Platelet Recruitment during Multiple Donor Platelet Apheresis Differs between Cell Separators

Abstract

Background: Recruitment of platelets (PLT) during donor PLT apheresis may facilitate the harvest of multiple units within a single donation. Methods: We compared two PLT apheresis procedures (Amicus and Trima Accel) in a prospective, randomized, paired cross-over study in 60 donors. The 120 donations were compared for depletion of circulating PLT in the donors, PLT yields and PLT recruitment. A recruitment was defined as ratio of total PLT yield and donor PLT depletion > 1. Results: Despite comparable differences of pre- and post-apheresis PLT counts (87 × 10⁹/l in Trima Accel vs. 92 × 10⁹/l in Amicus, p = 0.383), PLT yields were higher with Trima Accel (7.48 × 10¹¹ vs. 6.06 × 10¹¹, p < 0.001), corresponding to a higher PLT recruitment (1.90 vs. 1.42, p < 0.001). We observed a different increase of WBC counts after aphereses, which was more pronounced with Trima Accel than with Amicus (1.30 × 10⁹/l vs. 0.46 × 10⁹/l, p < 0.001). Conclusion: Both procedures induced PLT recruitment. This was higher in Trima Accel, contributing to a higher yield in spite of a comparable depletion of circulating PLT in the donors. This recruitment facilitates the harvest of multiple units within a single donation and seems to be influenced by the procedure utilized. The different increases of circulating donor white blood cells after donation need further investigation.