Pathophysiology, epidemiology, diagnosis and treatment of heparin-induced thrombocytopenia (HIT).
Due to the widespread use of unfractionated (UFH) and low molecular weight heparins (LWH) for prophylaxis and treatment of thrombosis, heparin-induced thrombocytopenia is considered to be the most frequent (and potentially the most devastating) drug-induced thrombocytopenia. Induced by an immune response, excessive activation of platelets and endothelium cells causes massive thrombin generation and, as a result, life-threatening venous and arterial thrombotic vessel occlusion. The rate of mortality and amputation in HIT II is estimated to be 30% and 20%, respectively. The clinical course of HIT II depends highly on early therapeutic intervention consisting of immediate interruption of heparin application and, most important, of compatible thrombin inhibition. All measures implying a potentially procoagulant risk such as begin of oral anticoagulation or platelet substitution may result in disastrous side effects.
Picker
Susanne M
SM
Transfusion Medicine, University of Cologne, Germany. susanne.picker@medizin.uni-koeln.de
Gathof
Birgit S
BS
D000925:Anticoagulants / Q000008:administration & dosage / Q000009:adverse effects*; D001780:Blood Coagulation Tests; D006495:Heparin, Low-Molecular-Weight / Q000009:adverse effects* / Q000627:therapeutic use*; D006629:Hirudins / Q000031:analogs & derivatives; D006801:Humans; D008954:Models, Biological; D010976:Platelet Count; D011994:Recombinant Proteins / Q000627:therapeutic use*; D013921:Thrombocytopenia / Q000097:blood / Q000139:chemically induced / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy; D013923:Thromboembolism / Q000097:blood / Q000188:drug therapy*
D000925:Anticoagulants; D006495:Heparin, Low-Molecular-Weight; D006629:Hirudins; D011994:Recombinant Proteins; C083544:lepirudin