T E Warkentin

Summary

Affiliation: McMaster University
Country: Canada

Publications

  1. ncbi request reprint Warfarin-associated multiple digital necrosis complicating heparin-induced thrombocytopenia and Raynaud's phenomenon after aortic valve replacement for adenocarcinoma-associated thrombotic endocarditis
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
    Am J Hematol 75:56-62. 2004
  2. ncbi request reprint Heparin, low molecular weight heparin, and heparin-induced thrombocytopenia in the ICU
    Theodore E Warkentin
    Hamilton Regional Laboratory Medicine Program, Hamilton Health Sciences, 237 Barton Street East, Hamilton, Ontario L8L 2X2, Canada
    Crit Care Clin 21:513-29. 2005
  3. doi request reprint Bleeding risk and the management of bleeding complications in patients undergoing anticoagulant therapy: focus on new anticoagulant agents
    Mark A Crowther
    Department of Medicine, Michael G DeGroote School of Medicine, McMaster University, Hamilton, ON, USA
    Blood 111:4871-9. 2008
  4. doi request reprint Delayed-onset HIT caused by low-molecular-weight heparin manifesting during fondaparinux prophylaxis
    Khalid A Alsaleh
    Department of Medicine, Michael G DeGroote School of Medicine McMaster University, Hamilton, Ontario, Canada
    Am J Hematol 83:876-8. 2008
  5. doi request reprint Anticoagulant failure in coagulopathic patients: PTT confounding and other pitfalls
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, McMaster University, Hamilton Regional Laboratory Medicine Program, Hamilton General Hospital, Hamilton Health Sciences, 237 Barton St E, Hamilton, Ontario L8L 2X2, Canada
    Expert Opin Drug Saf 13:25-43. 2014
  6. doi request reprint Anti-PF4/heparin antibodies and venous graft occlusion in postcoronary artery bypass surgery patients randomized to postoperative unfractionated heparin or fondaparinux thromboprophylaxis
    T E Warkentin
    Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
    J Thromb Haemost 11:253-60. 2013
  7. doi request reprint HITlights: a career perspective on heparin-induced thrombocytopenia
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, Michael G DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
    Am J Hematol 87:S92-9. 2012
  8. pmc Anti-platelet factor 4/heparin antibodies in orthopedic surgery patients receiving antithrombotic prophylaxis with fondaparinux or enoxaparin
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
    Blood 106:3791-6. 2005
  9. ncbi request reprint An overview of the heparin-induced thrombocytopenia syndrome
    Theodore E Warkentin
    Hamilton Regional Laboratory Medicine Program, Hamilton Health Sciences, Hamilton, Ontario, Canada
    Semin Thromb Hemost 30:273-83. 2004
  10. ncbi request reprint Bivalent direct thrombin inhibitors: hirudin and bivalirudin
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, McMaster University, and Hamilton Regional Laboratory Medicine Program, Hamilton General Site, Hamilton Health Sciences, Ont, Canada L8L 2X2
    Best Pract Res Clin Haematol 17:105-25. 2004

Detail Information

Publications107 found, 100 shown here

  1. ncbi request reprint Warfarin-associated multiple digital necrosis complicating heparin-induced thrombocytopenia and Raynaud's phenomenon after aortic valve replacement for adenocarcinoma-associated thrombotic endocarditis
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
    Am J Hematol 75:56-62. 2004
    ....
  2. ncbi request reprint Heparin, low molecular weight heparin, and heparin-induced thrombocytopenia in the ICU
    Theodore E Warkentin
    Hamilton Regional Laboratory Medicine Program, Hamilton Health Sciences, 237 Barton Street East, Hamilton, Ontario L8L 2X2, Canada
    Crit Care Clin 21:513-29. 2005
    ..This article describes clinical features of HIT and interpretation of laboratory tests for HIT antibodies from the perspective of the intensive care unit...
  3. doi request reprint Bleeding risk and the management of bleeding complications in patients undergoing anticoagulant therapy: focus on new anticoagulant agents
    Mark A Crowther
    Department of Medicine, Michael G DeGroote School of Medicine, McMaster University, Hamilton, ON, USA
    Blood 111:4871-9. 2008
    ..Available data on the efficacy and safety of current and experimental agents for anticoagulant reversal are reviewed, and a plan for management of anticoagulant-induced bleeding is presented...
  4. doi request reprint Delayed-onset HIT caused by low-molecular-weight heparin manifesting during fondaparinux prophylaxis
    Khalid A Alsaleh
    Department of Medicine, Michael G DeGroote School of Medicine McMaster University, Hamilton, Ontario, Canada
    Am J Hematol 83:876-8. 2008
    ..Confirmed delayed-onset HIT with LMWH has not been previously reported. Low dose fondaparinux does not necessarily prevent thrombotic complications of HIT...
