What is the normal range for activated protein C resistance?

What is the normal range for activated protein C resistance?

Reference Range The normal reference value for the activated protein C resistance (APCR) ratio is greater than 2.1.

What does activated protein C resistance mean?

Resistance to activated protein C (APC resistance) is a term used to describe abnormal resistance of human plasma to the anticoagulant effects of human APC. APC resistance is characterized by a reduced anticoagulant response of patient plasma after adding a standard amount of APC.

Is activated protein C resistance the same as factor V Leiden?

Activated protein C resistance results in hypercoagulability and an increased risk of deep vein thrombosis. While resistance to APC is most commonly caused by the presence of factor V Leiden, the results of the clotting test for resistance to APC can be positive without factor V Leiden.

What is normal protein C activity?

The normal range of protein C activity in healthy adults is between 65 to 135 IU dL-1. Patients with mild protein C deficiency have activity levels between 20 IU dL-1 and the lower limit of normal values, as determined by age.

What is the most common cause of activated protein C resistance?

Activated protein C resistance (APCR) caused by a factor V gene mutation, FV Arg506Gln or FV Leiden, has been identified as the most common inherited risk factor for venous thrombosis.

What does low antithrombin III mean?

The abnormal gene leads to a low level of the antithrombin III protein. This low level of antithrombin III can cause abnormal blood clots (thrombi) that can block blood flow and damage organs. People with this condition will often have a blood clot at a young age.

Is Factor V Leiden an autoimmune disease?

Examples include abnormalities in Protein C, Protein S, Antithrombin, and Prothrombin 20210. Another disorder which leads to increased clotting is the Anti-Phospholipid Syndrome. This is an autoimmune disorder in which one’s own immune system attacks normal anti-clotting mechanisms.

How is activated protein C resistance treated?

APC-resistant persons with an initial DVT are treated with a standard regimen (for example, intravenous heparin therapy followed by oral anticoagulation with an international normalized ratio therapeutic range of 2.0 to 3.0 for 3 to 6 months).

How is activated protein C resistance diagnosed?

The activated protein C resistance phenotype is typically diagnosed with an activated partial thromboplastin time-based assay, which detects factor V:Q506-dependent as well as acquired activated protein C resistance. However, the sensitivity and specificity for the factor V mutation are usually below 90%.

What does high protein C antigen mean?

Elevated levels of protein C and/or protein S are not clinically significant and usually are not associated with medical problems. If the activity and concentrations of protein C and protein S antigens are normal, this usually indicates clotting regulation is adequate.

Are protein C and S anticoagulants?

Proteins C and S are two vitamin K-dependent plasma proteins that work in concert as a natural anticoagulant system.

What is a good antithrombin level?

Different labs use slightly different normal ranges. But in general, 80% to 120% is considered normal for adults. The normal range for newborns is usually about 44% to 76%.

What is the prevalence of activated protein C resistance?

Activated protein C resistance has a reported prevalence of 10–15% and is a common cause of thrombophilia. The majority of activated protein C resistance is directly attributable to heritable mutations in coagulation factor V (FV), primarily the FV Leiden (FVL) R506Q mutation,…

What should the APC resistance ratio be in blood?

An activated protein C (APC) resistance ratio of less than 2.3 suggests abnormal resistance to APC of hereditary origin. If the APC resistance test is abnormal, DNA-based testing for the factor V Leiden mutation (F5DNA / Factor V Leiden [R506Q] Mutation, Blood) may be helpful in confirming or excluding hereditary APC resistance.

Is the apcrv assay sensitive for APC resistance?

This assay is highly sensitive and specific for inherited activated protein C (APC) resistance, most commonly due to the factor V Leiden mutation, but it will not detect patients with acquired APC resistance. Persons with acquired APC resistance are at similar risk for venous thromboembolism.

Which is activated protein C inactivates Factor V?

Activated protein C (APC) is the enzymatically active form of protein C after proteolytic cleavage by thrombomodulin-bound thrombin. An important natural anticoagulant, APC inactivates factors Va and VIIa. APC resistance (APCR) is a hypercoagulability disorder in which factor V cannot be inactivated by APC.