Filtration of cryoprecipitate: a microscopic assessment of filter depostion.

A recent survey indicated that many Canadian hemophiliacs and physicians did not consider it necessary to filter cryoprecipitate prior to infusion. Experiments were performed to demonstrate that no loss of factor activity resulted from filtration of cryoprecipitate through standard blood filters. Furthermore, examination of the material retained on standard and ultrafiltration elements using scanning and transmission electron microscopy demonstrated the presence of amorphous and fibrillar proteins that proved to be largely composed of fibrin. This was accompanied by cellular material including intact and disintegrating leukocytes, erythrocytes, and platelets. Nonbiologic material was also discovered, including cellulose and plastic debris. This study emphasizes the need for effective filtration of cryoprecipitate.