1
|
Attah A, Peterson C, Jacobs M, Bhagavatula R, Shah D, Kaplan R, Samhouri Y. Anti-PF4 ELISA-Negative, SRA-Positive Heparin-Induced Thrombocytopenia. Hematol Rep 2024; 16:295-298. [PMID: 38804282 PMCID: PMC11130879 DOI: 10.3390/hematolrep16020029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 01/31/2024] [Accepted: 02/19/2024] [Indexed: 05/29/2024] Open
Abstract
Heparin products are frequently used in the inpatient setting to prevent and treat venous thromboembolism, but they simultaneously put patients at risk of developing heparin-induced thrombocytopenia (HIT). The 4Ts score determines the pretest probability of HIT. Diagnosis is made with a screening antiplatelet factor (PF4) immunoassay and the serotonin-release assay (SRA) as a confirmatory test. Anti-PF4 assays have high sensitivity (98%) but lower specificity (50%) and result in frequent false-positive tests. We present a rare case from our institution of a patient with anti-PF4-Polyanion ELISA-negative, SRA-positive HIT and describe the challenges in making a timely diagnosis in this case.
Collapse
Affiliation(s)
- Abraham Attah
- Department of Internal Medicine, Allegheny Health Network, Pittsburgh, PA 15212, USA
| | - Chelsea Peterson
- Division of Hematology and Cellular Therapy, Allegheny Health Network Cancer Institute, Pittsburgh, PA 15212, USA (Y.S.)
| | - Max Jacobs
- Department of Internal Medicine, Allegheny Health Network, Pittsburgh, PA 15212, USA
| | - Rama Bhagavatula
- Division of Hematology and Cellular Therapy, Allegheny Health Network Cancer Institute, Pittsburgh, PA 15212, USA (Y.S.)
| | - Deep Shah
- Division of Hematology and Cellular Therapy, Allegheny Health Network Cancer Institute, Pittsburgh, PA 15212, USA (Y.S.)
| | - Robert Kaplan
- Division of Hematology and Cellular Therapy, Allegheny Health Network Cancer Institute, Pittsburgh, PA 15212, USA (Y.S.)
| | - Yazan Samhouri
- Division of Hematology and Cellular Therapy, Allegheny Health Network Cancer Institute, Pittsburgh, PA 15212, USA (Y.S.)
| |
Collapse
|
2
|
Arachchillage DJ, Thachil J, Anderson JAM, Baker P, Poles A, Kitchen S, Laffan M. Diagnosis and management of heparin-induced thrombocytopenia: Third edition. Br J Haematol 2024; 204:459-475. [PMID: 38153164 DOI: 10.1111/bjh.19180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 10/16/2023] [Accepted: 10/19/2023] [Indexed: 12/29/2023]
Affiliation(s)
- Deepa J Arachchillage
- Centre for Haematology, Department of Immunology and Inflammation, Imperial College London, London, UK
- Department of Haematology, Imperial College Healthcare NHS Trust, London, UK
| | - Jecko Thachil
- Department of Haematology, Manchester Royal Infirmary, Manchester, UK
| | - Julia A M Anderson
- Department of Haematology, Edinburgh Royal Infirmary, Edinburgh, Scotland
| | - Peter Baker
- Oxford Haemophilia and Thrombosis Centre, Oxford University Hospitals NHS Trust, Oxford, UK
| | - Anthony Poles
- Bristol NHS Blood and Transplant Centre, Bristol, UK
| | - Steve Kitchen
- Department of Haematology, Royal Hallamshire Hospital, Sheffield, UK
| | - Mike Laffan
- Centre for Haematology, Department of Immunology and Inflammation, Imperial College London, London, UK
- Department of Haematology, Imperial College Healthcare NHS Trust, London, UK
| |
Collapse
|
3
|
Machhi R, Lindholm PF, Cooke D, Groth M, Martin KA. Improving Judicious Use of Heparin-Induced Thrombocytopenia Testing Through Electronic Health Record-Based Intervention. Jt Comm J Qual Patient Saf 2023; 49:648-654. [PMID: 37479590 PMCID: PMC10615670 DOI: 10.1016/j.jcjq.2023.06.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 06/26/2023] [Accepted: 06/28/2023] [Indexed: 07/23/2023]
Abstract
BACKGROUND Heparin-induced thrombocytopenia (HIT) is an immune-mediated drug reaction that can cause thromboembolism in the setting of thrombocytopenia. An enzyme-linked immunosorbent assay (ELISA)-based assay to screen for HIT antibodies (HAb) is available but has relatively low specificity and a correspondingly high false positive rate. The 4Ts score has been validated to determine the pretest probability of HIT. The authors hypothesized that an electronic health record (EHR)-based clinical decision support (CDS) tool incorporating the 4Ts score would reduce the volume of HAb orders. METHODS After implementing a CDS tool into the EHR, the researchers retrospectively evaluated the impact from November 2019 to October 2021, compared to a preintervention period (January to October 2019). The primary outcome was average tests per month. Secondary outcomes included rates of tests ordered per total inpatient encounters and proportion of HAb sent despite low 4Ts score in the postintervention study period. RESULTS Of 1,833 HAb sent during the study period, 1,217 occurred in the postintervention period. In the postintervention period compared with the preintervention period, the average orders per month was 50.5 (standard deviation [SD] 9.7) vs. 61.6 (SD 7.2) (p = 0.003), and the order incidence rate was 8.0 per 1,000 patient encounters postintervention vs. 9.2 per 1,000 patient encounters preintervention (rate ratio [RR] 0.87, 95% confidence interval [CI] 0.79-0.96, p = 0.002). Postintervention, 252 (20.7%) had a 4Ts score calculated as low probability, 759 (62.4%) as intermediate probability, and 131 (10.8%) as high probability, and 75 had no associated 4Ts score. CONCLUSION Implementation of a simple CDS tool reduced the rate of HAb orders, reducing unnecessary HAb testing.
Collapse
|
4
|
Hammerer-Lercher A, Nilius H, Studt JD, Tsakiris DA, Greinacher A, Mendez A, Schmidt A, Wuillemin WA, Gerber B, Kremer Hovinga JA, Vishnu P, Graf L, Bakchoul T, Nagler M. Limited concordance of heparin/platelet factor 4 antibody assays for the diagnosis of heparin-induced thrombocytopenia: an analysis of the TORADI-HIT study. J Thromb Haemost 2023; 21:2559-2568. [PMID: 37247669 DOI: 10.1016/j.jtha.2023.05.016] [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: 01/28/2023] [Revised: 04/26/2023] [Accepted: 05/17/2023] [Indexed: 05/31/2023]
Abstract
BACKGROUND Anecdotal reports suggest that the correlation between heparin/platelet factor 4 (PF4) antibody assays for the diagnosis of heparin-induced thrombocytopenia (HIT) is limited. OBJECTIVES To investigate the correlation between widely used assays and examine possible factors contributing to variability. METHODS This is a large, prospective cohort study with 10 participating tertiary care hospitals including 1393 patients with suspected HIT in clinical practice. HIT was defined by a positive heparin-induced platelet activation (HIPA) assay (washed platelet reference standard test). Three different immunoassays were used to measure heparin/PF4 antibodies: chemiluminescent immunoassay, enzyme-linked immunosorbent assay, and particle gel immunoassay. Various factors that could influence the assays were examined: sex (male or female), age (<65 years or ≥65 years), unfractionated heparin exposure, presence of thrombosis, cardiovascular surgery, and intensive care unit. Spearman's correlation coefficients were calculated. Z-scores and diagnostic odds ratios were determined in the aforementioned subgroups of patients. RESULTS Among 1393 patients, 119 were classified as HIT-positive (prevalence, 8.5%). The median 4Ts score was 5 (IQR, 4-6) in patients with HIT compared with 3 (IQR, 2-4) in patients without HIT. Correlations (rs) between immunoassays were weak (0.53-0.65). Inconsistencies between immunoassays could not be explained by further analyses of z-scored test results and diagnostic odds ratios in subgroups of patients. CONCLUSION The correlation between widely used heparin/PF4 antibody assays was weak, and key factors could not explain this variability. Standardization of immunoassays is requested to improve comparability.
Collapse
Affiliation(s)
- Angelika Hammerer-Lercher
- Department of Clinical Chemistry, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; Institute of Laboratory Medicine, Kantonsspital Aarau, Aarau, Switzerland
| | - Henning Nilius
- Department of Clinical Chemistry, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; Graduate School for Health Sciences, University of Bern, Bern, Switzerland
| | - Jan-Dirk Studt
- Division of Medical Oncology and Hematology, University and University Hospital Zurich, Zurich, Switzerland
| | | | - Andreas Greinacher
- Institut für Transfusionsmedizin, Universitätsmedizin Greifswald, Greifswald, Germany
| | - Adriana Mendez
- Institute of Laboratory Medicine, Kantonsspital Aarau, Aarau, Switzerland
| | - Adrian Schmidt
- Clinic of Medical Oncology and Hematology, Municipal Hospital Zurich Triemli, Zurich, Switzerland
| | - Walter A Wuillemin
- Division of Hematology and Central Hematology Laboratory, Cantonal Hospital of Lucerne, University of Bern, Bern, Switzerland
| | - Bernhard Gerber
- Clinic of Hematology, Oncology Institute of Southern Switzerland, Bellinzona, Switzerland
| | - Johanna A Kremer Hovinga
- Department of Hematology and Central Hematology Laboratory, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Prakash Vishnu
- Division of Hematology, CHI Franciscan Medical Group, Seattle, USA
| | - Lukas Graf
- Cantonal Hospital of St. Gallen, St. Gallen, Switzerland
| | - Tamam Bakchoul
- Centre for Clinical Transfusion Medicine, University Hospital of Tübingen, Tübingen, Germany
| | - Michael Nagler
- Department of Clinical Chemistry, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
| |
Collapse
|
5
|
May J, Westbrook B, Cuker A. Heparin-induced thrombocytopenia: An illustrated review. Res Pract Thromb Haemost 2023; 7:100283. [PMID: 37601013 PMCID: PMC10439402 DOI: 10.1016/j.rpth.2023.100283] [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: 02/24/2023] [Revised: 05/25/2023] [Accepted: 05/31/2023] [Indexed: 08/22/2023] Open
Abstract
Heparin-induced thrombocytopenia (HIT) is an immune-mediated adverse drug effect from unfractionated or low-molecular-weight heparin that results in thrombocytopenia and potentially catastrophic thrombosis. HIT occurs due to the development of platelet-activating antibodies against multimolecular complexes of platelet factor 4 and heparin. Given the frequency of thrombocytopenia and heparin use among hospitalized patients, calculation of the 4Ts Score is recommended to identify patients at increased likelihood of HIT and direct further evaluation. In patients with an intermediate or high probability 4Ts Score, an immunoassay and functional assay are recommended to confirm or refute the diagnosis of HIT. Heparin avoidance and initiation of nonheparin anticoagulation are the mainstays of acute HIT management. In this illustrated review, we provide visual summaries of the diagnosis and management of HIT, highlighting connections between pathophysiology and clinical care as well as summarizing efforts in quality improvement in the field. We further emphasize common pitfalls and pearls in diagnosis and management to encourage evidence-based care. We include graphical representation of the unique challenges of HIT with cardiopulmonary bypass and also delineate autoimmune HIT and its subtypes.
