1
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Warkentin TE. Autoimmune Heparin-Induced Thrombocytopenia. J Clin Med 2023; 12:6921. [PMID: 37959386 PMCID: PMC10649402 DOI: 10.3390/jcm12216921] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 10/27/2023] [Accepted: 11/01/2023] [Indexed: 11/15/2023] Open
Abstract
Autoimmune thrombocytopenia (aHIT) is a severe subtype of heparin-induced thrombocytopenia (HIT) with atypical clinical features caused by highly pathological IgG antibodies ("aHIT antibodies") that activate platelets even in the absence of heparin. The clinical features of aHIT include: the onset or worsening of thrombocytopenia despite stopping heparin ("delayed-onset HIT"), thrombocytopenia persistence despite stopping heparin ("persisting" or "refractory HIT"), or triggered by small amounts of heparin (heparin "flush" HIT), most cases of fondaparinux-induced HIT, and patients with unusually severe HIT (e.g., multi-site or microvascular thrombosis, overt disseminated intravascular coagulation [DIC]). Special treatment approaches are required. For example, unlike classic HIT, heparin cessation does not result in de-escalation of antibody-induced hemostasis activation, and thus high-dose intravenous immunoglobulin (IVIG) may be indicated to interrupt aHIT-induced platelet activation; therapeutic plasma exchange may be required if high-dose IVIG is ineffective. Also, aHIT patients are at risk for treatment failure with (activated partial thromboplastin time [APTT]-adjusted) direct thrombin inhibitor (DTI) therapy (argatroban, bivalirudin), either because of APTT confounding (where aHIT-associated DIC and resulting APTT prolongation lead to systematic underdosing/interruption of DTI therapy) or because DTI inhibits thrombin-induced protein C activation. Most HIT laboratories do not test for aHIT antibodies, contributing to aHIT under-recognition.
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Affiliation(s)
- Theodore E. Warkentin
- Department of Pathology and Molecular Medicine and Department of Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, ON L8N 3Z5, Canada; ; Tel.: +1-(905)-527-0271 (ext. 46139)
- Service of Benign Hematology, Hamilton Health Sciences (General Site), Hamilton, ON L8L 2X2, Canada
- Transfusion Medicine, Hamilton Regional Laboratory Medicine Program, Hamilton, ON L8L 2X2, Canada
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2
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Koster A, Erdoes G, Nagler M, Birschmann I, Alberio L. How would we treat our own heparin-induced thrombocytopenia during cardiac surgery? J Cardiothorac Vasc Anesth 2020; 35:1585-1593. [PMID: 33342734 DOI: 10.1053/j.jvca.2020.11.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 10/27/2020] [Accepted: 11/02/2020] [Indexed: 12/29/2022]
Abstract
The aim of this article is to provide a comprehensive review of the current state of knowledge on heparin-induced thrombocytopenia (HIT) in cardiac surgery. The management of HIT patients undergoing cardiac surgery with cardiopulmonary bypass is complex and requires an interdisciplinary and patient-tailored approach because available evidence is limited and current anticoagulation strategies have potential risks. An index case is used to discuss both the established and new perioperative therapeutic options in HIT patients undergoing urgent cardiac surgery with cardiopulmonary bypass.
