INCREASED IN-VITRO AGGREGATION OF STORED PLATELETS AT ROOM-TEMPERATURE IN CONTRAST TO 37-DEGREES-C

Platelet concentrates were stored at room temperature and the reactivi ty of platelets to aggregating agents was studied at temperatures betw een 23 and 39 degrees C. Fresh platelets showed increased reactivity a t higher temperatures. When stored platelets were considered, maximal aggregation was not statistically different when compared with fresh p latelets in the temperature range of 23-29 degrees C (5 mu M ADP). In addition, platelets stored either in Terumo or Baxter (PL 146 and PL 7 32) plastic bags at room temperature, showed an increased ADP-induced aggregation (10 mu M) when studied at room temperature compared to 37 degrees C. This pattern was confirmed by the difference in released AT P during aggregation. Collagen, although not resulting in detectable a ggregation at 25 degrees C, caused a similar release of ATP as that ob served at 37 degrees C. Since the observed differences in platelet rea ctivity seem to be similar using different types of plastic bags, the increased aggregation observed at room temperature is unlikely to be d ue to a special effect of a storage bag. Since the recovery of ADP agg regability is better at room temperature than at 37 degrees C, ADP-ind uced aggregation determined at room temperature might be a better inde x of the clinical results expected when using stored platelets.