary W Moore
- Haemostasis Unit, Department of Haematology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom.,Department of Natural Sciences, Faculty of Science and Technology, Middlesex University, London, United Kingdom
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Moore GW, Jones PO, Platton S, Hussain N, White D, Thomas W, Rigano J, Pouplard C, Gray E, Devreese KMJ. International multicenter, multiplatform study to validate Taipan snake venom time as a lupus anticoagulant screening test with ecarin time as the confirmatory test: Communication from the ISTH SSC Subcommittee on Lupus Anticoagulant/Antiphospholipid Antibodies. J Thromb Haemost 2021; 19:3177-3192. [PMID: 34192404 DOI: 10.1111/jth.15438] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 06/08/2021] [Accepted: 06/28/2021] [Indexed: 11/29/2022]
Abstract
BACKGROUND Lupus anticoagulant (LA) assays are compromised in anticoagulated patients, and existing strategies to overcome the interferences have limitations. The prothrombin-activating Taipan snake venom time (TSVT) screening test and ecarin time (ET) confirmatory test are innately insensitive to vitamin K antagonists (VKA) and direct factor Xa inhibitors (DFXaI). OBJECTIVES Validate standardized TSVT/ET reagents for LA detection, in a multicenter, multiplatform study. PATIENTS/METHODS Six centers from four countries analyzed samples with TSVT/ET from 81 nonanticoagulated patients with LA, patients with established antiphospholipid syndrome (APS), and proven persistent LA who were either not anticoagulated (n = 120) or were anticoagulated with VKAs (n = 180) or DFXaIs (n = 71). Additionally, 339 nonanticoagulated LA-negative patients, and 575 anticoagulated non-APS patients (172 VKA, 403 DFXaI) were tested. Anticoagulant spiking experiments were performed and 112 samples containing potential interferences (i.e., direct thrombin inhibitors) were tested. Results were evaluated against locally derived cutoffs. Imprecision was evaluated. RESULTS Cutoffs were remarkably similar despite use of different analyzers and donor populations. Cutoffs for TSVT ratio, ET ratio, percent correction, and normalized TSVT ratio/ET ratio ranged between 1.08 and 1.10, 1.09 and 1.12, 9.3% and 14.8%, and 1.10 and 1.15, respectively. Coefficients of variation for TSVT and ET ratios were ≤5.0%. TSVT/ET exhibited sensitivity, specificity, and negative and positive predictive values of 78.2%/95.0%/86.3%/91.5%, respectively, with established APS as the LA-positive population, and 86.9%/95.0%/76.8%/97.4%, respectively, with triple-positive APS. Interference was seen with direct thrombin inhibitors, unfractionated heparin, and low molecular weight heparins, but not VKAs or DFXaIs. CONCLUSIONS TSVT/ET are validated for LA detection in nonanticoagulated patients and those on VKAs or DFXaIs.
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Affiliation(s)
- Gary W Moore
- Department of Haemostasis and Thrombosis, Viapath Analytics, Guy's & St. Thomas' Hospitals, London, UK
- Specialist Haemostasis Unit, Department of Haematology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
- Faculty of Science and Technology, Middlesex University, London, UK
| | - Paul O Jones
- Department of Haemostasis and Thrombosis, Viapath Analytics, Guy's & St. Thomas' Hospitals, London, UK
| | - Sean Platton
- The Royal London Hospital Haemophilia Centre, Barts Health NHS Trust, London, UK
| | - Nadia Hussain
- Clinical Biochemistry Department, Barts Health NHS Trust, London, UK
| | - Danielle White
- Specialist Haemostasis Unit, Department of Haematology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Will Thomas
- Specialist Haemostasis Unit, Department of Haematology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Joseph Rigano
- Haematology Department, Alfred Health, Melbourne, Vic., Australia
| | - Claire Pouplard
- Department of Hemostasis, University Hospital of Tours, University of Tours, Tours, France
| | - Elaine Gray
- Haemostasis Section, The National Institute for Biological Standards and Control, Potters Bar, UK
| | - Katrien M J Devreese
- Coagulation Laboratory, Department of Laboratory Medicine, Ghent University Hospital, Ghent, Belgium
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Abstract
Snake venoms have evolved primarily to immobilize and kill prey, and consequently, they contain some of the most potent natural toxins. Part of that armory is a range of hemotoxic components that affect every area of hemostasis, which we have harnessed to great effect in the study and diagnosis of hemostatic disorders. The most widely used are those that affect coagulation, such as thrombin-like enzymes unaffected by heparin and direct thrombin inhibitors, which can help confirm or dispute their presence in plasma. The liquid gold of coagulation activators is Russell's viper venom, since it contains activators of factor X and factor V. It is used in a range of clotting-based assays, such as assessment of factor X and factor V deficiencies, protein C and protein S deficiencies, activated protein C resistance, and probably the most important test for lupus anticoagulants, the dilute Russell's viper venom time. Activators of prothrombin, such as oscutarin C from Coastal Taipan venom and ecarin from saw-scaled viper venom, are employed in prothrombin activity assays and lupus anticoagulant detection, and ecarin has a valuable role in quantitative assays of direct thrombin inhibitors. Snake venoms affecting primary hemostasis include botrocetin from the jararaca, which can be used to assay von Willebrand factor activity, and convulxin from the cascavel, which can be used to detect deficiency of the platelet collagen receptor, glycoprotein VI. This article takes the reader to every area of the diagnostic hemostasis laboratory to appreciate the myriad applications of snake venoms available in diagnostic practice.