Collapse
Affiliation(s)
- Jori May
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Brian Westbrook
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Adam Cuker
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| |
Collapse
|
6
|
Nilius H, Cuker A, Haug S, Nakas C, Studt JD, Tsakiris DA, Greinacher A, Mendez A, Schmidt A, Wuillemin WA, Gerber B, Kremer Hovinga JA, Vishnu P, Graf L, Kashev A, Sznitman R, Bakchoul T, Nagler M. A machine-learning model for reducing misdiagnosis in heparin-induced thrombocytopenia: A prospective, multicenter, observational study. EClinicalMedicine 2023; 55:101745. [PMID: 36457646 PMCID: PMC9706528 DOI: 10.1016/j.eclinm.2022.101745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 10/26/2022] [Accepted: 10/27/2022] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Diagnosing heparin-induced thrombocytopenia (HIT) at the bedside remains challenging, exposing a significant number of patients at risk of delayed diagnosis or overtreatment. We hypothesized that machine-learning algorithms could be utilized to develop a more accurate and user-friendly diagnostic tool that integrates diverse clinical and laboratory information and accounts for complex interactions. METHODS We conducted a prospective cohort study including 1393 patients with suspected HIT between 2018 and 2021 from 10 study centers. Detailed clinical information and laboratory data were collected, and various immunoassays were conducted. The washed platelet heparin-induced platelet activation assay (HIPA) served as the reference standard. FINDINGS HIPA diagnosed HIT in 119 patients (prevalence 8.5%). The feature selection process in the training dataset (75% of patients) yielded the following predictor variables: (1) immunoassay test result, (2) platelet nadir, (3) unfractionated heparin use, (4) CRP, (5) timing of thrombocytopenia, and (6) other causes of thrombocytopenia. The best performing models were a support vector machine in case of the chemiluminescent immunoassay (CLIA) and the ELISA, as well as a gradient boosting machine in particle-gel immunoassay (PaGIA). In the validation dataset (25% of patients), the AUROC of all models was 0.99 (95% CI: 0.97, 1.00). Compared to the currently recommended diagnostic algorithm (4Ts score, immunoassay), the numbers of false-negative patients were reduced from 12 to 6 (-50.0%; ELISA), 9 to 3 (-66.7%, PaGIA) and 14 to 5 (-64.3%; CLIA). The numbers of false-positive individuals were reduced from 87 to 61 (-29.8%; ELISA), 200 to 63 (-68.5%; PaGIA) and increased from 50 to 63 (+29.0%) for the CLIA. INTERPRETATION Our user-friendly machine-learning algorithm for the diagnosis of HIT (https://toradi-hit.org) was substantially more accurate than the currently recommended diagnostic algorithm. It has the potential to reduce delayed diagnosis and overtreatment in clinical practice. Future studies shall validate this model in wider settings. FUNDING Swiss National Science Foundation (SNSF), and International Society on Thrombosis and Haemostasis (ISTH).
Collapse
Affiliation(s)
- Henning Nilius
- Department of Clinical Chemistry, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Adam Cuker
- Department of Medicine and Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Sigve Haug
- Mathematical Institute, University of Bern, Bern, Switzerland
- Albert Einstein Center for Fundamental Physics and Laboratory for High Energy Physics, University of Bern, Bern, Switzerland
| | - Christos Nakas
- Department of Clinical Chemistry, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Laboratory of Biometry, School of Agriculture, University of Thessaly, Volos, Greece
| | - Jan-Dirk Studt
- Division of Medical Oncology and Hematology, University and University Hospital Zurich, Zurich, Switzerland
| | | | - Andreas Greinacher
- Institut für Immunologie und Transfusionsmedizin, Universitätsmedizin Greifswald, Greifswald, Germany
| | - Adriana Mendez
- Department of Laboratory Medicine, Kantonsspital Aarau, Aarau, Switzerland
| | - Adrian Schmidt
- Clinic of Medical Oncology and Hematology, Municipal Hospital Zurich Triemli, Zurich, Switzerland
| | - Walter A. Wuillemin
- Division of Hematology and Central Hematology Laboratory, Cantonal Hospital of Lucerne and University of Bern, Switzerland
| | - Bernhard Gerber
- Clinic of Hematology, Oncology Institute of Southern Switzerland, Bellinzona, Switzerland
| | - Johanna A. Kremer Hovinga
- Department of Hematology and Central Hematology Laboratory, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Prakash Vishnu
- Division of Hematology, CHI Franciscan Medical Group, Seattle, United States
| | - Lukas Graf
- Cantonal Hospital of St Gallen, Switzerland
| | | | - Raphael Sznitman
- ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland
| | - Tamam Bakchoul
- Centre for Clinical Transfusion Medicine, University Hospital of Tübingen, Tübingen, Germany
| | - Michael Nagler
- Department of Clinical Chemistry, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Corresponding author. Inselspital, Bern University Hospital, University of Bern, 3010 Bern, Switzerland.
| |
Collapse
|
7
|
Rittener‐Ruff L, Marchetti M, Matthey‐Guirao E, Grandoni F, Gomez FJ, Alberio L. Combinations of rapid immunoassays for a speedy diagnosis of heparin-induced thrombocytopenia. J Thromb Haemost 2022; 20:2407-2418. [PMID: 35808841 PMCID: PMC9796930 DOI: 10.1111/jth.15811] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 05/23/2022] [Accepted: 06/27/2022] [Indexed: 01/07/2023]
Abstract
BACKGROUND Early recognition and treatment of heparin-induced thrombocytopenia (HIT) are key to prevent severe complications. OBJECTIVE To assess the diagnostic performance of rapid immunoassays (IA) in detecting anti-PF4/heparin-antibodies. METHODS Diagnostic performances of lateral-flow IA (LFIA; STic Expert HIT) and latex IA (LIA; HemosIL HIT-Ab) were analyzed in pilot (n = 74) and derivation cohorts (n = 267). Two novel algorithms based on the combination of HIT clinical probability with sequentially performed LIA and chemiluminescent IA (CLIA; HemosIL AcuStar-HIT-IgG) were compared with published rapid diagnostic algorithms: the "Lausanne algorithm" sequentially combining CLIA and particle-gel IA (PaGIA) and the "Hamilton algorithm" based on simultaneously performed LIA and CLIA. RESULTS LFIA missed 6/30 HIT. The sensitivity and specificity of LIA were 90.9% and 93.5%. The Lausanne algorithm correctly predicted HIT in 19/267 (7.1%), excluded it in 240/267 (89.9%), leaving 8/267 (3%) cases unsolved. The algorithm sequentially combining CLIA and LIA predicted HIT in 19/267 (7.1%) with 1/19 wrong prediction, excluded it in 236/267 (88.4%), leaving 11/267 (4.1%) cases unsolved. The algorithm employing LIA as a first assay predicted HIT in 22/267 (8.2%), excluded it in 235/267 (88%), leaving 9/267 (3.4%) cases unsolved. Finally, the Hamilton algorithm correctly predicted HIT in 10/267 (3.7%), excluded it in 229/267 (85.7%), leaving 28/267 (10.5%) cases unsolved. CONCLUSION LFIA cannot be used to exclude or predict HIT when using frozen plasma. A Bayesian approach sequentially employing two rapid immunoassays for anti-PF4/heparin antibodies is most effective for the accurate diagnosis of HIT. Based on retrospective data, the combination LIA/CLIA is a candidate for a prospective validation.
Collapse
Affiliation(s)
- Luana Rittener‐Ruff
- Division of Haematology and Central Haematology LaboratoryLausanne University Hospital (CHUV) and University of Lausanne (UNIL)LausanneSwitzerland
| | - Matteo Marchetti
- Division of Haematology and Central Haematology LaboratoryLausanne University Hospital (CHUV) and University of Lausanne (UNIL)LausanneSwitzerland
| | - Elena Matthey‐Guirao
- Division of Haematology and Central Haematology LaboratoryLausanne University Hospital (CHUV) and University of Lausanne (UNIL)LausanneSwitzerland
| | - Francesco Grandoni
- Division of Haematology and Central Haematology LaboratoryLausanne University Hospital (CHUV) and University of Lausanne (UNIL)LausanneSwitzerland
| | - Francisco J. Gomez
- Division of Haematology and Central Haematology LaboratoryLausanne University Hospital (CHUV) and University of Lausanne (UNIL)LausanneSwitzerland
| | - Lorenzo Alberio
- Division of Haematology and Central Haematology LaboratoryLausanne University Hospital (CHUV) and University of Lausanne (UNIL)LausanneSwitzerland
| |
Collapse
|
8
|
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.
Collapse
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
| |
Collapse
|
9
|
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.
