Antithrombin III Function Test

Test Description

Antithrombin III is a small glycoprotein anticoagulant that inactivates several enzymes of the coagulation system and accounts for most of the antithrombin activity in plasma and also inhibits other proteolytic enzymes. It circulates in the plasma and inactivates thrombin[1]. Antithrombin III (ATIII) is a protein that helps control blood clotting. A blood test can determine the amount of AT III present in your body[4]. The antithrombin activity test measures how well the protein inhibits thrombin. The antithrombin antigen test measures how much antithrombin protein your body has made, regardless of how well it functions[5].

Indications of Antithrombin III test

Antithrombin III is used to help find out what may be causing abnormal blood clots in your body. A lack of antithrombin (AT) can make it more likely for you to form blood clots. You may need one or both of these tests if you have had a problem with blood clots. Your healthcare provider might especially recommend an antithrombin test if you have had a venous thromboembolism before you are 50 years old[5].

Patient preparation/Instructions

Certain medicines may affect the results of the test. Inform your healthcare provider about any medications you are taking. No other special preparation is needed for the test[4].

Typical reference values

The normal range for antithrombin III activity is 80-120% [4].

Turn around Time

The turnaround time for the antithrombin III test is typically 1-2 days[4].

Order Antithrombin III test

To order the antithrombin III test, click the “Order Test” button and add it to the cart.

External resources

[1] Antithrombin III – an overview | ScienceDirect Topics https://www.sciencedirect.com/topics/medicine-and-dentistry/antithrombin-iii

[2] Biochemistry, Antithrombin III https://www.ncbi.nlm.nih.gov/books/NBK545295/

[3] Antithrombin III Deficiency: Practice Essentials, Pathophysiology, Epidemiology https://emedicine.medscape.com/article/954688-overview

[4] Antithrombin III https://www.ucsfhealth.org/medical-tests/antithrombin-iii-blood-test

[5] Antithrombin (Activity and Antigen) – Health Encyclopedia – University of Rochester Medical Center https://www.urmc.rochester.edu/encyclopedia/content.aspx?contentid=antithrombin_activity_antigen&contenttypeid=167

By Perplexity at https://www.perplexity.ai/search/0b1b1a3f-3483-4ca4-8bca-9bab326e26ba?s=m