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Affiliation(s)
- Gary William Moore
- Department of Haematology, Specialist Haemostasis Unit, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom.,Faculty of Science and Technology, Middlesex University London, London, United Kingdom
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Moore GW. Alternative assays to dRVVT and aPTT for lupus anticoagulant detection. Am J Hematol 2020; 95:992-998. [PMID: 32311119 DOI: 10.1002/ajh.25836] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 04/13/2020] [Indexed: 01/15/2023]
Abstract
Lupus anticoagulants (LA) are heterogeneous antibodies and no single assay will detect every LA. Consequently, testing is commonly undertaken with both dilute Russell's viper venom time (dRVVT) and LA-responsive activated partial thromboplastin time (aPTT) to maximize detection rates. Although a huge body of evidence attests to the diagnostic utility of these assays, they have limitations that can render them unreliable in certain circumstances. Other assays are available for detecting LA but unfamiliarity, variable availability and technical concerns expressed in guidelines contribute to less usage than dRVVT and aPTT. However, assays such as Taipan snake venom time and Textarin time are insensitive to anticoagulants that compromise dRVVT and aPTT, and assays such as dilute prothrombin time can detect LA unreactive in dRVVT and aPTT. The pros and cons of alternative assays to dRVVT and APTT for LA detection are discussed.
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Affiliation(s)
- Gary W. Moore
- Specialist Haemostasis UnitAddenbrooke's Hospital Cambridge UK
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Tripodi A, Cohen H, Devreese KMJ. Lupus anticoagulant detection in anticoagulated patients. Guidance from the Scientific and Standardization Committee for lupus anticoagulant/antiphospholipid antibodies of the International Society on Thrombosis and Haemostasis. J Thromb Haemost 2020; 18:1569-1575. [PMID: 32619349 DOI: 10.1111/jth.14846] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 03/16/2020] [Accepted: 04/10/2020] [Indexed: 12/22/2022]
Abstract
BACKGROUND The laboratory detection of lupus anticoagulants (LA) in anticoagulated patients represents a challenge and there is no consensus on the types of assays/procedures to be adopted. OBJECTIVES This communication of the International Society on Thrombosis and Haemostasis (ISTH), Scientific and Standardization Committee (SSC) aims to give guidance on the procedures to be adopted. METHODS Members of the ISTH-SSC on Lupus Anticoagulant/Antiphospholipid Antibodies reviewed the literature to search for evidence on the most appropriate assays/procedures to be adopted. RESULTS Anticoagulants are able to interfere with the tests used for LA detection, giving rise to occasional false-positive or false-negative LA. Some commercial tests include in their composition heparin-neutralizers able to quench unfractionated or low molecular weight heparin up to 1.0 U/mL. LA tests are less affected by low molecular weight heparin, but caution is needed in the interpretation of results. Vitamin K antagonists (VKAs) may affect LA detection. Dilution of test plasma into pooled normal plasma is not a reliable solution as false-negative or false-positive LA may occur. Direct oral anticoagulants (DOACs) affect LA detection. Hence, it is not recommended to attempt LA detection in those patients. The use of DOAC adsorbents is a promising solution and should be further investigated on LA-positive and LA-negative patient populations. Taipan/Ecarin tests may be a solution for VKAs and anti-FXa DOACs, but independent evidence on their value and standardized kits is needed. CONCLUSIONS LA detection during anticoagulation remains a challenge, especially for VKAs. DOAC removal by in vitro addition to plasma of appropriate absorbents is promising.
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Affiliation(s)
- Armando Tripodi
- Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Angelo Bianchi Bonomi Hemophilia and Thrombosis Center and Fondazione Luigi Villa, Milano, Italy
| | - Hannah Cohen
- Haemostasis Research Unit, Department of Haematology, University College London, London, UK
- Department of Haematology, University College London Hospitals NHS Foundation Trust, London, UK
| | - Katrien M J Devreese
- Coagulation Laboratory, Department of Diagnostic Sciences, Ghent University Hospital, Ghent, Belgium
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Gosselin RC, Douxfils J. Ecarin based coagulation testing. Am J Hematol 2020; 95:863-869. [PMID: 32350907 DOI: 10.1002/ajh.25852] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 04/06/2020] [Accepted: 04/08/2020] [Indexed: 12/15/2022]
Abstract
Ecarin is derived from venom of Echis carinatus, and will activate prothrombin into meizothrombin which will then cleave fibrinogen to result in clot formation. Ecarin based testing has been described for decades, but these assays were typically restricted to reference or speciality coagulation laboratories. This test was initially described for the assessment of direct thrombin inhibitors (eg, bivalirudin lepirudin, or argatroban) and was not affected by heparins or heparinoids. Ecarin based assays were rarely used for anticoagulation monitoring until the emergence of the direct oral thrombin inhibitor dabigatran etexilate in 2010. As this test was mentioned in the prescribing information for dabigatran etexilate, there was increased interest for use by clinical laboratories as the preferred method for assessing the anticoagulant effect of this drug. The purpose of this document is to review the current status of ecarin based assays for assessing dabigatran. This is with the understanding that these methods can also be exploited for determining the anticoagulation effect of parenteral direct thrombin inhibitors, such as argatroban and bivalirudin.