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Affiliation(s)
- Andreas Koster
- Institute of Anesthesiology and Pain Therapy, Heart, and Diabetes Center NRW, Bad Oeynhausen, Ruhr-University Bochum, Bochum, Germany
| | - Gabor Erdoes
- Department of Anesthesiology and Pain Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
| | - Michael Nagler
- University Institute of Clinical Chemistry, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Ingvild Birschmann
- Institute of Laboratory and Transfusion Medicine, Heart, and Diabetes Center NRW, Bad Oeynhausen, Ruhr-University Bochum, Bochum, Germany
| | - Lorenzo Alberio
- Division of Hematology and Central Hematology Laboratory, Lausanne University Hospital (CHUV), University of Lausanne (UNIL), Lausanne, Switzerland
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3
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Onuoha C, Barton KD, Wong EC, Raval JS, Rollins‐Raval MA, Ipe TS, Kiss JE, Boral LI, Adamksi J, Zantek ND, Onwuemene OA. Therapeutic plasma exchange and intravenous immune globulin in the treatment of
heparin‐induced
thrombocytopenia: A systematic review. Transfusion 2020; 60:2714-2736. [DOI: 10.1111/trf.16018] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 05/29/2020] [Accepted: 07/01/2020] [Indexed: 01/19/2023]
Affiliation(s)
- Chinonso Onuoha
- Department of Pediatrics East Carolina University, Vidant Medical Center Greenville North Carolina USA
| | - Karen D. Barton
- Medical Center Library Duke University Medical Center Durham North Carolina USA
| | - Edward C.C. Wong
- Department of Pediatrics and Pathology George Washington School of Medicine and Health Sciences Washington, DC USA
- Department of Coagulation Quest Diagnostics, Nichols Institute Centreville Virginia USA
| | - Jay S. Raval
- Department of Pathology University of New Mexico Albuquerque New Mexico USA
| | | | - Tina S. Ipe
- Department of Pathology and Laboratory Medicine University of Arkansas for Medical Sciences Little Rock Arkansas USA
| | - Joseph E. Kiss
- Department of Medicine Vitalant Northeast Division and The University of Pittsburgh Pittsburgh Pennsylvania USA
| | - Leonard I. Boral
- Department of Pathology and Laboratory Medicine University of Kentucky Health Care Lexington Kentucky USA
| | - Jill Adamksi
- Department of Laboratory Medicine and Pathology Mayo Clinic Arizona Phoenix Arizona USA
| | - Nicole D. Zantek
- Department of Laboratory Medicine and Pathology University of Minnesota Minneapolis Minnesota USA
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Dougherty JA, Yarsley RL. Intravenous Immune Globulin (IVIG) for Treatment of Autoimmune Heparin-Induced Thrombocytopenia: A Systematic Review. Ann Pharmacother 2020; 55:198-215. [PMID: 32693627 DOI: 10.1177/1060028020943542] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
OBJECTIVE To evaluate intravenous immune globulin (IVIG) for autoimmune heparin-induced thrombocytopenia (aHIT), including platelet recovery, IVIG dose, dosing weight, IVIG product used, and complications reported. DATA SOURCES PubMed and EMBASE were searched from inception through June 21, 2020. Search terms included heparin-induced thrombocytopenia, HIT, intravenous immune globulin, IVIG, autoimmune HIT, aHIT, and immune globulin. STUDY SELECTION AND DATA EXTRACTION Patients administered IVIG for HIT and diagnosed by immunoassay (optical density ≥2) or positive activation assay were included. DATA SYNTHESIS Twenty-four cases were reviewed; 92% had persistent aHIT. Time to IVIG administration post-nonheparin anticoagulant initiation was 9 days (median). Most common IVIG cumulative dose was 2 g/kg (dosed as 1 g/kg/d for 2 consecutive days); 75% had a favorable platelet increase (≥50 × 109/L) within 5 days of initial IVIG dosing. RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE aHIT is characterized by critically low platelets, thrombosis, and a persistent delay in platelet recovery despite treatment with a nonheparin anticoagulant. An immunoassay and subsequent confirmatory activation assay (at low, high, and 0 IU/mL unfractionated heparin levels) is recommended to confirm diagnosis. Patients nonresponsive to nonheparin anticoagulants within 5 days of initiation should be evaluated for IVIG treatment (2 g/kg cumulative dose). More data are needed to clarify appropriate IVIG dosing weight, although based on current published literature, it is recommended to use actual body weight. CONCLUSIONS Data reported support use of IVIG as adjunctive therapy for patients with aHIT. Judicious IVIG use based on key clinical and laboratory findings is critical.
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5
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Gonzales M, Pipalia A, Weil A. Refractory Heparin-Induced Thrombocytopenia With Cerebral Venous Sinus Thrombosis Treated With IVIg, Steroids, and a Combination of Anticoagulants: A Case Report. J Investig Med High Impact Case Rep 2020; 7:2324709619832324. [PMID: 30939936 PMCID: PMC6448115 DOI: 10.1177/2324709619832324] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Heparin-induced thrombocytopenia (HIT) type II is caused by antibody production that bind complexes between heparin and platelet factor 4 leading to platelet consumption and thrombosis. In a small subset of cases referred to as autoimmune HIT, the antibodies activate platelets even in the absence of heparin. Refractory HIT is a type of autoimmune HIT in which thrombocytopenia persists for weeks after heparin discontinuation and carries increased risk for thrombosis and more severe thrombocytopenia. We present a case of refractory HIT with cerebral venous sinus thrombosis (CVST) that was successfully treated with a change in anticoagulant alongside steroids and a second trial of intravenous immunoglobulin (IVIg).
