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Lüsebrink E, Lanz H, Binzenhöfer L, Hoffmann S, Höpler J, Kraft M, Gade N, Gmeiner J, Roden D, Saleh I, Hagl C, Nickenig G, Massberg S, Zimmer S, Jamin RN, Scherer C. Heparin-Induced Thrombocytopenia in Patients Suffering Cardiogenic Shock. Crit Care Explor 2024; 6:e1117. [PMID: 39045433 PMCID: PMC11265775 DOI: 10.1097/cce.0000000000001117] [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] [Indexed: 07/25/2024] Open
Abstract
OBJECTIVES Cardiogenic shock (CS) is associated with high mortality. Patients treated for CS mostly require heparin therapy, which may be associated with complications such as heparin-induced thrombocytopenia (HIT). HIT represents a serious condition associated with platelet decline and increased hypercoagulability and remains a poorly researched field in intensive care medicine. Primary purpose of this study was to: 1) determine HIT prevalence in CS, 2) assess the performance of common diagnostic tests for the workup of HIT, and 3) compare outcomes in CS patients with excluded and confirmed HIT. DESIGN Retrospective dual-center study including adult patients 18 years old or older with diagnosed CS and suspected HIT from January 2010 to November 2022. SETTING Cardiac ICU at the Ludwig-Maximilians University hospital in Munich and the university hospital of Bonn. PATIENTS AND INTERVENTIONS In this retrospective analysis, adult patients with diagnosed CS and suspected HIT were included. Differences in baseline characteristics, mortality, neurologic and safety outcomes between patients with excluded and confirmed HIT were evaluated. MEASUREMENTS AND MAIN RESULTS In cases of suspected HIT, positive screening antibodies were detected in 159 of 2808 patients (5.7%). HIT was confirmed via positive functional assay in 57 of 2808 patients, corresponding to a prevalence rate of 2.0%. The positive predictive value for anti-platelet factor 4/heparin screening antibodies was 35.8%. Total in-hospital mortality (58.8% vs. 57.9%; p > 0.999), 1-month mortality (47.1% vs. 43.9%; p = 0.781), and 12-month mortality (58.8% vs. 59.6%; p > 0.999) were similar between patients with excluded and confirmed HIT, respectively. Furthermore, no significant difference in neurologic outcome among survivors was found between groups (Cerebral Performance Category [CPC] score 1: 8.8% vs. 8.8%; p > 0.999 and CPC 2: 7.8% vs. 12.3%; p = 0.485). CONCLUSIONS HIT was a rare complication in CS patients treated with unfractionated heparin and was not associated with increased mortality. Also, HIT confirmation was not associated with worse neurologic outcome in survivors. Future studies should aim at developing more precise, standardized, and cost-effective strategies to diagnose HIT and prevent complications.
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Affiliation(s)
- Enzo Lüsebrink
- Medizinische Klinik und Poliklinik I, Klinikum der Universität München, Munich, Germany
- DZHK (German Center for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany
| | - Hugo Lanz
- Medizinische Klinik und Poliklinik I, Klinikum der Universität München, Munich, Germany
- DZHK (German Center for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany
| | - Leonhard Binzenhöfer
- Medizinische Klinik und Poliklinik I, Klinikum der Universität München, Munich, Germany
- DZHK (German Center for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany
| | - Sabine Hoffmann
- Institute for Medical Information Processing, Biometry, and Epidemiology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Julia Höpler
- Institute for Medical Information Processing, Biometry, and Epidemiology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Marie Kraft
- Institute for Medical Information Processing, Biometry, and Epidemiology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Nils Gade
- Medizinische Klinik und Poliklinik I, Klinikum der Universität München, Munich, Germany
- DZHK (German Center for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany
| | - Jonas Gmeiner
- Medizinische Klinik und Poliklinik I, Klinikum der Universität München, Munich, Germany
- DZHK (German Center for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany
| | - Daniel Roden
- Medizinische Klinik und Poliklinik I, Klinikum der Universität München, Munich, Germany
- DZHK (German Center for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany
| | - Inas Saleh
- Medizinische Klinik und Poliklinik I, Klinikum der Universität München, Munich, Germany
- DZHK (German Center for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany
| | - Christian Hagl
- DZHK (German Center for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany
- Herzchirurgische Klinik und Poliklinik, Klinikum der Universität München, Munich, Germany
| | - Georg Nickenig
- Medizinische Klinik und Poliklinik II, Universitätsklinikum Bonn, Bonn, Germany
| | - Steffen Massberg
- Medizinische Klinik und Poliklinik I, Klinikum der Universität München, Munich, Germany
- DZHK (German Center for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany
| | - Sebastian Zimmer
- Medizinische Klinik und Poliklinik II, Universitätsklinikum Bonn, Bonn, Germany
| | - Raúl Nicolás Jamin
- Medizinische Klinik und Poliklinik II, Universitätsklinikum Bonn, Bonn, Germany
| | - Clemens Scherer
- Medizinische Klinik und Poliklinik I, Klinikum der Universität München, Munich, Germany
- DZHK (German Center for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany
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Giles JB, Rollin J, Martinez KL, Selleng K, Thiele T, Pouplard C, Sheppard JAI, Heddle NM, Phillips EJ, Roden DM, Gruel Y, Warkentin TE, Greinacher A, Karnes JH. Laboratory and demographic predictors of functional assay positive status in suspected heparin-induced thrombocytopenia: A multicenter retrospective cohort study. Thromb Res 2023; 229:198-208. [PMID: 37541168 PMCID: PMC10528503 DOI: 10.1016/j.thromres.2023.07.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 06/16/2023] [Accepted: 07/18/2023] [Indexed: 08/06/2023]
Abstract
Heparin-induced thrombocytopenia (HIT) is an antibody-mediated immune response against platelet factor 4 (PF4) bound to heparin anticoagulants. A priori identification of patients at-risk for HIT remains elusive and a number of risk factors have been identified, but these associations and their effect sizes have limited validation in large cohorts of suspected HIT patients. The aim of this study was to investigate existing anti-PF4/heparin antibody thresholds and model the relationship of demographic variables and anti-PF4/heparin antibody levels with functional assay positivity across multiple institutions in the absence of detailed clinical data. In a large collection of suspected HIT patients (n = 8904), we tested for associations between laboratory and demographic variables and functional assay positive status as well as anti-PF4/heparin antibody levels. We also tested for correlation between IgG-specific and polyspecific (IgG/IgA/IgM) anti-PF4/heparin antibody values and their ability to predict functional assay positive status using area under the receiver operating characteristic (AUROC). Logistic regression identified increasing anti-PF4/heparin antibody OD levels (OR = 51.84 [37.27-74.34], p < 2.0 × 10-16) and female sex (OR = 1.47 [1.19-1.82], p = 3.5 × 10-4) as risk factors for positive functional assay in the largest cohort with consistent effect sizes in two other cohorts. In a subset of 1175 patients, polyspecific and IgG-specific anti-PF4/heparin antibody values were heterogeneous (mean coefficient of variation = 31.9 %), but strongly correlated (rho = 0.878; p < 2 × 10-16) with similar prediction of functional assay positivity (polyspecific AUROC = 0.976 and IgG-specific AUROC = 0.980). Thus, we recapitulate previously identified risk factors of functional assay positivity, providing precise effect sizes in a large observational population of suspected HIT patients. Our data reinforce the necessity of functional assay confirmation and suggest that, despite heterogeneity, polyspecific and IgG-specific anti-PF4/heparin antibody assays predict functional assay positive status similarly, even in the absence of 4Ts scores and detailed clinical data.
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Affiliation(s)
- Jason B Giles
- Department of Pharmacy Practice and Science, University of Arizona R. Ken Coit College of Pharmacy, Tucson, AZ, USA
| | - Jerome Rollin
- Regional University Hospital Centre Tours, Department of Hemostasis, Tours, France; University of Tours, EA4245, T2i, Tours, France
| | - Kiana L Martinez
- Department of Pharmacy Practice and Science, University of Arizona R. Ken Coit College of Pharmacy, Tucson, AZ, USA
| | - Kathleen Selleng
- Institute of Immunology and Transfusion Medicine, University of Greifswald, Greifswald, Germany
| | - Thomas Thiele
- Institute of Immunology and Transfusion Medicine, University of Greifswald, Greifswald, Germany
| | - Claire Pouplard
- Regional University Hospital Centre Tours, Department of Hemostasis, Tours, France; University of Tours, EA4245, T2i, Tours, France
| | - Jo-Ann I Sheppard
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
| | - Nancy M Heddle
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
| | - Elizabeth J Phillips
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Dan M Roden
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Yves Gruel
- Regional University Hospital Centre Tours, Department of Hemostasis, Tours, France; University of Tours, EA4245, T2i, Tours, France
| | - Theodore E Warkentin
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
| | - Andreas Greinacher
- Institute of Immunology and Transfusion Medicine, University of Greifswald, Greifswald, Germany
| | - Jason H Karnes
- Department of Pharmacy Practice and Science, University of Arizona R. Ken Coit College of Pharmacy, Tucson, AZ, USA; Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN, USA.