  5. doi request reprint Anticoagulant failure in coagulopathic patients: PTT confounding and other pitfalls
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, McMaster University, Hamilton Regional Laboratory Medicine Program, Hamilton General Hospital, Hamilton Health Sciences, 237 Barton St E, Hamilton, Ontario L8L 2X2, Canada
    Expert Opin Drug Saf 13:25-43. 2014
    ..In these disorders, acquired abnormalities of the partial thromboplastin time (PTT) and international normalized ratio (INR) can confound monitoring of PTT- and INR-adjusted anticoagulant therapies, contributing to treatment failure...
  6. doi request reprint Anti-PF4/heparin antibodies and venous graft occlusion in postcoronary artery bypass surgery patients randomized to postoperative unfractionated heparin or fondaparinux thromboprophylaxis
    T E Warkentin
    Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
    J Thromb Haemost 11:253-60. 2013
    ..It is controversial whether non-platelet-activating antibodies are associated with thrombosis...
  7. doi request reprint HITlights: a career perspective on heparin-induced thrombocytopenia
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, Michael G DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
    Am J Hematol 87:S92-9. 2012
    ....
  8. pmc Anti-platelet factor 4/heparin antibodies in orthopedic surgery patients receiving antithrombotic prophylaxis with fondaparinux or enoxaparin
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
    Blood 106:3791-6. 2005
    ..We conclude that despite similar immunogenicity of fondaparinux and LMWH, PF4/fondaparinux, but not PF4/LMWH, is recognized poorly by the antibodies generated, suggesting that the risk of HIT with fondaparinux likely is very low...
  9. ncbi request reprint An overview of the heparin-induced thrombocytopenia syndrome
    Theodore E Warkentin
    Hamilton Regional Laboratory Medicine Program, Hamilton Health Sciences, Hamilton, Ontario, Canada
    Semin Thromb Hemost 30:273-83. 2004
    ..When using these agents, coumarin anticoagulation should be delayed pending substantial resolution of thrombocytopenia, before cautiously introducing overlapping coumarin therapy...
  10. ncbi request reprint Bivalent direct thrombin inhibitors: hirudin and bivalirudin
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, McMaster University, and Hamilton Regional Laboratory Medicine Program, Hamilton General Site, Hamilton Health Sciences, Ont, Canada L8L 2X2
    Best Pract Res Clin Haematol 17:105-25. 2004
    ..Further work is required to define the scope of clinical thrombosis problems that could benefit from these novel agents...
  11. ncbi request reprint Heparin-induced thrombocytopenia and cardiac surgery
    Theodore E Warkentin
    Department of Pathology, McMaster University, Hamilton, Ontario, Canada
    Ann Thorac Surg 76:2121-31. 2003
    ..As heparin-induced thrombocytopenia antibodies are transient, unfractionated heparin alone is appropriate in a patient with previous heparin-induced thrombocytopenia whose antibodies have disappeared...
  12. ncbi request reprint An improved definition of immune heparin-induced thrombocytopenia in postoperative orthopedic patients
    Theodore E Warkentin
    McMaster University, The Henderson Research Centre, and the Hamilton Regional Laboratory Medicine Program, Hamilton, Ontario, Canada
    Arch Intern Med 163:2518-24. 2003
    ..We sought to determine an improved definition of thrombocytopenia indicating HIT in postoperative orthopedic patients, including its impact on frequency and thrombotic risk of HIT...
  13. ncbi request reprint Gastrointestinal bleeding, angiodysplasia, cardiovascular disease, and acquired von Willebrand syndrome
    Theodore E Warkentin
    Department of Pathology, McMaster University, Hamilton, Ontario, Canada
    Transfus Med Rev 17:272-86. 2003
    ....
  14. ncbi request reprint Heparin-induced thrombocytopenia and cardiac surgery
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
    Ann Thorac Surg 76:638-48. 2003
    ..As heparin-induced thrombocytopenia antibodies are transient, unfractionated heparin alone is appropriate in a patient with previous heparin-induced thrombocytopenia whose antibodies have disappeared...
  15. doi request reprint Quantitative interpretation of optical density measurements using PF4-dependent enzyme-immunoassays
    T E Warkentin
    Department of Pathology and Molecular Medicine, Michael G DeGroote School of Medicine, McMaster University, Hamilton, ON, Canada
    J Thromb Haemost 6:1304-12. 2008
    ..An advantage of the EIA is its simplicity; a disadvantage is that it only indirectly detects heparin-dependent, platelet-activating antibodies ('HIT antibodies')...
  16. ncbi request reprint Heparin-induced thrombocytopenia
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, Michael G DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
    Hematol Oncol Clin North Am 21:589-607, v. 2007
    ..Warfarin must be avoided or postponed, as the acute phase of HIT poses a high risk for coumarin necrosis, particularly limb loss due to venous limb gangrene...
  17. ncbi request reprint Heparin-induced thrombocytopenia and vascular surgery
    T E Warkentin
    Department of Pathology and Molecular Medicine, and Department of Medicine, McMaster University, and the Hamilton Regional Laboratory Medicine Program, Hamilton, Ontario, Canada
    Acta Chir Belg 104:257-65. 2004
    ..The transience of HIT antibodies provides a rationale for intraoperative use of heparin in a patient who has recovered from HIT and in whom HIT antibodies are no longer detectable...
