Activated partial thromboplastin time (APTT)


Reference values of activated partial thromboplastin time (APTT)

Activated partial thromboplastin time (APTT) is one of the most valuable common tests to obtain an idea of the blood coagulation system. APTTV is a test that detects exclusively plasma defects of the internal X-factor activation system in phase I (formation of prothrombinase) of blood coagulation.

Determination of activated partial thromboplastin time - modification of the test for determining the recalcification time of stabilized blood (plasma). It has a higher sensitivity to deficiency of plasma clotting factors (except VII and XIII), however, when using this test, it is not possible to reveal the insufficiency of coagulation activity of platelets.

The elongation of activated partial thromboplastin time (APTT) reflects a deficiency of plasma factors (except VII and XIII) and is observed with their significant (below 25-10%) decrease. Elongation of activated partial thromboplastin time (APTT) indicates a predominance of hypocoagulation.

Reference values: 38-55 s. However, it should be noted that reference values in different laboratories may vary depending on the sensitivity and composition of the diagnostic kits.

It is important to know!

The system of hemostasis is a set of functional-morphological and biochemical mechanisms ensuring the preservation of the liquid state of the blood, preventing and stopping bleeding, and the integrity of the blood vessels. Read more..

Last reviewed by: Aleksey Portnov , medical expert, on 31.05.2018
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