Current management of heparin-induced thrombocytopenia.

Heparin-induced thrombocytopenia (HIT) is an immune adverse reaction to heparin (both unfractionated and low-molecular-weight), which is mediated by the formation of IgG antibodies against platelet factor 4-heparin complexes. The IgG/platelet factor 4 immunocomplexes activate platelets with resulting thrombocytopenia, which is not associated with bleeding, but with paradoxical life-threatening thrombotic complications, for coagulation activation. HIT diagnosis requires the assessment of pre-test clinical probability in combination with the measurement of platelet activating antibodies against platelet factor 4-heparin complexes with immunological and functional assays. When HIT is diagnosed, any form of heparin should be stopped and a non-heparin alternative anticoagulant should be started. Argatroban and danaparoid are currently the only drugs licensed for HIT, with different country availability. Bivalirudin is an option in cardiac surgery and procedures in HIT patients.