SOLUBLE P-SELECTIN AS PARAMETER FOR PLATELET ACTIVATION DURING STORAGE

Platelet concentrates stored at room temperature deteriorate. The so-c alled storage lesion is characterised by morphological changes and a l oss of functionality. To find an assay for early platelet activation i n platelet concentrates the morphological score, beta-TG release and P -selectin expression were determined, and compared with the amount of soluble P-selectin. An ELISA was used to quantify soluble P-selectin i n the storage medium. We found a significant correlation between the a mount of soluble P-selectin and the percentage of P-selectin positive platelets (flow-cytometric analysis) (r=0.7449; p <0.0001) or the amou nt of beta-TG release (r=0.6837; p <0.0001). The morphological score a lso correlated significantly (negative) with the amount of soluble P-s electin (r=-0.7669; p=0.0002). From day 0 till day 8, the amount of so luble P-selectin increased constantly from 219+/-49.2 ng/ml to 556+/-1 02.3 ng/ml. The detection of soluble P-selectin can be used to quantif y activation of platelets during storage. The immune-assay for soluble P-selectin is more sensitive than flow-cytometric analysis of the per centage of P-selectin-positive cells and allows earlier detection of p latelet activation.