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

Objectives: Potentially harmful leukocyte- and platelet-derived bioactive s ubstances are accumulated extracellularly during storage of different blood products. Therefore, we studied the effect of prestorage leukocyte filtrat ion on concentrations of bioactive substances in whole blood (WB) and salin e-adenine-glucose-mannitol (SAGM) erythrocyte suspension during storage. Methods: Ten units of WB and 10 units of SAGM blood from 20 blood donors we re stored at +4 degrees C for 24 h. Subsequently, half of every unit was le ukocyte-reduced by filtration. The 40 half units (20 filtered and 20 unfilt ered) were stored at +4 degrees C for further 34 days. Samples were collect ed from all 40 half blood units on day 1, 21 and 35. Total content and extr acellular concentration of myeloperoxidase (MPO), eosinophil cationic prote in (ECP), histamine and plasminogen activator inhibitor-1 (PAI-1) was analy sed by ELISA or RIA methods. Results: In unfiltered WB, the total content of all 4 substances decreased during storage, and extracellular concentrations increased significantly an d storage time dependently. Similarly, this was also seen with MPO and ECP in unfiltered SAGM blood. Prestorage filtration of WB resulted in a signifi cant reduction of total content and of extracellular concentrations of all 4 substances as well. Additionally, storage time dependent extracellular ac cumulation 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 accumulat ion. Filtered SAGM blood contained significantly lower concentrations of al l analysed substances compared to filtered WB. Conclusion: Prestorage leukocyte filtration reduces total content of leukoc yte- and platelet-derived bioactive substances and prevents the storage tim e dependent extracellular accumulation of these substances in WB and the pa rtly accumulation in SAGM blood.