Heparin-induced thrombocytopenia.

[heparin-induced thrombocytopenia]

Abstract A summary of heparin-induced thrombocytopenia (HIT ) is presented . HIT is an adverse drug reaction characterized by thrombocytopenia and a high risk for venous or arterial thrombosis . The frequency of HIT ranges from 1 to 5 % of patients receiving heparin with exact frequencies ranging between specific agents . Interestingly , this immune-mediated syndrome is ironically associated with thrombosis , not bleeding , with thrombin formation playing a major role . It is caused by heparin-dependent , platelet -activating antibodies that identifies a self-protein , PF 4 , bound to heparin that results in an antibody formation . The resulting platelet activation is associated with increased thrombin generation . Typically , the platelet count fall begins 5 -10 days after starting heparin , although a rapid platelet count fall can occur in a patient who has antibodies from recent heparin use . Typical causes of HIT as well as the best diagnostic studies and treatment are discussed in this review . HIT was reviewed using a pubmed ™ search ; google scholar ™ using key words : "Heparin-induced thrombocytopenia "; "heparin ", and "drug AND thrombocytopenia ."