Acquired von Willebrand's disease. Evidence for a quantitative and qualitative factor VIII disorder.

To define further the factor VIII abnormality in acquired von Willebrand's disease, we performed immunoelectrophoresis of factor VIII antigen, as well as quantitative measurements of the antigen, factor VIII procoagulant activity and von Willebrand factor activity on plasma from an affected 57-year-old man who also had a poorly differentiated lymphocytic lymphoma. No evidence for an inhibitor against factor VIII procoagulant activity or von Willebrand factor activity was detected, but immunoelectrophoresis showed none of the less anodic forms of factor VIII antigen. There were concomitant decreases in total antigen (0.19 U per milliliter) and von Willebrand factor levels (0.12 U per milliliter). Factor VIII-procoagulant activity was borderline low (0.45 U per milliliter). Correction of both the abnormal immunoelectrophoresis pattern and the quantitative abnormalities followed radiotherapy of the lymphoma. The factor VIII abnormalities might have resulted from binding or destruction of theless anodic forms of factor VIII antigen by the malignant lymphocytes.