  18. ncbi request reprint PF4-dependent immunoassays and inferential detection of HIT antibodies
    T E Warkentin
    Michael G DeGroote School of Medicine, McMaster University, Hamilton, ON, Canada
    J Thromb Haemost 5:232-4. 2007
  19. ncbi request reprint Laboratory testing for the antibodies that cause heparin-induced thrombocytopenia: how much class do we need?
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada Department of Medicine, McMaster University, Hamilton, Ontario, Canada
    J Lab Clin Med 146:341-6. 2005
    ..We conclude that an EIA that detects anti-PF4/polyanion antibodies of only the IgG class has greater diagnostic usefulness in revealing clinical HIT than does an assay that also detects IgA and IgM class antibodies...
  20. ncbi request reprint Bivalirudin: a review
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
    Expert Opin Pharmacother 6:1349-71. 2005
    ..Anecdotal 'off-label' experience for the treatment of heparin-induced thrombocytopenia shows promise...
  21. ncbi request reprint Differences in the clinically effective molar concentrations of four direct thrombin inhibitors explain their variable prothrombin time prolongation
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
    Thromb Haemost 94:958-64. 2005
    ..DTIs with a relatively low affinity for thrombin require high plasma concentrations to double the APTT; these higher plasma concentrations, in turn, quench more of the thrombin generated in the PT, thereby more greatly prolonging the PT...
  22. ncbi request reprint Heparin-induced skin lesions and other unusual sequelae of the heparin-induced thrombocytopenia syndrome: a nested cohort study
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
    Chest 127:1857-61. 2005
    ....
  23. ncbi request reprint Gender imbalance and risk factor interactions in heparin-induced thrombocytopenia
    Theodore E Warkentin
    Department of Pathology, Hamilton Regional Laboratory Medicine Program, Rm 1 180A, Hamilton Health Sciences, Hamilton General Site, McMaster University, 237 Barton St E, Hamilton, ON L8L2X2 Canada
    Blood 108:2937-41. 2006
    ..93 vs 1.75; P = .005). We conclude that females are at greater risk for HIT and that using LMWH to prevent HIT may have greatest absolute benefit in females undergoing surgical thromboprophylaxis...
  24. ncbi request reprint New approaches to the diagnosis of heparin-induced thrombocytopenia
    Theodore E Warkentin
    Hamilton Regional Laboratory Medicine Program, Hamilton General Hospital, 237 Barton St E, Hamilton, ON L8L 2X2, Canada
    Chest 127:35S-45S. 2005
    ..By this approach, the magnitude of a positive test result determines its likelihood ratio in influencing the posttest probability of HIT...
  25. ncbi request reprint Heparin-induced thrombocytopenia: diagnosis and management
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
    Circulation 110:e454-8. 2004
  26. ncbi request reprint Heparin-induced thrombocytopenia: recognition, treatment, and prevention: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy
    Theodore E Warkentin
    Hamilton Regional Laboratory Medicine Program, Hamilton Health Sciences, General Site, 237 Barton St E, Hamilton, Ontario L8L 2X2, Canada
    Chest 126:311S-337S. 2004
    ....
  27. doi request reprint Treatment and prevention of heparin-induced thrombocytopenia: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition)
    Theodore E Warkentin
    Hamilton Regional Laboratory Medicine Program, Hamilton Health Sciences, 237 Barton Street E, Hamilton, Ontario, Canada
    Chest 133:340S-380S. 2008
    ..For patients receiving VKAs at the time of diagnosis of HIT, we recommend use of vitamin K (10 mg po or 5 to 10 mg IV) [Grade 1C]...
  28. ncbi request reprint Management of heparin-induced thrombocytopenia: a critical comparison of lepirudin and argatroban
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, McMaster University, Canada
    Thromb Res 110:73-82. 2003
    ..Thus, the DTI should be given alone during acute HIT, with oral anticoagulants deferred until substantial resolution of the thrombocytopenia has occurred...
  29. ncbi request reprint HIT: lessons learned
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
    Pathophysiol Haemost Thromb 35:50-7. 2006
    ....
  30. doi request reprint How I diagnose and manage HIT
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, Michael G DeGroote School of Medicine, McMaster University, Hamilton, ON, Canada
    Hematology Am Soc Hematol Educ Program 2011:143-9. 2011
    ....
  31. doi request reprint Heparin-induced thrombocytopenia in critically ill patients
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
    Crit Care Clin 27:805-23, v. 2011
    ..A recent study showing that dalteparin is associated with a reduced frequency of HIT indicates that critically ill patients too can benefit from the HIT-reducing potential of this low molecular weight heparin preparation...
  32. ncbi request reprint Laboratory diagnosis of immune heparin-induced thrombocytopenia
    Theodore E Warkentin
    Hamilton Regional Laboratory Medicine Program, Hamilton Health Sciences, Hamilton General Site, 237 Baron Street East, Hamilton, ON L8L 2X2, Canada
    Curr Hematol Rep 2:148-57. 2003
    ..However, optimal diagnostic information requires that laboratory test results be interpreted in the appropriate clinical context...
