Leucocyte-derived bioactive substances in fresh frozen plasma

Bioactive substances in fresh frozen plasma (FFP) are considered to be related to adverse reactions after transfusion, particularly in septic or traumatized patients. Therefore, we analysed the concentration of various bioactive substances (histamine, eosinophil cationic protein, eosinophil protein X, myeloperoxidase and interleukin-6) in 25 u. of thawed FFP from healthy donors. These were compared with donor plasma concentrations of 24 healthy controls. In addition, we analysed the concentration of the bioactive substances, except interleukin-6, in 25 u. of thawed FFP, which were subjected to leucocyte filtration before freezing and storage. Finally, we analysed the substances in 10 leucocyte non-filtered plasma units before freezing and storage, and after thawing, respectively. Before analyses, which were performed by ELISA and RIA methods, these latter samples were sterile filtered through a 0.20-micron filter. Histamine, eosinophil cationic protein, eosinophil protein X and myeloperoxidase concentrations were significantly greater (P < 0.05) in the 25 u. of FFP compared with normal donor plasma. Pre-storage leucocyte filtration reduced concentrations of the bioactive substances in FFP to concentrations comparable with normal donor plasma concentrations. Interleukin-6 was undetectable in all FFP units and in 21 of the 24 control donors. Histamine, eosinophil cationic protein and myeloperoxidase concentrations were significantly higher (P < 0.05) in samples collected from the 10 u. of FFP after freezing and thawing compared with samples collected before freezing. We conclude that fresh frozen plasma prepared by a conventional separation method contains various leucocyte-derived bioactive substances, which may be reduced by pre-storage leucocyte filtration.