In patients with acute HIT complicated by thrombosis (HITT) or acute HIT without thrombosis (isolated HIT), the ASH guideline panel recommends discontinuation of heparin and initiation of a non-heparin

Heparin-induced thrombocytopenia (HIT) is a complication of heparin therapy. HIT is characterized by a 30–50% decrease in platelet count and an increased thrombotic risk due to platelet activation. Without treatment, up to 50% of patients can experience thrombotic events.

Aug 14, 2017 · The widely used laboratory assessment for HIT antibodies is an enzyme-linked immunosorbent assay (ELISA) that detects antibodies against H-PF4. These assays are highly sensitive; however, they have only moderate specificity.

May 16, 2023 · A donor platelet that becomes activated in the presence of heparin and a sample of the patient's blood (containing IgG) will release serotonin. A positive SRA confirms the diagnosis of HIT, and negative SRA rules out HIT, even in the setting of a positive ELISA.

Nov 13, 2019 · Heparin-induced thrombocytopenia (HIT) is an adverse complication of unfractionated and low molecular weight heparin caused by antibodies recognizing platelet factor 4-heparin (PF4/hep) complexes leading to platelet activation.

In patients with an intermediate or high pretest probability of HIT, an enzyme-linked immunosorbent assay (ELISA) to detect heparin-platelet factor 4 (PF4) immunoglobulin G (IgG) antibodies is the first diagnostic step.

An algorithm combining the 4T score and the PF4-Heparin ELISA Assay has been shown to have a high diagnostic accuracy and potentially could eliminate the need for SRA testing in at least 90% patients with suspected HIT - see 4T HIT Score.

This ELISA assay detects the presence of IgG antibodies to heparin-platelet factor 4 (PF4) complexes. Most cases of heparin-induced thrombocytopenia (HIT) are caused by IgG antibodies to heparin-PF4, rather than IgA or IgM antibodies. Negative results have a good negative predictive value for HIT, although rare false-negative results may occur.

Heparin-induced thrombocytopenia (HIT) is typically caused by heparin-dependent, platelet-activating antibodies of IgG class. The target antigen is comprised of a complex of platelet factor 4 (PF4) bound to heparin 1–5.

Enzyme-linked immunosorbent assays (ELISA) are available to detect HIT type 2 (HIT-II) antibodies and are based on the detection of human IgG antibodies that react with solid phase antigen complexes of heparinoid and human PF4 (H/PF4) complexes.