Use

Diagnosis of Heparin‑Induced Thrombocytopenia (HIT) is based on clinical criteria; serological confirmation is often necessary. The ELISA measures IgG antibodies against the platelet factor 4/heparin complex, and a reflex to a Serotonin Release Assay (SRA) is performed, which is more predictive of thrombocytopenia and thrombosis when the initial immunoassay is weakly positive or positive. Patients should not be on ticagrelor as it may result in a false‑negative SRA.