Optimized Protocol for Producing Pathogen-inactivated Double-dose Platelet Concentrates From Six Pooled Buffy Coats

Pooled platelet (PLT) production methods differ worldwide. In Europe, the buffy coat (BC) method is predominantly used, with four to eight BCs being pooled to produce single- or double-dose PLT products. The European Directorate for the Quality of Medicines & HealthCare (EDQM) blood guide and Austrian legislation define a therapeutic PLT unit as ≥ 2 × 10¹¹ PLTs/unit. We optimized the manufacturing steps to produce double-dose PLT products from six BCs, aiming to enhance production efficiency while maintaining product quality.

We stepwise optimized our protocol starting from five BCs (BC5) (N=107). First, we included an additional BC (BC6) (N=110). Second, we used a hematology analyzer (Sysmex XN-1000) equipped with blood bank mode, which is a novel software application for measuring PLT counts in PLT units (BC6+XN-1000) (N=106). Third, we optimized the blood cell separator (BCS) settings to produce higher-volume BCs (BC6+XN-1000+BCS) (N=107). Fourth, we adapted the centrifugation (BC6+XN-1000+BCS+CF) (N=197). All units were pathogen-inactivated using the INTERCEPT blood system (amotosalen/ultraviolet A).

Each optimization step significantly increased the yield ( × 10¹¹/PLT concentrate) (P <0.001). The mean yield increased from 2.83 (SD 0.39) for BC5 to 4.81 (SD 0.58) for BC6+XN-1000+BCS+CF. The mean BC volume increased from 47.78 mL (SD 5.09) to 55.59 mL (SD 5.11) following BCS adaptions (P <0.001).

After stepwise protocol optimization, we could produce pathogen-inactivated double-dose PLT concentrates by pooling six BCs, complying with national regulations and EDQM quality requirements while reducing costs and minimizing blood wastage.