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Affiliation(s)
- Robert C. Gosselin
- Davis Health System, Thrombosis and Hemostasis CenterUniversity of California Sacramento California
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12
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Efthymiou M, Mackie IJ, Lane PJ, Andrade D, Willis R, Erkan D, Sciascia S, Krillis S, Bison E, Borges Galhardo Vendramini M, Romay-Penabad Z, Qi M, Tektonidou M, Ugarte A, Chighizola C, Belmont HM, Aguirre MA, Ji L, Branch DW, de Jesus G, Fortin PR, Andreoli L, Petri M, Cervera R, Rodriguez E, Knight JS, Atsumi T, Vega J, Sevim E, Bertolaccini ML, Pengo V, Cohen H. Comparison of real world and core laboratory lupus anticoagulant results from the Antiphospholipid Syndrome Alliance for Clinical Trials and International Networking (APS ACTION) clinical database and repository. J Thromb Haemost 2019; 17:2069-2080. [PMID: 31364274 DOI: 10.1111/jth.14596] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 07/25/2019] [Indexed: 12/12/2022]
Abstract
BACKGROUND Variability remains a challenge in lupus anticoagulant (LA) testing. OBJECTIVE To validate LA test performance between Antiphospholipid Syndrome Alliance for Clinical Trials and International Networking (APS ACTION) Core laboratories and examine agreement in LA status between Core and local/hospital laboratories contributing patients to this prospective registry. METHODS Five Core laboratories used the same reagents, analyzer type, protocols, and characterized samples for LA validation. Non-anticoagulated registry samples were retested at the corresponding regional Core laboratories and anticoagulated samples at a single Core laboratory. Categorical agreement and discrepancies in LA status between Core and local/hospital laboratories were analyzed. RESULTS Clotting times for the reference/characterized plasmas used for normalized ratios were similar between Core laboratories (CV <4%); precision and agreement for LA positive/negative plasma were similar (all CV ≤5%) in the four laboratories that completed both parts of the validation exercise; 418 registry samples underwent LA testing. Agreement for LA positive/negative status between Core and local/hospital laboratories was observed in 87% (115/132) non-anticoagulated and 77% (183/237) anticoagulated samples. However, 28.7% (120/418) of samples showed discordance between the Core and local/hospital laboratories or equivocal LA results. Some of the results of the local/hospital laboratories might have been unreliable in 24.7% (41/166) and 23% (58/252) of the total non-anticoagulated and anticoagulated samples, respectively. Equivocal results by the Core laboratory might have also contributed to discordance. CONCLUSIONS Laboratories can achieve good agreement in LA performance by use of the same reagents, analyzer type, and protocols. The standardized Core laboratory results underpin accurate interpretation of APS ACTION clinical data.
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Affiliation(s)
- Maria Efthymiou
- Haemostasis Research Unit, Department of Haematology, University College London, London, UK
| | - Ian J Mackie
- Haemostasis Research Unit, Department of Haematology, University College London, London, UK
| | - Philip J Lane
- Haemostasis Research Unit, Department of Haematology, University College London, London, UK
| | | | - Rohan Willis
- Antiphospholipid Standardization Laboratory, University of Texas Medical Branch, Galveston, TX, USA
| | - Doruk Erkan
- Barbara Volcker Center for Women and Rheumatic Diseases, Hospital for Special Surgery, Weill Cornell Medicine, New York, NY, USA
| | - Savino Sciascia
- Center of Research of Immunopathology and Rare Diseases, University of Turin, Turin, Italy
| | - Steven Krillis
- Department of Infectious Diseases, Immunology and Sexual Health, St George Hospital, Sydney, NSW, Australia
| | | | | | - Zurina Romay-Penabad
- Antiphospholipid Standardization Laboratory, University of Texas Medical Branch, Galveston, TX, USA
| | - Miao Qi
- Department of Infectious Diseases, Immunology and Sexual Health, St George Hospital, Sydney, NSW, Australia
| | | | - Amaia Ugarte
- Internal Medicine, Hospital Universitario Cruces, Barakaldo, País Vasco, Spain
| | | | | | | | - Lanlan Ji
- Rheumatology and Immunology Department, Peking University First Hospital, Beijing, China
| | - D Ware Branch
- University of Utah and Intermountain Healthcare, Salt Lake City, UT, USA
| | | | - Paul R Fortin
- CHU de Quebec - Université Laval, Quebec, QC, Canada
| | - Laura Andreoli
- Rheumatology and Clinical Immunology, Spedali Civili, Brescia, Italy
- Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Michelle Petri
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ricard Cervera
- Department of Autoimmune Diseases, Hospital Clínic Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Catalonia, Spain
| | | | - Jason S Knight
- Division of Rheumatology, University of Michigan, Ann Arbor, MI, USA
| | | | - Joann Vega
- University Hospital Padova, Padova, Italy
| | - Ecem Sevim
- University Hospital Padova, Padova, Italy
| | - Maria Laura Bertolaccini
- Academic Department of Vascular Surgery, School of Cardiovascular Medicine & Sciences, King's College London, London, UK
| | - Vittorio Pengo
- Department of Infectious Diseases, Immunology and Sexual Health, St George Hospital, Sydney, NSW, Australia
| | - Hannah Cohen
- Haemostasis Research Unit, Department of Haematology, University College London, London, UK
- Department of Haematology, University College London Hospitals NHS Foundation Trust, London, UK
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Adamkewicz JI, Kiialainen A, Paz-Priel I. Effects and interferences of emicizumab, a humanized bispecific antibody mimicking activated factor VIII cofactor function, on lupus anticoagulant assays. Int J Lab Hematol 2019; 42:e71-e75. [PMID: 31670901 PMCID: PMC7079058 DOI: 10.1111/ijlh.13114] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 09/09/2019] [Accepted: 09/13/2019] [Indexed: 01/15/2023]
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Cohen H, Mackie IJ, Devreese KMJ. Clinical and laboratory practice for lupus anticoagulant testing: An International Society of Thrombosis and Haemostasis Scientific and Standardization Committee survey. J Thromb Haemost 2019; 17:1715-1732. [PMID: 31271706 DOI: 10.1111/jth.14560] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 06/28/2019] [Indexed: 01/16/2023]
Abstract
BACKGROUND Current guidelines have contributed to more uniformity in the performance and interpretation of lupus anticoagulant (LA) testing. However, points to reconsider include testing for LA in patients on anticoagulation, cut-off values, and interpretation of results. OBJECTIVES The aim of this International Society of Thrombosis and Haemostasis Scientific and Standardization committee (ISTH SSC) questionnaire was to capture the spectrum of clinical and laboratory practice in LA detection, focusing on variability in practice, so that the responses could inform further ISTH SSC recommendations. METHODS Members of the ISTH SSC on Lupus Anticoagulant/Antiphospholipid Antibodies and participants of the Lupus Anticoagulant/Antiphospholipid Antibodies Programme of the External quality Control of diagnostic Assays and Tests Foundation were invited to complete a questionnaire on LA testing that was placed on the ISTH website using RedCap, with data tallied using simple descriptive statistics. RESULTS There was good agreement on several key recommendations in the ISTH and other guidelines on LA testing, such as sample processing, principles of testing, choice of tests, repeat testing to confirm persistent positivity and the use of interpretative reporting. However, the results highlight that there is less agreement on some other aspects, including the timing of testing in relation to thrombosis or pregnancy, testing in patients on anticoagulation, cut-off values, and calculation and interpretation of results. CONCLUSIONS Although some of the variability in practice in LA testing reflects the lack of substantive data to underpin evidence-based recommendations, a more uniform approach, based on further guidance, should reduce the inter-center variability of LA testing.