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Affiliation(s)
- Mia Gonzales
- 1 East Carolina University, Greenville, NC, USA.,2 Vidant Medical Center, Greenville, NC, USA
| | - Amrish Pipalia
- 1 East Carolina University, Greenville, NC, USA.,2 Vidant Medical Center, Greenville, NC, USA
| | - Andrew Weil
- 1 East Carolina University, Greenville, NC, USA.,2 Vidant Medical Center, Greenville, NC, USA
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6
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Effectiveness of intravenous immunoglobulin use in heparin-induced thrombocytopenia. Blood Coagul Fibrinolysis 2020; 31:287-292. [DOI: 10.1097/mbc.0000000000000918] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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7
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Warkentin TE. High-dose intravenous immunoglobulin for the treatment and prevention of heparin-induced thrombocytopenia: a review. Expert Rev Hematol 2019; 12:685-698. [DOI: 10.1080/17474086.2019.1636645] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Theodore E. Warkentin
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
- McMaster Centre for Transfusion Research, McMaster University, Hamilton, Ontario, Canada
- Department of Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
- Hamilton Regional Laboratory Medicine Program, Hamilton General Hospital, Hamilton Health Sciences, Hamilton, Ontario, Canada
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8
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Arcinas LA, Manji RA, Hrymak C, Dao V, Sheppard JAI, Warkentin TE. Autoimmune heparin-induced thrombocytopenia and venous limb gangrene after aortic dissection repair: in vitro and in vivo effects of intravenous immunoglobulin. Transfusion 2019; 59:1924-1933. [PMID: 30903805 DOI: 10.1111/trf.15263] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 02/19/2019] [Accepted: 02/21/2019] [Indexed: 12/12/2022]
Abstract
BACKGROUND Heparin-induced thrombocytopenia (HIT) is a prothrombotic disorder characterized by heparin-dependent antibodies that activate platelets (PLTs) via PLT FcγIIa receptors. "Autoimmune" HIT (aHIT) indicates a HIT subset where thrombocytopenia progresses or persists despite stopping heparin; aHIT sera activate PLTs strongly even in the absence of heparin (heparin-independent PLT-activating properties). Affected patients are at risk of severe complications, including dual macro- and microvascular thrombosis leading to venous limb gangrene. High-dose intravenous immunoglobulin (IVIG) offers an approach to interrupt heparin-independent PLT-activating effects of aHIT antibodies. CASE REPORT A 78-year-old male who underwent cardiopulmonary bypass for aortic dissection developed aHIT, disseminated intravascular coagulation, and deep vein thrombosis; progression to venous limb gangrene occurred during partial thromboplastin time (PTT)-adjusted bivalirudin infusion (underdosing from "PTT confounding"). Thrombocytopenia recovered with high-dose IVIG, although the PLT count increase began only after the third dose of a 5-day IVIG regimen (0.4 g/kg/day × 5 days). We reviewed case reports and case series of IVIG for treating HIT, focusing on various IVIG dosing regimens used. RESULTS Patient serum-induced PLT activation was inhibited in vitro by IVIG in a dose-dependent fashion; inhibition of PLT activation by IVIG was much more marked in the absence of heparin versus the presence of heparin (0.2 U/mL). Our literature review indicated 1 g/kg × 2 IVIG dosing as most common for treating HIT, usually associated with rapid PLT count recovery. CONCLUSION Our clinical and laboratory observations support dose-dependent efficacy of IVIG for decreasing PLT activation and thus correcting thrombocytopenia in aHIT. Our case experience and literature review suggests dosing of 1 g/kg IVIG × 2 for patients with severe aHIT.
