Toward Universal Single-Session Allogeneic Peripheral Blood Stem Cell Collection: An Algorithm-Guided Approach

Optimized allogeneic stem cell apheresis overcame collection challenges: 100% male success, 5.1% female failure, and 0% tertiary collections Single-session collection maintained robust engraftment kinetics and 91.2% day-100 survival while remarkably minimizing donor risks Single-session stem cell collection in allogeneic transplantation remains a significant clinical challenge, with failure rates exceeding 60% at some centers, compelling donors to undergo repeated consecutive procedures and imposing cumulative G-CSF toxicity, apheresis-related complications, and substantial institutional burden on otherwise healthy volunteers. In our pre-protocol cohort of 58 donors, 27.6% failed single-session collection, with 2 donors requiring three procedures and one donor requiring four separate sessions. We developed a predictive algorithm integrating peripheral CD34 + concentration, processed blood volume, apheresis duration, and recipient weight, combined with systematic optimization of technical collection parameters. Protocol implementation in 138 consecutive allogeneic donors transformed collection outcomes dramatically: single-session failure fell from 27.6% to 5.1%, an 82% relative reduction (χ 2 =19.984; p<0.001; OR=7.13), achieving an unprecedented 100% single-session success in male donors and 94.9% overall, with only 7 female donors requiring a second procedure and third collections abolished entirely. Critically, these outcomes were achieved without exceeding the 15-liter volumetric ceiling or 5-hour duration limit, demonstrating that collection excellence derives from algorithmic precision rather than procedural excess. Female donors requiring repeat collection demonstrated severely impaired G-CSF mobilization (peak CD34 + : 51.4 vs 135.7 cells/μL; p<0.001), identifying a physiologically addressable target for future intervention. Predictive accuracy reached 91.6% (AUC: 0.84; 95% CI: 0.69–0.99). Transplant outcomes were robust, with median neutrophil and platelet engraftment at days 16 and 18, respectively, and 100-day survival of 91.2%. These findings challenge the field's acceptance of repeat apheresis as inevitable and support algorithm-guided single-session collection as an achievable standard in allogeneic transplantation.