  33. doi request reprint Bivalirudin
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, Michael G DeGroote School of Medicine, McMaster Unniversity, Hamilton, Ontario, L8L 2X2 Canada
    Thromb Haemost 99:830-9. 2008
    ....
  34. doi request reprint Fondaparinux: does it cause HIT? Can it treat HIT?
    Theodore E Warkentin
    Michael G DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
    Expert Rev Hematol 3:567-81. 2010
    ..An emerging issue: will clinicians accept this favorable experience of fondaparinux for treating HIT when a lack of randomized trials will hinder regulatory approval for this indication?..
  35. doi request reprint Agents for the treatment of heparin-induced thrombocytopenia
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, Michael G DeGroote School of Medicine, McMaster University, Hamilton, ON, Canada
    Hematol Oncol Clin North Am 24:755-75, ix. 2010
    ....
  36. ncbi request reprint Platelet count monitoring and laboratory testing for heparin-induced thrombocytopenia
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine and the Department of Medicine, McMaster University, Hamilton, Ontario, Canada
    Arch Pathol Lab Med 126:1415-23. 2002
    ..The objective of this article is to provide practical recommendations for platelet count monitoring in patients receiving heparin, as well as for selection of laboratory assays to detect pathogenic HIT antibodies...
  37. doi request reprint Anti-PF4/heparin antibody formation postorthopedic surgery thromboprophylaxis: the role of non-drug risk factors and evidence for a stoichiometry-based model of immunization
    T E Warkentin
    Department of Pathology and Molecular Medicine, Michael G DeGroote School of Medicine, McMaster University, Hamilton, ON, Canada
    J Thromb Haemost 8:504-12. 2010
    ..Heparin-induced thrombocytopenia is an antibody-mediated disorder exhibiting variable frequency in different clinical settings. Antibodies recognize PF4/heparin complexes formed at optimal stoichiometric molar ratios...
  38. ncbi request reprint Heparin-induced thrombocytopenia: pathogenesis and management
    Theodore E Warkentin
    Hamilton Regional Laboratory Medicine Program, Hamilton Health Sciences, Hamilton, Ontario, Canada
    Br J Haematol 121:535-55. 2003
  39. doi request reprint A spontaneous prothrombotic disorder resembling heparin-induced thrombocytopenia
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
    Am J Med 121:632-6. 2008
    ..We describe a novel syndrome, spontaneous heparin-induced thrombocytopenia, in which clinical and serologic features characteristic of this adverse drug reaction develop in patients despite the absence of preceding heparin therapy...
  40. doi request reprint Studies of the immune response in heparin-induced thrombocytopenia
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, Michael G DeGroote School of Medicine, McMaster University, Hamilton, ON, Canada
    Blood 113:4963-9. 2009
    ..Compared with seropositive non-HIT controls, HIT patients develop significantly higher anti-PF4/heparin IgG levels that are detectable before the onset of thrombocytopenia...
  41. ncbi request reprint Heparin-induced anaphylactic and anaphylactoid reactions: two distinct but overlapping syndromes
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, McMaster University, Hamilton Health Sciences, General Site, Hamilton, Ontario, Canada
    Expert Opin Drug Saf 8:129-44. 2009
    ..However, heparin-induced anaphylactoid reactions also have been reported to be a consequence of immune-mediated heparin-induced thrombocytopenia (HIT)...
  42. doi request reprint Heparin-induced thrombocytopenia in patients with ventricular assist devices: are new prevention strategies required?
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
    Ann Thorac Surg 87:1633-40. 2009
    ..Given the apparent high risk of HIT and its complications, and the diagnostic challenges, we suggest that the VAD patient population be evaluated using alternative, nonheparin agents for routine postimplantation anticoagulation...
  43. ncbi request reprint Impact of the patient population on the risk for heparin-induced thrombocytopenia
    T E Warkentin
    Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
    Blood 96:1703-8. 2000
    ..HIT-IgG antibodies are more likely to form in patients who undergo cardiac surgery than in orthopedic patients, but among patients in whom antibodies do form, orthopedic patients are more likely to develop HIT. (Blood. 2000;96:1703-1708)..
  44. ncbi request reprint Multicentric warfarin-induced skin necrosis complicating heparin-induced thrombocytopenia
    T E Warkentin
    Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
    Am J Hematol 62:44-8. 1999
    ..Neither patient had an identifiable hypercoagulable syndrome, other than HIT. HIT may represent a risk factor for the development of multicentric warfarin-induced skin necrosis (WISN)...
  45. doi request reprint FcγRIIa proteolysis as a diagnostic biomarker for heparin-induced thrombocytopenia
    I Nazi
    Department of Medicine, Michael G DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
    J Thromb Haemost 11:1146-53. 2013
    ..HIT is characterized by platelet activation, which leads to FcγRIIa proteolysis. This raises the possibility that identification of the proteolytic fragment of FcγRIIa could serve as a surrogate marker for HIT...