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Affiliation(s)
- Liane A Arcinas
- Department of Internal Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Rizwan A Manji
- Section of Cardiac Surgery, Department of Surgery, University of Manitoba, Winnipeg, Manitoba, Canada.,Section of Critical Care, Department of Internal Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Carmen Hrymak
- Section of Critical Care, Department of Internal Medicine, University of Manitoba, Winnipeg, Manitoba, Canada.,Department of Emergency Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Vi Dao
- Section of Hematology, Department of Internal Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Jo-Ann I Sheppard
- Department of Pathology and Molecular Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Theodore E Warkentin
- Department of Pathology and Molecular Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada.,Department of Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
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9
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Kuitunen A, Sinisalo M, Vahtera A, Hiltunen L, Javela K, Laine O. Autoimmune heparin-induced thrombocytopenia of delayed onset: a clinical challenge. Transfusion 2018; 58:2757-2760. [PMID: 30284726 DOI: 10.1111/trf.14814] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 05/07/2018] [Accepted: 05/16/2018] [Indexed: 12/24/2022]
Abstract
BACKGROUND Heparin-induced thrombocytopenia (HIT) usually appears at 5 to 10 days after initiation of heparin. Autoimmune HIT can arise after discontinuation of heparin treatment (delayed-onset HIT) or without any preceding heparin exposure (spontaneous HIT syndrome). CASE REPORT This case presents a course of autoimmune HIT with delayed onset. The patient was hospitalized due to influenza pneumonia and received low-molecular-weight heparin thromboprophylaxis for 9 days. Seven days after discharge, she was readmitted because of a cerebral sinus vein thrombosis and severe thrombocytopenia. Intracranial bleeding and brain infarction caused her death. DISCUSSION Autoimmune HIT was confirmed by functional heparin-induced platelet (PLT) activation test. Intracranial bleeding prevented continuous and effective anticoagulation. PLT transfusions were given, although they are generally advised against in HIT patients due to potential risk of thromboembolic events. CONCLUSION This case presents that testing PLT-activating antibodies both in the presence and in the absence of current heparin treatment helps to diagnose patients with autoimmune HIT. There is conflicting evidence to refuse PLT transfusion when HIT is complicated with life-threatening bleeding.
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Affiliation(s)
- Anne Kuitunen
- Department of Intensive Care, Tampere University Hospital, Tampere, Finland
| | - Marjatta Sinisalo
- the Department of Internal Medicine, Tampere University Hospital, Tampere, Finland
| | - Annukka Vahtera
- Department of Intensive Care, Tampere University Hospital, Tampere, Finland
| | | | - Kaija Javela
- the Finnish Red Cross Blood Service, Helsinki, Finland
| | - Outi Laine
- the Department of Internal Medicine, Tampere University Hospital, Tampere, Finland.,the Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland
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10
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Park BD, Kumar M, Nagalla S, De Simone N, Aster RH, Padmanabhan A, Sarode R, Rambally S. Intravenous immunoglobulin as an adjunct therapy in persisting heparin-induced thrombocytopenia. Transfus Apher Sci 2018; 57:561-565. [PMID: 30244713 DOI: 10.1016/j.transci.2018.06.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 06/21/2018] [Indexed: 01/19/2023]
Abstract
Heparin induced thrombocytopenia (HIT) is a serious adverse drug reaction caused by transient antibodies against platelet factor 4 (PF4)/heparin complexes, resulting in platelet activation and potentially fatal arterial and/or venous thrombosis. Most cases of HIT respond to cessation of heparin and administration of an alternative non-heparin anticoagulant, but there are cases of persisting HIT, defined as thrombocytopenia due to platelet activation/consumption for greater than seven days despite standard therapy. These patients remain at high risk for thrombotic events, which may result in limb-loss and mortality. Intravenous immunoglobulin (IVIg) has been proposed as an adjunct therapy for these refractory cases based on its ability to saturate FcγRIIa receptors on platelets, thus preventing HIT antibody binding and platelet activation. We describe 2 cases of persisting HIT (strongly positive antigen and functional assays, and persisting thrombocytopenia >7 days) with rapid clinical response to IVIg. We performed in-vitro experiments to support IVIg response. Healthy donor platelets (1 × 10e6) were treated with PF4 (3.75 μg/mL) for 20 min followed by 1-hour incubation with patients' sera. Platelet activation with and without addition of IVIg (levels equivalent to those reached in a patient after treatment with 2 gm/Kg) was evaluated in the PF4-dependent P-selectin expression assay (PEA). A significantly decreased platelet activation was demonstrated after the addition of IVIg to both patient samples, which correlated well with the rapid clinical response that each patient experienced. Thus, our study supports the use of IVIg as an adjunct therapy for persisting HIT.
