Quality of platelet concentrates after three‐day storage following 265 nm ultraviolet C‐light‐emitting diode irradiation

Objectives We aimed to investigate the quality of platelets after storage following irradiation with ultraviolet C (UVC) light‐emitting diodes (LED). Background Controlling transfusion‐related infections, particularly bacterial contamination of platelet concentrates (PCs), is urgently required. UVC‐LEDs have attracted considerable attention as potential solutions to this problem. Methods PCs (5.5 mL) were irradiated with 265 nm UVC‐LED for up to 60 min and then stored at 22°C with shaking for 3 days. PC quality parameters, such as platelet count, biochemical profiles, including electrolytes and metabolism, activation markers and platelet aggregability, were analysed before and after storage. Prior to the storage study, to validate the appropriateness of the UVC‐LED dose used, the PCs were inoculated with Staphylococcus aureus or Bacillus cereus , and their colony‐forming ability was evaluated after irradiation with the same dose of UVC‐LED. Results We confirmed that S. aureus and B. cereus colonies decreased with the irradiation dose (by 1.7 log and 1.2 log at 38.7 and 40.4 mJ cm −2 , respectively). Platelet count decreased immediately after 60‐minute irradiation to 32.5 mJ cm −2 , reaching approximately 80% of the level in the control without irradiation, but no further decrease was recorded after storage. The biochemical profiles and activation markers showed little alterations. Conclusion These results indicate that UVC‐irradiated platelets maintain sufficient quality for practical use even after storage. Although this was a bench‐scale study, our findings suggest that irradiation of PCs with 265 nm UVC‐LED may enhance the safety of blood transfusions while preserving their efficacy.