Effect of temperature on functional response of platelet concentrates stored in PVC bags

Haemostatic efficacy of platelet concentrates prepared and stored in locally available PVC triple bags was compared against a Japanese bag. In vitro functional parameters studied included shape change, aggregation and secretion in response to ADP. We have observed remarkable difference in the aggregatory response of platelets stored at slightly varying temperatures. The stimulatory responses of platelets stored with constant agitation at 70 strokes per min and 23 +/- 2 degrees C, deteriorated drastically by the time platelets were stored for 48 h. Both the rate and the extent of aggregation were affected showing no response to ADP at 72 h. However, when platelets were stored in a BOD incubator, thermostated at 22 +/- 0.5 degrees C, with continuous horizontal agitation at 70 strokes per min, 50 per cent functional response was retained till 72 h. We also demonstrated fragmentation of platelet membrane during storage. The membrane fragments collected by high speed centrifugation, expressed PF3 activity. Shedding of microvesicles indicates alterations at the membrane level that possibly cause functional lesion during storage. Our data suggest the significance of controlling the storage temperature steadily, to get maximum post transfusion efficacy.