The Unsuitability of Outdated Blood for Making Therapeutically Effective Cryoprecipitate

The factor VIII activity in cryoprecipitates prepared from plasma separated from whole blood stored for 21 days was examined. The concentration of factor VIII in plasma separated from outdated blood averaged less than 25 per cent of that found in fresh plasma, and the cryoprecipitate prepared from outdated plasma averaged only 23 factor VIII units per bag. A significant amount of free hemoglobin was present in cryoprecipitates prepared from outdated plasma. Factors in the decrease in plasma factor VIII activity in stored whole blood include both degradation and a change in the cryoprecipitability of factor VIII itself. The findings indicate that cryoprecipitate prepared from plasma separated from outdated blood is of little therapeutic effectiveness.