Heparin-Induced Thrombocytopenia with Thrombosis

Abstract

Heparin-induced thrombocytopenia type II (HIT II) is an immune-mediated adverse drug reaction to heparin and heparinoid compounds. Unlike other etiologies of thrombocytopenia, HIT II frequently manifests with arterial or venous thromboemboli, leading to significant morbidity and mortality. Diagnosis of HIT II requires a high clinical suspicion, pretest probability scoring, and laboratory confirmation through immunologic and functional assays. Moderate probability for HIT II should be met with discontinuation of the offending agent and initiation of an alternative anticoagulant. Key words: heparin-induced thrombocytopenia, heparin-induced thrombocytopenia with thrombosis, HIT II, HITT