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Affiliation(s)
- Hannah Cohen
- Haemostasis Research Unit, Department of Haematology, University College London, London, UK
- Department of Haematology, University College London Hospitals NHS Foundation Trust, London, UK
| | - Ian J Mackie
- Haemostasis Research Unit, Department of Haematology, University College London, London, UK
| | - Katrien M J Devreese
- Coagulation Laboratory, Department of Diagnostic Sciences, Ghent University Hospital, Ghent, Belgium
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Kumano O, Amiral J, Dunois C, Peyrafitte M, Moore GW. Paired APTTs of low and high lupus anticoagulant sensitivity permit distinction from other abnormalities and achieve good lupus anticoagulant detection rates in conjunction with dRVVT. Int J Lab Hematol 2018; 41:60-68. [PMID: 30248243 DOI: 10.1111/ijlh.12921] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 07/22/2018] [Accepted: 07/31/2018] [Indexed: 01/03/2023]
Abstract
INTRODUCTION A prolonged activated partial thromboplastin time (APTT) may be indicative of a specific or multiple factor deficiency, therapeutic anticoagulation, presence of a nonspecific factor inhibitor, or lupus anticoagulant (LA). Recently, pairing of the LA-sensitive APTT and standard APTT reagents, Cephen LS and Cephen, respectively, has been shown to be effective in LA detection. The present study aimed to evaluate the usefulness of this reagent pair for discriminating between causes of APTT elevation and the detection of LA in conjunction with dilute Russell's viper venom time (dRVVT). METHODS Plasma samples from 50 normal and 105 non-anticoagulated LA-positive patients in routine dRVVT and/or dilute APTT (dAPTT) via the percent correction formula were employed. Cephen LS/Cephen and dRVVT reagents LA1/LA2 were used to screen/confirm, respectively. Thirty-four symptomatic LA-negative, 25 warfarinised non-antiphospholipid syndrome, 6 coagulation inhibitors, 17 samples with hereditary elevated APTT, and 24 FVIII/IX/XI/XII and 17 FII/V/X artificial single deficiency plasmas were used. RESULTS Thirty-three samples out of 105 (31%) were LA-positive in Cephen LS/Cephen. The total percent positivity in Cephen LS/Cephen and LA1/LA2 pairs was 89.1% against samples with the routine dRVVT/dAPTT double positive. The percent corrections of Cephen LS/Cephen in the routine dAPTT/dRVVT positive group were significantly higher than those in all other groups. CONCLUSIONS The percent correction of the APTT reagent pair showed higher values in LA-positive samples. The combination will be useful with respect to differentiating LA from other abnormal samples and is effective in LA detection when paired with dRVVT.
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Affiliation(s)
- Osamu Kumano
- Protein Technology, Sysmex Corporation, Kobe, Hyogo, Japan
| | | | | | | | - Gary W Moore
- Department of Haemostasis and Thrombosis, Viapath Analytics, Guy's & St Thomas' Hospitals, London, UK
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Pouplard C, Vayne C, Berthomet C, Guery EA, Delahousse B, Gruel Y. The Taipan snake venom time can be used to detect lupus anticoagulant in patients treated by rivaroxaban. Int J Lab Hematol 2016; 39:e60-e63. [DOI: 10.1111/ijlh.12611] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- C. Pouplard
- Department of Haematology-Haemostasis; Trousseau hospital; Tours France
- Unité Mixte de Recherche Centre National de la Recherche Scientifique 7292 and Université François Rabelais; Tours France
| | - C. Vayne
- Department of Haematology-Haemostasis; Trousseau hospital; Tours France
- Unité Mixte de Recherche Centre National de la Recherche Scientifique 7292 and Université François Rabelais; Tours France
| | - C. Berthomet
- Department of Haematology-Haemostasis; Trousseau hospital; Tours France
| | - E. A. Guery
- Department of Haematology-Haemostasis; Trousseau hospital; Tours France
- Unité Mixte de Recherche Centre National de la Recherche Scientifique 7292 and Université François Rabelais; Tours France
| | - B. Delahousse
- Department of Haematology-Haemostasis; Trousseau hospital; Tours France
| | - Y. Gruel
- Department of Haematology-Haemostasis; Trousseau hospital; Tours France
- Unité Mixte de Recherche Centre National de la Recherche Scientifique 7292 and Université François Rabelais; Tours France
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Moore GW. Current Controversies in Lupus Anticoagulant Detection. Antibodies (Basel) 2016; 5:E22. [PMID: 31558003 PMCID: PMC6698846 DOI: 10.3390/antib5040022] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 11/17/2016] [Accepted: 11/18/2016] [Indexed: 01/19/2023] Open
Abstract
Antiphospholipid syndrome is an autoimmune, acquired thrombophilia diagnosed when vascular thrombosis or pregnancy morbidity are accompanied by persistent antiphospholipid antibodies. Lupus anticoagulants (LA) are one of the criteria antibodies but calibration plasmas are unavailable and they are detected by inference based on antibody behaviour in a medley of coagulation-based assays. Elevated screening tests suggest the presence of a LA, which is confirmed with mixing tests to evidence inhibition and confirmatory tests to demonstrate phospholipid-dependence. At least two screening tests of different principle must be used to account for antibody heterogeneity and controversy exists on whether assays, in addition to dilute Russell's viper venom time and activated partial thromboplastin time, should be employed. A variety of approaches to raw data manipulation and interpretation attract debate, as does inclusion or exclusion of mixing studies in circumstances where the presence of a LA is already evident from other results. Therapeutic anticoagulation compromises coagulation-based assays but careful data interpretation and use of alternative reagents can detect or exclude LA in specific circumstances, and this aspect of LA detection continues to evolve. This review focuses on the main areas of debate in LA detection.
