Abstract
Preservation of platelet concentrates at a low temperature is desired for the prevention of bacterial contamination. However, platelets incubated at a low temperature are not put into practical use because their lifetime in vivo after transfusion decreases. It was reported that this decrease in lifetime is closely associated with shape change under cold conditions. Therefore, we examined the shape change of chilled platelets using highfrequency light scattering and explored the mechanism of the shape change at a low temperature. There was a good correlation between the amplitude of light scattering and the ratio of the number of discoid platelets. The amplitude of light scattering from chilled platelets gradually decreased with decreasing temperature, indicating the change in platelet shape from discoid to spherical. Although this tendency of the amplitude of light scattering to decrease was observed at temperatures below 37°C, a low temperature affected the restoration of platelet shape on rewarming at 37°C. These findings suggested that the thermocontrol at a low temperature is important to maintain the reversibility of platelet shape. Real-time detection of shape change of chilled platelets using high-frequency light scattering should facilitate the study of the mechanism of cold activation.