Collapse
|
10
|
Ahmadinejad M, Shahbazi M, Chegini A. Heparin-Induced Thrombocytopenia in Iranian Cardiac Surgery Patients Using the 4Ts Clinical Scoring System and Laboratory Methods. Int J Hematol Oncol Stem Cell Res 2021; 15:230-238. [PMID: 35291665 PMCID: PMC8888360 DOI: 10.18502/ijhoscr.v15i4.7478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 09/11/2021] [Indexed: 11/29/2022] Open
Abstract
Background: Heparin-induced thrombocytopenia (HIT) is a serious adverse drug reaction. HIT diagnosis needs an algorithmic approach including clinical evaluation and laboratory tests (screening and confirmatory). Few studies have been conducted on HIT in Iran, and most existing research has been general and based on clinical evaluations alone. The present study was conducted to determine the prevalence of HIT among cardiac surgery patients using an algorithmic approach. Materials and Methods: A cross-sectional study was carried out over a period of 10 months, at Modares Hospital (Tehran, Iran) on 92 patients who were candidates for cardiac surgery. For the clinical evaluation, the 4Ts scoring system was used; in cases with 4Ts scores ≥4, a laboratory evaluation of anti-PF4/heparin antibody (Ab) was performed by enzyme-linked immunosorbent assay (ELISA) and a HIPA test too as a functional confirmatory method. The patients with 4Ts scores ≥4 who were ELISA positive (OD ≥0.2) and HIPA positive were taken as a definite case of HIT. Results: Of the 92 patients who had undergone cardiac surgery, 14 (15%) had 4Ts scores ≥4. Anti- PF4/heparin Ab was detected in eight patients using the ELISA and in six patients using the HIPA. Ultimately, definite HIT was confirmed in five of the patients. Conclusion: The prevalence of HIT was 5.4% among the cardiac surgery patients assessed in the present study. To the researchers’ knowledge, this is the first time that HIT has been evaluated in Iran using a comprehensive algorithmic approach including clinical history-taking and both immunological and functional laboratory tests, and the findings showed a slightly higher HIT frequency in this single-center study in comparison with the other studies carried out in other countries.
Collapse
Affiliation(s)
- Minoo Ahmadinejad
- Blood Transfusion Research Center, High Institute for Research and Education in Transfusion Medicine, Tehran, Iran
| | - Massoumeh Shahbazi
- Blood Transfusion Research Center, High Institute for Research and Education in Transfusion Medicine, Tehran, Iran
| | - Azita Chegini
- Blood Transfusion Research Center, High Institute for Research and Education in Transfusion Medicine, Tehran, Iran
| |
Collapse
|
11
|
Halprin C, Czer LS, Cole R, Emerson D, Esmailian F, Hayes C, Kitahara S, Lam L, Martin-Stone S, Megna D, Moriguchi J, Okwan-Duodu D, Ramzy D, Yur J, Volod O. Diagnosing heparin-induced thrombocytopenia in mechanical circulatory support device patients. J Heart Lung Transplant 2021; 41:80-85. [PMID: 34656418 DOI: 10.1016/j.healun.2021.09.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 09/09/2021] [Accepted: 09/09/2021] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Mechanical circulatory support device (MCSD) patients with positive heparin-induced thrombocytopenia (HIT) screening pose a unique challenge, as clinicians must make rapid decisions about their anticoagulation and whether they can safely undergo cardiopulmonary bypass. We identified screening practices at our institution and other institutions nationwide that differed from American Society of Hematology (ASH) guidelines. This discovery prompted a data review to confirm the applicability of guidelines to this unique population and to highlight complications of "gestalt" screening. METHODS Our study included MCSD patients with HIT testing from April 2014 to August 2020. We evaluated 510 PF4 IgG ELISA results. RESULTS HIT was confirmed in 4.2% of patients. There was an increased prevalence of HIT in patients with nondurable (5.3%) vs durable devices (2.9%) or those in the preimplantation setting (1.3%), however this difference was not statistically significant (p = 0.26). None of the patients with a low probability 4T Score had HIT. All patients with a high probability 4T Score and PF4 immunoassay OD >2.0 had HIT. False positive results occurred in 22% of assays ordered for patients with a low probability 4T Score. Twelve patients with a low probability 4T Score and a false positive immunoassay were switched to a direct thrombin inhibitor (DTI) while awaiting confirmatory results. Two patients experienced clinically significant bleeding after conversion to a DTI. An organ was refused in one patient with false positive HIT screening. CONCLUSIONS Our findings demonstrate that an opportunity exists to improve clinical outcomes by re-emphasizing the utility of established guidelines and highlighting their safe use in the MCSD patient population.
Collapse
Affiliation(s)
- Chelsea Halprin
- Pathology, Cedars Sinai Medical Center, Los Angeles, California.
| | - Lawrence S Czer
- Cedars Sinai Comprehensive Transplant Center, Cedars Sinai Medical Center, Los Angeles, California
| | - Robert Cole
- Smidt Heart Institute, Cedars Sinai Medical Center, Los Angeles, California
| | - Dominic Emerson
- Smidt Heart Institute, Cedars Sinai Medical Center, Los Angeles, California
| | - Fardad Esmailian
- Smidt Heart Institute, Cedars Sinai Medical Center, Los Angeles, California
| | - Chelsea Hayes
- Pathology, Cedars Sinai Medical Center, Los Angeles, California
| | - Sumire Kitahara
- Pathology, Cedars Sinai Medical Center, Los Angeles, California
| | - Lee Lam
- Cedars Sinai Comprehensive Transplant Center, Cedars Sinai Medical Center, Los Angeles, California
| | - Sylvia Martin-Stone
- Department of Pharmacy Services, Cedars Sinai Medical Center, Los Angeles, California
| | - Dominick Megna
- Smidt Heart Institute, Cedars Sinai Medical Center, Los Angeles, California
| | - Jaime Moriguchi
- Cedars Sinai Comprehensive Transplant Center, Cedars Sinai Medical Center, Los Angeles, California
| | | | - Danny Ramzy
- Smidt Heart Institute, Cedars Sinai Medical Center, Los Angeles, California
| | - Justin Yur
- Department of Pharmacy Services, Cedars Sinai Medical Center, Los Angeles, California
| | - Oksana Volod
- Pathology, Cedars Sinai Medical Center, Los Angeles, California.
| |
Collapse
|
12
|
Abstract
Not applicable (no abstract in Invited Editorial Focus).
Collapse
|
13
|
Pishko AM, Cuker A. Diagnosing heparin-induced thrombocytopenia: The need for accuracy and speed. Int J Lab Hematol 2021; 43 Suppl 1:96-102. [PMID: 34288442 DOI: 10.1111/ijlh.13564] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 04/06/2021] [Accepted: 04/14/2021] [Indexed: 01/15/2023]
Abstract
Heparin-induced thrombocytopenia (HIT) is a prothrombotic condition resulting from pathogenic antibodies to complexes of heparin and platelet factor 4 (PF4). The diagnosis of HIT can be challenging due to the widespread use of heparin and the frequency of thrombocytopenia in hospitalized patients. Laboratory testing for HIT typically includes an immunoassay to detect antibodies to PF4-heparin and a functional assay. Current HIT diagnostic algorithms recommend using the 4Ts score to determine the need for HIT laboratory testing. Automated calculation of HIT clinical prediction scores in the electronic health record may improve the identification of patients who should undergo HIT testing. Another challenge in the management of patients with suspected HIT is the turnaround time of the laboratory testing needed to confirm the diagnosis. Due to the high daily thrombotic risk of HIT, clinicians must treat patients with intermediate to high pretest likelihood of HIT empirically while awaiting the test results. Treatment for HIT often involves alternative anticoagulants that lack reversal agents, which may increase bleeding risk, prolong hospital stays, and increase costs for patients suspected of having HIT. Rapid immunoassays hold promise to improve the speed of HIT diagnosis. These assays must retain a very high sensitivity for this "can't miss" diagnosis, yet have sufficient specificity to be of diagnostic value. A Bayesian approach has been proposed using two rapid immunoassays in succession, which decreased analytic turnaround time to 60 minutes. Such an approach has the potential to be a much-needed clinical advance in improving accuracy and speed in the diagnosis of HIT.
Collapse
Affiliation(s)
- Allyson M Pishko
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Adam Cuker
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| |
Collapse
|
14
|
Behandlung der heparininduzierten Thrombozytopenie unter extrakorporaler Membranoxygenierung. ZEITSCHRIFT FUR HERZ THORAX UND GEFASSCHIRURGIE 2021. [DOI: 10.1007/s00398-021-00437-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
15
|
Hvas AM, Favaloro EJ, Hellfritzsch M. Heparin-induced thrombocytopenia: pathophysiology, diagnosis and treatment. Expert Rev Hematol 2021; 14:335-346. [PMID: 33736552 DOI: 10.1080/17474086.2021.1905512] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Introduction: Immune-mediated heparin-induced thrombocytopenia (HIT) is an infrequent complication following heparin exposure but with potentially fatal outcome due to thrombotic complications. Prompt suspension of heparin is necessary if HIT is suspected, followed by initiation of non-heparin anticoagulant therapy.Areas covered: In this review, the pathophysiology and challenges in diagnosing HIT are elucidated. Current and emerging treatment options are discussed with special focus on parenteral thrombin inhibitors (argatroban, bivalirudin), parenteral factor Xa inhibitors (danaparoid, fondaparinux) and direct oral anticoagulants (DOACs [rivaroxaban, apixaban, dabigatran]) including dosing strategies for DOACs. The database PubMed was employed without time boundaries.Expert opinion: Only argatroban holds regulatory approval for HIT treatment in both U.S. and Europe. This treatment is, however, challenged by the need for close monitoring and high costs. Fondaparinux has been increasingly used for off-label treatment and during recent years, evidence for the use of DOACs has emerged. Preliminary results from observational studies hold promise for future use of DOACs in the acute and subacute phase of HIT. However, so far, the use of DOACs in acute HIT should be reserved for clinically stable patients without severe thrombotic complications. Importantly, both fondaparinux and DOAC use is contraindicated in severe renal insufficiency.