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Affiliation(s)
- Gary W Moore
- Diagnostic Haemostasis & Thrombosis Laboratories, Department of Haemostasis and Thrombosis, Viapath Analytics, Guy's & St. Thomas' NHS Foundation Hospitals Trust, 4th floor North Wing, St. Thomas' Hospital, Westminster Bridge Road, London SE1 7EH, UK.
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Taipan snake venom time coupled with ecarin time enhances lupus anticoagulant detection in nonanticoagulated patients. Blood Coagul Fibrinolysis 2016; 27:477-80. [DOI: 10.1097/mbc.0000000000000486] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Isert M, Miesbach W, Stoever G, Lindhoff-Last E, Linnemann B. Screening for lupus anticoagulants in patients treated with vitamin K antagonists. Int J Lab Hematol 2015. [DOI: 10.1111/ijlh.12409] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- M. Isert
- Division of Vascular Medicine; Department of Internal Medicine; Goethe University Hospital; Frankfurt/Main Germany
| | - W. Miesbach
- Haemophilia Center; Department of Internal Medicine; Goethe University Hospital; Frankfurt/Main Germany
| | - G. Stoever
- Division of Haemostaseology; Department of Internal Medicine; Goethe University Hospital; Frankfurt/Main Germany
| | - E. Lindhoff-Last
- Division of Haemostaseology; Department of Internal Medicine; Goethe University Hospital; Frankfurt/Main Germany
| | - B. Linnemann
- Division of Vascular Medicine; Department of Internal Medicine; Goethe University Hospital; Frankfurt/Main Germany
- Praxis am Grueneburgweg; Medical Practice of Angiology and Haemostaseology; Frankfurt/Main Germany
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Ames PRJ, Montero D, Archer J. Co-existent Acquired Haemophilia and Lupus Anticoagulant. A Thorny Issue. Indian J Hematol Blood Transfus 2015; 32:248. [PMID: 27408404 DOI: 10.1007/s12288-015-0572-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Accepted: 07/09/2015] [Indexed: 11/28/2022] Open
Affiliation(s)
- Paul R J Ames
- Haemostasis & Thrombosis Centre, St George's Hospital, Blackshaw Road, London, UK
| | - Daniel Montero
- Haemostasis & Thrombosis Centre, St George's Hospital, Blackshaw Road, London, UK
| | - Jeremy Archer
- Haemostasis & Thrombosis Centre, St George's Hospital, Blackshaw Road, London, UK
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Arachchillage DRJ, Mackie IJ, Efthymiou M, Isenberg DA, Machin SJ, Cohen H. Interactions between rivaroxaban and antiphospholipid antibodies in thrombotic antiphospholipid syndrome. J Thromb Haemost 2015; 13:1264-73. [PMID: 25850997 DOI: 10.1111/jth.12917] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 03/24/2015] [Indexed: 12/30/2022]
Abstract
INTRODUCTION Rivaroxaban can affect lupus anticoagulant (LA) testing and antiphospholipid antibodies (aPL) may interfere with the anticoagulant action of rivaroxaban. AIMS To establish the influence of rivaroxaban on LA detection and of aPL on the anticoagulant action of rivaroxaban. METHODS Rivaroxaban and 52 IgG preparations (20 LA+ve, 12 LA-ve thrombotic antiphospholipid syndrome [APS] patients, and 20 normal controls [NC]) were spiked into pooled normal plasma (PNP) for relevant studies. LA detection was also studied in APS patients receiving rivaroxaban 20 mg once daily. RESULTS In vitro spiking of samples with rivaroxaban showed no false positive LA with Textarin time, Taipan venom time/Ecarin clotting time (TVT/ECT), dilute prothrombin time (dPT) and in-house dilute Russell's viper venom time (DRVVT), but false positives in the majority of NC and LA negative IgG with two commercial DRVVT reagents at 250 ng/mL but not 50 ng/mL rivaroxaban. Ex vivo studies: six LA+ve patients on rivaroxaban remained LA positive with TVT/ECT and DRVVT at peak (162-278 ng/mL) and trough (30-85 ng/mL) rivaroxaban levels. Six LA-ve patients became (apparently) LA+ve with two DRVVT reagents (test/confirm ratio median [confidence interval], 1.6 [1.3-1.8], 1.6 [1.4-1.9]) but not with TVT/ECT at peak rivaroxaban levels, and remained LA-ve with both DRVVT reagents and TVT/ECT at trough levels. aPL positive IgG spiking of PNP had no effect on rivaroxaban's anticoagulant action on thrombin generation or rivaroxaban anti-Xa levels. CONCLUSIONS The TVT/ECT ratio and Textarin time were not affected even at peak rivaroxaban levels, enabling detection of LA ex vivo. aPL had no effects on rivaroxaban's anticoagulant action in vitro.
