BRADYKININ GENERATION IN RED CELL CONCENTRATE FILTERED WITH LEUKOCYTE-REDUCTION FILTERS

Abstract

BRADYKININ GENERATION IN RED CELL CONCENTRATE FILTERED WITH LEUKOCYTE-REDUCTION FILTERS Yoshiko Ohnishi, Tsuneo A. Takahashi, Mani Hosoda, Hideki Abe, Kenji Ikebuchi and Sadayoshi Sekiguchi Hokkaido Red Cross Blood Center We have previously reported bradykinin (BK) generation during filtration of platelet concen trates with leukocyte-reduction filters made of polyester fibers with a negative zeta-potential through contact activation. In the present study we investigated whether BK was generated when red cell concentrates containing MAP (RC-MAP) was filtered with 7 different leukocytereduction filters (Filters A-G) made for red cell concentrates. Mean BK level in RC-MAP stored one day was 39.8-78.8 pg/m l before filtration. However, concentration increased several thousand-fold to ng/ml levels during filtration with Filters A-F with a negative zeta-potential. In contrast, generation of BK was suppressed during filtration with Filter G with a positive zeta-potential to a maximum level of 601-350 pg/ml. As the pre-filtration storage period of RC-MAP was extended, BK levels after filtration with Filter A decreased with 95% suppression and almost no BK generation observed in RC-MAP stored for 20 or 43 days. As the post-filtration storage period of RC-MAP was extended, BK levels after filtration with Filter A decreased to pre-filtration levels in 3 hours. Further, kal likrein levels in RC-MAP increased significantly and high molecular weight kininogen levels decreased after filtration with Filter A. The clinical significance of this BK generation during filtration remains unclear, but should be considered with regard to the clinical application of leukocyte-reduction filters.