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3
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Testa S, Meijer P, Lasne D, Mullier F. Implementation of the new EUR IVD regulation and relation with ISO15189 accreditation: Guidance is urgently required for haemostasis testing. Int J Lab Hematol 2022; 44 Suppl 1:71-78. [PMID: 36074714 DOI: 10.1111/ijlh.13936] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 06/24/2022] [Indexed: 12/17/2022]
Abstract
On May 26th 2017 the European Parliament and the Council of The European Union adopted the new regulation on in vitro diagnostic medical devices (IVDR)-Regulation EU 2017/746-planned to be applied from May 26th 2022 in substitution to the previous IVD directives (IVDD 98/79 EC). After several health and legal causes due to medical device malfunctions, the European Union (EU) extensively reviewed the previous regulatory, which had remained unchanged since 1998. Aim of the work is to analyse the effects of the new IVDR on the field of haemostasis and thrombosis testing with particular attention to specific clinical conditions. Clinical laboratories will mainly deal with three different situations: (1) Diagnostic test performed with IVDR products used according with clinical indication certified by manufacturers. (2) Diagnostic test performed with certified IVDR products without clinical validation. (3) Diagnostic test performed with reagents classified as Research Use Only (RUO). At present, only few clinical laboratories through different European countries have been prepared to the new IVDR, while many laboratories are not yet aware about crucial aspects of the new process that deeply involves laboratory medicine. In conclusion, each laboratory should be aware of the IVDR certification of the reagents/instruments used in its laboratory. There are several urgent needs regarding IVDR certification: studies about the clinical performance of haemostasis tests, guidelines for LDTs (definition and documentation), internal and external quality controls for the tests recommended/suggested in the guidance/guidelines and finally implementation and/or update of clinical and laboratory guidelines.
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Affiliation(s)
- Sophie Testa
- Haemostasis and Thrombosis Centre, Cremona Hospital, Cremona, Italy
| | - Piet Meijer
- ECAT Foundation (External Quality Control for Assays and Tests), Voorschoten, The Netherlands
| | - Dominique Lasne
- Haematology Laboratory, AP-HP, Hôpital Universitaire Necker-Enfants Malades, Paris, France
| | - François Mullier
- CHU UCL NAMUR, Namur Thrombosis and Hemostasis Center (NTHC), Université Catholique de Louvain, Yvoir, Belgium
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Karnes JH, Rollin J, Giles JB, Martinez KL, Steiner HE, Shaffer CM, Momozawa Y, Inai C, Bombin A, Shi M, Mosley JD, Stanaway I, Selleng K, Thiele T, Mushiroda T, Pouplard C, Heddle NM, Kubo M, Phillips EJ, Warkentin TE, Gruel Y, Greinacher A, Roden DM. ABO O blood group as a risk factor for platelet reactivity in heparin-induced thrombocytopenia. Blood 2022; 140:274-284. [PMID: 35377938 PMCID: PMC9305089 DOI: 10.1182/blood.2021014240] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 03/08/2022] [Indexed: 11/20/2022] Open
Abstract
Heparin-induced thrombocytopenia (HIT) is an unpredictable, potentially catastrophic adverse effect resulting from an immune response to platelet factor 4 (PF4)/heparin complexes. We performed a genome-wide association study (GWAS) with positive functional assay as the outcome in a large discovery cohort of patients divided into 3 groups: (1) functional assay-positive cases (n = 1269), (2) antibody-positive (functional assay-negative) controls (n = 1131), and (3) antibody-negative controls (n = 1766). Significant associations (α = 5 × 10-8) were investigated in a replication cohort (α = 0.05) of functional assay-confirmed HIT cases (n = 177), antibody-positive (function assay-negative) controls (n = 258), and antibody-negative controls (n = 351). We observed a strong association for positive functional assay with increasing PF4/heparin immunoglobulin-G (IgG) level (odds ratio [OR], 16.53; 95% confidence interval [CI], 13.83-19.74; P = 1.51 × 10-209) and female sex (OR, 1.15; 95% CI, 1.01-1.32; P = .034). The rs8176719 C insertion variant in ABO was significantly associated with positive functional assay status in the discovery cohort (frequency = 0.41; OR, 0.751; 95% CI, 0.682-0.828; P = 7.80 × 10-9) and in the replication cohort (OR, 0.467; 95% CI, 0.228-0.954; P = .0367). The rs8176719 C insertion, which encodes all non-O blood group alleles, had a protective effect, indicating that the rs8176719 C deletion and the O blood group were risk factors for HIT (O blood group OR, 1.42; 95% CI, 1.26-1.61; P = 3.09 × 10-8). Meta-analyses indicated that the ABO association was independent of PF4/heparin IgG levels and was stronger when functional assay-positive cases were compared with antibody-positive (functional assay-negative) controls than with antibody-negative controls. Sequencing and fine-mapping of ABO demonstrated that rs8176719 was the causal single nucleotide polymorphism (SNP). Our results clarify the biology underlying HIT pathogenesis with ramifications for prediction and may have important implications for related conditions, such as vaccine-induced thrombotic thrombocytopenia.
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Affiliation(s)
- Jason H Karnes
- Department of Pharmacy Practice and Science, University of Arizona College of Pharmacy, Tucson, AZ
- Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN
| | - Jerome Rollin
- Regional University Hospital Centre Tours, Department of Hemostasis, Tours, France
- University of Tours, EA7501 GICC, Tours, France
| | - Jason B Giles
- Department of Pharmacy Practice and Science, University of Arizona College of Pharmacy, Tucson, AZ
| | - Kiana L Martinez
- Department of Pharmacy Practice and Science, University of Arizona College of Pharmacy, Tucson, AZ
| | - Heidi E Steiner
- Department of Pharmacy Practice and Science, University of Arizona College of Pharmacy, Tucson, AZ
| | | | - Yukihide Momozawa
- RIKEN Center for Integrative Medical Sciences (IMS), Yokohama, Kanagawa, Japan
| | - Chihiro Inai
- RIKEN Center for Integrative Medical Sciences (IMS), Yokohama, Kanagawa, Japan
| | - Andrei Bombin
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
| | - Mingjian Shi
- Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN
| | - Jonathan D Mosley
- Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
| | - Ian Stanaway
- Department of Medicine, Kidney Research Institute, University of Washington, Seattle, WA
| | - Kathleen Selleng
- Institute of Immunology and Transfusion Medicine, University of Greifswald, Greifswald, Germany
| | - Thomas Thiele
- Institute of Immunology and Transfusion Medicine, University of Greifswald, Greifswald, Germany
| | - Taisei Mushiroda
- RIKEN Center for Integrative Medical Sciences (IMS), Yokohama, Kanagawa, Japan
| | - Claire Pouplard
- Regional University Hospital Centre Tours, Department of Hemostasis, Tours, France
- University of Tours, EA7501 GICC, Tours, France
| | - Nancy M Heddle
- Department of Medicine, McMaster University, Hamilton, ON, Canada; and
| | - Michiaki Kubo
- RIKEN Center for Integrative Medical Sciences (IMS), Yokohama, Kanagawa, Japan
| | - Elizabeth J Phillips
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN
| | | | - Yves Gruel
- Regional University Hospital Centre Tours, Department of Hemostasis, Tours, France
- University of Tours, EA7501 GICC, Tours, France
| | - Andreas Greinacher
- Institute of Immunology and Transfusion Medicine, University of Greifswald, Greifswald, Germany
| | - Dan M Roden
- Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN
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Pouplard C, Rollin J, Vayne C, Charuel N, Ahmadi Z, Alberio L, Azjenberg N, Althaus K, Bakchoul T, Chong B, Curtis BR, Faille D, Gomez FJ, Gresele P, Morel-Kopp MC, Mullier F, Nazy I, Smith JW, Greinacher A, Gruel Y. Multicentre evaluation of 5B9, a monoclonal anti-PF4/heparin IgG mimicking human HIT antibodies, as an internal quality control in HIT functional assays: Communication from the ISTH SSC Subcommittee on Platelet Immunology. J Thromb Haemost 2022; 20:252-259. [PMID: 34657390 DOI: 10.1111/jth.15560] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 10/13/2021] [Accepted: 10/14/2021] [Indexed: 12/29/2022]
Abstract
BACKGROUND Functional tests for the diagnosis of heparin-induced thrombocytopenia (HIT) exhibit variable performance. OBJECTIVES We evaluated in a multicenter study whether 5B9, a monoclonal anti-PF4/heparin IgG mimicking human HIT antibodies, could be used as an internal quality control. METHODS 5B9 was sent to 11 laboratories in seven countries, and six initial concentrations ranging from 10 to 400 μg/mL were tested by heparin-induced platelet activation assay (HIPA), serotonin release assay (SRA), platelet aggregation test (PAT), flow cytometry (FC), or heparin-induced multiple-electrode aggregometry (HIMEA). Each method was evaluated in three different laboratories using experimental procedures identical to those usually applied for the diagnosis of HIT by testing platelets from 10 different healthy donors. RESULTS The procedures used varied among the laboratories, particularly when platelet-rich plasma and whole blood were used. Nevertheless, positive results were obtained with at least 100 μg/ml of 5B9 for most donors tested by all centers (except one) performing HIPA, SRA, or HIMEA. FC and PAT results were more heterogeneous. FC results from one center that used washed platelets preincubated with PF4 were positive with all donors at 50 µg/ml 5B9, but at least 200 μg/ml of 5B9 were required to activate cells with most donors tested using PAT. CONCLUSION This study confirms that HIT functional tests are not well standardized and exhibit variable sensitivity for the detection of platelet-activating antibodies. However, 5B9 is a potentially useful tool to standardize functional tests, to select responding platelet donors, and consequently to improve the performance of these assays and comparability between laboratories.
