influence of exposure to light and dark environment on platelet concentrates during storage

ABSTRACT

There is increased demand for stored platelet concentrates [PCs] for therapeutic transfusions. Despite all efforts to simulate the physiological environment Loss of the platelet functionality due to platelet activation occurs during preparation and storage of PCs "platelet storage lesion" [PSL]. Intensive investigations are currently undertaken to improve the storage of PCs however, the quality of the stored platelets is still questionable. Was to compare the influence of light and dark environment on the physiological function of routinely prepared random-donor PCs. And to teste the changes in platelet indices [platelet count [PLT count], and mean platelet volume [MPV]J, pH, lactic acid dehydrogenase [LDH] levels, the release of alpha-granule content through cell surface expression of specific activation-dependent antigens GPIIIa [CD 61], P- selectin [CD62] and, platelet membrane glycoprotein GP Ib [CD42 alpha] and GP IIb-IlIa [PAC1] in the PCs. Platelet concentrates were prepared using 450 ml of whole blood collected from 20 adult random volunteer male donors divide into two bags. The first one was left in continuous light exposure [light group]. The other one was raped in aluminum foil to avoid exposure to light [Dark Group]. Both bags were placed at room temperature for 5 days Platelet indices [PLT, MPV], pH, lactic acid dehydrogenase levels in addition to the expression of activation antigens CD61 and CD62 along with modulation of platelet membrane glycoproteins [GP] Ib [CD42 alpha] and IIb-IIIa [PAC1] in the PCs were measured on day 1 and day 5 of the storage period for both groups. The differences [delta] in these parameters for both groups were compared. The platelet indices [delta PLT count, and delta MPV "which reflects change in the platelet morphology"], delta pH, delta LDH, in addition to the activation markers [delta CD42alpha, CD61, CD62, and delta PAC1] were significantly lower in the dark Group compared with the Light group The most significant changes were in the level of the released LDH [P= .000] and the production of CD62 [[P= .00]. The PLT count significantly decreased in both groups after 5 days of storage. However, the platelets MPV significantly decreased in the light group only, which may be due loss of the large sized platelet during storage. There was statistically significant increase in LDH production in the light group [P= .000] "which is used as a marker for PLT lysis", in addition their pH also significantly decreased. In the dark Group, although there was a significant increase in the production of LDH, but it was statistically less significant than in the light group [P= .0] so that it may be buffered by the plasma and did not reflect on the changes in the pH in this group. There was a statistically significant influence of pH changes "as an independent variable" in the PCs on the changes in MPV "as a dependent variable" in both groups. However, there was no such influence regarding the PLT count. In the light group, the platelet activation markers CD61, CD62, and PAC1 were significantly increased in the PCs at day 5 compared to day 1. In addition, CD42alpha, was significantly decreased. While in the dark Group, there were no significant changes in those parameters, except for PAC1 which was significantly decreased although difference was less than that in the light group. In this study, platelets stored in light environment seemed to be more active with more platelet storage lesion [PSL], than platelets stored in dark environment. Platelet activation was associated with an increase in the, pH, LDH production and release of alpha-granule content and modulation of platelet surface glycoproteins. All these parameters may affect the post infusion quality of the stored platelets