LEUKOCYTE AND PLATELET-DERIVED BIOACTIVE SUBSTANCES IN STORED-BLOOD -EFFECT OF PRESTORAGE LEUKOCYTE FILTRATION

Adverse reactions to transfusion of allogeneic blood may depend on con tent of leucocytes and platelets and on storage-time of the erythrocyt e suspensions. Therefore, we studied the efficacy of prestorage leucoc yte reduction by filtration on total content and extracellular accumul ation of histamine, eosinophil cationic protein (ECP), eosinophil prot ein X (EPX), myeloperoxidase (MPO), plasminogen activator inhibitor ty pe-1 (PAI-1) and interleukin-6 (IL-6) in samples obtained from 5 units of SAGM blood, 7 units of plasma-reduced whole-blood and 6 units of w hole-blood before and after filtration, respectively. In addition, we analysed supernatants from the same units after storage at +4 degrees C for 0, 21 and 35 d, respectively. The filtration was performed at ro om temperature within 2-4 h after donation. The substances were analys ed by ELISA and RIA methods and we also analysed the donor plasma leve ls of the same bioactive substances. The total content of histamine, E CP, EPX, and MPO were 10-70-fold higher in all unfiltered erythrocyte products compared to donor plasma concentrations, while PAI-1 content was 15-20-fold higher only in plasma-reduced whole-blood and whole-blo od. Prestorage leucocyte filtration significantly reduced the total hi stamine, ECP, EPX, MPO and PAI-1 content to levels similar to donor pl asma levels in plasma-reduced whole-blood and whole-blood, while PAI-1 was still low in filtered SAGM blood. In addition, the levels of extr acellular bioactive substances at d 0 after donation and filtration we re within the range of concentrations in donor plasma, and there was n o time-dependent accumulation during storage for 35 d at +4 degrees C. IL-6 was not detected in either plasma or samples obtained from the b lood bags. These results suggest prestorage leucocyte filtration to de plete leucocyte contents to levels, which prevent the previously shown time-dependent accumulation of leucocyte derived bioactive substances in various erythrocyte suspensions. In addition, the PAI-1 results su ggest leucocyte filters to reduce the obligatory platelet content in w hole-blood products.