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Affiliation(s)
- Claire Pouplard
- University of Tours, EA7501 GICC, CHRU de Tours, Department of Haemostasis, Tours, France
| | - Jérôme Rollin
- University of Tours, EA7501 GICC, CHRU de Tours, Department of Haemostasis, Tours, France
| | - Caroline Vayne
- University of Tours, EA7501 GICC, CHRU de Tours, Department of Haemostasis, Tours, France
| | - Noémie Charuel
- University of Tours, EA7501 GICC, CHRU de Tours, Department of Haemostasis, Tours, France
| | - Zohra Ahmadi
- Haematology Research Unit, St George and Sutherland Clinical School, University of New South Wales, Sydney, NSW, Australia
| | - Lorenzo Alberio
- Service and Central Laboratory of Hematology, Lausanne University Hospital (CHUV) and University of Lausanne, Lausanne, Switzerland
| | - Nadine Azjenberg
- University of Paris, INSERM U1148 LVTS, Department of Hematology, AP-HP, Bichat-Claude Bernard Hospital, Paris, France
| | - Karina Althaus
- Transfusion Medicine, Medical Faculty of Tubingen, University of Tubingen, Tubingen, Germany
| | - Tamam Bakchoul
- Transfusion Medicine, Medical Faculty of Tubingen, University of Tubingen, Tubingen, Germany
| | - Beng Chong
- Haematology Research Unit, St George and Sutherland Clinical School, University of New South Wales, Sydney, NSW, Australia
| | - Brian R Curtis
- Blood Research Institute, Versiti, Blood Center of Wisconsin, Milwaukee, Wisconsin, USA
| | - Dorothée Faille
- University of Paris, INSERM U1148 LVTS, Department of Hematology, AP-HP, Bichat-Claude Bernard Hospital, Paris, France
| | - Francisco-Javier Gomez
- Service and Central Laboratory of Hematology, Lausanne University Hospital (CHUV) and University of Lausanne, Lausanne, Switzerland
| | - Paolo Gresele
- Department of Medicine and Surgery, Section of Internal and Cardiovascular Medicine, University of Perugia, Perugia, Italy
| | - Marie-Christine Morel-Kopp
- Department of Haematology and Transfusion Medicine, Royal North Shore Hospital, and Northern Blood Research Centre, Kolling Institute, The University of Sydney, Sydney, NSW, Australia
| | - François Mullier
- Université catholique de Louvain, CHU UCL Namur, Namur Thrombosis and Hemostasis Center (NTHC), Hematology Laboratory, Namur Research for Life Sciences, Yvoir, Belgium
| | - Izhac Nazy
- Department of Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, ON, Canada
- McMaster Centre for Transfusion Research, Hamilton, ON, Canada
| | - James W Smith
- Department of Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, ON, Canada
| | - Andreas Greinacher
- Institut fuer Immunologie und Transfusionsmedizin, Universitaetsmedizin Greifswald, Greifswald, Germany
| | - Yves Gruel
- University of Tours, EA7501 GICC, CHRU de Tours, Department of Haemostasis, Tours, France
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Abstract
Heparin-induced thrombocytopenia is a severe prothrombotic disease. Timely diagnosis and treatment are essential. Application of diagnostic algorithms based on validated clinical scoring tools and rapid, specific laboratory assays may improve outcomes.
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Gonthier MC, Gendron N, Eloy P, Bourrienne MC, Alhenc-Gelas M, Pouplard C, Tardy B, Szymezak J, Burdet C, Gkalea V, Faille D, Ajzenberg N. Heparin-induced Thrombocytopenia Diagnosis: A Retrospective Study Comparing Heparin-induced Platelet Activation Test to 14 C-serotonin Release Assay. TH OPEN 2021; 5:e507-e512. [PMID: 34778697 PMCID: PMC8577886 DOI: 10.1055/a-1653-5065] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 09/08/2021] [Indexed: 11/23/2022] Open
Abstract
Laboratory confirmation of heparin-induced thrombocytopenia (HIT) is of crucial importance and remains challenging and relies on platelet functional assays highlighting the presence of heparin-dependent platelet-activating antibodies in patient serum or plasma. Platelet functional assays using washed platelets include the
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C-serotonin release assay (SRA), usually described as the gold standard, and the heparin-induced platelet activation assay (HIPA). Since its first comparison with SRA there has been no additional published study regarding HIPA diagnostic performances compared with SRA. Aim of our retrospective study was to compare the concordance between HIPA and SRA in HIT suspected-patients with positive anti-PF4/heparin antibodies between October 2010 and October 2015. Fifty-five HIT-suspected patients who beneficiated from both HIPA and SRA were included. Positive and negative percent agreements were 83.8% (95% CI 68.0–93.8%) and 66.7% (95% CI 41.0–86.7%), respectively. Overall percent agreement was 78.2% (95% CI 65.0–92.2%). Agreement was higher in patients who underwent cardiopulmonary bypass with extracorporeal circulation circuit for cardiac surgery. We also confirm that the use of a minimum of 2 platelet donors to establish positive HIT diagnosis and 4 platelet donors to exclude HIT diagnosis allows obtaining a good agreement with SRA. Although HIPA and SRA were performed with different platelet donors and in different laboratories, HIPA had a good positive agreement with SRA for HIT diagnosis, showing that HIPA is a useful functional assay that does not require radioactivity and could be developed worldwide to improve HIT diagnosis.