  46. ncbi request reprint Delayed-onset heparin-induced thrombocytopenia and thrombosis
    T E Warkentin
    Hamilton Regional Laboratory Medicine Program, Hamilton General Hospital, Hamilton Health Sciences, 237 Barton Street East, Hamilton, Ontario L8L 2X2, Canada
    Ann Intern Med 135:502-6. 2001
    ..This syndrome could be caused by high titers of platelet-activating IgG induced by heparin...
  47. ncbi request reprint Venous thromboembolism in heparin-induced thrombocytopenia
    T E Warkentin
    Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
    Curr Opin Pulm Med 6:343-51. 2000
    ....
  48. ncbi request reprint Limitations of conventional treatment options for heparin-induced thrombocytopenia
    T E Warkentin
    Department of Pathology, McMaster University, Hamilton, Ontario, Canada
    Semin Hematol 35:17-25; discussion 35-6. 1998
    ..Moreover, clinically significant cross-reactivity during treatment with danaparoid appears to be uncommon, even in patients in whom in vitro cross-reactivity is demonstrable...
  49. doi request reprint A systematic evaluation of laboratory testing for drug-induced immune thrombocytopenia
    D M Arnold
    Department of Medicine, McMaster University, Hamilton, Ontario, Canada
    J Thromb Haemost 11:169-76. 2013
    ..Drug-induced immune thrombocytopenia (DITP) can be confirmed by the demonstration of drug-dependent platelet antibodies in vitro; however, laboratory testing is not readily accessible and test methods are not standardized...
  50. doi request reprint Fondaparinux treatment of acute heparin-induced thrombocytopenia confirmed by the serotonin-release assay: a 30-month, 16-patient case series
    T E Warkentin
    Departments of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
    J Thromb Haemost 9:2389-96. 2011
    ..Although reports of the use of fondaparinux for this indication have thus far been favorable, the diagnosis of HIT in most cases was not based on definitive laboratory confirmation of heparin-dependent, platelet-activating antibodies...
  51. ncbi request reprint Rapid anticoagulation using ancrod for heparin-induced thrombocytopenia
    C Demers
    Department of Medicine, McMaster University, Hamilton, Ontario, Canada
    Blood 78:2194-7. 1991
    ..No other side effects were noted. Our experience indicates that ancrod therapy is a reasonable approach for patients with heparin-induced thrombocytopenia who require anticoagulant therapy...
  52. ncbi request reprint Temporal aspects of heparin-induced thrombocytopenia
    T E Warkentin
    Hamilton Regional Laboratory Medicine Program, Hamilton Health Sciences Corporation, Ont, Canada
    N Engl J Med 344:1286-92. 2001
    ..CONCLUSIONS: Heparin-induced thrombocytopenia can begin rapidly in patients who have received heparin within the previous 100 days. Heparin-dependent antibodies do not invariably reappear with subsequent heparin use...
  53. ncbi request reprint Cardiobacterium hominis endocarditis associated with very severe thrombocytopenia and platelet autoantibodies
    Donald M Arnold
    Department of Hematology, McMaster University, Hamilton, Ontario, Canada
    Am J Hematol 76:373-7. 2004
    ..This report illustrates that the development of platelet autoantibodies can contribute to very severe thrombocytopenia in occasional patients with infective endocarditis...
  54. ncbi request reprint Central venous catheters and upper-extremity deep-vein thrombosis complicating immune heparin-induced thrombocytopenia
    Aaron P Hong
    Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
    Blood 101:3049-51. 2003
    ..0; P =.011). We conclude that a localizing vascular injury (CVC use) and a systemic hypercoagulability disorder (HIT) interact to explain upper-extremity DVT complicating HIT...
  55. ncbi request reprint Off-pump coronary artery bypass grafting for acute heparin-induced thrombocytopenia
    T E Warkentin
    Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
    Ann Thorac Surg 72:1730-2. 2001
    ....
  56. ncbi request reprint Venous limb gangrene during warfarin treatment of cancer-associated deep venous thrombosis
    T E Warkentin
    McMaster University and Hamilton Health Sciences, Hamilton, Ontario, Canada
    Ann Intern Med 135:589-93. 2001
    ..CONCLUSION: Warfarin may contribute to the pathogenesis of cancer-associated venous limb gangrene by leading to severe depletion of protein C while at the same time failing to reduce thrombin generation...
  57. pmc Multimerin is found in the alpha-granules of resting platelets and is synthesized by a megakaryocytic cell line
    C P Hayward
    Department of Medicine, McMaster University Medical Centre, Hamilton, Canada
    J Clin Invest 91:2630-9. 1993
    ..Biosynthesis of multimerin by a megakaryocytic cell line supports endogenous biosynthesis by megakaryocytes as the origin of this platelet alpha-granule protein...
  58. ncbi request reprint Decreased von Willebrand factor protease activity associated with thrombocytopenic disorders
    J C Moore
    Department of Medicine, Faculty of Health Science, McMaster University, Hamilton, ON, Canada
    Blood 98:1842-6. 2001
    ..This study indicates that abnormalities of vWF protease activity are not restricted to patients with the diagnosis of TTP...
