McMaster University

McMaster University

Theodore (Ted) Earl Warkentin

,
MD, BSc(Med), FRCPC, FACP, FRCP (Edin)

Professor, Pathology and Molecular Medicine

Division: Hematology (Transfusion Medicine)

Associate Member, Medicine

Hamilton General Hospital, 1-270B
Hamilton, Ontario
905-527-0271 ext. 46140/46139
twarken@mcmaster.ca

Assistant: Maria Adamek

Theodore E. Warkentin

Faculty Biography

Education and Professional Standing

  • FRCP (Edin) 2013
  • FACP (American College of Physicians), 1992
  • FRCPC Hematology, 1988
  • FRCPC Internal Medicine, 1987
  • MD, University of Manitoba 1983

Interests

Research Focus

To characterize the pathophysiology, frequency, clinical presentation, diagnostic testing, and treatment of heparin-induced thrombocytopenia.

To characterize the pathophysiology, frequency, clinical presentation, diagnostic testing, and treatment of ischemic limb injury in the setting of consumptive coagulopathies (disseminated intravascular disease).

Clinical Focus

Dr. Warkentin’s clinical focus includes:

  • Transfusion Medicine (Regional Director, Transfusion Medicine, Hamilton Regional Laboratory Medicine Program)
  • Inpatient-focused general hematology
    • acquired thrombocytopenia
    • acquired coagulopathy
    • prothrombotic and prohemorrhagic disorders

Academic Interests

Dr. Warkentin is responsible for haematology training of anaesthesia residents.