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Affiliation(s)
- Marie-Caroline Gonthier
- Laboratory of Vascular Translational Science, Université de Paris, INSERM, et Laboratoire d'Hématologie, AH-HP, Bichat-Claude Bernard Hospital, Paris, France
| | - Nicolas Gendron
- Laboratory of Vascular Translational Science, Université de Paris, INSERM, et Laboratoire d'Hématologie, AH-HP, Bichat-Claude Bernard Hospital, Paris, France.,Hematology Department and Biosurgical Research Lab (Carpentier Foundation), Assistance Publique Hôpitaux de Paris.Centre-Université de Paris (APHP-CUP), Paris, France
| | - Philippine Eloy
- Département d'Epidémiologie, Biostatistique et Recherche Clinique, AH-HP, Bichat-Claude Bernard Hospital, Paris, France
| | - Marie-Charlotte Bourrienne
- Laboratory of Vascular Translational Science, Université de Paris, INSERM, et Laboratoire d'Hématologie, AH-HP, Bichat-Claude Bernard Hospital, Paris, France
| | - Martine Alhenc-Gelas
- Hematology Department and Biosurgical Research Lab (Carpentier Foundation), Assistance Publique Hôpitaux de Paris.Centre-Université de Paris (APHP-CUP), Paris, France
| | - Claire Pouplard
- CHRU Tours, Service d'hématologie-hémostase, Université de Tours, Tours, France
| | - Bernard Tardy
- Inserm CIC 1408 CHU Saint Etienne, Saint-Etienne, France
| | - Jean Szymezak
- Laboratoire d'hématologie, CHU Robert Debré, Reims, France
| | - Charles Burdet
- Département d'Epidémiologie, Biostatistique et Recherche Clinique, AH-HP, Bichat-Claude Bernard Hospital, Paris, France.,Université de Paris, IAME, INSERM, Paris, France
| | - Vasiliki Gkalea
- Laboratory of Vascular Translational Science, Université de Paris, INSERM, et Laboratoire d'Hématologie, AH-HP, Bichat-Claude Bernard Hospital, Paris, France
| | - Dorothée Faille
- Laboratory of Vascular Translational Science, Université de Paris, INSERM, et Laboratoire d'Hématologie, AH-HP, Bichat-Claude Bernard Hospital, Paris, France
| | - Nadine Ajzenberg
- Laboratory of Vascular Translational Science, Université de Paris, INSERM, et Laboratoire d'Hématologie, AH-HP, Bichat-Claude Bernard Hospital, Paris, France
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Greinacher A, Selleng K, Mayerle J, Palankar R, Wesche J, Reiche S, Aebischer A, Warkentin TE, Muenchhoff M, Hellmuth JC, Keppler OT, Duerschmied D, Lother A, Rieg S, Gawaz MP, Mueller KAL, Scheer CS, Napp M, Hahnenkamp K, Lucchese G, Vogelgesang A, Flöel A, Lovreglio P, Stufano A, Marschalek R, Thiele T. Anti-platelet factor 4 antibodies causing VITT do not cross-react with SARS-CoV-2 spike protein. Blood 2021; 138:1269-1277. [PMID: 34280256 PMCID: PMC8294553 DOI: 10.1182/blood.2021012938] [Citation(s) in RCA: 83] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 07/12/2021] [Indexed: 11/21/2022] Open
Abstract
Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a severe adverse effect of ChAdOx1 nCoV-19 COVID-19 vaccine (Vaxzevria) and Janssen Ad26.COV2.S COVID-19 vaccine, and it is associated with unusual thrombosis. VITT is caused by anti-platelet factor 4 (PF4) antibodies activating platelets through their FcγRIIa receptors. Antibodies that activate platelets through FcγRIIa receptors have also been identified in patients with COVID-19. These findings raise concern that vaccination-induced antibodies against anti-SARS-CoV-2 spike protein cause thrombosis by cross-reacting with PF4. Immunogenic epitopes of PF4 and SARS-CoV-2 spike protein were compared using in silico prediction tools and 3D modeling. The SARS-CoV-2 spike protein and PF4 share at least 1 similar epitope. Reactivity of purified anti-PF4 antibodies from patients with VITT was tested against recombinant SARS-CoV-2 spike protein. However, none of the affinity-purified anti-PF4 antibodies from 14 patients with VITT cross-reacted with SARS-CoV-2 spike protein. Sera from 222 polymerase chain reaction-confirmed patients with COVID-19 from 5 European centers were tested by PF4-heparin enzyme-linked immunosorbent assays and PF4-dependent platelet activation assays. We found anti-PF4 antibodies in sera from 19 (8.6%) of 222 patients with COVID-19. However, only 4 showed weak to moderate platelet activation in the presence of PF4, and none of those patients developed thrombotic complications. Among 10 (4.5%) of 222 patients who had COVID-19 with thrombosis, none showed PF4-dependent platelet-activating antibodies. In conclusion, antibodies against PF4 induced by vaccination do not cross-react with the SARS-CoV-2 spike protein, indicating that the intended vaccine-induced immune response against SARS-CoV-2 spike protein is not the trigger of VITT. PF4-reactive antibodies found in patients with COVID-19 in this study were not associated with thrombotic complications.
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Affiliation(s)
- Andreas Greinacher
- Institute of Immunology and Transfusion Medicine, Department of Transfusion Medicine, Universitätsmedizin Greifswald, Greifswald, Germany
| | - Kathleen Selleng
- Institute of Immunology and Transfusion Medicine, Department of Transfusion Medicine, Universitätsmedizin Greifswald, Greifswald, Germany
| | - Julia Mayerle
- Department of Medicine II, University Hospital Munich, and German Centre for Infection Research (DZIF) (partner site Munich), Munich, Germany
| | - Raghavendra Palankar
- Institute of Immunology and Transfusion Medicine, Department of Transfusion Medicine, Universitätsmedizin Greifswald, Greifswald, Germany
| | - Jan Wesche
- Institute of Immunology and Transfusion Medicine, Department of Transfusion Medicine, Universitätsmedizin Greifswald, Greifswald, Germany
| | - Sven Reiche
- Department of Experimental Animal Facilities and Biorisk Management, Friedrich-Loeffler Institut, Greifswald, Germany
| | - Andrea Aebischer
- Department of Experimental Animal Facilities and Biorisk Management, Friedrich-Loeffler Institut, Greifswald, Germany
| | - Theodore E Warkentin
- Department of Pathology and Molecular Medicine, and Department of Medicine, McMaster University, Hamilton, ON, Canada
| | - Maximilian Muenchhoff
- Max von Pettenkofer Institute, Virology, Ludwig Maximilians University of Munich, and DZIF, Munich, Germany
| | | | - Oliver T Keppler
- Max von Pettenkofer Institute, Virology, Ludwig Maximilians University of Munich, and DZIF, Munich, Germany
| | - Daniel Duerschmied
- Heart Center Freiburg University, Cardiology and Angiology I and Medical Intensive Care, Medical Center
| | - Achim Lother
- Heart Center Freiburg University, Cardiology and Angiology I and Medical Intensive Care, Medical Center
- Institute of Experimental and Clinical Pharmacology and Toxicology, and
| | - Siegbert Rieg
- Division of Infectious Diseases, Department of Medicine II, Faculty of Medicine, Medical Center, University of Freiburg, Freiburg, Germany
| | - Meinrad Paul Gawaz
- Department of Cardiology and Angiology, University Hospital Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Karin Anne Lydia Mueller
- Department of Cardiology and Angiology, University Hospital Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany
| | | | - Matthias Napp
- Department of Anesthesiology and Intensive Care Medicine, and
| | | | - Guglielmo Lucchese
- Department of Neurology, University Medicine Greifswald, Greifswald, Germany
| | - Antje Vogelgesang
- Department of Neurology, University Medicine Greifswald, Greifswald, Germany
| | - Agnes Flöel
- Department of Neurology, University Medicine Greifswald, Greifswald, Germany
| | - Piero Lovreglio
- Interdisciplinary Department of Medicine, University of Bari Aldo Moro, Bari, Italy; and
| | - Angela Stufano
- Interdisciplinary Department of Medicine, University of Bari Aldo Moro, Bari, Italy; and
| | - Rolf Marschalek
- Institute of Pharmacology Biology, Biocenter, Goethe University, Frankfurt am Main, Germany
| | - Thomas Thiele
- Institute of Immunology and Transfusion Medicine, Department of Transfusion Medicine, Universitätsmedizin Greifswald, Greifswald, Germany
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9
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A flow cytometric assay to detect platelet-activating antibodies in VITT after ChAdOx1 nCov-19 vaccination. Blood 2021; 137:3656-3659. [PMID: 33945605 PMCID: PMC8105122 DOI: 10.1182/blood.2021012064] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 05/03/2021] [Indexed: 01/23/2023] Open
Abstract
Anti-PF4 antibodies as detected by some PF4/heparin enzyme immunoassays are not specific for VITT. We provide a functional whole-blood flow cytometry test for detection of platelet-activating anti-PF4 antibodies in VITT.