Collapse
Affiliation(s)
- Anne-Mette Hvas
- Department of Clinical Biochemistry, Aarhus University Hospital and Department of Clinical Medicine, Aarhus University. Address: Palle Juul-Jensens Boulevard 99, Aarhus N, Denmark
| | - Emmanuel J Favaloro
- Department of Haematology, Institute of Clinical Pathology and Medical Research (ICPMR), Sydney Centres for Thrombosis and Haemostasis, NSW Health Pathology, Westmead Hospital, Westmead, Australia
| | - Maja Hellfritzsch
- Department of Cardiology, Herning Regional Hospital, Herning, Denmark
| |
Collapse
|
16
|
Warkentin TE, Smythe MA, Ali MA, Aslam N, Sheppard JI, Smith JW, Moore JC, Arnold DM, Nazy I. Serotonin-release assay-positive but platelet factor 4-dependent enzyme-immunoassay negative: HIT or not HIT? Am J Hematol 2021; 96:320-329. [PMID: 33326124 DOI: 10.1002/ajh.26075] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 12/07/2020] [Accepted: 12/14/2020] [Indexed: 12/28/2022]
Abstract
IgG-specific and polyspecific PF4-dependent enzyme-immunoassays (EIAs) have exceptionally high sensitivity (≥99%) for diagnosis of heparin-induced thrombocytopenia (HIT), a drug reaction caused by platelet-activating antibodies detectable by serotonin-release assay (SRA). The IgG-specific EIAs are recommended for screening, as their high sensitivity is accompanied by relatively high specificity vis-à-vis polyspecific EIAs. We investigated the frequency of SRA-positive/EIA-negative (SRA+/EIA-) HIT, prompted by referral to our reference HIT laboratory of serial blood samples from a patient ("index case") with false-negative IgG-specific EIAs. Despite initial clinical suspicion for HIT, repeat negative IgG-specific EIAs prompted heparin resumption, which triggered recurrent thrombocytopenia and near-fatal cardiac arrest, indicating likely post-heparin HIT-associated anaphylactoid reaction. Further investigations revealed a strong-positive SRA, whether performed with heparin alone, PF4 alone, or PF4/heparin, with inhibition by Fc receptor-blocking monoclonal antibody (indicating IgG-mediated platelet activation); however, five different IgG-specific immunoassays yielded primarily negative (or weak-positive) results. To investigate the frequency of SRA+/EIA- HIT, we reviewed the laboratory and clinical features of patients with this serological profile during a 6-year period in which our reference laboratory investigated for HIT using both SRA and IgG-specific EIA. Although ~0.2% of 8546 patients had an SRA+/EIA- profile, further review of 15 such cases indicated clerical/laboratory misclassification or false-positive SRA in all, with no SRA+/EIA- HIT case identified. We conclude that while SRA+/EIA- HIT is possible-as shown by our index case-this clinical picture is exceptionally uncommon. Moreover, the requirement for a positive EIA is a useful quality control maneuver that reduces risk of reporting a false-positive SRA result.
Collapse
Affiliation(s)
- Theodore E. Warkentin
- Department of Pathology and Molecular Medicine Michael G. DeGroote School of Medicine Hamilton Ontario Canada
- Department of Medicine Michael G. DeGroote School of Medicine Hamilton Ontario Canada
- McMaster Centre for Transfusion Research Hamilton Ontario Canada
| | - Maureen A. Smythe
- Department of Pharmaceutical Services Beaumont Hospital Royal Oak Michigan USA
- Department of Pharmacy Practice Wayne State University Detroit Michigan USA
- Oakland University William Beaumont School of Medicine Rochester Michigan USA
| | - Mona A. Ali
- Department of Pharmaceutical Services Beaumont Hospital Royal Oak Michigan USA
| | - Naveed Aslam
- Oakland University William Beaumont School of Medicine Rochester Michigan USA
| | - Jo‐Ann I. Sheppard
- Department of Pathology and Molecular Medicine Michael G. DeGroote School of Medicine Hamilton Ontario Canada
| | - James W. Smith
- Department of Medicine Michael G. DeGroote School of Medicine Hamilton Ontario Canada
| | - Jane C. Moore
- Department of Medicine Michael G. DeGroote School of Medicine Hamilton Ontario Canada
| | - Donald M. Arnold
- Department of Medicine Michael G. DeGroote School of Medicine Hamilton Ontario Canada
- McMaster Centre for Transfusion Research Hamilton Ontario Canada
| | - Ishac Nazy
- Department of Medicine Michael G. DeGroote School of Medicine Hamilton Ontario Canada
- McMaster Centre for Transfusion Research Hamilton Ontario Canada
| |
Collapse
|
17
|
Heparin-Induced Thrombocytopenia: A Review of New Concepts in Pathogenesis, Diagnosis, and Management. J Clin Med 2021; 10:jcm10040683. [PMID: 33578859 PMCID: PMC7916628 DOI: 10.3390/jcm10040683] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/29/2021] [Accepted: 01/30/2021] [Indexed: 12/17/2022] Open
Abstract
Knowledge on heparin-induced thrombocytopenia keeps increasing. Recent progress on diagnosis and management as well as several discoveries concerning its pathogenesis have been made. However, many aspects of heparin-induced thrombocytopenia remain partly unknown, and exact application of these new insights still need to be addressed. This article reviews the main new concepts in pathogenesis, diagnosis, and management of heparin-induced thrombocytopenia.
Collapse
|
18
|
Waqar U, Ahmed S, Gardezi SM, Tahir MS, Abidin ZU, Hussain A, Ali N, Mahmood SF. Thrombosis with Thrombocytopenia Syndrome After Administration of AZD1222 or Ad26.COV2.S Vaccine for COVID-19: A Systematic Review. Clin Appl Thromb Hemost 2021; 27:10760296211068487. [PMID: 34907794 PMCID: PMC8689609 DOI: 10.1177/10760296211068487] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Cases of thrombosis with thrombocytopenia syndrome (TTS) have been reported following vaccination with AZD1222 or Ad26.COV2.S. This review aimed to explore the pathophysiology, epidemiology, diagnosis, management, and prognosis of TTS. METHODS A systematic review was conducted to identify evidence on TTS till 4th September 2021. Case reports and series reporting patient-level data were included. Descriptive statistics were reported and compared across patients with different sexes, age groups, vaccines, types of thrombosis, and outcomes. FINDINGS Sixty-two studies reporting 160 cases were included from 16 countries. Patients were predominantly females with a median age of 42.50 (22) years. AZD1222 was administered to 140 patients (87·5%). TTS onset occurred in a median of 9 (4) days after vaccination. Venous thrombosis was most common (61.0%). Most patients developed cerebral venous sinus thrombosis (CVST; 66.3%). CVST was significantly more common in female vs male patients (p = 0·001) and in patients aged <45 years vs ≥45 years (p = 0·004). The mortality rate was 36.2%, and patients with suspected TTS, venous thrombosis, CVST, pulmonary embolism, or intraneural complications, patients not managed with non-heparin anticoagulants or IVIG, patients receiving platelet transfusions, and patients requiring intensive care unit admission, mechanical ventilation, or inpatient neurosurgery were more likely to expire than recover. INTERPRETATION These findings help to understand the pathophysiology of TTS while also recommending diagnostic and management approaches to improve prognosis in patients. FUNDING This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
Collapse
Affiliation(s)
- Usama Waqar
- Medical College, Aga Khan University, Karachi, Pakistan
| | - Shaheer Ahmed
- Islamabad Medical and Dental College, Islamabad, Pakistan
| | | | | | | | - Ali Hussain
- Medical College, Aga Khan University, Karachi, Pakistan
| | - Natasha Ali
- Section of Hematology, Department of Pathology & Laboratory Medicine/Oncology, Aga Khan University, Karachi, Pakistan
| | - Syed Faisal Mahmood
- Section of Infectious Diseases, Department of Medicine, Aga Khan University, Karachi, Pakistan
| |
Collapse
|
19
|
Jousselme E, Guéry EA, Nougier C, Sobas F, Rollin J, Gruel Y, Vayne C, Pouplard C. Prospective evaluation of two specific IgG immunoassays (HemosIL ® AcuStar HIT-IgG and HAT45G ® ) for the diagnosis of heparin-induced thrombocytopenia: A Bayesian approach. Int J Lab Hematol 2020; 43:468-476. [PMID: 33244896 DOI: 10.1111/ijlh.13404] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 09/30/2020] [Accepted: 10/21/2020] [Indexed: 12/11/2022]
Abstract
INTRODUCTION The accurate diagnosis of heparin-induced thrombocytopenia (HIT) is essential to ensure adequate treatment and prevent complications. First step diagnosis test are immunoassays including enzyme-linked immunosorbent assays (ELISAs) and rapid immunoassays. METHODS Using a Bayesian approach, we prospectively evaluated the performance of the IgG PF4/polyvinylsulfonate ELISA and a chemiluminescent immunoassay (CLIA), which are specific for IgG and use the same antigenic target to detect HIT antibodies. RESULTS One hundred and eighty-four 184 consecutive patients with an intermediate (n = 159) or high (n = 25) clinical pretest probability of HIT based on the 4Ts score or platelet pattern were included. Both immunoassays (IAs) were performed on all 184 samples, and definite HIT was confirmed with a positive serotonin release assay in 29 patients (12.7%). The sensitivity (Ss) and negative predictive value (NPV) of ELISA were excellent (100%) allowing HIT to be excluded with good confidence when the test was negative. In addition, the Ss and NPV of the CLIA equalled 93.1% and 98.6%, respectively, as it was negative in two definite HIT. When the CLIA was negative, the post-test probability of HIT was 0.7% in case of intermediate risk. Although there was excellent agreement between CLIA and ELISA results, the quantitative values provided by the two IAs were not correlated. CONCLUSION AcuStar HIT® detects more than 90% of HIT, as do all rapid IAs, and appears to be a good tool for excluding HIT when the pretest probability is intermediate. A chemiluminescent signal higher than 10 IU/mL is highly predictive of definite HIT with a PPV of 100%.
Collapse
Affiliation(s)
- Emilie Jousselme
- Department of Haematology-Haemostasis, Civil Hospices of Lyon, Bron, France
| | - Eve-Anne Guéry
- Department of Haematology-Haemostasis, Regional University Hospital of Tours, Tours, France
| | - Christophe Nougier
- Department of Haematology-Haemostasis, Civil Hospices of Lyon, Bron, France
| | - Frédéric Sobas
- Department of Haematology-Haemostasis, Civil Hospices of Lyon, Bron, France
| | - Jérôme Rollin
- Department of Haematology-Haemostasis, Regional University Hospital of Tours, Tours, France.,EA 7501 GICC, University of Tours, Tours, France
| | - Yves Gruel
- Department of Haematology-Haemostasis, Regional University Hospital of Tours, Tours, France.,EA 7501 GICC, University of Tours, Tours, France
| | - Caroline Vayne
- Department of Haematology-Haemostasis, Regional University Hospital of Tours, Tours, France.,EA 7501 GICC, University of Tours, Tours, France
| | - Claire Pouplard
- Department of Haematology-Haemostasis, Regional University Hospital of Tours, Tours, France.,EA 7501 GICC, University of Tours, Tours, France
| |
Collapse
|
20
|
Arepally GM, Cines DB. Pathogenesis of heparin-induced thrombocytopenia. Transl Res 2020; 225:131-140. [PMID: 32417430 PMCID: PMC7487042 DOI: 10.1016/j.trsl.2020.04.014] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 04/15/2020] [Accepted: 04/21/2020] [Indexed: 01/19/2023]
Abstract
There are currently no effective substitutes for high intensity therapy with unfractionated heparin (UFH) for cardiovascular procedures based on its rapid onset of action, ease of monitoring and reversibility. The continued use of UFH in these and other settings requires vigilance for its most serious nonhemorrhagic complication, heparin induced thrombocytopenia (HIT). HIT is an immune prothrombotic disorder caused by antibodies that recognize complexes between platelet factor 4 (PF4) and polyanions such as heparin (H).The pathogenicity of anti-PF4/H antibodies is likely due to the formation of immune complexes that initiate intense procoagulant responses by vascular and hematopoietic cells that lead to the generation of platelet microparticles, monocyte and endothelial cell procoagulant activity, and neutrophil extracellular traps, among other outcomes. The development of anti-PF4/H antibodies after exposure to UFH greatly exceeds the incidence of clinical disease, but the biochemical features that distinguish pathogenic from nonpathogenic antibodies have not been identified. Diagnosis relies on pretest clinical probability, screening for anti-PF4/H antibodies and documentation of their platelet activating capacity. However, both clinical algorithms and test modalities have limited predictive values making diagnosis and management challenging. Given the unacceptable rates of recurrent thromboembolism and bleeding associated with current therapies, there is an unmet need for novel rational nonanticoagulant therapeutics based on the pathogenesis of HIT. We will review recent developments in our understanding of the pathogenesis of HIT and its implications for future approaches to diagnosis and management.
