Reasons, Preparation & Procedure For Conducting a Activated Protein C Resistance Test

Submitted on March 27, 2012

Activated Protein C Resistance Test

The activated protein C resistance test is a test for the potency of protein C to prevent venous thrombembolisms and venous thrombosis. Protein C should not be confused with the nearly similar sounding C-reactive protein, which is part of the liver's repertoire of weaponry to fight off infections. Activated Protein C or APC resistance usually manifests itself in a condition called APC resistance, Leiden type. This is a condition that is usually genetic in nature and if caught early enough can even be corrected with the correct APC administration. APC is one of the proteins that inhibits the clotting process. When the clotting enzyme thrombin starts polymerize the clotting factor fibrin, the clotting is regulated by APC. Without the effect of APC, clots can occur randomly and cause thrombosis or blood clots. Venous thrombosis and Deep Vein Thrombosis are usually the end result. DVT is an extremely dangerous condition since a blood clot that forms can break off, flow into the heart, and finally into the lungs, where it can be fatal. When clot breaks off and travels to another part of the body, it is called a thromboembolism.

Reason Why It is Conducted

The APC test is done to ascertain the levels of APC in the human body. APC levels dictate the predisposition to venous thrombosis in the body. APC resistance or deficiency usually indicates Leiden Type APC resistance.


You should ensure that you do not take any type of medication that is an anticoagulant. This includes NSAIDS and blood thinning drugs like acetylsalicylic acid, ibuprofen, and acetaminophen. It is probably not a good idea to consume any of the following foods like turmeric, ginger, feverfew, garlic, and basil, as these herbs do have some anti-inflammatory effects and could also have blood thinning effects.


The APC is a blood test that is done with the use of snake venom or another anti-coagulant medium. The blood is then separated into two cultures where in one APC is added and the other left as it is. The blood will clot faster in the culture without APC added and the ratio of time taken to clot is the deciding factor. APC  degrades the clotting factors Factor Va and Factor VIIIa. It is believed that too much Factor VIIIa levels are responsible for the state of venous thrombosis. This condition is mostly hereditary and there would be a familial history to the occurrence of this condition, which is something to note