Vaccination is crucial in combatting the severe acute respiratory syndrome coronavirus 2 pandemic. The rare complication of thrombocytopenia and thrombotic complications at unusual sites after ChAdOx1 nCov-19 vaccination is caused by platelet-activating antibodies directed against platelet factor 4 (PF4). We present a widely applicable whole-blood standard flow cytometric assay to identify the pathogenic antibodies associated with vaccine-induced immune-mediated thrombotic thrombocytopenia (VITT) after ChAdOx1 nCov-19 vaccination. This assay will enable rapid diagnosis by many laboratories. This trial was registered at www.clinicaltrials.gov as #NCT04370119.
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10
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Sachs UJ, Cooper N, Czwalinna A, Müller J, Pötzsch B, Tiede A, Althaus K. PF4-Dependent Immunoassays in Patients with Vaccine-Induced Immune Thrombotic Thrombocytopenia: Results of an Interlaboratory Comparison. Thromb Haemost 2021; 121:1622-1627. [PMID: 34169493 DOI: 10.1055/a-1535-9002] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND Coronavirus disease 2019 vaccine ChAdOx1 nCov-19 may rarely lead to vaccine-induced thrombotic thrombocytopenia (VITT). Antibody-mediated, platelet factor 4 (PF4)-dependent platelet activation appears to resemble a key mechanism in VITT, partially comparable to heparin-induced thrombocytopenia. The use of PF4/heparin immunoassays has been proposed as part of a diagnostic approach, but their sensitivity has not been established. METHODS Sera from 12 well-defined VITT patients were first studied by two different laboratories in functional assays. Sera where then used for an interlaboratory comparison, in which five different PF4/heparin immunoassays were used by four laboratories. RESULTS Results for functional testing were highly concordant. VITT antibodies were also reliably detected by PF4/heparin enzyme-linked immunosorbent assays (ELISAs) (92-100%). In contrast, only 25% of VITT antibodies were reactive in a particle gel immunoassay (PaGIA), and 8% in a lateral flow assay (LFA). An automated chemiluminescence immunoassay (CLIA) was negative for all sera tested (0%). CONCLUSION It seems feasible to establish functional antibody testing for the confirmation of VITT. For the initial screening of suspected VITT cases, PaGIA, LFA, and CLIA are useless when applied as single tests. Only ELISA-based PF4/heparin immunoassays are sensitive enough to be incorporated in the diagnostic workup. However, a combination of a positive ELISA and a negative CLIA may be useful to identify VITT antibodies in the absence of confirmatory functional assays.
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Affiliation(s)
- Ulrich J Sachs
- Department of Thrombosis and Haemostasis, Giessen University Hospital, Giessen, Germany.,Institute for Clinical Immunology and Transfusion Medicine, Justus Liebig University, Giessen, Germany
| | - Nina Cooper
- Department of Thrombosis and Haemostasis, Giessen University Hospital, Giessen, Germany.,Institute for Clinical Immunology and Transfusion Medicine, Justus Liebig University, Giessen, Germany
| | | | - Jens Müller
- Institute for Experimental Haematology and Transfusion Medicine, University of Bonn, Bonn, Germany
| | - Bernd Pötzsch
- Institute for Experimental Haematology and Transfusion Medicine, University of Bonn, Bonn, Germany
| | - Andreas Tiede
- Department of Haematology, Haemostasis, Oncology, and Stem Cell Transplantation, Hannover Medical School, Hannover, Germany
| | - Karina Althaus
- Institute for Clinical and Experimental Transfusion Medicine, Medical Faculty of Tuebingen, University Hospital of Tuebingen, Tuebingen, Germany
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11
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Greinacher A, Thiele T, Warkentin TE, Weisser K, Kyrle PA, Eichinger S. Thrombotic Thrombocytopenia after ChAdOx1 nCov-19 Vaccination. N Engl J Med 2021; 384:2092-2101. [PMID: 33835769 PMCID: PMC8095372 DOI: 10.1056/nejmoa2104840] [Citation(s) in RCA: 1547] [Impact Index Per Article: 515.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Several cases of unusual thrombotic events and thrombocytopenia have developed after vaccination with the recombinant adenoviral vector encoding the spike protein antigen of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (ChAdOx1 nCov-19, AstraZeneca). More data were needed on the pathogenesis of this unusual clotting disorder. METHODS We assessed the clinical and laboratory features of 11 patients in Germany and Austria in whom thrombosis or thrombocytopenia had developed after vaccination with ChAdOx1 nCov-19. We used a standard enzyme-linked immunosorbent assay to detect platelet factor 4 (PF4)-heparin antibodies and a modified (PF4-enhanced) platelet-activation test to detect platelet-activating antibodies under various reaction conditions. Included in this testing were samples from patients who had blood samples referred for investigation of vaccine-associated thrombotic events, with 28 testing positive on a screening PF4-heparin immunoassay. RESULTS Of the 11 original patients, 9 were women, with a median age of 36 years (range, 22 to 49). Beginning 5 to 16 days after vaccination, the patients presented with one or more thrombotic events, with the exception of 1 patient, who presented with fatal intracranial hemorrhage. Of the patients with one or more thrombotic events, 9 had cerebral venous thrombosis, 3 had splanchnic-vein thrombosis, 3 had pulmonary embolism, and 4 had other thromboses; of these patients, 6 died. Five patients had disseminated intravascular coagulation. None of the patients had received heparin before symptom onset. All 28 patients who tested positive for antibodies against PF4-heparin tested positive on the platelet-activation assay in the presence of PF4 independent of heparin. Platelet activation was inhibited by high levels of heparin, Fc receptor-blocking monoclonal antibody, and immune globulin (10 mg per milliliter). Additional studies with PF4 or PF4-heparin affinity purified antibodies in 2 patients confirmed PF4-dependent platelet activation. CONCLUSIONS Vaccination with ChAdOx1 nCov-19 can result in the rare development of immune thrombotic thrombocytopenia mediated by platelet-activating antibodies against PF4, which clinically mimics autoimmune heparin-induced thrombocytopenia. (Funded by the German Research Foundation.).
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Affiliation(s)
- Andreas Greinacher
- From Institut für Immunologie und Transfusionsmedizin, Universitätsmedizin Greifswald, Greifswald (A.G., T.T.), and the Division of Safety of Medicinal Products and Medical Devices, Paul-Ehrlich-Institut (Federal Institute for Vaccines and Biomedicines), Langen (K.W.) - both in Germany; the Departments of Pathology and Molecular Medicine and of Medicine, McMaster University, Hamilton, ON, Canada (T.E.W.); and the Department of Medicine I, Division of Hematology and Hemostaseology, Medical University of Vienna, Vienna (P.A.K., S.E.)
| | - Thomas Thiele
- From Institut für Immunologie und Transfusionsmedizin, Universitätsmedizin Greifswald, Greifswald (A.G., T.T.), and the Division of Safety of Medicinal Products and Medical Devices, Paul-Ehrlich-Institut (Federal Institute for Vaccines and Biomedicines), Langen (K.W.) - both in Germany; the Departments of Pathology and Molecular Medicine and of Medicine, McMaster University, Hamilton, ON, Canada (T.E.W.); and the Department of Medicine I, Division of Hematology and Hemostaseology, Medical University of Vienna, Vienna (P.A.K., S.E.)
| | - Theodore E Warkentin
- From Institut für Immunologie und Transfusionsmedizin, Universitätsmedizin Greifswald, Greifswald (A.G., T.T.), and the Division of Safety of Medicinal Products and Medical Devices, Paul-Ehrlich-Institut (Federal Institute for Vaccines and Biomedicines), Langen (K.W.) - both in Germany; the Departments of Pathology and Molecular Medicine and of Medicine, McMaster University, Hamilton, ON, Canada (T.E.W.); and the Department of Medicine I, Division of Hematology and Hemostaseology, Medical University of Vienna, Vienna (P.A.K., S.E.)
| | - Karin Weisser
- From Institut für Immunologie und Transfusionsmedizin, Universitätsmedizin Greifswald, Greifswald (A.G., T.T.), and the Division of Safety of Medicinal Products and Medical Devices, Paul-Ehrlich-Institut (Federal Institute for Vaccines and Biomedicines), Langen (K.W.) - both in Germany; the Departments of Pathology and Molecular Medicine and of Medicine, McMaster University, Hamilton, ON, Canada (T.E.W.); and the Department of Medicine I, Division of Hematology and Hemostaseology, Medical University of Vienna, Vienna (P.A.K., S.E.)
| | - Paul A Kyrle
- From Institut für Immunologie und Transfusionsmedizin, Universitätsmedizin Greifswald, Greifswald (A.G., T.T.), and the Division of Safety of Medicinal Products and Medical Devices, Paul-Ehrlich-Institut (Federal Institute for Vaccines and Biomedicines), Langen (K.W.) - both in Germany; the Departments of Pathology and Molecular Medicine and of Medicine, McMaster University, Hamilton, ON, Canada (T.E.W.); and the Department of Medicine I, Division of Hematology and Hemostaseology, Medical University of Vienna, Vienna (P.A.K., S.E.)
| | - Sabine Eichinger
- From Institut für Immunologie und Transfusionsmedizin, Universitätsmedizin Greifswald, Greifswald (A.G., T.T.), and the Division of Safety of Medicinal Products and Medical Devices, Paul-Ehrlich-Institut (Federal Institute for Vaccines and Biomedicines), Langen (K.W.) - both in Germany; the Departments of Pathology and Molecular Medicine and of Medicine, McMaster University, Hamilton, ON, Canada (T.E.W.); and the Department of Medicine I, Division of Hematology and Hemostaseology, Medical University of Vienna, Vienna (P.A.K., S.E.)
