Plasma Thromboplastin Component (Christmas Factor, Factor IX) Levels in Stored Human Blood and Plasma

Abstract

1. PTC activity was assayed in 26 units of human plasma prepared from whole blood stored for 3 weeks at 4° C. The plasma had been frozen and stored at — 20° C for additional periods ranging from a few days to 4 months. High PTC activity was still present in the plasma at the end of this period, the activity averaging 95% of normal. 2. The PTC activity of 19 samples of “reclaimed“ plasma stored for an additional 6 months at — 20° C decreased by an average of 23%. This decrease was statistically significant. 3. Liquid plasma kept at room temperature for 5½—7½ months contained no PTC activity. 4. Lyophilized plasma stored at room temperature for 6—8 years contained an average of 30% PTC activity. Lyophilized plasma stored at — 20° C for 4 years contained 68% PTC activity. 5. ACD and disodium hydrogen citrate anticoagulant solutions served equally well in preserving PTC activity in whole blood stored in glass tubes over a period of 3 weeks at 4° C. 6. “Reclaimed“ plasma from outdated bank blood provided effective hemostasis in two operations for the removal of 20 teeth from a severely PTC-deficient patient. 7. The high PTC activity of “reclaimed“ plasma was confirmed by the close agreement between the PTC level expected in a PTC deficient patient after transfusion of such plasma and that observed. ^* Supported (in part) by research grants H-1333 and H-3140 of the National Heart Institute, Public Health Service.