An Adaptable Quality Control Framework for Platelet-Rich Plasma as a Blood-Derived Product: A Multicenter Real-World...

Background and Objectives: Platelet-rich plasma (PRP) composition and activity vary with patient-related factors, medication exposure, and preparation procedures. We developed an adaptable manufacturing quality control score (QC-Score) framework and retained clinical outcomes as a secondary exploratory layer. Methods: This retrospective multicenter study included 13,283 hematological analyses associated with administered infiltrations. Its product-profile alignment index (PPAI; 0-100) summarizes the alignment of platelet enrichment and residual white blood cell (WBC) and red blood cell (RBC) ratios with a study-defined compositional profile. The criteria are research proxies and not manufacturer or regulatory release limits. Results: The full PPAI was reportable in 8937 analyses and a platelet-only partial index in 404 analyses. The median full PPAI values for Systems A, B, and D were 74.6, 90.6, and 48.8, and complete-case conformance to the frozen study-defined benchmark was 9.8%, 15.8%, and 10.2%, respectively. System C was evaluated on platelet enrichment only. Modeling the recorded final-product WBC and RBC zeros as residual concentrations of 0.01 changed nine individual PPAI values but no system median or conformance count. Center-system patterns were heterogeneous. Secondary exploratory Knee Injury and Osteoarthritis Outcome Score (KOOS) analyses were sensitive to incomplete questionnaire handling and showed no consistent association with the PPAI. Conclusions: The QC-Score framework and PPAI support product characterization and targeted process investigation. Their operational proxies are neither manufacturer release limits nor regulatory specifications, and the PPAI was not validated as a clinical predictor.