Evaluation of in vivo and in vitro quality of apheresis-collected RBC stored for 42 days

Background and Objectives: New technological developments make it possible to collect red blood cells (RBCs) by apheresis,which allows for better prod uct consistency and has the potential for improved RBC quality. The purpose of these studies was to evaluate the quality and consistency of units of R BCs collected by apheresis using the MCS+(R) machine (Haemonetics Corp., Br aintree, Mass., USA). Materials and Methods: Two studies were performed. In study 1 (n = 10), using containers and CP2D/AS-3 solutions from Medsep Cor p. Covina, Calif. USA), one-unit apheresis RBCs were compared to manually c ollected RBCs in. random crossover design. In study 2 (n = 12), 6 subjects had one unit collected, while the remaining 6 subjects had two units of RBC s collected with comparison to previously manually collected RBCs from the same donors. Haemone tics containers and solutions were used in study 2. Re sults: Low RBC volume variability was found for the apheresis collections w ith a standard deviation of only 6 mi difference between actual and target volumes. Combining the data from the two studies (n = 21 pairs), at 42 days of storage, the apheresis units showed slightly lower hemolysis (0.44+/-0. 26 vs. 0.61+/-0.50%), lower supernatant potassium levels (50+/-3 vs. 53+/-3 mEq/l), and improved tolerance to osmotic shock (47+/-3 vs. 49+/-3%) as co mpared to manual units (p<0.05). There was no statistically significant dif ference in RBC ATP (3.0+/-0.6 vs. 2.9+/-0.5 mu mol/g Hb) or in 24-hour perc ent recoveries (81+/-6 for apheresis vs. 81+4% for apheresis red cells). Ap heresis RBC quality was not: affected by the manufacturer (Haemonetics vs. Medsep) of solutions and containers. Conclusions: RBC units collected by ap heresis demonstrated low variability in volume of RBC mass collected, and s howed similar RBC properties as compared to manually collected RBCs after p rocessing and after 42 days of storage.