Collapse
Affiliation(s)
- Gowthami M Arepally
- Division of Hematology, Duke University Medical Center, Durham, North Carolina.
| | - Douglas B Cines
- Department of Pathology and Laboratory Medicine, Perelman-University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania
| |
Collapse
|
21
|
Warkentin TE, Cook RJ, Greinacher A. Limitations of the particle immunofiltration assay test for diagnosis of heparin-induced thrombocytopenia. Am J Hematol 2020; 95:E250-E254. [PMID: 32510647 PMCID: PMC7496181 DOI: 10.1002/ajh.25901] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 05/31/2020] [Accepted: 06/02/2020] [Indexed: 12/30/2022]
Affiliation(s)
- Theodore E. Warkentin
- Department of Pathology and Molecular MedicineMichael G. DeGroote School of Medicine, McMaster UniversityHamiltonOntarioCanada
- Department of MedicineMichael G. DeGroote School of Medicine, McMaster UniversityHamiltonOntarioCanada
| | - Richard J. Cook
- Department of Statistics and Actuarial ScienceUniversity of WaterlooWaterlooOntarioCanada
| | - Andreas Greinacher
- Institut für Immunologie und Transfusionsmedizin, Universitätsmedizin GreifswaldGreifswaldGermany
| |
Collapse
|
22
|
Warkentin TE, Sheppard JI, Smith JW, Li N, Moore JC, Arnold DM, Nazy I. Combination of two complementary automated rapid assays for diagnosis of heparin-induced thrombocytopenia (HIT). J Thromb Haemost 2020; 18:1435-1446. [PMID: 32167669 PMCID: PMC7317897 DOI: 10.1111/jth.14794] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 03/10/2020] [Indexed: 12/16/2022]
Abstract
BACKGROUND HIT diagnosis typically uses complementary diagnostic assays (eg, a PF4-dependent enzyme-immunoassay [EIA] and a platelet activation assay such as the serotonin-release assay [SRA]). OBJECTIVES To determine whether the combination of two automated assays-a latex immunoturbidimetric assay (LIA) that evaluates competitive inhibition of a HIT-like monoclonal antibody and a chemiluminescence immunoassay (CLIA) for detecting anti-PF4/heparin IgG-optimizes diagnostic sensitivity while also yielding good specificity, particularly at high assay reactivities. PATIENTS/METHODS We determined operating characteristics using combined LIA/CLIA results from a HIT observational trial (n = 430; derivation cohort) and 147 consecutive patients with HIT (n = 147; supplementary derivation cohort). We also evaluated 678 consecutive samples referred for HIT testing (replication cohort). LIA/CLIA reactivities were scored individually as "negative" (<1.00 U/mL, 0 points), "weak" (1.00-4.99 U/mL, 1 point), "moderate" (5.00-15.99 U/mL, 2 points) and "strong" (≥16.00 U/mL, 3 points), thus contributing up to 6 points (maximum) when LIA/CLIA results were combined. We also examined whether higher LIA/CLIA scores predicted presence of platelet-activating antibodies by conventional and modified (PF4- or PF4/heparin-enhanced) SRA. RESULTS Combined LIA/CLIA testing yielded high diagnostic sensitivity (~99%) similar to EIA. Interpretation of LIA/CLIA results using the 6-point scale indicated progressively greater likelihood for the presence of platelet-activating antibodies with increasing scores (semi-quantitative reactivity). A LIA/CLIA score ≥ 4 points predicted the presence of platelet-activating antibodies by SRA or PF4-enhanced SRA with high probability (~98%). CONCLUSION Combined LIA/CLIA testing optimizes diagnostic sensitivity, with progressively greater probability of detecting platelet-activating antibodies with higher assay reactivity that reaches 98% when both automated assays yield moderate or strong results.
Collapse
Affiliation(s)
- Theodore E. Warkentin
- Department of Pathology and Molecular MedicineMichael G. DeGroote School of MedicineMcMaster UniversityHamiltonONCanada
- Department of MedicineMichael G. DeGroote School of MedicineMcMaster UniversityHamiltonONCanada
- Hamilton Regional Laboratory Medicine ProgramHamilton Health SciencesHamiltonONCanada
- McMaster Centre for Transfusion ResearchHamiltonONCanada
| | - Jo‐Ann I. Sheppard
- Department of Pathology and Molecular MedicineMichael G. DeGroote School of MedicineMcMaster UniversityHamiltonONCanada
| | - James W. Smith
- Department of MedicineMichael G. DeGroote School of MedicineMcMaster UniversityHamiltonONCanada
| | - Na Li
- McMaster Centre for Transfusion ResearchHamiltonONCanada
- Department of Computing and SoftwareMcMaster UniversityHamiltonONCanada
| | - Jane C. Moore
- Department of MedicineMichael G. DeGroote School of MedicineMcMaster UniversityHamiltonONCanada
| | - Donald M. Arnold
- Department of MedicineMichael G. DeGroote School of MedicineMcMaster UniversityHamiltonONCanada
- McMaster Centre for Transfusion ResearchHamiltonONCanada
| | - Ishac Nazy
- Department of MedicineMichael G. DeGroote School of MedicineMcMaster UniversityHamiltonONCanada
- McMaster Centre for Transfusion ResearchHamiltonONCanada
| |
Collapse
|
23
|
Huang Z, Siddhanta S, Zheng G, Kickler T, Barman I. Rapid, Label-free Optical Spectroscopy Platform for Diagnosis of Heparin-Induced Thrombocytopenia. Angew Chem Int Ed Engl 2020; 59:5972-5978. [PMID: 31972060 PMCID: PMC7547846 DOI: 10.1002/anie.201913970] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 12/30/2019] [Indexed: 01/14/2023]
Abstract
The use of surface-enhanced Raman spectroscopy (SERS) to determine spectral markers for the diagnosis of heparin-induced thrombocytopenia (HIT), a difficult-to-diagnose immune-related complication that often leads to limb ischemia and thromboembolism, is proposed. The ability to produce distinct molecular signatures without the addition of labels enables unbiased inquiry and makes SERS an attractive complementary diagnostic tool. A capillary-tube-derived SERS platform offers ultrasensitive, label-free measurement as well as efficient handling of blood serum samples. This shows excellent reproducibility, long-term stability and provides an alternative diagnostic rubric for the determination of HIT by leveraging machine-learning-based classification of the spectroscopic data. We envision that a portable Raman instrument could be combined with the capillary-tube-based SERS analytical tool for diagnosis of HIT in the clinical laboratory, without perturbing the existing diagnostic workflow.
Collapse
Affiliation(s)
- Zufang Huang
- Department of Mechanical Engineering, Johns Hopkins
University, Baltimore, Maryland 21218, USA
- Key Laboratory of Opto Electronic Science and Technology
for Medicine of Ministry of Education, Fujian Provincial Key Laboratory of Photonics
Technology, Fujian Normal University, Fuzhou 350007, P. R. China
| | - Soumik Siddhanta
- Department of Mechanical Engineering, Johns Hopkins
University, Baltimore, Maryland 21218, USA
- Department of Chemistry, Indian Institute of Technology
Delhi, Hauz Khas, New Delhi 110016, India
| | - Gang Zheng
- Departments of Pathology, Johns Hopkins University School
of Medicine, Baltimore, Maryland 21287, USA
- Department of Laboratory Medicine and Pathology, Mayo
Clinic, Rochester, MN, 55906
| | - Thomas Kickler
- Departments of Pathology, Johns Hopkins University School
of Medicine, Baltimore, Maryland 21287, USA
| | - Ishan Barman
- Department of Mechanical Engineering, Johns Hopkins
University, Baltimore, Maryland 21218, USA
- Department of Oncology and Radiological Science, The Johns
Hopkins University School of Medicine, Baltimore, Maryland 21205, United
States
- The Russell H. Morgan Department of Radiology and
Radiological Science, The Johns Hopkins University School of Medicine, Baltimore,
Maryland 21205, United States
| |
Collapse
|
24
|
Huang Z, Siddhanta S, Zheng G, Kickler T, Barman I. Rapid, Label‐free Optical Spectroscopy Platform for Diagnosis of Heparin‐Induced Thrombocytopenia. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201913970] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Zufang Huang
- Department of Mechanical EngineeringJohns Hopkins University Baltimore MD 21218 USA
- Key Laboratory of Opto Electronic Science and Technology for Medicine of Ministry of EducationFujian Provincial Key Laboratory of Photonics TechnologyFujian Normal University Fuzhou 350007 P. R. China
| | - Soumik Siddhanta
- Department of Mechanical EngineeringJohns Hopkins University Baltimore MD 21218 USA
- Department of ChemistryIndian Institute of Technology Delhi Hauz Khas New Delhi 110016 India
| | - Gang Zheng
- Department of PathologyJohns Hopkins University School of Medicine Baltimore MD 21287 USA
- Department of Laboratory Medicine and PathologyMayo Clinic Rochester MN 55906 USA
| | - Thomas Kickler
- Department of PathologyJohns Hopkins University School of Medicine Baltimore MD 21287 USA
| | - Ishan Barman
- Department of Mechanical EngineeringJohns Hopkins University Baltimore MD 21218 USA
- Department of OncologyThe Johns Hopkins University School of Medicine Baltimore MD 21205 USA
- The Russell H. Morgan Department of Radiology and Radiological ScienceThe Johns Hopkins University School of Medicine Baltimore MD 21205 USA
| |
Collapse
|
25
|
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.
