Presurgical plasma exchange is ineffective in correcting amyloid associated factor X deficiency.

In patients with rare factor deficiencies, for which no factor concentrates are available, plasma exchange (PE) is an option for raising the desired factor level to approximately 80% for surgery. We report a case of acquired factor X (FX) deficiency due to amyloidosis that required urgent surgical repair of an AV fistula aneurysm. This patient had a FX level of 3% at presentation; after 1.5 volume PE with fresh frozen plasma (FFP), his post-exchange FX was only 5%, indicating rapid adsorption of FX to amyloid fibrils. He was managed successfully with FEIBA during surgery.