Contributions to the Optimal Use of Human Blood

Abstract

The influence of different variables on the yield of factor VIII in cryoprecipitate as prepared in the Central Laboratory of the Netherlands Red Cross Blood Transfusion Service, was studied. The following conclusions may be drawn: (1) In case blood should be stored, the use of the anticoagulant solution acid citrate dextrose (ACD) is preferable to citrate phosphate dextrose (CPD) or trisodium citrate (TSC). (2) The temperature of stored whole blood should not decrease below 8 degrees C because of a spontaneous precipitation of factor VIII from blood (and plasma) below this temperature. (3) Cryoprecipitate derived from rapidly frozen plasma (1 min) contains a decreased amount of proteins in comparison with cryoprecipitate prepared from slowly frozen plasma (45 min to 4 h). On the other hand, equal amounts of factor VIII activity were obtained in the precipitate after freezing of plasma at varying rates. (4) Rapid thawing of plasma results in both higher yields of factor VIII procoagulant activity and a higher specific activity of this factor in the resulting cryoprecipitate. (5) The sedimentation of cryoprecipitate is completed after 5 min centrifugation at 1,500 g. (6) At temperatures higher than 8 degrees C, cryoprecipitated factor VIII starts dissolving into the supernatant plasma or in buffer. (7) Factor VIII in lyophilized cryoprecipitate is stable at room temperature. At elevated temperatures it rapidly looses its activity. (8) Evidence was obtained that the improvements which are introduced in the preparation of factor VIII do not lead to a product which is less stable in vitro as well as in vivo.

Improved Yields of Factor VIII from Heparinized Plasma

“…Another contributing factor may be the relatively high pH of the heparin solution itself (6.5), since Vermeer et al (13) have reported that blood collected into anticoagu lants with pH values below 5.8 rapidly loses 10-15% of the Factor VIII activity. The pH of the heparin solution is well above this critical value, while that of CPD, or CPD plus heparin is 5.7.…”

“…While the recovery of Factor VIII depends on the original concentration in the plasma (7,13), a value of 55 ±13% of the initial activity appears to be a representative re covery in the cryoprecipitate from CPD plas ma (3). Approximately 20% of the activity is left in the cryosupernatant with the re maining 25% not accounted for.…”

“…When collecting blood into citrate phosphate dextrose (CPD) or acid citrate dextrose (ACD) solutions which have pH values below 5.8, there is a loss of 10% of the starting activity during the collection procedure (13).…”

Preparation of Improved Cryoprecipitated Factor VIII Concentrate

“…These apparently conflicting results are to a large extent explained by the bi-phasic decay of VIII:C in anticoagulated whole blood and plasma argued by several authors [11,12], Initial loss of VIII:C activity in anticoagulated whole blood was found to be rapid; the half-life of VIII:C in plasma separated very soon after collection was also short. In contrast, the second phase of decay was associated with a very long half-life.…”