Collapse
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
| |
Collapse
|
26
|
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.
Collapse
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
| |
Collapse
|
27
|
Bakchoul T, Marini I. Drug-associated thrombocytopenia. HEMATOLOGY. AMERICAN SOCIETY OF HEMATOLOGY. EDUCATION PROGRAM 2018; 2018:576-583. [PMID: 30504360 PMCID: PMC6246020 DOI: 10.1182/asheducation-2018.1.576] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Many drugs have been implicated in drug-induced immune thrombocytopenia (DITP). Patients with DITP develop a drop in platelet count 5 to 10 days after drug administration with an increased risk of hemorrhage. The diagnosis of DITP is often challenging, because most hospitalized patients are taking multiple medications and have comorbidities that can also cause thrombocytopenia. Specialized laboratory diagnostic tests have been developed and are helpful to confirm the diagnosis. Treatment of DITP involves discontinuation of the offending drug. The platelet count usually starts to recover after 4 or 5 half-lives of the responsible drug or drug metabolite. High doses of intravenous immunoglobulin can be given to patients with severe thrombocytopenia and bleeding. Although in most cases, DITP is associated with bleeding, life-threatening thromboembolic complications are common in patients with heparin-induced thrombocytopenia (HIT). Binding of antiplatelet factor 4/heparin antibodies to Fc receptors on platelets and monocytes causes intravascular cellular activation, leading to an intensely prothrombotic state in HIT. The clinical symptoms include a decrease in platelet counts by >50% and/or new thromboembolic complications. Two approaches can help to confirm or rule out HIT: assessment of the clinical presentation using scoring systems and in vitro demonstration of antiplatelet factor 4/heparin antibodies. The cornerstone of HIT management is immediate discontinuation of heparin when the disease is suspected and anticoagulation using nonheparin anticoagulant. In this review, we will provide an update on the pathophysiology, diagnosis, and management of both DITP and HIT.
Collapse
Affiliation(s)
- Tamam Bakchoul
- Transfusion Medicine, Medical Faculty of Tubingen, University of Tubingen, Tubingen, Germany
| | - Irene Marini
- Transfusion Medicine, Medical Faculty of Tubingen, University of Tubingen, Tubingen, Germany
| |
Collapse
|
28
|
Cuker A, Arepally GM, Chong BH, Cines DB, Greinacher A, Gruel Y, Linkins LA, Rodner SB, Selleng S, Warkentin TE, Wex A, Mustafa RA, Morgan RL, Santesso N. American Society of Hematology 2018 guidelines for management of venous thromboembolism: heparin-induced thrombocytopenia. Blood Adv 2018; 2:3360-3392. [PMID: 30482768 PMCID: PMC6258919 DOI: 10.1182/bloodadvances.2018024489] [Citation(s) in RCA: 351] [Impact Index Per Article: 58.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 09/14/2018] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Heparin-induced thrombocytopenia (HIT) is an adverse drug reaction mediated by platelet-activating antibodies that target complexes of platelet factor 4 and heparin. Patients are at markedly increased risk of thromboembolism. OBJECTIVE These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in their decisions about diagnosis and management of HIT. METHODS ASH formed a multidisciplinary guideline panel balanced to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline development process, including updating or performing systematic evidence reviews. The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess evidence and make recommendations, which were subject to public comment. RESULTS The panel agreed on 33 recommendations. The recommendations address screening of asymptomatic patients for HIT, diagnosis and initial management of patients with suspected HIT, treatment of acute HIT, and special situations in patients with acute HIT or a history of HIT, including cardiovascular surgery, percutaneous cardiovascular intervention, renal replacement therapy, and venous thromboembolism prophylaxis. CONCLUSIONS Strong recommendations include use of the 4Ts score rather than a gestalt approach for estimating the pretest probability of HIT and avoidance of HIT laboratory testing and empiric treatment of HIT in patients with a low-probability 4Ts score. Conditional recommendations include the choice among non-heparin anticoagulants (argatroban, bivalirudin, danaparoid, fondaparinux, direct oral anticoagulants) for treatment of acute HIT.
Collapse
Affiliation(s)
- Adam Cuker
- Department of Medicine and
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | | | - Beng H Chong
- Department of Haematology, University of New South Wales, Sydney, NSW, Australia
| | - Douglas B Cines
- Department of Medicine and
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Andreas Greinacher
- Institute of Immunology and Transfusion Medicine, University of Greifswald, Greifswald, Germany
| | - Yves Gruel
- Department of Haematology-Haemostasis, Trousseau Hospital, Tours, France
| | - Lori A Linkins
- Department of Medicine, McMaster University, Hamilton, ON, Canada
| | | | - Sixten Selleng
- Department of Anaesthesiology, University of Greifswald, Greifswald, Germany
| | - Theodore E Warkentin
- Department of Medicine, McMaster University, Hamilton, ON, Canada
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
| | | | - Reem A Mustafa
- Department of Health Research Methods, Evidence and Impact, McMaster University, Hamilton, ON, Canada; and
- Department of Medicine, University of Missouri-Kansas City, Kansas City, MO
| | - Rebecca L Morgan
- Department of Health Research Methods, Evidence and Impact, McMaster University, Hamilton, ON, Canada; and
| | - Nancy Santesso
- Department of Health Research Methods, Evidence and Impact, McMaster University, Hamilton, ON, Canada; and
| |
Collapse
|
29
|
Linkins L, Hu G, Warkentin TE. Systematic review of fondaparinux for heparin-induced thrombocytopenia: When there are no randomized controlled trials. Res Pract Thromb Haemost 2018; 2:678-683. [PMID: 30349886 PMCID: PMC6178656 DOI: 10.1002/rth2.12145] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Accepted: 07/05/2018] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Fondaparinux is commonly used for treatment of heparin-induced thrombocytopenia (HIT) despite lack of approval for this indication. High quality randomized controlled trials of this agent are unlikely to be forthcoming. OBJECTIVES The objective of this systematic review is to update the literature on the efficacy and safety of fondaparinux for treatment of confirmed and probable HIT based on the available evidence. METHODS Primary articles were identified using Web of Science and PubMed database searches for English-language studies from January 2006 to November 2017. Selected studies enrolled consecutive adult patients who received fondaparinux as the primary anticoagulant to treat acute HIT; confirmed the diagnosis by serological testing with a serotonin-release assay; heparin-induced platelet activation assay or enzyme-linked immunosorbent assay; provided clinical criteria used to define HIT and reported clinically important outcomes. RESULTS A total of 9 studies were identified with 154 HIT positive patients. Ten experienced a new thrombotic event while receiving fondaparinux (6.5%, 95% CI, 3.4 to 11.7%) and 26 experienced major bleeding (16.9%, 95% CI, 11.7 to 23.6%). Mortality due to thrombosis or bleeding was reported in 5 patients (3.2%, 95% CI, 1.2 to 7.6%). CONCLUSIONS Fondaparinux appears to be an effective and safe anticoagulant for treatment of acute HIT despite the absence of randomized trials. Caution should exercised when using fondaparinux in patients with renal insufficiency.
Collapse
Affiliation(s)
- Lori‐Ann Linkins
- Department of MedicineMichael G. DeGroote School of MedicineMcMaster UniversityHamiltonOntarioCanada
| | - George Hu
- McMaster UniversityHamiltonOntarioCanada
| | - Theodore E. Warkentin
- Department of MedicineMichael G. DeGroote School of MedicineMcMaster UniversityHamiltonOntarioCanada
- Department of Pathology and Molecular MedicineMichael G. DeGroote School of MedicineMcMaster UniversityHamiltonOntarioCanada
- Hamilton Regional Laboratory Medicine ProgramHamilton General HospitalHamiltonOntarioCanada
| |
Collapse
|
30
|
High sensitivity and specificity of an automated IgG-specific chemiluminescence immunoassay for diagnosis of HIT. Blood 2018; 132:1345-1349. [PMID: 30064975 DOI: 10.1182/blood-2018-04-847483] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
|
31
|
Witten A, Bolbrinker J, Barysenka A, Huber M, Rühle F, Nowak-Göttl U, Garbe E, Kreutz R, Stoll M. Targeted resequencing of a locus for heparin-induced thrombocytopenia on chromosome 5 identified in a genome-wide association study. J Mol Med (Berl) 2018; 96:765-775. [PMID: 29934777 DOI: 10.1007/s00109-018-1661-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 06/05/2018] [Accepted: 06/12/2018] [Indexed: 12/18/2022]
Abstract
Immune-mediated heparin-induced thrombocytopenia (HIT) is the clinically most important adverse drug reaction (ADR) in response to heparin therapy characterized by a prothrombotic state despite a decrease in platelet count. We conducted a genome-wide association study in 96 suspected HIT cases and 96 controls to explore the genetic predisposition for HIT within a case-control pharmacovigilance study followed by replication in additional 86 cases and 86 controls from the same study. One single nucleotide polymorphism (SNP, rs1433265, P = 6.5 × 10-5, odds ratio (OR) 2.79) from 16 identified SNPs was successfully replicated (P = 1.5 × 10-4, OR 2.77; combined data set P = 2.7 × 10-8, OR 2.77) and remained the most strongly associated SNP after imputing locus genotypes. Fine mapping revealed a significantly associated risk-conferring haplotype (P = 4.9 × 10-6, OR 2.41). In order to find rare variants contributing to the association signals, we applied a targeted resequencing approach in a subgroup of 73 HIT patients and 23 controls for the regions with the 16 most strongly HIT-associated SNPs. C-alpha testing was applied to test for the impact of rare variants and we detected two candidate genes, the discoidin domain receptor tyrosine kinase 1 (DDR1, P = 3.6 × 10-2) and the multiple C2 and transmembrane domain containing 2 (MCTP2, P = 4.5 × 10-2). For the genes interactor of little elongation complex ELL subunit 1 (ICE1) and a disintegrin-like and metalloproteinase with thrombospondin type 1 motif, 16 (ADAMTS16) nearby rs1433265, we identified several missense variants. Although replication in an independent population is warranted, these findings provide a basis for future studies aiming to identify and characterize genetic susceptibility factors for HIT. KEY MESSAGES: We identified and validated a HIT-associated locus on chromosome 5. Targeted NGS analysis for rare variants identifies DDR1 and MCTP2 as novel candidates. In addition, missense variants for ADAMTS16 and ICE1 were identified in the locus.
