Background: New technologic developments enable automated collection and preparation of red blood cells (RBCs). This study's aim was to evaluate quality of apheresis-derived RBCs (ARBCs) collected as single units along with platelets (RBC-Ps) or double units (2-RBCs) with four different apheresis systems.
Study design and methods: Sixty-six donors with similar baseline variables underwent RBC apheresis collection with various machines (Amicus [15 RBC-Ps] and Alyx [15 2-RBCs], Baxter; the Trima Accel [9 RBC-Ps, 8 2-RBCs], Gambro, and the MCS+[9 RBC-Ps, 10 2-RBCs], Haemonetics Corp.). In vitro properties were analyzed during 49 days of storage and compared to manual RBCs (MRBCs, n = 14).
Results: All units but one, Alyx, demonstrated white blood cell counts of less than 1 x 10(6). ARBCs showed lower variability in volume compared to MRBCs. All units met international requirements (European, AABB) for hematocrit (50%-70%), hemoglobin (>40 g/unit), and RBC mass (>or=153 mL). pH values remained similar between study groups without reaching critical limits in any unit. MRBCs had slight advantages for hemolysis at the end of storage and were significantly superior in energy maintenance as indicated by less ATP degradation and potassium leak most likely due to more pronounced anoxidative glycolysis particularly during the first half of storage. Owing to more declining oxidative glucose metabolism, ARBCs demonstrated higher methemoglobin formation and subsequent oxygen release until the end of storage.
Conclusion: ARBCs exhibited better predictability in volume and absolute RBC mass than MRBCs and demonstrated sufficient in vitro quality throughout storage, even though lower ATP preservation and higher methemoglobin formation were observed compared to MRBCs probably due to differences in glucose metabolism.