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Affiliation(s)
- D R J Arachchillage
- Haemostasis Research Unit, Department of Haematology, University College London, London, UK
| | - I J Mackie
- Haemostasis Research Unit, Department of Haematology, University College London, London, UK
| | - M Efthymiou
- Haemostasis Research Unit, Department of Haematology, University College London, London, UK
| | - D A Isenberg
- Centre for Rheumatology, Division of Medicine, University College London, London, UK
| | - S J Machin
- Haemostasis Research Unit, Department of Haematology, University College London, London, UK
| | - H Cohen
- Haemostasis Research Unit, Department of Haematology, University College London, London, UK
- Department of Haematology, University College London Hospitals NHS Foundation Trust, London, UK
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Ames PRJ, Graf M, Archer J, Scarpato N, Iannaccone L. Prolonged Activated Partial Thromboplastin Time. Clin Appl Thromb Hemost 2015; 21:149-154. [DOI: 10.1177/1076029614541516] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
Abstract
To review the diagnostic difficulties of a prolonged activated partial thromboplastin time (aPTT) when 2 inhibitors with opposite clinical presentations coexist, we searched MEDLINE from January 1970 to November 2013 using acquired, factor VIII (FVIII), factor IX, hemophilia A and B, inhibitor, lupus anticoagulant (LA), antiphospholipid, anticardiolipin, anti-β2-glycoprotein I, antibodies, syndrome, bleeding, and thrombosis. We identified 13 articles for a total of 15 cases of possible coexistence of FVIII inhibitor and LA. The presenting clinical manifestation was thrombosis in 6 cases and bleeding in 9 cases. Activated partial thromboplastin time was the presenting laboratory abnormality in all cases, and first-line investigations suggested the coexistence of LA and acquired FVIII inhibitor. None of the articles addressed the diagnostic accuracy of the screening tests by performing “second line” assays. We reviewed the diagnostic pitfalls of the cases under study and provide some guidance for alternative tests when facing a prolonged aPTT that may have a double meaning.
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Affiliation(s)
- Paul R. J. Ames
- Haemostasis & Thrombosis Department, William Harvey Research Institute, Charterhouse Square, London, United Kingdom
- Haemostasis & Thrombosis Department, St George’s Hospital, London, United Kingdom
| | - Maria Graf
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche - Università degli Studi di Napoli Federico II - VIa Pansini, Napoli, Italy
| | - Jeremy Archer
- Haemostasis & Thrombosis Department, St George’s Hospital, London, United Kingdom
| | - Nicola Scarpato
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche - Università degli Studi di Napoli Federico II - VIa Pansini, Napoli, Italy
| | - Luigi Iannaccone
- Chemical Pathology Department, A. Cardarelli Hospital, Naples, Italy
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Breen KA, Sanchez K, Kirkman N, Seed PT, Parmar K, Moore GW, Hunt BJ. Endothelial and platelet microparticles in patients with antiphospholipid antibodies. Thromb Res 2014; 135:368-74. [PMID: 25496997 DOI: 10.1016/j.thromres.2014.11.027] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 11/03/2014] [Accepted: 11/30/2014] [Indexed: 01/05/2023]
Abstract
BACKGROUND The antiphospholipid syndrome (APS) is the association of thrombosis and recurrent pregnancy loss and/or pregnancy morbidity with persistent antiphospholipid antibodies (aPL). Previous studies of microparticles in patients with APS/aPL have mainly been small and findings, contradictory. OBJECTIVES To quantify endothelial and platelet microparticle levels in patients with isolated antiphospholipid antibodies or primary antiphospholipid syndrome (PAPS). PATIENTS/METHODS We measured endothelial and platelet microparticle levels by flow cytometry in 66 aPL/PAPS patients and 18 healthy controls. RESULTS Levels of circulating platelet (CD41 and CD61) and endothelial microparticles (CD51 and CD105) were significantly increased in patients with PAPS and aPL compared to healthy controls. There were correlations between platelet and endothelial microparticles levels in all patients with aPL. CONCLUSIONS Platelet and endothelial microparticles are increased in all patient groups within this cohort of patients aPL. Whether they may have a role in the pathogenesis of APS merits further study.
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Affiliation(s)
- K A Breen
- Guys and St.Thomas' NHS Foundation Trust, London, United Kingdom.
| | - K Sanchez
- Viapath, Guys and St.Thomas' NHS Foundation Trust, London, United Kingdom
| | - N Kirkman
- Viapath, Guys and St.Thomas' NHS Foundation Trust, London, United Kingdom
| | - P T Seed
- King's College, London, United Kingdom
| | - K Parmar
- Guys and St.Thomas' NHS Foundation Trust, London, United Kingdom
| | - G W Moore
- Viapath, Guys and St.Thomas' NHS Foundation Trust, London, United Kingdom
| | - B J Hunt
- Guys and St.Thomas' NHS Foundation Trust, London, United Kingdom; King's College, London, United Kingdom
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Keeling D, Mackie I, Moore GW, Greer IA, Greaves M. Guidelines on the investigation and management of antiphospholipid syndrome. Br J Haematol 2012; 157:47-58. [PMID: 22313321 DOI: 10.1111/j.1365-2141.2012.09037.x] [Citation(s) in RCA: 313] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- David Keeling
- Oxford Haemophilia and Thrombosis Centre, Churchill Hospital, Oxford, UK.