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12
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Rubino JG, Arnold DM, Warkentin TE, Smith JW, Kelton JG, Nazy I. A comparative study of platelet factor 4-enhanced platelet activation assays for the diagnosis of heparin-induced thrombocytopenia. J Thromb Haemost 2021; 19:1096-1102. [PMID: 33387395 DOI: 10.1111/jth.15233] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 12/06/2020] [Accepted: 12/28/2020] [Indexed: 11/29/2022]
Abstract
BACKGROUND Functional platelet activation assays, such as the serotonin release assay (SRA), are the gold standard for the diagnosis of heparin-induced thrombocytopenia (HIT). Recently, platelet activation assays using added platelet factor 4 (PF4) have been described and suggest improved sensitivity. Direct comparisons of these assays have not been performed. OBJECTIVE We compare the performance characteristics of three PF4-enhanced platelet activation assays, the PF4/heparin-SRA (PF4/hep-SRA), the PF4-SRA, and the P-selectin expression assay (PEA), at a single reference laboratory. METHODS Serum samples from two cohorts of patients were used. The referral cohort (n = 84) included samples that had previously undergone routine diagnostic testing for HIT and tested positive or negative using the SRA. The clinical cohort (n = 101) consisted of samples from patients with clinically confirmed HIT whose serum contained platelet-activating antibodies. We simultaneously tested all samples in PF4-enhanced SRA-based assays (PF4/hep-SRA, PF4-SRA) and the flow cytometry-based PEA. RESULTS In the referral cohort, the three PF4-enhanced assays identified all samples that were previously determined to be positive in the SRA. However, specificity of the PF4/hep-SRA was 96.6%, the PF4-SRA was 84.7%, and the PEA was 67.8%. In the clinical cohort of samples, all SRA-based assays displayed high performance characteristics (>92.1% sensitivity, >98.4% specificity). Sensitivity and specificity of the PEA was the lowest, 65.8% and 63.5%, respectively; but improved to 92.1% and 96.8% using preselected platelet donors. CONCLUSIONS All PF4-enhanced assays demonstrated good performance characteristics when platelet donors were preselected. Further comparisons across multiple laboratories should be conducted for consensus on optimal HIT diagnostic testing.
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Affiliation(s)
- Julian G Rubino
- Department of Medicine, Michael G. DeGroote School of Medicine, Hamilton, ON, Canada
| | - Donald M Arnold
- Department of Medicine, Michael G. DeGroote School of Medicine, Hamilton, ON, Canada
- McMaster Centre for Transfusion Research, Hamilton, ON, Canada
| | - Theodore E Warkentin
- Department of Medicine, Michael G. DeGroote School of Medicine, Hamilton, ON, Canada
- McMaster Centre for Transfusion Research, Hamilton, ON, Canada
- Department of Pathology and Molecular Medicine, Michael G. DeGroote School of Medicine, Hamilton, ON, Canada
| | - James W Smith
- Department of Medicine, Michael G. DeGroote School of Medicine, Hamilton, ON, Canada
| | - John G Kelton
- Department of Medicine, Michael G. DeGroote School of Medicine, Hamilton, ON, Canada
- McMaster Centre for Transfusion Research, Hamilton, ON, Canada
| | - Ishac Nazy
- Department of Medicine, Michael G. DeGroote School of Medicine, Hamilton, ON, Canada
- McMaster Centre for Transfusion Research, Hamilton, ON, Canada
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13
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An Optimized and Standardized Rapid Flow Cytometry Functional Method for Heparin-Induced Thrombocytopenia. Biomedicines 2021; 9:biomedicines9030296. [PMID: 33805718 PMCID: PMC7999851 DOI: 10.3390/biomedicines9030296] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 03/04/2021] [Accepted: 03/10/2021] [Indexed: 11/17/2022] Open
Abstract
Heparin-induced thrombocytopenia (HIT) is a thrombocytopenia caused by heparin and mediated by an atypical immune mechanism leading to a paradoxical high thrombotic risk, associated with severe morbidity or death. The diagnosis of HIT combines a clinical scoring of pretest probability and laboratory testing. First-line routine tests are antigen binding assays detecting specific antibodies. The most sensitive of these tests have a high HIT-negative predictive value enabling HIT diagnosis to be ruled out when negative. However, HIT-positive predictive value is low, and a functional assay evaluating the pathogenicity of the antibodies should be performed to exclude false-positive results. In contrast to screening assays, functional assays are highly specific but technically challenging, and are thus performed in referral laboratories, where platelet activation is detected using radioactive serotonin (serotonin release assay, SRA) or visually (heparin-induced platelet activation, HIPA). Flow cytometry is a possible alternative. It is, however, currently not widely used, mostly because of the lack of standardization of the published assays. This article describes and discusses the standardization of a HIT flow cytometry assay (HIT-FCA) method, which subsequently led to the development and commercialization of a CE-marked assay (HIT Confirm®, Emosis, France) as a suitable rapid HIT functional test.
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14
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Warkentin TE. Challenges in Detecting Clinically Relevant Heparin-Induced Thrombocytopenia Antibodies. Hamostaseologie 2020; 40:472-484. [PMID: 33091948 PMCID: PMC7581458 DOI: 10.1055/a-1223-3329] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Heparin-induced thrombocytopenia (HIT) is an antibody-mediated hypercoagulable state featuring high thrombosis risk and distinct pathogenesis involving immunoglobulin G-mediated platelet activation. The target of the immune response is a cationic “self” protein, platelet factor 4 (PF4), rendered antigenic by heparin. A key problem is that only a minority of anti-PF4/polyanion antibodies induced by heparin are pathogenic, i.e., capable of causing platelet activation and thereby clinical HIT. Since thrombocytopenia occurs frequently in hospitalized, heparin-treated patients, testing for “HIT antibodies” is common; thus, the problem of distinguishing between pathogenic and nonpathogenic antibodies is important. The central concept is that those antibodies that have platelet-activating properties demonstrable in vitro correlate well with pathogenicity, as shown by platelet activation tests such as the serotonin-release assay (SRA) and heparin-induced platelet activation assay. However, in most circumstances, immunoassays are used for first-line testing, and so it is important for clinicians to appreciate which immunoassay result profiles—in the appropriate clinical context—predict the presence of platelet-activating antibodies (Bayesian analysis). Clinicians with access to rapid, on-demand HIT immunoassays (e.g., particle gel immunoassay, latex immunoturbidimetric assay, chemiluminescent immunoassay) can look beyond simple dichotomous result interpretation (“negative”/“positive”) and incorporate semiquantitative interpretation, where, for example, a strong-positive immunoassay result (or even combination of two immunoassays) points to a greater probability of detecting platelet-activating antibodies, and hence supporting a diagnosis of HIT. Recent recognition of “SRA-negative HIT” has increased the importance of semiquantitative interpretation of immunoassays, given that strong immunoassay reactivity is a potential clue indicating possible HIT despite a (false) negative platelet activation assay.
