Plasma factor VIII, variables affecting stability under standard blood bank conditions and correlation with recovery in concentrates.

Some of the variables affecting factor VIII during storage of plasma at 4 C prior to preparing factor VIII concentrates and cryoprecipitates were investigated. No significant difference in factor VIII levels could be demonstrated between whole blood, platelet-rich plasma or plasma depleted of platelets when stored at 4 C. However, in frozen plasma platelets were shown to have a deleterious effect on factor VIII. No significant difference in factor VIII levels was found in whole blood or plasma stored at 4 C for 6 hours as compared with blood or plasma stored for 18 hours (p = greater than 0.1). There was, however, a highly significant difference (p = less than 0.001) between plasma and whole blood stored at 4 C for 4 hours as compared with storage for 18 hours. There was a significant correlation (correlation coefficient 0.714) between factor VIII levels in the starting material and the factor VIII recovered in cryoprecipitates, but in a small pilot study no correlation between factor VIII levels in the starting material and that recovered in freeze-dried concentrates, could be found. There was no significant difference in factor VIII levels between the Group O and Group A donations used in this study (p = greater than 0.1), and no correlation was found between the drop in pH during storage and the factor VIII decay pattern.