Collapse
Affiliation(s)
- Anika Witten
- Department of Genetic Epidemiology, Institute of Human Genetics, University Hospital Münster, Münster, Germany
| | - Juliane Bolbrinker
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Clinical Pharmacology and Toxicology, Berlin, Germany
| | - Andrei Barysenka
- Department of Genetic Epidemiology, Institute of Human Genetics, University Hospital Münster, Münster, Germany
| | - Matthias Huber
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Clinical Pharmacology and Toxicology, Berlin, Germany
| | - Frank Rühle
- Department of Genetic Epidemiology, Institute of Human Genetics, University Hospital Münster, Münster, Germany
| | - Ulrike Nowak-Göttl
- Thrombosis and Hemostasis Unit, Department of Clinical Chemistry, University Hospital of Kiel and Lübeck, Kiel, Germany
| | - Edeltraut Garbe
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Clinical Pharmacology and Toxicology, Berlin, Germany.,Department of Clinical Epidemiology, Leibniz Institute for Prevention Research and Epidemiology - BIPS, Bremen, Germany
| | - Reinhold Kreutz
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Clinical Pharmacology and Toxicology, Berlin, Germany
| | - Monika Stoll
- Department of Genetic Epidemiology, Institute of Human Genetics, University Hospital Münster, Münster, Germany. .,Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands.
| |
Collapse
|
32
|
Favaloro EJ. Laboratory tests for identification or exclusion of heparin induced thrombocytopenia: HIT or miss? Am J Hematol 2018; 93:308-314. [PMID: 29164662 DOI: 10.1002/ajh.24979] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 11/07/2017] [Accepted: 11/16/2017] [Indexed: 11/08/2022]
Abstract
Heparin induced thrombocytopenia (HIT) is a potentially fatal condition that arises subsequent to formation of antibodies against complexes containing heparin, usually platelet-factor 4-heparin ("anti-PF4-heparin"). Assessment for HIT involves both clinical evaluation and, if indicated, laboratory testing for confirmation or exclusion, typically using an initial immunological assay ("screening"), and only if positive, a secondary functional assay for confirmation. Many different immunological and functional assays have been developed. The most common contemporary immunological assays comprise enzyme-linked immunosorbent assay [ELISA], chemiluminescence, lateral flow, and particle gel techniques. The most common functional assays measure platelet aggregation or platelet activation events (e.g., serotonin release assay; heparin-induced platelet activation (HIPA); flow cytometry). All assays have some sensitivity and specificity to HIT antibodies, but differ in terms of relative sensitivity and specificity for pathological HIT, as well as false negative and false positive error rate. This brief article overviews the different available laboratory methods, as well as providing a suggested approach to diagnosis or exclusion of HIT.
Collapse
Affiliation(s)
- Emmanuel J. Favaloro
- Department of Haematology; Institute of Clinical Pathology and Medical Research (ICPMR), Sydney Centres for Thrombosis and Haemostasis, NSW Health Pathology, Westmead Hospital; NSW Australia
| |
Collapse
|
33
|
Nagler M, Bakchoul T. Clinical and laboratory tests for the diagnosis of heparin-induced thrombocytopenia. Thromb Haemost 2017; 116:823-834. [DOI: 10.1160/th16-03-0240] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2016] [Accepted: 08/16/2016] [Indexed: 12/27/2022]
Abstract
SummaryA rapid diagnostic work-up is required in patients with suspected heparin-induced thrombocytopenia (HIT). However, diagnosis of HIT is challenging due to a number of practical issues and methodological limitations. Many laboratory tests and a few clinical scoring systems are available but the individual characteristics and the diagnostic accuracy of these are hard to appraise. The 4Ts score is a well evaluated clinical assessment tool with the potential to rule out HIT in many patients. Still, it requires experience and is subject to a relevant inter-observer variability. Immunoassays such as enzyme-linked immunosorbent assays or recently developed rapid assays are able to exclude HIT in a number of patients. But, accuracy of immunoassays differs depending on type of assay, threshold, antibody specificity and even manufacturer. Due to a comparatively low positive predictive value, HIT cannot be confirmed by immunoassays alone. In addition, only some of them are immediately accessible, particularly in small laboratories. While functional assays such as the serotonin release assay (SRA) and the heparin-induced platelet activation assay (HIPA) are considered as gold standard for diagnosis of HIT, they require a highly specialised laboratory. In addition, some of them are not adequately evaluated. In clinical practice, we recommend an integrated diagnostic approach combining not only clinical assessment (the 4Ts score) but immunoassays and functional assays as well. We propose a clear diagnostic algorithm supporting clinical decision-making. Furthermore, we provide an overview of all current laboratory techniques for HIT and discuss diagnostic pathways and strategies to reduce diagnostic errors, and future perspectives.
Collapse
|
34
|
Abstract
PURPOSE OF REVIEW The purpose of this review is to summarize recent findings on heparin-induced thrombocytopenia (HIT), a prothrombotic disorder caused by platelet-activating IgG targeting platelet factor 4 (PF4)/polyanion complexes. RECENT FINDINGS HIT can explain unusual clinical events, including adrenal hemorrhages, arterial/intracardiac thrombosis, skin necrosis, anaphylactoid reactions, and disseminated intravascular coagulation. Sometimes, HIT begins/worsens after stopping heparin ('delayed-onset' HIT). Various HIT-mimicking disorders are recognized (e.g., acute disseminated intravascular coagulation/'shock liver' with limb ischemia). HIT has features of both B-cell and T-cell immune responses; uptake of PF4/heparin complexes into macrophages ('macropinocytosis') facilitates the anti-PF4/heparin immune response. Antibody-induced activation of monocytes and platelets via their FcγIIA receptors triggers an intense procoagulant response. Sometimes, HIT antibodies recognize PF4 bound to (platelet-associated) chondroitin sulfate, explaining how HIT might occur without concurrent or recent heparin (delayed-onset HIT, 'spontaneous HIT syndrome'). The molecular structure of HIT antigen(s) has been characterized, providing a rationale for future drug design to avoid HIT and improve its treatment. The poor correlation between partial thromboplastin time and plasma argatroban levels (risking subtherapeutic anticoagulation) and need for intravenous administration of argatroban have led to increasing 'off-label' treatment with fondaparinux or one of the direct oral anticoagulants. SUMMARY Understanding the molecular mechanisms and unusual clinical features of HIT will improve its management.
Collapse
|
35
|
Implementation of a rapid HIT immunoassay at a university hospital - Retrospective analysis of HIT laboratory orders in patients with thrombocytopenia. Thromb Res 2017; 158:65-70. [PMID: 28843825 DOI: 10.1016/j.thromres.2017.08.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 07/19/2017] [Accepted: 08/15/2017] [Indexed: 12/21/2022]
Abstract
BACKGROUND Heparin-induced thrombocytopenia (HIT) is a rare cause of thrombocytopenia and a potentially life-threatening adverse drug reaction. Clinical overdiagnosis of HIT results in costly laboratory tests and anticoagulation. Criteria and algorithms for diagnosis are established, but their translation into clinical practice is still challenging. STUDY DESIGN AND METHODS In a retrospective approach we studied all HIT related laboratory test requests within four years and evaluated data before (1st period, 24month) and after (2nd period, 24month) replacing particle gel immunoassay (PaGIA) and enzyme-linked immunosorbent assay (ELISA) by a chemiluminescent immunoassay (CLIA). HIT was confirmed by heparin-induced platelet activation (HIPA) test. Clinical pretest probability for HIT using an implemented simplified 4Ts score and platelet count were evaluated. Costs for laboratory tests and alternative anticoagulation were calculated. RESULTS In 1850 patients with suspected HIT, 2327 laboratory orders were performed. In 87.2% of these orders an intermediate/high simplified 4Ts score was found. Thrombocytopenia was present in 87.1%. After replacing PaGIA and ELISA by CLIA the number of immunological and functional laboratory tests was reduced by 38.2%. The number of positive HIT immunoassays declined from 22.6% to 6.0%, while the number of positive HIPA tests among positive immunological tests increased by 19%. Altogether, acute HIT was confirmed in 59 patients. A decline in the use of alternative anticoagulants was observed in the 2nd period. CONCLUSION Our study shows that in a university hospital setting HIT is well-known, but diagnosis requires a precise laboratory confirmation. Replacing PaGIA and ELISA by CLIA did not influence laboratory order behavior but results in reduced overall costs for laboratory diagnostics and alternative anticoagulation.
Collapse
|
36
|
Pishko AM, Cuker A. Heparin-Induced Thrombocytopenia in Cardiac Surgery Patients. Semin Thromb Hemost 2017; 43:691-698. [PMID: 28597462 DOI: 10.1055/s-0037-1602664] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Allyson M Pishko
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Adam Cuker
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| |
Collapse
|
37
|
Rapid immunoassays for diagnosis of heparin-induced thrombocytopenia: Comparison of diagnostic accuracy, reproducibility, and costs in clinical practice. PLoS One 2017; 12:e0178289. [PMID: 28594835 PMCID: PMC5464550 DOI: 10.1371/journal.pone.0178289] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 05/10/2017] [Indexed: 01/01/2023] Open
Abstract
Background Immunoassays are crucial in the work-up of patients with suspected heparin-induced thrombocytopenia (HIT) and rapid tests have been recently developed. However, comparative data on diagnostic accuracy, reproducibility, and analytical costs of different immunoassays in clinical practice are limited. Methods Samples of 179 consecutive patients evaluated for suspected HIT in clinical practice using a polyspecific enzyme-linked immunoabsorbent assay (GTI diagnostics; ELISA) and a rapid particle gel immunoassay (PaGIA), were additionally analysed with a IgG-specific chemiluminescent immunoassay (AcuStar HIT-IgG). Presence of HIT was defined as a positive functional heparin-induced platelet aggregation test. Diagnostic accuracy was determined for low, intermediate and high thresholds as previously established (ELISA: optical density 0.4, 1.3, and 2.0 respectively; PaGIA: positive/negative, titre of 4, titre of 32; AcuStar HIT-IgG: 1.0 U/ml, 2.8, 9.4) and reproducibility was assessed by repeated measurements. Costs of test determination were calculated taking reagents, controls, and working time of technicians according to Swiss health care system into account. Results Data on PaGIA results were available for 171 patients (95.5%), ELISA for 144 patients (80.4%), and AcuStar HIT-IgG for 179 patients (100%). Sensitivity was above 95% for all assays at low and intermediate thresholds. Specificity increased with higher thresholds and was above 90% for all assays with intermediate and high thresholds. Specificity of AcuStar HIT-IgG (92.8%; 95% CI 87.7, 96.2) was significantly higher than PaGIA (83.0%; 95% CI 76.3, 88.5) and higher than ELISA (81.8%, 95% CI 74.2, 88.0) at low threshold (p<0.05). Reproducibility was adequate for all assays. Total costs per test were CHF 51.02 for ELISA, 117.70 for AcuStar HIT-IgG, and 83.13 for PaGIA. Conclusions We observed favourable diagnostic accuracy measures and a high reproducibility for PaGIA and AcuStar HIT-IgG. Implementation into 24-hours-service might improve patient care but the results must be confirmed in other settings and larger populations as well.