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Affiliation(s)
- Theodore E Warkentin
- Department of Pathology and Molecular Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada.,Department of Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada.,Transfusion Medicine, Hamilton Regional Laboratory Medicine Program, Hamilton, Ontario, Canada.,Service of Clinical Hematology, Hamilton Health Sciences, Hamilton General Hospital, Hamilton, Ontario, Canada.,McMaster Centre for Transfusion Research, Hamilton, Ontario, Canada
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15
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Ticagrelor causes false-negative functional tests for heparin-induced thrombocytopenia. Blood 2020; 135:875-878. [PMID: 31914174 DOI: 10.1182/blood.2019003582] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Heparin-induced thrombocytopenia (HIT) occurs in 1-2% of patients with acute coronary events or cardiac surgery. Eekels and colleagues report that ticagrelor comedication must be taken into account by laboratory physicians for interpretation of functional tests for HIT, as the presence of the drug can cause false-negative results.
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16
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Tardy B, Lecompte T, Mullier F, Vayne C, Pouplard C. Detection of Platelet-Activating Antibodies Associated with Heparin-Induced Thrombocytopenia. J Clin Med 2020; 9:jcm9041226. [PMID: 32344682 PMCID: PMC7230370 DOI: 10.3390/jcm9041226] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 04/17/2020] [Accepted: 04/19/2020] [Indexed: 12/13/2022] Open
Abstract
Heparin-induced thrombocytopenia (HIT) is a prothrombotic immune drug reaction caused by platelet-activating antibodies that in most instances recognize platelet factor 4 (PF4)/polyanion complexes. Platelet activation assays (i.e., functional assays) are more specific than immunoassays, since they are able to discern clinically relevant heparin-induced antibodies. All functional assays used for HIT diagnosis share the same principle, as they assess the ability of serum/plasma from suspected HIT patients to activate fresh platelets from healthy donors in the presence of several concentrations of heparin. Depending on the assay, donors’ platelets are stimulated either in whole blood (WB), platelet-rich plasma (PRP), or in a buffer medium (washed platelets, WP). In addition, the activation endpoint studied varies from one assay to another: platelet aggregation, membrane expression of markers of platelet activation, release of platelet granules. Tests with WP are more sensitive and serotonin release assay (SRA) is considered to be the current gold standard, but functional assays suffer from certain limitations regarding their sensitivity, specificity, complexity, and/or accessibility. However, the strict adherence to adequate preanalytical conditions, the use of selected platelet donors and the inclusion of positive and negative controls in each run are key points that ensure their performances.
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Affiliation(s)
- Brigitte Tardy
- Inserm U1059 Sainbiose, University of Lyon St Etienne, CIC 1408, FCRIN-INNOVTE, Hémostase Clinique CHU, 42055 Saint Etienne, France
| | - Thomas Lecompte
- Department of Medicine, Geneva University Hospitals, and Geneva Platelet Group (GpG), Faculty of Medicine, University of Geneva, CH-1211 Genève 14
| | - François Mullier
- CHU UCL Namur, Namur Thrombosis and Hemostasis center (NTHC), Hematology Laboratory, Université Catholique de Louvain, 5530 Yvoir, Belgium
| | - Caroline Vayne
- Department of Hemostasis, University Hospital of Tours, 37044 Tours, France
- University of Tours, EA 7501 GICC, 37000 Tours, France
| | - Claire Pouplard
- Department of Hemostasis, University Hospital of Tours, 37044 Tours, France
- University of Tours, EA 7501 GICC, 37000 Tours, France
- Correspondence:
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17
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Vayne C, Guéry EA, Charuel N, Besombes J, Lambert WC, Rollin J, Gruel Y, Pouplard C. Evaluation of functional assays for the diagnosis of heparin induced thrombocytopenia using 5B9, a monoclonal IgG that mimics human antibodies. J Thromb Haemost 2020; 18:968-975. [PMID: 31997532 DOI: 10.1111/jth.14749] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 01/24/2020] [Accepted: 01/27/2020] [Indexed: 12/13/2022]
Abstract
BACKGROUND Serotonin release assay (SRA) is considered as the "gold standard" for detecting pathogenic heparin-induced thrombocytopenia (HIT) antibodies. However, this method is time consuming, expensive, and uses radioelements. Heparin-induced multiple electrode aggregometry (HIMEA), light transmission aggregometry (LTA) with platelet rich plasma (PRP) or washed platelets (WP), adenosine triphosphate (ATP) release, and flow cytometry (FC) are available alternatives. OBJECTIVES To evaluate the performance of these assays, comparatively with SRA, for detecting HIT antibodies, using 5B9, a monoclonal IgG fully mimicking human HIT antibodies. PATIENTS/METHODS Heparin-dependent platelet activation induced by 5B9 (50/20/10 µg/mL) was evaluated by all assays performed on the same day using platelets from 20 healthy donors. The three methods exhibiting the highest sensitivity to 5B9 were then assessed by testing samples from patients with either likely (n = 10), or indeterminate/unlikely HIT (n = 10). RESULTS All methods exhibited good sensitivity for detecting 5B9 50 µg/mL, but only SRA and HIMEA were positive with 100% of donors using 5B9 20 µg/mL, followed by FC (83%). SRA detected 5B9 10 μg/mL with 90% of donors, while HIMEA and FC were positive in 45% and 44% of cases, respectively. Whereas SRA was positive with 9/10 samples from likely HIT, HIMEA and FC were positive with 6 and 7 of them, respectively. Neither SRA nor HIMEA was positive with indeterminate/unlikely HIT samples, while FC was positive or doubtful in three cases. CONCLUSIONS Serotonin release assay likely remains the most sensitive and specific assay for detecting platelet activating HIT antibodies, but HIMEA or FC are potential alternatives, despite being less performant.
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Affiliation(s)
- Caroline Vayne
- Department of Haemostasis, University Hospital of Tours, Tours, France
- EA 7501 GICC, University of Tours, Tours, France
| | - Eve-Anne Guéry
- Department of Haemostasis, University Hospital of Tours, Tours, France
| | | | - Joevin Besombes
- Department of Haemostasis, University Hospital of Tours, Tours, France
| | - Wayne C Lambert
- Department of Haemostasis, University Hospital of Tours, Tours, France
| | - Jérôme Rollin
- Department of Haemostasis, University Hospital of Tours, Tours, France
- EA 7501 GICC, University of Tours, Tours, France
| | - Yves Gruel
- Department of Haemostasis, University Hospital of Tours, Tours, France
- EA 7501 GICC, University of Tours, Tours, France
| | - Claire Pouplard
- Department of Haemostasis, University Hospital of Tours, Tours, France
- EA 7501 GICC, University of Tours, Tours, France
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18
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Song ZK, Cao H, Wu H, Wei Q, Tang M, Yang S, Liu Y, Qin L. Current status of rivaroxaban in elderly patients with pulmonary embolism (Review). Exp Ther Med 2020; 19:2817-2825. [PMID: 32256765 PMCID: PMC7086161 DOI: 10.3892/etm.2020.8559] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 01/22/2020] [Indexed: 01/14/2023] Open
Abstract
Acute pulmonary embolism (PE) occurs with a high incidence rate in elderly patients, demonstrating complex clinical manifestations, as well as a difficult anticoagulant treatment strategy. Currently, there is limited understanding of the selection criteria for anticoagulant treatment in elderly patients with PE. In fact, the vitamin K antagonist warfarin, a commonly prescribed anticoagulant, has multiple disadvantages, including a narrow therapeutic range, unpredictable pharmacokinetics, multiple food and drug interactions and genetic polymorphisms resulting in poor response to this therapy; therefore, routine laboratory monitoring is required. Most elderly patients with PE fail to adhere to the treatment regimen or even discontinue it, and clinicians are equally hesitant to initiate oral anticoagulants in elderly patients with PE. This leads to a dilemma regarding the use of anticoagulation therapies and a worse prognosis for the patients. Rivaroxaban, a direct Xa factor inhibitor, has demonstrated considerable practical and clinical advantages, exhibits fast-start action pharmacokinetic and pharmacodynamic characteristics, and has an enhanced predictable anticoagulant effect with fewer drug-drug interactions. Based on randomized controlled trials and real-world clinical practice, rivaroxaban has also been recognized as a safe and effective anticoagulant, and these advantages have improved the therapeutic compliance of elderly patients with PE. Thus, this review focused on the current status of rivaroxaban treatment for elderly patients with PE, and described its significance in changing the current anticoagulation treatment regimens for patients. It is expected that rivaroxaban will become a good choice for the treatment of PE in elderly patients.
