MAINTENANCE OF HIGH FACTOR VIII ACTIVITY IN SOURCE PLASMA FROZEN AND STORED IN THE MPIII AND MPIIIs PORTABLE FREEZING SYSTEMS

Abstract

MAINTENANCE OF HIGH FACTOR VIII ACTIVITY IN SOURCE PLASMA FROZEN AND STORED IN THE MPIII AND MPIIIs PORTABLE FREEZING SYSTEMS Kimiko Segawa, Seiji Chiba, Tsuneo A. Takahashi, Toshie Nakase and Sadayoshi Sekiguchi Hokkaido Red Cross Blood Center A new freezing system for preparing high quality source plasma was investigated. The MPIIITM portable freezing system consists of a freezer called the "Cell Unit" and a storage case. The MPIII cell unit and the MPIIIs cell unit, about half the size of the MPIII, were transferred to storage cases after "recharging" (storage at -40C) and their ability to freeze apheresis plasma bags was tested. The MPIII and the MPIIIs freezers could freeze 8 and 4 plasma bags respectively to a temperature below -20C. However, the MPIII could freeze 16 bags and the MPIIIs 9 bags, before the cell unit temperature rose up to -20C. They could freeze and store plasma bags below -20C for about one day when there were 12 bags in the MPIII or 6 bags in the MPIIIs. The recovery of factor VIII activity (FVIII: C) of the plasma frozen in the MPIIIs was high (97%) and was similar to that of plasma frozen in a blast freezer. This high FVIII: C did not decrease even after overnight storage in the MPIIIs. In addition, the MPIIITM portable freezing system has several other merits. No electricity is required after "recharging" the cell unit, it is safe because neither liquid nitrogen nor ethanol is required and the plasma bags are flat after freezing, which allows easy bar code reading and safe, efficient storage and transportation. Thus it is possible for the MPIII and MPIIIs systems to freeze the collected plasma at blood collection sites and to retain high FVIII: C.