From the Guidelines
Acquired Factor VIII deficiency is primarily caused by autoantibodies directed against circulating coagulation factor VIII.
Causes and Risk Factors
- Autoantibodies against factor VIII are the primary cause of acquired hemophilia A, which is characterized by an isolated prolonged activated partial thromboplastin time (aPTT) and bleeding symptoms in patients with no prior history of a bleeding disorder 1.
- The development of autoantibodies against factor VIII can occur in various clinical settings, including post-partum, elderly patients, and those with underlying medical conditions such as cancer, autoimmune disorders, or chronic diseases 1.
- Certain risk factors, such as smoking, hypertension, previous cardiovascular events, type 2 diabetes, and high body mass index, are frequently present in patients with acquired hemophilia A 1.
Diagnosis and Presentation
- Patients with acquired hemophilia A may present with spontaneous bleeding, an isolated prolonged aPTT, or both, and the diagnosis should be considered in any patient with an acute or recent onset of bleeding and an unexplained prolonged aPTT 1.
- The diagnosis of acquired hemophilia A requires a close collaboration between clinicians, laboratory staff, and a hemophilia center experienced in the management of inhibitors 1.
From the Research
Causes of Acquired Factor VIII Deficiency
The causes of acquired Factor VIII deficiency are varied and can be associated with several conditions, including:
- Autoimmune disorders, such as Sjogren's syndrome and myositis 2
- Malignancies, including prostate adenocarcinoma 3 and chronic myeloid leukemia 4
- Certain medications 3
- Infections, such as parvovirus B19 2
- Autoantibodies to factor VIII, which can develop spontaneously or in response to underlying conditions 5, 3, 2, 6
Associated Conditions
Acquired Factor VIII deficiency has been associated with several conditions, including:
- Autoimmune disorders, which can increase the risk of developing autoantibodies to factor VIII 2
- Malignancies, which can cause acquired Factor VIII deficiency through various mechanisms, including the production of autoantibodies or the disruption of normal coagulation pathways 3, 4
- Infections, which can trigger the development of autoantibodies to factor VIII 2
Pathogenesis
The pathogenesis of acquired Factor VIII deficiency involves the development of autoantibodies to factor VIII, which can neutralize or remove factor VIII from the circulation, leading to a deficiency of this essential clotting protein 5, 3, 2, 6