Activated Protein C Resistance (APCR) is a hereditary blood disorder characterized by a reduced ability of activated protein C, a key component in the regulation of blood clotting, to effectively break down and prevent the formation of blood clots. APCR is primarily caused by a genetic mutation in the factor V gene, known as factor V Leiden mutation, which leads to the production of an abnormal form of factor V protein.
Under normal circumstances, activated protein C plays a crucial role in controlling the coagulation process by inhibiting the activity of factor Va and factor VIIIa, both of which are essential in the formation and stabilization of blood clots. However, in individuals with APCR, the mutated factor V protein is resistant to degradation by activated protein C, resulting in exaggerated thrombin generation and an increased risk of abnormal clot formation.
The clinical manifestations of APCR vary widely, ranging from mild to severe. Some individuals may remain asymptomatic, while others may experience recurrent blood clots in veins, a condition known as venous thromboembolism (VTE). VTE can manifest as deep vein thrombosis (DVT) or pulmonary embolism (PE) and can potentially lead to serious complications, including organ damage or death.
Diagnosis of APCR is typically performed through specialized laboratory tests, such as the polymerase chain reaction (PCR) or functional coagulation assays, which determine the ability of activated protein C to inhibit clotting. Treatment options for APCR usually involve lifelong administration of anticoagulant medications, such as heparin or warfarin, to prevent the formation of blood clots. Additionally, individuals with APCR are advised to adopt lifestyle modifications, including regular exercise, healthy diet, and avoidance of risk factors for blood clot formation,
