What is a HIT blood test?

A test for heparin-induced thrombocytopenia (HIT) antibody, also called heparin-PF4 antibody, is performed to detect antibodies that develop in some people who have been treated with heparin.

What does HIT stand for medical?

Abstract. Heparin‐induced thrombocytopenia (HIT) is a potentially devastating immune mediated adverse drug reaction caused by the emergence of antibodies that activate platelets in the presence of heparin.

What is a positive HIT antibody?

The test is considered positive if the sample causes a greater than 20% serotonin release at a (therapeutic) dosage of 0.1 U/mL heparin. The14C-SRA is considered the “gold standard” assay for the detection of heparin-dependent antibodies in heparin-induced thrombocytopenia (HIT).

How is HIT diagnosed?

HIT can often be diagnosed by measuring the platelet count and PF4 antibody level in the blood. Symptoms of new blood clot formation may suggest HIT. Symptoms of deep vein thrombosis include pain or tenderness, sudden swelling, discoloration, visibly large veins, and skin that is warm to the touch.

What causes HIT?

Heparin-induced thrombocytopenia (HIT) is caused by antibodies that bind to complexes of heparin and platelet factor 4 (PF4), activating the platelets and promoting a prothrombotic state. HIT is more frequently encountered with unfractionated heparin (UFH) than with low molecular weight heparin (LMWH).

What is HIT stand for?

Heparin-induced thrombocytopenia (HIT) is a complication of heparin therapy.

What is HIT illness?

HIT predisposes to thrombosis (the abnormal formation of blood clots inside a blood vessel) because platelets release microparticles that activate thrombin, thereby leading to thrombosis. When thrombosis is identified the condition is called heparin-induced thrombocytopenia and thrombosis (HITT).

Does HIT cause blood clots?

But with heparin-induced thrombocytopenia (HIT), your body reacts to heparin in a way that may cause clots instead of preventing them. Thrombocytopenia means you have a low level of platelets, which are blood cells that help your blood clot. Usually, low platelets would cause you to bleed.

When should you do a HIT test?

Laboratory testing is performed in patients with intermediate or high 4Ts scores due to the system’s poor positive predictive value. In patients who undergo laboratory testing, the combination of the clinical score and test results is used to determine the likelihood of HIT.

What is the treatment for HIT?

Treatment of HIT entails immediate withdrawal of all heparin, including heparin-containing flushes and catheters. Heparin cessation alone, however, is often insufficient to prevent thrombosis.

Does HIT cause bleeding?

What is the hit test for?

Specifically, the HIT assesses horizontal semicircular canal (HSCC) and superior vestibular nerve function in response to discrete, small amplitude (~10◦), high acceleration (~3000-4000 ◦s2) rotational head impulses. During the HIT, the patient is asked to fix his or her eyes on a target (e.g. the examiner’s nose).

What does hit stand for?

Heparin-Induced Thrombocytopenia (HIT) PF4 Antibody, IgG with Reflex to Serotonin Release Assay (Heparin Dependent Platelet Antibody), Unfractionated Heparin For additional information, please call ARUP Client Services at 800-522-2787 and mention keyword: HIT.

How is hit diagnosed and treated?

Diagnosis of HIT is based on clinical assessment and laboratory results. Primary laboratory tests for HIT include immunologic assays, such as an enzyme-linked immunosorbent assay (ELISA), and functional, platelet-activation assays, such as the serotonin release assay (SRA). 4, 5

What is HitHit and what causes it?

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. How Does HIT Occur?