RT Book, Section A1 Cuker, Adam A1 Poncz, Mortimer A2 Kaushansky, Kenneth A2 Levi, Marcel SR Print(0) ID 1148371856 T1 Heparin-Induced Thrombocytopenia T2 Williams Hematology Hemostasis and Thrombosis YR 2017 FD 2017 PB McGraw-Hill Education PP New York, NY SN 9781260117080 LK hemonc.mhmedical.com/content.aspx?aid=1148371856 RD 2024/11/14 AB SUMMARYHeparin-induced thrombocytopenia (HIT) is a prothrombotic complication of treatment with heparin. It is associated with mild-to-moderate thrombocytopenia, although the main clinical concern is the high frequency of both arterial and venous thromboembolism, which may be limb- or life-threatening. HIT is an immune complex–based disorder involving platelet factor 4 complexed to negatively charged multimeric molecules, especially surface heparan side chains. It is initiated by exposure to heparin, particularly unfractionated heparin. There is growing understanding of the unusual nature of the underlying immune response in HIT, why certain individuals develop this disorder, and why HIT is prothrombotic. Diagnosis is based on an assessment of clinical probability and specialized laboratory testing. Management involves immediate cessation of heparin and initiation of inhibitors of thrombin or factor Xa.