Team Members

Technologist

Jo-Ann Sheppard

Selected Publications

Articles

  • Warkentin TE, et al. Combination of two complementary automated rapid assays for diagnosis of heparin-induced thrombocytopenia (HIT). J Thromb Haemost 2020 Mar 13. doi: 10.1111/jth.14794. [Epub ahead of print]
  • Warkentin TE, et al. Serotonin-release assay-negative heparin-induced thrombocytopenia. Am J Hematol 2020; 95 (1): 38-47.
  • Warkentin TE. High-dose intravenous immunoglobulin for the treatment and prevention of heparin-induced thrombocytopenia: a review. Exp Rev Hematol 2019; 12 (8): 685-698.
  • Warkentin TE. Laboratory diagnosis of heparin-induced thrombocytopenia. Int J Lab Hematol 2019; 41 (Suppl. 1): 15-25.
  • Warkentin TE, et al. Timeline of heparin-induced thrombocytopenia seroconversion in serial plasma samples tested using an automated latex immunoturbidimetric assay. Int J Lab Hematol 2019; 41 (4): 493-502.
  • Warkentin TE. Microvascular thrombosis and ischaemic limb losses in critically ill patients. Hämostaseologie 2019 Feb 18; 39 (1): 6-19.
  • Warkentin TE, et al. High sensitivity and specificity of an automated IgG-specific chemiluminescence immunoassay for diagnosis of HIT. Blood 2018 Sep 20; 132 (12): 1345-1349.
  • Warkentin TE, et al. Intravenous immune globulin to prevent heparin-induced thrombocytopenia. N Engl J Med 2018; 378 (19): 1845-1848.
  • Warkentin TE. Symmetrical peripheral gangrene: mechanisms for limb loss in the ICU in patients with retained pulses. Clin Pulm Med 2018 Mar; 25 (2): 61-66.
  • Warkentin TE, et al. Platelet-activating antibodies are detectable at the earliest onset of heparin-induced thrombocytopenia, with implications for the operating characteristics of the serotonin-release assay. Chest 2018; 153 (6): 1396-1404.
  • Greinacher A, Selleng K, Warkentin TE. Autoimmune heparin-induced thrombocytopenia. J Thromb Haemost 2017; 15 (11): 2099-2114.
  • Warkentin TE, Pai M, Linkins LA. Direct oral anticoagulants for treatment of HIT: update of Hamilton experience and literature review. Blood 2017; 130 (9): 1104-1113.
  • Warkentin TE, et al. Performance characteristics of an automated latex immunoturbidimetric assay [HemosIL® HIT-Ab(PF4-H)] for the diagnosis of immune heparin-induced thrombocytopenia. Thromb Res 2017 May; 153: 108-117.
  • Warkentin TE, Anderson JAM. How I treat patients with a history of heparin-induced thrombocytopenia. Blood 2016 Jul 21; 128 (3): 348-359.
  • Warkentin TE. Ischemic limb gangrene with pulses. N Engl J Med 2015; 373 (7): 642-655. 
  • Warkentin TE, et al. Warfarin-induced venous limb ischemia/gangrene complicating cancer: a novel and clinically distinct syndrome. Blood 2015; 126 (4): 486-493.
  • Warkentin TE, et al. Spontaneous heparin-induced thrombocytopenia syndrome: 2 new cases and a proposal for defining this disorder. Blood 2014; 123 (23): 3651-3654.
  • Warkentin TE, Sheppard JI. Serological investigation of patients with a previous history of heparin-induced thrombocytopenia who are reexposed to heparin. Blood 2014; 123 (16): 2485-2493.
  • Warkentin TE. Anticoagulant failure in coagulopathic patients: PTT confounding and other pitfalls. Exp Opin Drug Saf 2014 Jan; 13 (1): 25-43.
  • Siegal DM, Cook RJ, Warkentin TE. Acute hepatic necrosis and ischemic limb necrosis. N Engl J Med 2012; 367 (9): 879-881
  • Warkentin TE. Aspirin for dual prevention of venous and arterial thrombosis. N Engl J Med 2012; 367: 2039-2041
  • Warkentin TE. HITlights: a career perspective on heparin-induced thrombocytopenia. Am J Hematol 2012; 87 (Suppl. 1): S92-S99.
  • Warkentin TE, Greinacher A, Gruel Y, et al. on behalf of the Scientific and Standardization Committee of the International Society on Thrombosis and Haemostasis. Laboratory testing for heparin-induced thrombocytopenia: a conceptual framework and implications for diagnosis. J Thromb Haemost 2011; 9: 2498-2500.
  • Warkentin TE. How I diagnose and manage heparin-induced thrombocytopenia. Hematology Am Soc Hematol Educ Program 2011; 2011: 143-149.
  • McFarlane A, Warkentin TE, Cartin W. A novel sickling hemoglobinopathy. N Engl J Med 2011; 365: 1548-1549.
  • Warkentin TE, Davidson BL, Büller HR, et al. Prevalence and risk of preexisting heparin-induced thrombocytopenia antibodies in patients with acute VTE. Chest 2011; 140: 366-373.
  • Warkentin TE, Cook RJ, Marder VJ, Greinacher A. Anti-PF4/heparin antibody formation post-orthopedic surgery thromboprophylaxis: the role of non-drug risk factors and evidence for a stoichiometry-based model of immunization. J Thromb Haemost 2010; 8: 504-512.
  • Warkentin TE, Greinacher A. Heparin-induced anaphylactic and anaphylactoid reactions: two distinct but overlapping syndromes. Expert Opin Drug Saf 2009; 8: 129-144.
  • Warkentin TE, et al. Studies of the immune response in heparin-induced thrombocytopenia. Blood 2009; 113: 4963-4969
  • Greinacher A, Warkentin TE. Contaminated heparin. N Engl J Med 2008; 359: 1291-1292.
  • Warkentin TE, Makris M, Jay RM, Kelton JG. A spontaneous prothrombotic disorder resembling heparin-induced thrombocytopenia. Am J Med 2008; 121: 632-636.
  • Warkentin TE, Greinacher A, Koster A, Lincoff AM. Treatment and prevention of heparin-induced thrombocytopenia. American College of Chest Physicians evidence-based clinical practice guidelines (8th edition). Chest 2008; 133 (6 Suppl.): 340S-380S.
  • Warkentin TE. Drug-induced immune-mediated thrombocytopenia—from purpura to thrombosis. N Engl J Med 2007;356: 891-893.
  • Warkentin TE, Moore JC, Morgan DG. Resolution of bleeding from gastrointestinal angiodysplasia and von Willebrand syndrome type 2A after aortic valve replacement. N Engl J Med 2002; 347: 858-859.
  • Warkentin TE, Kelton JG. Delayed-onset heparin-induced thrombocytopenia and thrombosis. Ann Intern Med 2001; 135: 502-506.
  • Warkentin TE. Venous limb gangrene during warfarin treatment of cancer-associated deep venous thrombosis. Ann Intern Med 2001; 135: 589-593.
  • Warkentin TE, Kelton JG. Temporal aspects of heparin-induced thrombocytopenia. N Engl J Med 2001; 344: 1286-1292.
  • Warkentin TE, Levine MN, Hirsh J, et al. Heparin-induced thrombocytopenia in patients treated with low-molecular-weight heparin or unfractionated heparin. N Engl J Med 1995; 332: 1330-1335.

