Factor VII is a protein in the blood that plays a role in coagulation, the process by which blood clots to stop bleeding. Without sufficient Factor VII, the body’s ability to form clots effectively is compromised.
Understanding Acquired Factor VII Deficiency
Factor VII is a protein often referred to as a coagulation factor, and it is a part of the complex system that helps blood clot normally.
Acquired Factor VII deficiency means the condition develops later in life, rather than being inherited from parents. This distinguishes it from congenital Factor VII deficiency, which is a genetic disorder present from birth due to mutations in the F7 gene. Acquired Factor VII deficiency typically arises from an underlying medical condition or medication, and it is considered a rare bleeding disorder. The severity of acquired Factor VII deficiency can vary, ranging from mild to severe, depending on the degree of Factor VII insufficiency.
Identifying the Causes
Acquired Factor VII deficiency can stem from various underlying health issues or certain medications. A common cause is severe liver disease, as Factor VII is produced in the liver. Impaired liver function can directly lead to a reduction in Factor VII synthesis.
Another cause is severe vitamin K deficiency, because Factor VII is a vitamin K-dependent clotting factor. Without adequate vitamin K, the liver cannot properly produce functional Factor VII. Additionally, the use of certain anticoagulant medications, such as warfarin, can interfere with vitamin K metabolism and consequently lead to acquired Factor VII deficiency. Less common causes include autoantibodies that inhibit Factor VII, disseminated intravascular coagulation (DIC), and certain systemic diseases like sepsis or blood cell disorders.
Recognizing the Symptoms
The signs and symptoms of acquired Factor VII deficiency primarily involve bleeding manifestations, which can range from mild to severe depending on the level of Factor VII activity. Common presentations include easy bruising and prolonged bleeding from minor cuts. Individuals may experience frequent nosebleeds.
Gum bleeding is another common symptom. Women may experience heavy or prolonged menstrual bleeding. More severe bleeding can occur internally, such as gastrointestinal bleeding, which may manifest as blood in the stool, or blood in the urine. In the most severe cases, bleeding can occur into joints or even lead to intracranial hemorrhage.
Diagnosis and Treatment Approaches
Diagnosis of acquired Factor VII deficiency begins with clinical suspicion, based on a patient’s history of bleeding symptoms. Initial laboratory tests are used to assess blood clotting function. A characteristic finding in Factor VII deficiency is a prolonged Prothrombin Time (PT), while the Activated Partial Thromboplastin Time (aPTT) usually remains within the normal range.
To confirm the diagnosis, a specific Factor VII activity assay is performed, which measures the functional level of Factor VII in the blood. Further tests are often necessary to identify the underlying cause of the deficiency, such as liver function tests to assess liver health, or vitamin K levels to check for vitamin deficiency. If an inhibitor is suspected, additional screening for autoantibodies against Factor VII may be conducted.
Treatment for acquired Factor VII deficiency typically involves two main strategies: addressing the underlying cause and managing acute bleeding episodes. Treating the root cause might include therapies for liver disease, vitamin K supplementation for deficiencies, or adjusting or discontinuing medications like warfarin that interfere with Factor VII. For acute bleeding or to prevent bleeding before procedures, replacement therapies are often used.
Recombinant Factor VIIa (rFVIIa), a lab-produced version of Factor VIIa, is approved for treating bleeding episodes in individuals with Factor VII deficiency. Other options include fresh frozen plasma (FFP), which contains various clotting factors, or prothrombin complex concentrates (PCCs), which are concentrated sources of several vitamin K-dependent clotting factors, including Factor VII. The choice of treatment depends on the severity and location of the bleeding, as well as the patient’s baseline Factor VII activity level. Ongoing monitoring of Factor VII levels and clinical symptoms is important for effective long-term management.