  59. ncbi request reprint Evaluation of pretest clinical score (4 T's) for the diagnosis of heparin-induced thrombocytopenia in two clinical settings
    G K Lo
    Department of Medicine, McMaster University, Hamilton, ON, Canada
    J Thromb Haemost 4:759-65. 2006
    ..As thrombocytopenia is common in hospitalized patients receiving heparin, it would be useful to have a clinical scoring system that could differentiate patients with HIT from those with other reasons for thrombocytopenia...
  60. ncbi request reprint The IgG subclasses of platelet-associated autoantibodies directed against platelet glycoproteins IIb/IIIa in patients with idiopathic thrombocytopenic purpura
    Howard Chan
    Department of Medicine, McMaster University, Hamilton, Ontario, Canada
    Br J Haematol 122:818-24. 2003
    ..Our results are consistent with the hypothesis that ITP is a heterogeneous disorder and that some patients have evidence of oligoclonality, whereas other patients have polyclonal autoantibodies...
  61. doi request reprint HIT paradigms and paradoxes
    T E Warkentin
    Department of Pathology and Molecular Medicine, Michael G DeGroote School of Medicine, McMaster University, Hamilton, ON, Canada
    J Thromb Haemost 9:105-17. 2011
    ....
  62. ncbi request reprint Current agents for the treatment of patients with heparin-induced thrombocytopenia
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
    Curr Opin Pulm Med 8:405-12. 2002
    ....
  63. ncbi request reprint Heparin-induced thrombocytopenia and the anesthesiologist
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, Department of Medicine, McMaster University, Hamilton Regional Laboratory Medicine Program, Hamilton Health Sciences, Hamilton, Ontario, Canada
    Can J Anaesth 49:S36-49. 2002
    ....
  64. doi request reprint Heparin-induced thrombocytopenia: a historical perspective
    John G Kelton
    Michael G DeGroote School of Medicine, McMaster University, Hamilton, ON, Canada
    Blood 112:2607-16. 2008
  65. ncbi request reprint What is the potential for overdiagnosis of heparin-induced thrombocytopenia?
    Gregory K Lo
    Department of Medicine, Michael G DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
    Am J Hematol 82:1037-43. 2007
    ..20 OD units). We conclude there is the potential to overdiagnose HIT by approximately 100% if any positive EIA is considered to "confirm" the diagnosis of HIT irrespective of the clinical scenario...
  66. doi request reprint Combination immunosuppressant therapy for patients with chronic refractory immune thrombocytopenic purpura
    Donald M Arnold
    Department of Medicine, Michael G DeGroote School of Medicine, McMaster University, Hamilton, ON, Canada
    Blood 115:29-31. 2010
    ..Severe adverse events did not occur. Combination immunosuppressant therapy can produce a rise in the platelet count that is sometimes sustained in refractory ITP patients...
  67. ncbi request reprint Drug-induced immune-mediated thrombocytopenia--from purpura to thrombosis
    Theodore E Warkentin
    Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada
    N Engl J Med 356:891-3. 2007
  68. ncbi request reprint Should aspirin be discontinued before coronary artery bypass surgery?
    Jack C J Sun
    Division of Cardiac Surgery, McMaster University, Hamilton, Canada
    Circulation 112:e85-90. 2005
  69. ncbi request reprint Testing for heparin-induced thrombocytopenia antibodies
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
    Transfus Med Rev 20:259-72. 2006
    ..Whether such antibodies impart "forme fruste" HIT or are simply a surrogate marker for a non-HIT adverse risk factor such as inflammation is unresolved...
  70. doi request reprint The 4Ts scoring system for heparin-induced thrombocytopenia in medical-surgical intensive care unit patients
    Mark Andrew Crowther
    Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
    J Crit Care 25:287-93. 2010
    ..The 4Ts score (Thrombocytopenia, Timing of thrombocytopenia, Thrombosis, and oTher reason) might identify individual patients at risk of having this disorder...
  71. ncbi request reprint Warfarin cessation before cardiopulmonary bypass: lessons learned from a randomized controlled trial of oral vitamin K
    Richard P Whitlock
    Division of Cardiac Surgery, HHSC, McMaster University, Hamilton, Ontario, Canada
    Ann Thorac Surg 84:103-8. 2007
    ..Administration of preoperative oral vitamin K was investigated in a randomized, placebo-controlled trial. A post hoc analysis examined residual anti-Xa activity of enoxaparin bridging...
  72. ncbi request reprint Prothrombotic genetic risk factors and heparin-induced thrombocytopenia
    Theodore E Warkentin
    Department of Pathology and Molecualr Medicine, McMaster University, Hamilton, Ontario, Canada
    Pharmacogenetics 13:245-6. 2003
  73. ncbi request reprint Heparin-induced thrombocytopenia
    Theodore E Warkentin
    Hamilton General Hospital, 237 Barton St East, Hamilton, Ontario L8L 2X2, Canada
    Curr Hematol Rep 1:63-72. 2002
    ..Recent reports suggest that HIT could explain approximately 5% of cases of acute adrenal failure caused by bilateral adrenal hemorrhagic infarction...
