BIOACTIVE SUBSTANCES IN BUFFY-COAT-DERIVED PLATELET POOLS STORED IN PLATELET-ADDITIVE SOLUTIONS

We studied extracellular accumulation in buffy-coat-derived platelet p ools suspended in platelet additive solutions (PAS). 20 platelet pools were prepared from buffy coats of 60 donors and stored in either PAS I (n = 10) or PAS II (n = 10), Samples were drawn from the donors to d etermine the normal range of histamine, plasminogen activator inhibito r 1 (PAI-1), myeloperoxidase (MPO) and interleukin (IL)-6, After prepa ration samples were collected on days 0, 5 and from the 20 platelet po ols respectively, to determine extracellular accumulation of the same substances. Extracellular histamine, PAI-1 and MPO were detected in si gnificant levels (P < 0.0001) immediately after preparation of the pla telet pools. Only the extracellular level of PAI-1 increased significa ntly during storage from day 0 to day 7 (P < 0.01). After preparation and storage to day 7 IL-6 was found in only three of the 20 platelet p ools. Even though platelets were prepared by the buffy-coat method, to produce a low leucocyte count and thereby low cytokine (IL-6) content , there was still significant contamination by other bioactive substan ces.