Studies of the minimum temperature at which human platelets can be stored with full maintenance of viability.

Platelet concentrates from normal donors were stored for 3 days under identical conditions except for the temperature of storage, which was maintained at 21 +/- 0.5, 19.5 +/- 0.5, or 18 +/- 0.5 degrees C. Immediate posttransfusion recovery of the stored platelets determined by 51Cr labeling averaged 47, 47, and 48 percent after storage at 21, 19.5, and 18 degrees C, respectively (differences not significant). Mean life span of the transfused platelets, however, was 8.12, 5.21, and 1.85 days at 21, 19.5, and 18 degrees C, respectively. The difference between mean life span following storage at 21 degrees C was significantly different from that after storage at 18 degrees C (p less than 0.03). Reduction in viability after storage at the lower temperature correlated with the reduction in the number of discoid platelets. These findings indicate that platelet viability is compromised after storage for 3 days at 18 degrees C and, possibly, at 19.5 degrees C, and illustrate the need for quality control of temperature in short-term platelet storage.