Morning Report Pearls: Acquired Coagulation Factor Deficiencies

Yesterday, Dr. Zasadzinski presented an interesting case of acquired factor VIII deficiency. Acquired inhibitors of coagulation are autoantibodies that either inhibit the activity or increase the clearance of a clotting factor. Although rare, acquired factor deficiencies are important to consider in adult patients presenting with new hypocoaguable states. Here are some high yield clinical pearls for acquired factor VIII deficiency:
  •  Factor VIII inhibitors are the most common autoantibodies affecting clotting factor activity. Acquired factor VIII deficiency is also known as auired hemophilia A and occurs with an incidence of 1.3 to 1.5 cases per million population per year.
  • Associated conditions include post-partum period, autoimmune diseases, drug reactions and malignancy.
  • Clinical Presentation
    •     Sudden/New onset easy brusing, prolonged post procedural bleeding, mucosal bleeding, hemarthrosis.
  • Diagnostic Features
    •     Prolonged aPTT; normal PT/INR.
    •     Negative  mixing test (Additional factor is still inhibited by autoantibodies)
    •     Positive Bethesda test (Serial dilutions of patient plasma are incubated with pooled normal plasma; factor VIII activity is then measured using a clotting assay and increases with each dilution as the autoantibody is washed out)
  • Acute Treament
    • Control of active bleeding with DDAVP, factor VIII inhibitor bypassing activity (FEIBA) or activated factor VII
  • Maintenance Therapy
    • Immunosuppression to quite autoantibody production – steroids, cyclophosphamide, rituximab.