  74. ncbi request reprint Reversing anticoagulants both old and new
    Theodore E Warkentin
    Department of Pathology and Molecular Medicine, McMaster University, Hamilton Regional Laboratory Medicine Program, Hamilton Health Sciences, Hamilton, Ontario, Canada
    Can J Anaesth 49:S11-25. 2002
    ..Reversal of pharmacologic anticoagulation is an issue that arises when an anticoagulated patient has major bleeding or when a patient on chronic anticoagulant therapy requires urgent reversal of anticoagulation, for example, for surgery...
  75. ncbi request reprint A prospective study measuring the development of antibodies against platelet factor 4-heparin in healthy males after exposure to heparins
    J G Kelton
    Michael G DeGroote School of Medicine, Departments of Medicine, Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada Division of Hematology, Duke University Medical Center, Durham, NC, USA Momenta Pharmaceutics, Cambridge, MA, USA
    J Thromb Haemost 10:1446-9. 2012
    ..A prospective study measuring the development of antibodies against platelet factor 4-heparin in healthy males after exposure to heparins. J Thromb Haemost 2012; 10: 1446-9...
  76. doi request reprint Managing bleeding in anticoagulated patients with a focus on novel therapeutic agents
    M A Crowther
    Division of Hematology, Department of Medicine, McMaster University, Hamilton, ON, Canada
    J Thromb Haemost 7:107-10. 2009
    ..However, these new agents have one general limitation--a lack of a widely available antidote. We focus on the management of bleeding in anticoagulated patients, with particular regard to novel anticoagulants...
  77. doi request reprint The approach to heparin-induced thrombocytopenia
    Lori Ann Linkins
    Department of Medicine, McMaster University, Hamilton, Ontario, Canada
    Semin Respir Crit Care Med 29:66-74. 2008
    ....
  78. ncbi request reprint Thrombocytopenia in medical-surgical critically ill patients: prevalence, incidence, and risk factors
    Mark A Crowther
    Department of Medicine and Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada L8N 3Z5
    J Crit Care 20:348-53. 2005
    ....
  79. ncbi request reprint Gova/b alloantigen system on human platelets
    J G Kelton
    Department of Medicine, McMaster Medical Centre, Hamilton, Ontario, Canada
    Blood 75:2172-6. 1990
    ..The phenotypic frequencies were Gova/Gova, 26%; Gova/Govb, 55%; Govb/Govb, 19%; giving gene frequencies of 0.532 and 0.468 for Gova and Govb, respectively (n = 33)...
  80. ncbi request reprint Analysis of a nonsusceptible fraction with current status data
    Richard J Cook
    Department of Statistics and Actuarial Science, University of Waterloo, Waterloo, ON, Canada
    Stat Med 27:2715-30. 2008
    ..The methods are applied to motivating studies examining an immunological response to low molecular weight heparin in patients undergoing orthopedic surgery...
  81. ncbi request reprint Case report: management of immediate post-cardiopulmonary bypass massive intra-cardiac thrombosis
    Victor M Neira
    Department of Anesthesia HSC 2U1, McMaster University, 1200 Main Street West, Hamilton, Ontario L8N 3Z5, Canada
    Can J Anaesth 54:461-6. 2007
    ..To describe the management of severe acute intracardiac thrombosis in a patient who underwent redo multiple valve replacement and valvular repair. The diagnostic features, associated risk factors, and anesthetic management are reviewed...
  82. ncbi request reprint Hypotensive transfusion reactions can occur with blood products that are leukoreduced before storage
    Donald M Arnold
    Canadian Blood Services, Ontario, Canada
    Transfusion 44:1361-6. 2004
    ..Leukoreduction before storage, rather than bedside white blood cell filtration, is recommended to prevent hypotensive transfusion reactions...
  83. doi request reprint Transfusion premedication to prevent acute transfusion reactions: a retrospective observational study to assess current practices
    Jessica L Fry
    Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada
    Transfusion 50:1722-30. 2010
    ....
  84. doi request reprint Posttransfusion platelet count increments after ABO-compatible versus ABO-incompatible platelet transfusions in noncancer patients: an observational study
    Katerina Pavenski
    Department of Medicine, McMaster University, and Canadian Blood Services, Hamilton, Ontario, Canada
    Transfusion 50:1552-60. 2010
    ..However, most studies to date have been small and involved hematology/oncology patients...
  85. ncbi request reprint Gastrointestinal angiodysplasia and aortic stenosis
    Theodore E Warkentin
    N Engl J Med 347:858-9. 2002
  86. ncbi request reprint Venous limb gangrene during overlapping therapy with warfarin and a direct thrombin inhibitor for immune heparin-induced thrombocytopenia
    Maureen A Smythe
    Department of Pharmaceutical Services, William Beaumont Hospital, Royal Oak, Michigan 48073 6769, USA
    Am J Hematol 71:50-2. 2002
    ..These data suggest that warfarin anticoagulation be postponed in patients with acute heparin-induced thrombocytopenia until substantial recovery of the platelet count has occurred...
