Factor VIII inhibitor developed in a 60-year-old patient with mild hemophilia A after surgery for colon cancer.

Most factor VIII inhibitors are developed at an early age and in patients with severe type of hemophilia A. We report a case of newly developed factor VIII inhibitor in a 60-year-old patient with mild hemophilia A who had been treated with several kinds of factor VIII concentrates. The patient was treated with a total of 103,580 units of recombinant factor VIII concentrate by continuous and bolus infusions for the open surgery of sigmoid colon cancer. On the 95th postoperative day, the patient had right low limb muscle bleeding and was infused with 1,000 units of recombinant factor VIII concentrate for three days. Subsequently, the level of factor VIII inhibitor in the patient's plasma was 2 Bethesda units (BU)/ml. Since then numerous subcutaneous hemorrhages developed, but an adequate hemostatic effect was not obtained even with the administration of a high dose of recombinant factor VIII concentrate. The patient was switched to bypass therapy using human plasma-derived factor VIIa concentrate, which showed a favorable hemostatic effect.