Collapse
|
38
|
Warkentin TE, Sheppard JAI, Linkins LA, Arnold DM, Nazy I. Performance characteristics of an automated latex immunoturbidimetric assay [HemosIL ® HIT-Ab (PF4-H) ] for the diagnosis of immune heparin-induced thrombocytopenia. Thromb Res 2017; 153:108-117. [DOI: 10.1016/j.thromres.2017.03.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 02/14/2017] [Accepted: 03/09/2017] [Indexed: 12/13/2022]
|
39
|
Abstract
Heparin-induced thrombocytopenia (HIT) is an immune complication of heparin therapy caused by antibodies to complexes of platelet factor 4 (PF4) and heparin. Pathogenic antibodies to PF4/heparin bind and activate cellular FcγRIIA on platelets and monocytes to propagate a hypercoagulable state culminating in life-threatening thrombosis. It is now recognized that anti-PF4/heparin antibodies develop commonly after heparin exposure, but only a subset of sensitized patients progress to life-threatening complications of thrombocytopenia and thrombosis. Recent scientific developments have clarified mechanisms underlying PF4/heparin immunogenicity, disease susceptibility, and clinical manifestations of disease. Insights from clinical and laboratory findings have also been recently harnessed for disease prevention. This review will summarize our current understanding of HIT by reviewing pathogenesis, essential clinical and laboratory features, and management.
Collapse
|
40
|
Seidel H, Kolde HJ. Monitoring of Argatroban and Lepirudin: What is the Input of Laboratory Values in "Real Life"? Clin Appl Thromb Hemost 2017; 24:287-294. [PMID: 28320219 DOI: 10.1177/1076029617699087] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Monitoring of direct thrombin inhibitors (DTIs) in patients with heparin-induced thrombocytopenia (HIT) is primarily performed using the activated partial thromboplastin time (aPTT). This assay is poorly standardized, reagent dependent, and not DTI specific. We compared aPTT, thrombin time (TT), and prothrombin time (PT) to drug levels obtained by the ecarin chromogenic assay (ECA). We analyzed 495 samples of patients with confirmed or suspected HIT on treatment with either argatroban (n = 37) or lepirudin (n = 80). Mean DTI levels ± standard deviation (SD) were 0.41 ± 0.36 µg/mL for argatroban and 0.20 ± 0.21 µg/mL for lepirudin. Results of aPTT were highly variable: 67 ± 22 seconds for argatroban and 55 ± 20 seconds for lepirudin. Significant correlations ( P < .01) were found between ECA-based DTI level and TT (argatroban, r = .820 and lepirudin, r = .830), PT (argatroban, r = -.544), and aPTT (lepirudin, r = .572). However, there was no correlation of aPTT with argatroban or PT with lepirudin concentration. Multiple regression analyses revealed that the TT predicted 54% of argatroban and 42% of lepirudin levels, but no significant impact was seen for PT or aPTT. The aPTT-guided monitoring of DTI therapy leads to a high percentage of patients with inaccurate plasma levels, hence resulting to either undertreatment or overtreatment. Knowledge of baseline values prior to DTI therapy and inclusion of clinical settings are essential for dosing DTIs when using aPTT. However, due to several limitations of aPTT, monitoring according to exact plasma concentrations as obtained by specific tests such as ECA may be more appropriate.
Collapse
Affiliation(s)
- Holger Seidel
- 1 Centrum für Blutgerinnungsstörungen und Transfusionsmedizin (CBT), Bonn, Germany.,2 Department of Experimental and Clinical Hemostasis, Hemotherapy and Transfusion Medicine, Heinrich Heine University Medical Center, Dusseldorf, Germany
| | | |
Collapse
|
41
|
Nagler M, Cuker A. Profile of Instrumentation Laboratory's HemosIL® AcuStar HIT-Ab(PF4-H) assay for diagnosis of heparin-induced thrombocytopenia. Expert Rev Mol Diagn 2017; 17:419-426. [PMID: 28271738 DOI: 10.1080/14737159.2017.1304213] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
INTRODUCTION Immunoassays play an essential role in the diagnosis of heparin-induced thrombocytopenia (HIT). The objective of this article is to review HemosIL® AcuStar HIT-Ab(PF4-H) (Instrumentation Laboratory, Bedford, MA, USA), a new chemiluminescent immunoassay for HIT. Areas covered: The authors searched the published literature for evaluation studies of HemosIL® AcuStar HIT-Ab(PF4-H) and sought information from the manufacturer. In this paper, the authors discuss the analytical principle and technical aspects of the assay; describe its diagnostic performance in validation studies; report on its reproducibility, cost-effectiveness, and regulatory status; and discuss the implications of the assay on clinical practice and means of integrating it in diagnostic pathways. HemosIL® AcuStar HIT-Ab(PF4-H) is compared with other rapid assays and widely used enzyme-linked immunoassays for the diagnosis of HIT. Expert commentary: HemosIL® AcuStar HIT-Ab(PF4-H) is automatable, can be performed 24 h per day, offers a rapid turnaround time, and appears to have favorable diagnostic accuracy, particularly at thresholds above that listed in the label. These advantages could lead to improved patient outcomes through rapid provision of results at the point of care, enhancing the accuracy of initial diagnosis.
Collapse
Affiliation(s)
- Michael Nagler
- a Department of Haematology and Central Haematology Laboratory , University of Bern , Bern , Switzerland
| | - Adam Cuker
- b Departments of Medicine and Pathology & Laboratory Medicine , University of Pennsylvania , Philadelphia , PA , USA
| |
Collapse
|
42
|
Choxi AA, Patel PA, Augoustides JG, Benitez-Lopez J, Gutsche JT, Murad H, Rodriguez-Blanco YF, Fabbro M, Crookston KP, Gerstein NS. Bivalirudin for Cardiopulmonary Bypass in the Setting of Heparin-Induced Thrombocytopenia and Combined Heart and Kidney Transplantation—Diagnostic and Therapeutic Challenges. J Cardiothorac Vasc Anesth 2017; 31:354-364. [DOI: 10.1053/j.jvca.2016.07.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2016] [Indexed: 12/25/2022]
|
43
|
Onwuemene O, Arepally GM. Heparin-induced thrombocytopenia: research and clinical updates. HEMATOLOGY. AMERICAN SOCIETY OF HEMATOLOGY. EDUCATION PROGRAM 2016; 2016:262-268. [PMID: 27913490 PMCID: PMC6142447 DOI: 10.1182/asheducation-2016.1.262] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Heparin-induced thrombocytopenia (HIT) remains an important diagnosis to consider in hospitalized patients developing thrombocytopenia. HIT is an immune-mediated prothrombotic disorder caused by antibodies to platelet factor 4 (PF4) and heparin. Recent basic scientific studies have advanced our understanding of disease pathogenesis through studies of the PF4/heparin structure, immune mechanisms, and cellular basis of thrombosis. Clinical advances have also occurred in areas of HIT prevention, description of disease variants, and diagnostic strategies. Emerging anticoagulants with the potential to change HIT treatment are evolving, although with limited data. This review will provide a current perspective on HIT pathogenesis, disease features, diagnostic strategies, and role of emerging therapies for the management of HIT.
Collapse
Affiliation(s)
- Oluwatoyosi Onwuemene
- Division of Hematology, Department of Medicine, Duke University Medical Center, Durham, NC
| | - Gowthami M Arepally
- Division of Hematology, Department of Medicine, Duke University Medical Center, Durham, NC
| |
Collapse
|
44
|
Morel-Kopp MC, Mullier F, Gkalea V, Bakchoul T, Minet V, Elalamy I, Ward CM. Heparin-induced multi-electrode aggregometry method for heparin-induced thrombocytopenia testing: communication from the SSC of the ISTH. J Thromb Haemost 2016; 14:2548-2552. [PMID: 27864862 DOI: 10.1111/jth.13516] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 09/09/2016] [Indexed: 11/28/2022]
Affiliation(s)
- M-C Morel-Kopp
- Department of Haematology and Transfusion Medicine, Royal North Shore Hospital, Sydney Local Health District and Northern Blood Research Centre, Kolling Institute, The University of Sydney, Sydney, Australia
| | - F Mullier
- Université Catholique de Louvain, and CHU UCL Namur, Namur Thrombosis and Hemostasis Center, Namur, Belgium
| | - V Gkalea
- Service d'Hématologie Biologique Hôpital Tenon, Hôpitaux Universitaires Est Parisien, Assistance Publique Hôpitaux de Paris, Paris, France
| | - T Bakchoul
- Institut für Immunologie und Transfusionsmedizin, Universitätsmedizin Greifswald, Greifswald, Germany
| | - V Minet
- Université Catholique de Louvain, and CHU UCL Namur, Namur Thrombosis and Hemostasis Center, Namur, Belgium
| | - I Elalamy
- Service d'Hématologie Biologique Hôpital Tenon, Hôpitaux Universitaires Est Parisien, Assistance Publique Hôpitaux de Paris, Paris, France
| | - C M Ward
- Department of Haematology and Transfusion Medicine, Royal North Shore Hospital, Sydney Local Health District and Northern Blood Research Centre, Kolling Institute, The University of Sydney, Sydney, Australia
| |
Collapse
|
45
|
Bakchoul T. An update on heparin-induced thrombocytopenia: diagnosis and management. Expert Opin Drug Saf 2016; 15:787-97. [DOI: 10.1517/14740338.2016.1165667] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Tamam Bakchoul
- Institute for Immunology and Transfusion Medicine, Universitätsmedizin Greifswald, Greifswald, Germany
| |
Collapse
|
46
|
Demand on-demand testing for the diagnosis of heparin-induced thrombocytopenia. Thromb Res 2016; 140:163-164. [DOI: 10.1016/j.thromres.2016.02.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 02/13/2016] [Indexed: 12/31/2022]
|