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van Os GMA, de Laat B, Kamphuisen PW, Meijers JCM, de Groot PG. Detection of lupus anticoagulant in the presence of rivaroxaban using Taipan snake venom time. J Thromb Haemost 2011; 9:1657-9. [PMID: 21668740 DOI: 10.1111/j.1538-7836.2011.04395.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Pengo V, Tripodi A, Reber G, Rand JH, Ortel TL, Galli M, De Groot PG. Update of the guidelines for lupus anticoagulant detection. Subcommittee on Lupus Anticoagulant/Antiphospholipid Antibody of the Scientific and Standardisation Committee of the International Society on Thrombosis and Haemostasis. J Thromb Haemost 2009; 7:1737-40. [PMID: 19624461 DOI: 10.1111/j.1538-7836.2009.03555.x] [Citation(s) in RCA: 832] [Impact Index Per Article: 55.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
One of the conclusions of the subcommittee meeting on Lupus Anticoagulant/Phospholipid dependent antibodies, held in Geneva on 2007, was the need to update the guidelines on Lupus Anticoagulant (LA) detection. Particular emphasis was given to several aspects discussed in this official communication. A new paragraph is dedicated to the patient selection, and aims to minimize inappropriate requests for LA testing. Modalities for blood collection and processing are fully delineated and the choice of tests is limited to dRVVT and a sensitive aPTT. Calculation of cut-off values for each diagnostic step are clearly stated. A final paragraph reports the interpretation of the results in general and in particular situations.
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Affiliation(s)
- V Pengo
- Clinical Cardiology, Thrombosis Center, University Hospital, 35128 Padova, Italy.
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Abstract
AbstractThe antiphospholipid syndrome (APS) is an acquired thrombophilia, characterized by the occurrence of venous and arterial events. This article examines the laboratory and key clinical aspects of APS. Particular focus is given to anti–beta 2-glycoprotein I (β2GPI) antibodies in view of their recent inclusion in the APS classification criteria. The clinical utility of using the β2GPI enzyme-linked immunosorbent assay, in conjunction with the established lupus anticoagulant assays and cardiolipin enzyme-linked immunosorbent assay, for diagnosing and risk stratifying patients suspected of having APS is discussed. The relative importance of the various assays in diagnosing obstetric APS (early and late gestation miscarriages) is explored. The implications of recent epidemiologic findings for possibly understanding the underlying pathophysiologic mechanisms of obstetric APS are highlighted. Insights into which patients with obstetric APS may be at most risk of thrombotic complications are presented.
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Moore GW, Rangarajan S, Savidge GF. The Activated Seven Lupus Anticoagulant Assay Detects Clinically Significant Antibodies. Clin Appl Thromb Hemost 2008; 14:332-7. [PMID: 17895508 DOI: 10.1177/1076029607305099] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Lupus anticoagulants are a heterogeneous group of autoantibodies detected by their effects on phospholipid-dependent coagulation assays. Persistent lupus anticoagulants are associated with thrombotic disease, but not all are clinically significant. Antibody heterogeneity and reagent and test variability dictate that at least 2 tests, of different types, should be used to screen lupus anticoagulants. The objective of this study was to investigate whether the activated seven lupus anticoagulant assay detects clinically significant antibodies. Eighty-two patients with antiphospholipid syndrome (APS) and 32 with systemic lupus erythematosus + positive for activated seven lupus anticoagulant and who were without thrombosis, who were positive by activated seven lupus anticoagulant assay, were investigated for lupus anticoagulants by dilute Russell's viper venom time, dilute activated partial thromboplastin time, and Taipan snake venom time, and for anticardiolipin antibodies. Fifty-seven of the APS patients were positive for lupus anticoagulants in multiple assays, 25 in activated seven lupus anticoagulant alone. Fourteen of the latter group were previously positive in other antiphospholipid antibodies assays, and 11 had only been positive for lupus anticoagulants by activated seven lupus anticoagulant. Twenty-eight had elevated anticardiolipin antibodies, 6 of whom were from the group that was positive in activated seven lupus anticoagulant only. Eight of the systemic lupus erythematosus + lupus anticoagulants (without thrombosis) patients were positive for lupus anticoagulant by activated seven lupus anticoagulant alone and had only been positive in activated seven lupus anticoagulant previously, and none had elevated anticardiolipin antibodies. The remaining 24 patients were lupus-anticoagulant positive in multiple assays, and 9 had elevated anticardiolipin antibodies. Dilute Russell's viper venom time and Dilute activated partial thromboplastin time are widely used to detect lupus anticoagulants and are considered to detect clinically significant antibodies. Activated seven lupus anticoagulant detected antibodies in APS patients who were positive by these assays and also lupus anticoagulants undetectable by the dilute Russell's viper venom time/dilute activated partial thromboplastin time reagents used, demonstrating its utility as a first-line or second-line assay.
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Affiliation(s)
- Gary W Moore
- Centre for Haemostasis and Thrombosis (Haemophilia Reference Centre), St Thomas' Hospital, London, England.
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Moore GW, Henley A, Greenwood CK, Rangarajan S. Further evidence of false negative screening for lupus anticoagulants. Thromb Res 2008; 121:477-84. [PMID: 17602725 DOI: 10.1016/j.thromres.2007.05.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2007] [Revised: 04/16/2007] [Accepted: 05/22/2007] [Indexed: 11/23/2022]
Abstract
INTRODUCTION Accurate and timely detection of lupus anticoagulants (LA) is of diagnostic and prognostic importance due to the association of persistent LA with thrombotic disease. Antibody heterogeneity and assay variability complicate LA detection and weak antibodies can go undetected. METHODS Screen and confirm assays on equal volume mixing studies were performed on known LA using dilute Russell's viper venom time (DRVVT), dilute activated partial thromboplastin time (DAPTT) and activated seven lupus anticoagulant (ASLA) assay. Two established calculations for phospholipid dependence were applied to ascertain whether any antibodies diluted to within screening test reference ranges maintained a significant difference between screen and confirm results sufficient to imply LA activity. We then performed confirmatory tests on neat plasma samples from patients with thrombotic disease whose screening tests were within reference ranges. RESULTS Forty nine of 155 DRVVT positive LA were conventionally positive in the mixing studies and 8 of the 106 negative mixing studies showed significant screen and confirm test discordance. This was the case for 21 of 56 negative DAPTT mixing studies and 2 of 39 negative ASLA mixing studies. Performance of confirm assays on the neat plasma samples with screen results within reference ranges revealed possible LA activity in 19 of 166 DRVVT results, 63 of 184 DAPTT results and 9 of 117 ASLA results. CONCLUSIONS LA activity can be demonstrated by assessment of screen and confirm data irrespective of screening test elevation above a reference range. Other workers have demonstrated this phenomenon in APTT using different study designs and it may be that standard interpretation criteria warrant re-assessment.