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Affiliation(s)
- Zi-Kai Song
- Department of Cardiology, The First Hospital of Jilin University, Changchun, Jilin 130000, P.R. China
| | - Hongyan Cao
- Department of Cardiology, The First Hospital of Jilin University, Changchun, Jilin 130000, P.R. China
| | - Haidi Wu
- Department of Cardiology, The First Hospital of Jilin University, Changchun, Jilin 130000, P.R. China
| | - Qi Wei
- Department of Cardiology, The First Hospital of Jilin University, Changchun, Jilin 130000, P.R. China
| | - Minglong Tang
- Department of Cardiology, The First Hospital of Jilin University, Changchun, Jilin 130000, P.R. China
| | - Shuo Yang
- Department of Cardiology, The First Hospital of Jilin University, Changchun, Jilin 130000, P.R. China
| | - Yang Liu
- Department of Cardiology, The First Hospital of Jilin University, Changchun, Jilin 130000, P.R. China
| | - Ling Qin
- Department of Cardiology, The First Hospital of Jilin University, Changchun, Jilin 130000, P.R. China
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19
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Liederman Z, Van Cott EM, Smock K, Meijer P, Selby R. Heparin-induced thrombocytopenia: An international assessment of the quality of laboratory testing. J Thromb Haemost 2019; 17:2123-2130. [PMID: 31420903 DOI: 10.1111/jth.14611] [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: 11/29/2018] [Accepted: 08/12/2019] [Indexed: 01/15/2023]
Abstract
BACKGROUND Accurate diagnosis of heparin-induced thrombocytopenia (HIT) is essential to ensure timely treatment and prevent complications. Current diagnostic assays include enzyme-linked immunosorbent assays (ELISAs) and rapid immunoassays (RIs). RIs offer fast turnaround times but were not significantly represented in previous external proficiency testing challenges. OBJECTIVES To use external proficiency testing to assess qualitative concordance for heparin/PF4 antibody detection. METHODS From 2013 to 2017, the External Quality Control for Assays and Tests (ECAT) Foundation distributed 10 samples internationally. RESULTS In total, 437 laboratories submitted 3149 results. ELISAs accounted for 1484 (47%) responses with RIs accounting for 1665 (53%) responses. RI use increased over the 5-year period. ELISAs classified 96% of both consensus positive and consensus negative samples concordantly. The coefficient of variation (CV) for positive sample optical densities (ODs) ranged from 35% to 50% when combining ELISA assay methods together. Quantitative RIs classified 97% of consensus-positive and 98% of consensus-negative samples concordantly. Qualitative RIs had a higher proportion of discordant responses and classified 88% of consensus-positive samples and 73% of consensus-negative samples concordantly. Of RIs only latex immunoassays and IgG specific chemiluminescent assays identified > 95% of samples concordantly with consensus. CONCLUSION Quantitative RIs and ELISAs classify > 95% of samples concordantly. The ODs from different ELISA methods vary considerably and are not interchangeable. Qualitative RI use is increasing despite a greater proportion of discordant classifications. This includes a higher than expected number of negative classifications for consensus-positive samples among many RIs, challenging their use as "rule out" tests.
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Affiliation(s)
| | - Elizabeth M Van Cott
- Department of Pathology, Harvard Medical School, Massachusetts General Hospital, Boston, MA, USA
| | - Kristi Smock
- Department of Pathology, University of Utah, Salt Lake City, UT, USA
- ARUP Laboratories, Hemostasis/Thrombosis Laboratory, Salt Lake City, UT, USA
| | - Piet Meijer
- ECAT Foundation, External Quality Control for Assays and Tests, Voorschoten, the Netherlands
| | - Rita Selby
- Department of Laboratory Medicine and Medicine, University of Toronto, Toronto, ON, Canada
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20
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Warkentin TE. Laboratory diagnosis of heparin-induced thrombocytopenia. Int J Lab Hematol 2019; 41 Suppl 1:15-25. [PMID: 31069988 DOI: 10.1111/ijlh.12993] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 01/25/2019] [Accepted: 02/01/2019] [Indexed: 12/18/2022]
Abstract
Heparin-induced thrombocytopenia (HIT) is a clinical-pathological disorder; thus, laboratory testing for the pathogenic platelet-activating antiplatelet factor 4 (PF4)/heparin antibodies is central for diagnosis. The "iceberg" model summarizes the inter-relationship between platelet activation assays and PF4-dependent immunoassays, with platelet-activating antibodies comprising a subset of anti-PF4/heparin antibodies. The platelet serotonin-release assay (SRA), performed by reference laboratories, has high sensitivity and specificity for HIT (~95% each), and is especially suited for detecting highly pathogenic HIT sera containing both heparin-dependent and heparin-independent platelet-activating antibodies; this latter subgroup of antibodies explains "autoimmune HIT" disorders (delayed-onset, persisting, spontaneous, heparin "flush," fondaparinux-associated). Recently, SRA-negative HIT has become recognized, in which serum from some HIT patients contains subthreshold levels of platelet-activating antibodies (by SRA) that become detectable using a PF4-enhanced platelet activation assay. Unusual immunologic features of HIT include early antibody detectability (at onset of platelet count fall) and antibody transience (seroreversion). Widely available PF4-dependent enzyme immunoassays (EIAs) have high sensitivity but poor specificity for HIT, although specificity is enhanced with IgG-specific EIAs and strong positive results; unfortunately, EIA results are usually not available in real time. Automated rapid immunoassays, such as the chemiluminescence immunoassay (CLIA) and latex immunoturbidimetric assay (LIA), facilitate real-time laboratory diagnosis. Recently available likelihood ratio (LR) data for positive (LR+) and negative (LR-) test results allow clinicians to adjust their pretest probabilities for HIT, using Bayesian analysis, into real-time posttest probabilities that are dramatically increased (test positive) or decreased (test negative). Moreover, (semi-)quantitative CLIA- and LIA-positive results (weak, moderate, strong positive) can further refine the posttest probability of HIT.
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Affiliation(s)
- Theodore E Warkentin
- Department of Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada.,Department of Pathology and Molecular Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada.,Hamilton Regional Laboratory Medicine Program, Hamilton Health Sciences, Hamilton General Hospital, Hamilton, Ontario, Canada.,McMaster Centre for Transfusion Research, Hamilton, Ontario, Canada
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21
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Evaluation of a flow cytometer-based functional assay using platelet-rich plasma in the diagnosis of heparin-induced thrombocytopenia. Thromb Res 2019; 180:55-61. [PMID: 31220752 DOI: 10.1016/j.thromres.2019.05.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 05/07/2019] [Accepted: 05/20/2019] [Indexed: 01/25/2023]
Abstract
BACKGROUND Heparin-induced thrombocytopenia (HIT) is caused by platelet-activating antibodies that recognize platelet factor 4/heparin (PF4/hep)-complexes. The in vitro demonstration of PF4/hep antibodies using functional assays is essential for an optimal management of patients suspected to have HIT. However, conventional functional assays are technically challenging and limited to specialized laboratories. In contrast, flow cytometers are commonly used in routine laboratories. The aim of this study is to investigate the performance characteristics of a commercially available, flow cytometer based assay in the diagnosis of HIT. STUDY DESIGN Sera of consecutive patients with suspected HIT were investigated using the Emo-test HIT Confirm® assay and compared to the standard method consisting of an IgG-specific enzyme immunoassay (EIA) for anti-PF4/hep antibodies and the heparin induced platelet aggregation (HIPA) test. RESULTS 390 sera were included in the study, 164 sera tested IgG EIA-positive, of which 33 also tested HIPA-positive. No HIPA-positive samples were EIA-negative. In the Emo-test HIT Confirm® assay, 112 sera revealed positive results (%Hepla > 13); however, 51 (45.5%) were EIA-negative. Of the 33 HIPA-positive/EIA-positive HIT sera, 23 tested positive in the Emo-test HIT Confirm® assay, 2 gave ambiguous results, and 8 sera yielded false-negative results. Accordingly, the HIT Confirm® assay showed a sensitivity of 69.7% with a slightly better specificity of 75.4% compared to the EIA (sensitivity 100%, specificity 63.3%). An increase in diagnostic specificity for HIT to 85% was found when positive results were obtained in both the Emo-test HIT Confirm® assay and EIA. CONCLUSION The Emo-Test HIT Confirm® assay may improve the specificity of laboratory investigations of HIT. However, the assay can only be recommended in combination with an immunoassay due to the high rate of false negativity. Our observation indicates a need to establish external quality assessment for functional assays to avoid such clinically relevant pitfalls.
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