Effects of rejuvenation and frozen storage on 42-day-old AS-3 RBCs

BACKGROUND: A storage period of 42 days has been approved by the FDA for RBCs stored in NUTRICEL (AS-3). This study was undertaken to provide data to the FDA about the feasibility of salvaging AS-3 RBCs at the end of their storage period by rejuvenation and freezing, and to evaluate the effect of rejuvenation on indicators of RBC function. STUDY DESIGN AND METHODS: Healthy adults (n = 22) donated 450 mL of whole blood, and RBC components were prepared at two study sites. The components were stored at 1 to 6 degrees C for either 41 days (nonrejuvenated frozen controls, n = 6) or 42 days (rejuvenated frozen study group, n = 10; nonrejuvenated nonfrozen controls, n = 6). Rejuvenated study components and nonrejuvenated frozen controls were stored at -70 degrees C for longer than 2 weeks. Frozen units were then deglycerolized and kept for an additional 24 hours at 1 to 6 degrees C. RESULTS: 2,3-DPG, and ATP were reduced after 42-day storage to near 0 and 65 percent, respectively, of their original values. After rejuvenation and deglycerolization, the mean ATP level was 146 percent and the mean 2,3-DPG was 115 percent. The percent freeze-thaw-wash recovery was similar for rejuvenated and nonrejuvenated RBCs. Trace amounts of hypoxanthine and inosine were detected in rejuvenated units. The mean 24-hour survival (single- or double-label technique) of all components exceeded 75 percent. The t1/2 of study and control RBCs was similar. CONCLUSION: The ability of 42-day-old AS-3 RBCs to deliver oxygen after rejuvenation and freezing is not impaired. These data indicate that rejuvenated AS-3 RBCs can provide a safe and beneficial blood component immediately upon infusion.