Clinical entity | Description |
aHIT disorders (autoimmune, heparin-induced) | |
Delayed-onset HIT | HIT that begins or worsens after stopping of heparin |
Refractory (also called persisting) HIT | HIT that persists for >1 week despite stopping of heparin |
Heparin flush HIT | HIT that is induced by exposure to heparin flushes |
Fondaparinux-associated HIT | HIT that is believed to be triggered by exposure to fondaparinux |
Severe HIT with overt DIC | HIT with unusually severe thrombocytopenia (platelet count <20,000/microL) or with 1 or more of the following:
|
Non-heparin-induced anti-PF4 disorders | |
VITT | Anti-PF4 antibodies, associated with proximal exposure to an adenoviral vectored COVID-19 vaccine, that activate platelets in the absence of heparin |
Spontaneous HIT (spHIT) | Disorder that clinically and serologically mimics HIT despite absence of proximate* exposure to heparin or vaccination (eg, after knee replacement surgery) |
Spontaneous VITT (spVITT) | Disorder that clinically and serologically mimics VITT despite absence of proximate* exposure to heparin or vaccination (eg, post-adenoviral infection) |
aHIT: autoimmune HIT; COVID-19: coronavirus disease 2019; DIC: disseminated intravascular coagulation; HIT: heparin-induced thrombocytopenia; INR: international normalized ratio; PF4: platelet factor 4; RBCs: red blood cells; VITT: vaccine-induced immune thrombotic thrombocytopenia.
* Proximate refers to exposure within approximately the previous 3 months.Do you want to add Medilib to your home screen?