Production of viable and functional neutrophils in granulocyte concentrates with the Reveos automated system

Granulocyte transfusions may benefit patients with neutropaenia and life-threatening infections unresponsive to antimicrobial therapies. Current aphaeresis-based granulocyte concentrate (GC) production requires donor stimulation and hydroxyethyl starch (HES), which raises safety and supply concerns. This study assessed the feasibility and quality of GCs derived from pooling 10 residual leukocyte units (RLUs) processed via the Reveos automated blood processing system.

Whole blood (WB) from 10 ABO-compatible donors was processed using the Reveos system to obtain 10 mL RLUs. A modified platelet pooling device enabled sterile pooling of RLUs with added plasma. The final product was irradiated and analysed on days 0, 1 and 2 post-irradiation. Parameters assessed included cell counts, sterility, biochemical properties, viability, surface markers (CD15, CD10, CD62L and CD11b) and neutrophil functions: chemotaxis, phagocytosis, oxidative burst and H₂O₂ release.

All GCs (n = 10) met sterility criteria and contained a mean granulocyte dose of 0.95 ± 0.17 × 10¹⁰. Neutrophils were mature (CD15⁺CD10⁺) and remained viable on day 2. Functional assays demonstrated sustained phagocytic and respiratory activity up to 48 h post-processing, although chemotactic response and reactive oxygen species (ROS) production declined significantly from 24 h after processing (p < 0.05).

Pooling of Reveos-derived RLUs is a feasible, HES-free strategy to produce viable and functional GCs over 24 h from processing and irradiation. This approach provides a readily available alternative to aphaeresis products that could potentially enhance transfusion coordination.