Extracellular accumulation of bioactive substances during preparation and storage of various platelet concentrates

Background: Side effects of platelet transfusion may be associated with inf usion of bioactive substances. We therefore studied extracellular accumulat ion of histamine, plasminogen activator inhibitor (PAI)-1, vascular endothe lial growth factor (VEGF), and interleukin (IL)-6 during preparation and st orage of various platelet concentrates. Methods: Twenty buffy-coat-derived platelet pools (BCPC) were prepared and stored in platelet additive solutio ns (PAS). Twelve apheresis platelet (APC) units were prepared using the COB E Spectra LRS, and 14 were prepared using the Fenwal Amicus Separator. Afte r preparation half of the content was drawn from each APC unit. The normal ranges of the substances were determined in plasma from all donors, and the extracellular concentrations of the substances were determined in supernat ants collected on days 0, 1, 3, 5, and 7 of storage from all platelet prepa rations, Results: The platelet counts were not significantly different in B CPC units and APC units. The BCPC units had a significantly higher white ce ll count than the APC units (P < 0.0001), but the count was significantly h igher in the Amicus APC units than in the COBE APC units (P < 0.0001), The extracellular histamine concentration was significantly (P < 0.001) increas ed in BCPC units after preparation and without further increase during stor age, while there was no accumulation of histamine in APC units. After prepa ration the PAI-1 concentration was significantly (P < 0.02) higher in BCPC units than in APC units, but during storage PAI-1 increased significantly ( P < 0.05) more in APC units than in BCPC units. Similarly, VEGF concentrati on was significantly (P < 0.05) higher in BCPC units than in APC units afte r preparation. During storage, however, VEGF increased more in BCPC units c ompared with COBE Spectra APC units (P < 0.05), but compared with Amicus Se parator APC units only for the first 3 days of storage. At days 5 and 7 of storage the VEGF concentration was significantly higher in the Amicus APC u nits than in the COBE APC units (P < 0.05). IL-6 was not detectable in any of the concentrates after preparation or during storage. Conclusion: platel et concentrates prepared by the apheresis method may contain less white cel l derived bioactive substances than platelet concentrates prepared by the b uffy-coat method. However, a substantial storage time dependent platelet de rived bioactive substance accumulation takes place in all platelet concentr ates tested, presumably due to platelet disintegration. (C) 2001 WiIey-Liss , Inc.