Excess factor VIII: a common cause of hypercoagulability.

BACKGROUND Elevations of coagulation factor VIII have recently been described in significant numbers of patients with venous thromboembolism (VTE) previously thought to have had an "idiopathic" event. Three patients from a family practice are presented with recurrent VTE and increased factor VIII levels. METHOD The case histories and results of laboratory tests were reviewed. RESULTS The 3 patients had no other clear coagulopathy. In 2 of the 3, the increase was confirmed with a second reading. CONCLUSIONS Factor VIII assay should be considered in the work-up of idiopathic, recurrent VTE. Long-term anticoagulation may be appropriate in this setting.