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Affiliation(s)
- B D Park
- UT Southwestern Medical Center, Department of Internal Medicine, Dallas, TX, United States.
| | - M Kumar
- UT Southwestern Medical Center, Department of Internal Medicine, Dallas, TX, United States
| | - S Nagalla
- UT Southwestern Medical Center, Department of Internal Medicine, Dallas, TX, United States
| | - N De Simone
- UT Southwestern Medical Center, Department of Pathology, Dallas, TX, United States
| | - R H Aster
- Blood Research Institute, Blood Center of Wisconsin, Milwaukee, WI, United States; Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, United States
| | - A Padmanabhan
- Medical Sciences Institute, Blood Center of Wisconsin, Milwaukee, WI, United States; Blood Research Institute, Blood Center of Wisconsin, Milwaukee, WI, United States; Department of Pathology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - R Sarode
- UT Southwestern Medical Center, Department of Pathology, Dallas, TX, United States
| | - S Rambally
- UT Southwestern Medical Center, Department of Internal Medicine, Dallas, TX, United States
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11
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McKenzie DS, Anuforo J, Morgan J, Neculiseanu E. Successful Use of Intravenous Immunoglobulin G to Treat Refractory Heparin-Induced Thrombocytopenia With Thrombosis Complicating Peripheral Blood Stem Cell Harvest. J Investig Med High Impact Case Rep 2018; 6:2324709618755414. [PMID: 29404376 PMCID: PMC5791472 DOI: 10.1177/2324709618755414] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2017] [Revised: 12/10/2017] [Accepted: 12/14/2017] [Indexed: 12/13/2022] Open
Abstract
Heparin-induced thrombocytopenia is a well-known, life-threatening complication that occurs in 5% of patients exposed to heparin. It causes thrombocytopenia in roughly 85% to 90% of affected individuals, with expected recovery in approximately 4 to 10 days following heparin withdrawal. However, there is an entity known as refractory heparin-induced thrombocytopenia with thrombosis in which patients have prolonged thrombocytopenia, refractory to the current standard of care. We present one such case of a 48-year-old male with R-ISS (Revised International Staging System) stage II kappa light chain multiple myeloma in stringent complete response status postinduction therapy. He developed heparin-induced thrombocytopenia with thrombosis during peripheral blood stem cell harvesting, manifesting as acute right coronary artery thrombus and severe thrombocytopenia. Although his clinical course was prolonged, he was ultimately successfully treated with intravenous immunoglobulin G 500 mg/kg/day over 4 days.
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12
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East JM, Cserti-Gazdewich CM, Granton JT. Heparin-Induced Thrombocytopenia in the Critically Ill Patient. Chest 2017; 154:678-690. [PMID: 29253554 DOI: 10.1016/j.chest.2017.11.039] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 11/22/2017] [Accepted: 11/29/2017] [Indexed: 01/19/2023] Open
Abstract
Heparin-induced thrombocytopenia (HIT) is associated with clinically significant morbidity and mortality. Patients who are critically ill are commonly thrombocytopenic and exposed to heparin. Although HIT should be considered, it is not usually the cause of thrombocytopenia in the medical-surgical ICU population. A systematic approach to the patient who is critically ill who has thrombocytopenia according to clinical features, complemented by appropriate laboratory confirmation, should lead to a reduction in inappropriate laboratory testing and reduce the use of more expensive and less reliable anticoagulants. If the patient is deemed as being at intermediate or high risk for HIT or if HIT is confirmed by means of the serotonin-release assay, heparin should be stopped, heparin-bonded catheters should be removed, and a direct antithrombin or fondaparinux should be initiated to reduce the risk of thrombosis. Warfarin is absolutely contraindicated in the acute phase of HIT; if administered, its effects must be reversed by using vitamin K.
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Affiliation(s)
- James M East
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, ON, Canada
| | | | - John T Granton
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, ON, Canada.
