Three‐buffy‐coat platelet concentrates: Evaluation of a Welsh blood supply chain contingency strategy with wider opportunities for European practice

Background and Objectives Platelet concentrates (PC) are essential for haemostatic support in clinical care. The Welsh Blood Service (WBS) previously showed through data modelling that three‐buffy‐coat‐derived PC (3BC‐PC) could meet UK contingency and European Directorate for the Quality of Medicines & HealthCare (EDQM) Council of Europe specifications. This study aimed to validate the real‐world manufacture of 3BC‐PC, assessing quality and compliance against UK and European regulatory standards. Materials and Methods Three ABO ‐compatible BCs were pooled with platelet additive solution‐E ( PAS ‐E) and processed per standard WBS protocols. Sixteen 3BC ‐ PC were manufactured and stored at 20–24°C with agitation for 7 days. Samples were tested on Days 1, 2, 6 and 8 for platelet yield, recovery and specification compliance. Functional and quality assessments included platelet activation ( CD62P , Annexin V, soluble CD62P ), biochemistry ( pH , glucose, lactate), light transmission aggregometry (adenosine diphosphate [ ADP] , thrombin receptor activator peptide‐6 [ TRAP ‐6]) and thromboelastography (TEG) (R, K, α‐angle, maximum amplitude [ MA] ). Results Mean platelet yield was 247 ± 26 × 10 9 /unit following Day 2 bacteriology sampling. All 3BC‐PC met UK contingency (≥150 × 10 9 /unit) and EDQM routine (≥200 × 10 9 /unit) specifications throughout storage, although UK routine compliance (≥240 × 10 9 /unit) declined to 62.5% following Day 2 bacteriology sampling. Biochemical, activation and functional changes reflected expected platelet storage lesions, while TEG showed preserved global haemostatic function. Conclusion Practical validation supports the feasibility of 3BC‐PC as a contingency component. Quality metrics aligned with UK and European specifications, suggesting operational and clinical viability. These findings bridge prior modelling with practical manufacture and support both UK contingency and routine European adoption while identifying future optimisation considerations for potential routine UK use.