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Affiliation(s)
- G W Moore
- Centre for Haemostasis and Thrombosis, Haemophilia Reference Centre, 1st Floor North Wing, St. Thomas' Hospital, Lambeth Palace Road, London SE1 7EH, England.
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Senff-Ribeiro A, Henrique da Silva P, Chaim OM, Gremski LH, Paludo KS, Bertoni da Silveira R, Gremski W, Mangili OC, Veiga SS. Biotechnological applications of brown spider (Loxosceles genus) venom toxins. Biotechnol Adv 2007; 26:210-8. [PMID: 18207690 DOI: 10.1016/j.biotechadv.2007.12.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2007] [Revised: 12/06/2007] [Accepted: 12/06/2007] [Indexed: 11/18/2022]
Abstract
Loxoscelism (the term used to define accidents by the bite of brown spiders) has been reported worldwide. Clinical manifestations following brown spider bites are frequently associated with skin degeneration, a massive inflammatory response at the injured region, intravascular hemolysis, platelet aggregation causing thrombocytopenia and renal disturbances. The mechanisms by which the venom exerts its noxious effects are currently under investigation. The whole venom is a complex mixture of toxins enriched with low molecular mass proteins in the range of 5-40 kDa. Toxins including alkaline phosphatase, hyaluronidase, metalloproteases (astacin-like proteases), low molecular mass (5.6-7.9 kDa) insecticidal peptides and phospholipases-D (dermonecrotic toxins) have been identified in the venom. The purpose of the present review is to describe biotechnological applications of whole venom or some toxins, with especial emphasis upon molecular biology findings obtained in the last years.
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Affiliation(s)
- Andrea Senff-Ribeiro
- Department of Cell Biology, Federal University of Paraná, Curitiba, Paraná, Brazil
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Moore GW, Savidge GF. The dilution effect of equal volume mixing studies compromises confirmation of inhibition by lupus anticoagulants even when mixture specific reference ranges are applied. Thromb Res 2006; 118:523-8. [PMID: 16263154 DOI: 10.1016/j.thromres.2005.09.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2005] [Revised: 07/21/2005] [Accepted: 09/26/2005] [Indexed: 11/29/2022]
Abstract
INTRODUCTION One of the recommended criteria for the laboratory diagnosis of lupus anticoagulants (LA) is demonstration of inhibitory activity. This is confirmed by performing mixing tests with normal plasma, usually in a 1:1 ratio, and demonstrating persistence of an abnormal clotting time in the screening test with significant confirmatory test reduction. However, the mixing with normal plasma can dilute the antibodies to undetectable levels and generate apparent negative results. No guidelines or consensus exist in how to interpret mixing study results. PATIENTS AND METHODS The present study assessed the 1:1 mixing study results from 600 patients with a thrombotic history positive for LA demonstrated in neat plasma by individual assays, or combinations, of dilute Russell's viper venom time, dilute activated partial thromboplastin time, activated seven lupus anticoagulant assay and Taipan snake venom time, plus confirmatory tests. Mixing tests were assessed initially using locally derived neat plasma reference ranges and subsequently with mixture specific ranges. RESULTS The mixture specific ranges had lower upper limits. Of the total LA positive results, 32.5% were positive in the mixing studies when neat plasma reference ranges were applied, and a further 11.2% demonstrated LA activity when using the mixture specific ranges. The remaining 56.3% had been diluted such that they did not elevate the screening test above the upper limit of normal or generated minimal prolongation with an insignificant difference between the screen and confirmatory test result sufficient to confirm LA activity. CONCLUSIONS The significant impact of the dilution effect in 1:1 mixing studies emphasises the limitations of mixing studies as a vehicle for confirmation of inhibition by LA antibodies.
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Affiliation(s)
- Gary W Moore
- Centre for Haemostasis and Thrombosis, (Haemophilia Reference Centre), St Thomas' Hospital, Lambeth Palace Road, London, England, UK.
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Abstract
Snake venom toxins affecting haemostasis have facilitated extensively the routine assays of haemostatic parameters in the coagulation laboratory. Snake venom thrombin-like enzymes (SVTLE) are used for fibrinogen/fibrinogen breakdown product assay and for the detection of fibrinogen dysfunction. SVTLE are not inhibited by heparin and can thus can be used for assaying antithrombin III and other haemostatic variables in heparin-containing samples. Snake venoms are a rich source of prothrombin activators and these are utilised in prothrombin assays, for studying dysprothrombinaemias and for preparing meizothrombin and non-enzymic forms of prothrombin. Russell's viper (Daboia russelli) venom (RVV) contains toxins which have been used to assay blood clotting factors V, VII, X, platelet factor 3 and, importantly, lupus anticoagulants (LA). Other prothrombin activators (from the taipan, Australian brown snake and saw-scaled viper) have now been used to assay LA. Protein C and activated protein C resistance can be measured by means of RVV and Protac, a fast acting inhibitor from Southern copperhead snake venom and von Willebrand factor can be studied with botrocetin from Bothrops jararaca venom. The disintegrins, a large family of Arg-Gly-Asp (RGD)-containing snake venom proteins, show potential for studying platelet glycoprotein receptors, notably, GPIIb/IIIa and Ib. Snake venom toxins affecting haemostasis are also used in the therapeutic setting: Ancrod (from the Malayan pit viper, Calloselasma rhodostoma), in particular, has been used as an anticoagulant to achieve 'therapeutic defibrination'. Other snake venom proteins show promise in the treatment of a range of haemostatic disorders.
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