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13
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Greinacher A, Selleng K, Warkentin TE. Autoimmune heparin-induced thrombocytopenia. J Thromb Haemost 2017; 15:2099-2114. [PMID: 28846826 DOI: 10.1111/jth.13813] [Citation(s) in RCA: 280] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2017] [Indexed: 01/18/2023]
Abstract
Autoimmune heparin-induced thrombocytopenia (aHIT) indicates the presence in patients of anti-platelet factor 4 (PF4)-polyanion antibodies that are able to activate platelets strongly even in the absence of heparin (heparin-independent platelet activation). Nevertheless, as seen with serum obtained from patients with otherwise typical heparin-induced thrombocytopenia (HIT), serum-induced platelet activation is inhibited at high heparin concentrations (10-100 IU mL-1 heparin). Furthermore, upon serial dilution, aHIT serum will usually show heparin-dependent platelet activation. Clinical syndromes associated with aHIT include: delayed-onset HIT, persisting HIT, spontaneous HIT syndrome, fondaparinux-associated HIT, heparin 'flush'-induced HIT, and severe HIT (platelet count of < 20 × 109 L-1 ) with associated disseminated intravascular coagulation (DIC). Recent studies have implicated anti-PF4 antibodies that are able to bridge two PF4 tetramers even in the absence of heparin, probably facilitated by non-heparin platelet-associated polyanions (chondroitin sulfate and polyphosphates); nascent PF4-aHIT-IgG complexes recruit additional heparin-dependent HIT antibodies, leading to the formation of large multimolecular immune complexes and marked platelet activation. aHIT can persist for several weeks, and serial fibrin, D-dimer, and fibrinogen levels, rather than the platelet count, may be helpful for monitoring treatment response. Although standard anticoagulant therapy for HIT ought to be effective, published experience indicates frequent failure of activated partial thromboplastin time (APTT)-adjusted anticoagulants (argatroban, bivalirudin), probably because of underdosing in the setting of HIT-associated DIC, known as 'APTT confounding'. Thus, non-APTT-adjusted therapies with drugs such as danaparoid and fondaparinux, or even direct oral anticoagulants, such as rivaroxaban or apixaban, are suggested therapies, especially for long-term management of persisting HIT. In addition, emerging data indicate that high-dose intravenous immunoglobulin can interrupt HIT antibody-induced platelet activation, leading to rapid platelet count recovery.
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MESH Headings
- Administration, Oral
- Animals
- Anticoagulants/administration & dosage
- Anticoagulants/adverse effects
- Anticoagulants/immunology
- Autoantibodies/blood
- Autoimmunity/drug effects
- Blood Coagulation/drug effects
- Blood Platelets/drug effects
- Blood Platelets/immunology
- Blood Platelets/metabolism
- Heparin/adverse effects
- Heparin/immunology
- Humans
- Immunoglobulins, Intravenous/administration & dosage
- Immunologic Factors/administration & dosage
- Partial Thromboplastin Time
- Platelet Activation/drug effects
- Platelet Factor 4/immunology
- Purpura, Thrombocytopenic, Idiopathic/blood
- Purpura, Thrombocytopenic, Idiopathic/chemically induced
- Purpura, Thrombocytopenic, Idiopathic/drug therapy
- Purpura, Thrombocytopenic, Idiopathic/immunology
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Affiliation(s)
- A Greinacher
- Institut für Immunologie und Transfusionsmedizin, Universitätsmedizin Greifswald, Greifswald, Germany
| | - K Selleng
- Institut für Immunologie und Transfusionsmedizin, Universitätsmedizin Greifswald, Greifswald, Germany
| | - T E Warkentin
- Department of Pathology and Molecular Medicine, Department of Medicine, and McMaster Centre for Transfusion Research, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
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14
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Doucette K, DeStefano CB, Jain NA, Cruz AL, Malkovska V, Fitzpatrick K. Treatment of refractory delayed onset heparin-induced thrombocytopenia after thoracic endovascular aortic repair with intravenous immunoglobulin (IVIG). Res Pract Thromb Haemost 2017; 1:134-137. [PMID: 30046682 PMCID: PMC6058197 DOI: 10.1002/rth2.12009] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 05/05/2017] [Indexed: 02/02/2023] Open
Abstract
Delayed onset heparin induced thrombocytopenia (HIT), is characterized by a late nadir due to persistent platelet-activating IgG antibodies. It typically begins or worsens 5 or more days after heparin is discontinued with complications such as thrombosis up to 3 weeks after exposure to heparin.1-3 In 50% of cases, the platelet count can decrease to very low numbers (<20 000/μL), which is not usual for typical HIT. Here we report 2 cases of post-operative delayed onset HIT manifesting as severe thrombocytopenia that persisted despite cessation of heparin and initiation of argatroban. Key Clinical Question: Is intravenous immunoglulin beneficial in severe refractory delayed-onset HIT?
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Affiliation(s)
- Kimberley Doucette
- Department of Internal MedicineMedstar Washington Hospital CenterWashingtonDCUSA
| | | | - Natasha A. Jain
- Department of Internal MedicineMedstar Washington Hospital CenterWashingtonDCUSA
| | - Allan L. Cruz
- Department of Hematology/OncologyMedstar Washington Hospital CenterWashingtonDCUSA
| | - Vera Malkovska
- Department of Hematology/OncologyMedstar Washington Hospital CenterWashingtonDCUSA
| | - Kelly Fitzpatrick
- Department of Hematology/OncologyMedstar Washington Hospital CenterWashingtonDCUSA
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