Low Level Platelet-Activating Antibodies in Patients Suspected of Having Heparin-Induced Thrombocytopenia but Testing Negative in the ”Gold Standard” Functional Test

Abstract Background: Heparin-induced thrombocytopenia (HIT) is a common drug reaction that causes arterial or venous thrombosis as a result of heparin therapy. Platelet-activating antibodies, against complexes of platelet factor 4 (PF4) and heparin, cause intense platelet activation, ultimately leading to an increased risk of thrombosis, limb-loss and even death. Most patients exposed to heparin will produce non-pathogenic …