From the Guidelines
An elevated factor VIII level of 196% is a significant finding that may indicate an increased risk of thrombosis, and therefore, warrants further investigation and consideration of anticoagulation therapy to mitigate this risk. This elevation is notable because factor VIII is a clotting protein, and excessive amounts can promote unwanted clot formation in blood vessels. According to the most recent study 1, patients with factor VIII levels above the normal range have an increased risk of developing venous thromboembolism. The study suggests that a baseline factor VIII coagulation activity level >20 IU/dL appears to be a reasonable threshold for antithrombotic use, but it does not directly address the management of elevated factor VIII levels.
However, considering the potential thrombotic risk associated with elevated factor VIII levels, anticoagulation therapy might be considered for patients with this finding, especially if they have other risk factors for clotting. The decision to initiate anticoagulation therapy should be individualized, taking into account the patient's overall thrombotic risk and bleeding phenotype. Regular monitoring of factor VIII levels may be necessary, particularly in patients with a history of thrombosis or those requiring anticoagulation therapy.
Some key points to consider in the management of patients with elevated factor VIII levels include:
- Assessment of underlying causes of the elevation, such as inflammation, infection, pregnancy, surgery, malignancy, or liver disease
- Evaluation of overall thrombotic risk, including consideration of other risk factors for clotting
- Individualized decision-making regarding anticoagulation therapy, taking into account the patient's bleeding phenotype and thrombotic risk
- Regular monitoring of factor VIII levels and adjustment of anticoagulation therapy as needed.
From the Research
Significance of Elevated Factor VIII Levels
- Elevated factor VIII levels are associated with an increased risk of thrombosis, as seen in studies 2, 3, 4, 5
- A level of 196% is considered elevated, although the exact threshold for increased risk may vary
- Elevated factor VIII levels can contribute to thrombotic events, including arterial and venous thrombosis, as well as coronary artery disease 2, 3
Mechanisms and Associations
- Factor VIII is a common acute phase reactant, and its levels can be influenced by the acute phase reaction 4
- High factor VIII levels are a risk factor for venous thrombosis and coronary artery disease, with a greater impact on venous than arterial thrombosis 3
- The protein plays a key role in the blood coagulation system, increasing the catalytic efficiency of factor IXa in the activation of factor X 6
Clinical Implications
- Elevated factor VIII levels may be associated with a hypercoagulable state, increasing the risk of thrombotic events 2, 3, 5
- The measurement of factor VIII levels may not be recommended as part of routine thrombophilia screening due to a lack of international consensus on laboratory testing methods 3
- In trauma patients, early systemic increases of factor VIII/VWF levels may result in a lower sensitivity of contact-activated clotting time, while severely injured patients may have prolonged aPTT and elevated activation markers of FXa, plasmin, and APC 5