TY - CHAP M1 - Book, Section TI - Heparin-Induced Thrombocytopenia A1 - Gollomp, Kandace A1 - Rauova, Lubica A1 - Poncz, Mortimer A2 - Kaushansky, Kenneth A2 - Prchal, Josef T. A2 - Burns, Linda J. A2 - Lichtman, Marshall A. A2 - Levi, Marcel A2 - Linch, David C. Y1 - 2021 N1 - T2 - Williams Hematology, 10e AB - SUMMARYHeparin-induced thrombocytopenia (HIT) is a complication of treatment with heparin associated with mild-to-moderate thrombocytopenia and a severe prothrombotic state. The main clinical concern is the high frequency of both venous and arterial thromboembolism, which may be limb- or life-threatening. HIT is an immune-mediated disorder initiated by the development of antibodies directed against complexes of the positively charged chemokine, platelet factor 4 (PF4), and the negatively charged multimeric anticoagulant, heparin, particularly unfractionated heparin. HIT develops as a result of interactions between these antibodies and complexes of PF4 and cell-surface glycosaminoglycan side chains and other polyanions, resulting in platelet, leukocyte, and endothelial activation. There is a growing understanding of the unusual nature of the underlying immune response in HIT, why only certain individuals develop this disorder, and why HIT is prothrombotic. Diagnosis is based on an assessment of clinical probability and specialized laboratory testing. Management includes immediate cessation of heparin and administration of inhibitors of thrombin or factor Xa. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - hemonc.mhmedical.com/content.aspx?aid=1180468484 ER -