Background The combination of pathogen reduction technologies (PRTs) and cryopreservation can contribute to building a safe and durable platelet (PLT) inventory. Information about cryopreserved riboflavin and UV light‐treated PLTs is scarce. Study Design and Methods Twenty‐four buffy coat (BC) PLT concentrates were grouped into 12 type‐matched pairs, pooled, and divided into 12 non‐PRT‐treated control units and 12 riboflavin and UV light PRT‐treated test units. Both were cryopreserved with 5% DMSO and stored at −80°C for 1 year. The cryopreservation method used was designed to avoid the formation of aggregates. PLT variables (PLT recovery, swirling, pH, MPV, and LDH) and hemostatic function measured by thromboelastography (TEG) were analyzed before cryopreservation (day 1) and post‐cryopreservation at day 14 and months 3, 6, and 12 of storage at −80°C. The analyses were carried out within 1‐h post‐thaw. Results No aggregates were found in either PLT group at any time. Swirling was observed in both groups. MPV increased and mean pH values decreased over time (p < .001), but the mean pH value was never below 6.4 in either group after 12 months of storage at −80°C. PLT recovery was good and clotting time became significantly shorter over the storage period in both groups (p < .001). Conclusion Our cryopreservation and thawing method prevented aggregate formation in cryopreserved riboflavin‐UV‐light‐treated PLTs, which exhibited good recovery, swirling, pH > 6.4, and procoagulant potential, as evidenced by a reduced clotting time after 12 months of storage at −80°C. The clinical relevance of these findings should be further investigated in clinical trials.

Research on alternative platelet (PLT) storage methods is focused on extending shelf‐life in order to improve PLT inventory management while maintaining quality and function. After decades of investigation, cryopreservation and cold storage are gaining prominence as methods that can dramatically improve PLT availability in remote, rural and isolated areas, including war zones. Patients with active bleeding who need to clot rapidly benefit from the procoagulant phenotype of cryopreserved or cold‐stored PLTs, which can quickly bind to the damaged endothelium. An innovative research area is combining pathogen reduction technologies (PRTs) with different storage methods. The advantages of refrigeration and cryopreservation can be maximized when used together with PRT treatment, allowing longer storage with a considerably reduced risk of infectious disease transmission.