  87. ncbi request reprint Anticoagulation for cardiopulmonary bypass: is a replacement for heparin on the horizon?
    Theodore E Warkentin
    J Thorac Cardiovasc Surg 131:515-6. 2006
  88. ncbi request reprint Results of a systematic evaluation of treatment outcomes for heparin-induced thrombocytopenia in patients receiving danaparoid, ancrod, and/or coumarin explain the rapid shift in clinical practice during the 1990s
    Norbert Lubenow
    Department of Immunology and Transfusion Medicine, Ernst Moritz Arndt University Greifswald, Greifswald, Germany
    Thromb Res 117:507-15. 2006
    ..During the 1990s, danaparoid+/-coumarin began to replace ancrod (+/-coumarin), or coumarin alone, for treating HIT, despite danaparoid not being approved for treatment of HIT...
  89. ncbi request reprint Heparin-induced thrombocytopenia
    Theodore E Warkentin
    Dis Mon 51:141-9. 2005
  90. ncbi request reprint Heparin-induced thrombocytopenia in intensive care patients
    Kathleen Selleng
    Department of Immunology and Transfusion Medicine, Ernst Moritz Arndt Universitat, Greifswald, Germany
    Crit Care Med 35:1165-76. 2007
    ....
  91. ncbi request reprint Recognition, treatment, and prevention of heparin-induced thrombocytopenia: review and update
    Andreas Greinacher
    Ernst Moritz Arndt Univerität Greifswald, Institut für Immunologie und Transfusionsmedizin, Germany
    Thromb Res 118:165-76. 2006
    ....
  92. ncbi request reprint Clinical features of heparin-induced thrombocytopenia including risk factors for thrombosis. A retrospective analysis of 408 patients
    Andreas Greinacher
    Institute for Immunology and Transfusion Medicine, Ernst Moritz Arndt University Greifswald, Sauerbruchstr Diagnostikzentrum, 17487 Greifswald, Germany
    Thromb Haemost 94:132-5. 2005
    ..HIT-associated thrombosis occurs in a considerable proportion of patients before platelet counts decrease by more than 50%...
  93. ncbi request reprint Thrombosis of the cerebral veins and sinuses
    Theodore E Warkentin
    N Engl J Med 353:314-5. 2005
  94. ncbi request reprint Immune heparin-induced thrombocytopenia can occur in patients receiving clopidogrel and aspirin
    Kathleen Selleng
    Institute of Immunology and Transfusion Medicine, Ernst Moritz Arndt University, Greifswald, Germany
    Am J Hematol 78:188-92. 2005
    ..We conclude that combined therapy with aspirin and clopidogrel does not necessarily protect against clinical HIT, at least in patients with HIT antibodies that have strong platelet-activating characteristics...
  95. ncbi request reprint Heparin-induced thrombocytopenia associated with fondaparinux
    Theodore E Warkentin
    N Engl J Med 356:2653-5; discussion 2653-5. 2007
  96. ncbi request reprint Minimizing costs for treating deep vein thrombosis: the role for fondaparinux
    Andrew F Shorr
    Pulmonary and Critical Care Medicine, Washington Hospital Center, 110 Irving St, NW, Washington, DC 20010, USA
    J Thromb Thrombolysis 23:229-36. 2007
    ....
  97. ncbi request reprint So, does low-molecular-weight heparin cause less heparin-induced thrombocytopenia than unfractionated heparin or not?
    Theodore E Warkentin
    Chest 132:1108-10. 2007
  98. ncbi request reprint Laboratory testing for heparin-induced thrombocytopenia is inconsistent in North America: a survey of North American specialized coagulation laboratories
    Elizabeth A Price
    Department of Medicine, Stanford University, Stanford, California, USA
    Thromb Haemost 98:1357-61. 2007
    ..The variability in HIT platelet activation assay methods among institutions indicates a need for proficiency testing to assess assay performance, and for consensus guidelines on HIT laboratory testing...
  99. doi request reprint Fondaparinux versus direct thrombin inhibitor therapy for the management of heparin-induced thrombocytopenia (HIT)--bridging the River Coumarin
    Theodore E Warkentin
    Thromb Haemost 99:2-3. 2008
  100. doi request reprint The direct thrombin inhibitor hirudin
    Andreas Greinacher
    Institute for Immunology and Transfusion Medicine, Ernst Moritz Arndt University Greifswald, Sauerbruchstrasse, 17489 Greifswald, Germany
    Thromb Haemost 99:819-29. 2008
    ..Drawbacks of hirudin and important precautions for avoiding potential adverse effects are discussed in detail in the third part of this review...
  101. ncbi request reprint Heparin-induced thrombocytopenia in the critical care setting: diagnosis and management
    Lena M Napolitano
    Acute Care Surgery, Trauma, Burn, Critical Care, Emergency Surgery, Department of Surgery, University of Michigan Health System, Ann Arbor, MI, USA
    Crit Care Med 34:2898-911. 2006
    ..Although sepsis and hemodilution are more common etiologies of thrombocytopenia in critical illness, heparin-induced thrombocytopenia (HIT) is one potential etiology that warrants consideration...