Heparin induced thrombocytopenia. Antibody forms to heparin-PF4 complex that sits on surface of platelet. IgG antibodies. Usually about 10 days after heparin starts. Gold standard is Serotonin Release Assay but can also just detect the antibodies (IgG by far most common and significant) and then see if adding extra heparin quenches them (you should get a negative or much more decreased result after adding excess heparin)
Heparin-induced thrombocytopenia (HIT) is thrombocytopenia due to heparin. HIT predisposes to thrombosis and when thrombosis is identified the condition is called heparin-induced thrombocytopenia and thrombosis (HITT). HIT is caused by the formation of abnormal antibodies that activate platelets. The treatment of HIT requires both protection from thrombosis and an agent that will not reduce the platelet count further. Several agents exist for this purpose, mainly lepirudin and argatroban.
Argatroban is a thrombin inhibitor. It is for thrombosis in patients with heparin-induced thrombocytopenia (HIT). Because of its hepatic metabolism, it may be used in patients with renal dysfunction. (This is in contrast to lepirudin, a direct thrombin inhibitor that is primarily renally cleared). Argatroban is used as an anticoagulant in individuals with thrombosis and heparin induced thrombocytopenia. Often these individuals require long term anticoagulation.