Book Chapters

  • Warkentin TE. Acquired coagulation disorders. In: Warrell DA, Cox TM, Firth JD, eds. Oxford Textbook of Medicine, 6th edn. Oxford: Oxford University Press, 2020: 5546-5562.
  • Warkentin TE, Mithoowani S, Arnold DM. Acquired thrombocytopenia. In: Concise guide to hematology, 2nd edn. Schmaier AH, Lazarus HM, eds. Cham, Switzerland: Springer International, 2019: 135-148.
  • Warkentin TE. Heparin-induced thrombocytopenia. In: Kitchens CS, Kessler CM, Konkle BA, Streiff MB, Garcia DA, eds. Consultative Hemostasis and Thrombosis, 4th edn. Philadelphia: Elsevier, 2019: 491-527.
  • Warkentin TE. Thrombocytopenia caused by platelet destruction, hypersplenism, or hemodilution. In: Hoffman R, Benz EJ Jr, Silberstein LE, Heslop HE, Weitz JI, Anastasi J, Salama ME, Abutalib AS, eds. Hematology: Basic Principles and Practice, 7th edn. Philadelphia: Elsevier, 2018: 1955-1972.
  • Warkentin TE. Heparin-induced thrombocytopenia. In: Hoffman R, Benz EJ Jr, Silberstein LE, Heslop HE, Weitz JI, Anastasi J, Salama ME, Abutalib AS, eds. Hematology: Basic Principles and Practice, 7th edn. Philadelphia: Elsevier, 2018: 1973-1983.
  • Warkentin TE. Quantitative abnormalities in platelets: thrombocytopenia and thrombocytosis. In: Principles and Practice of Hospital Medicine. McKean SC, Ross JJ, Dressler DD, Scheurer DB, eds. New York: McGraw-Hill Medical, 2017: 1381-1391.
  • Warkentin TE. Diagnosis and management of heparin-induced thrombocytopenia. In: Bergan JJ, Bunke-Paquette N, eds. The Vein Book, 2nd edn. New York, NY: Oxford University Press, 2014: 332-339.
  • Warkentin TE, Marder VJ. Overview of complex thrombohemorrhagic problems. In: Marder VJ, Aird WC, Bennett JS, Schulman S, White GC, eds. Hemostasis and Thrombosis: Basic Principles and Clinical Practice, 6th edn. Philadelphia: Lippincott Williams & Wilkins, 2013: 1173-1177.
  • Warkentin TE, Greinacher A. Heparin-induced thrombocytopenia. In: Marder VJ, Aird WC, Bennett JS, Schulman S, White GC, eds. Hemostasis and Thrombosis: Basic Principles and Clinical Practice, 6th edn. Philadelphia: Lippincott Williams & Wilkins, 2013: 1292-1307.
  • Warkentin TE. Coumarin-induced skin necrosis and venous limb gangrene. In: Marder VJ, Aird WC, Bennett JS, Schulman S, White GC, eds. Hemostasis and Thrombosis: Basic Principles and Clinical Practice, 6th edn. Philadelphia: Lippincott Williams & Wilkins, 2013: 1308-1317.
  • Warkentin TE. Acquired coagulation disorders. In: Warrell DA, Cox TM, Firth JD, eds. Oxford Textbook of Medicine, 5th edn. Oxford: Oxford University Press, 2010: 4531-4546.

Books

  • Warkentin TE, Greinacher A, eds. Heparin-Induced Thrombocytopenia, 5th edn. Boca Raton, FL, CRC Press, 2013 (641 pages)
  • Warkentin TE, Greinacher A, eds. Heparin-Induced Thrombocytopenia, 4th edn. New York, Informa Healthcare USA, 2007.
Valid XHTML 1.0 Transitional Level Double-A conformance, W3C WAI Web Content Accessibility Guidelines 2.0