Prestorage leukofiltration of whole blood and SAGM blood prevents extracellular bioactive substance accumulation

Objectives: Potentially harmful leukocyte- and platelet-derived bioactive substances are accumulated extracellularly during storage of different blood products. Therefore, we studied the effect of prestorage leukocyte filtration on concentrations of bioactive substances in whole blood (WB) and saline-adenine-glucose-mannitol (SAGM) erythrocyte suspension during storage. Methods: Ten units of WB and 10 units of SAGM blood from 20 blood donors were stored at +4 degrees C for 24 h. Subsequently, half of every unit was leukocyte-reduced by filtration. The 40 half units (20 filtered and 20 unfiltered) were stored at +4 degrees C for further 34 days. Samples were collected from all 40 half blood units on day 1, 21 and 35. Total content and extracellular concentration of myeloperoxidase (MPO), eosinophil cationic protein (ECP), histamine and plasminogen activator inhibitor-1 (PAI-1) was analysed by ELISA or RIA methods. Results: In unfiltered WB, the total content of all 4 substances decreased during storage, and extracellular concentrations increased significantly and storage time dependently. Similarly, this was also seen with MPO and ECP in unfiltered SAGM blood. Prestorage filtration of WB resulted in a significant reduction of total content and of extracellular concentrations of all 4 substances as well. Additionally, storage time dependent extracellular accumulation was prevented for all substances. Prestorage filtration of SAGM blood significantly reduced total content and extracellular concentrations of MPO and ECP and prevented storage time dependent extracellular accumulation. Filtered SAGM blood contained significantly lower concentrations of all analysed substances compared to filtered WB. Conclusion: Prestorage leukocyte filtration reduces total content of leukocyte- and platelet-derived bioactive substances and prevents the storage time dependent extracellular accumulation of these substances in WB and the partly accumulation in SAGM blood.