Activated protein C resistance


Activated protein C resistance is a hypercoagulability characterized by a lack of a response to activated protein C, which normally helps prevent blood from clotting excessively. This results in an increased risk of venous thrombosis, which resulting in medical conditions such as deep vein thrombosis and pulmonary embolism.

Presentation

Associated conditions

An estimated 64 percent of patients with venous thromboembolism may have activated protein C resistance.

Genetics

The disorder can be acquired or inherited, the hereditary form having an autosomal dominant inheritance pattern.

Pathophysiology

Activated protein C degrades Factor Va and Factor VIIIa. Activated protein C resistance is the inability of protein C to cleave Factor Va and/or Factor VIIIa, which allows for longer duration of thrombin generation and may lead to a hypercoagulable state. This may be hereditary or acquired. The best known and most common hereditary form is Factor V Leiden. Acquired forms occur in the presence of elevated Factor VIII concentrations.

Diagnosis

"APC ratio: To diagnose functional assays | PCR/ Restriction enzyme analysis: To detect the specific genetic anomaly responsible for FVL

Treatment