Red blood cell metabolic responses to refrigerated storage, rejuvenation, and frozen storage.

BACKGROUND: Storage of red blood cells (RBCs) under blood bank conditions promotes metabolic modulation within the RBC. This "metabolic storage lesion" may affect the quality and safety of the transfused RBCs. The aim of this study is to determine the metabolic changes in stored RBCs over 42 days of routine storage followed by a US Food and Drug Administration-approved method of rejuvenation, freezing, and preparation for transfusion. STUDY DESIGN AND METHODS: We exploited a mass spectrometry-based metabolomics approach to monitor 42-day-stored citrate phosphate dextrose/AS-1 RBCs (n = 29) that were rejuvenated, glycerolized and frozen, then thawed and deglycerolized, and held for 24 hours at 1 to 6ºC in saline-glucose. RESULTS: Previously reported metabolic alterations were confirmed in 42-day-old RBCs. In this study, in total, 181 (62%) of the biochemical compounds exhibited significant (p ≤ 0.05) change compared with Day 0 values. Rejuvenation restored adenosine triphosphate and 2,3-diphosphoglycerate levels, replenished purine reservoirs, up regulated glycolysis, increased levels of pentose phosphate pathway intermediates, and partially rescued glutathione biosynthesis. Increased levels of lysophospholipid in rejuvenated RBCs suggests the activation of recycling pathways of damaged membrane lipids, in which a total of 167 (57%) biochemical compounds showed significant change compared with Day 42 values. CONCLUSION: Rejuvenation reversed over one-half of the metabolic biochemical compounds evaluated compared with Day 42 values, and the compounds were stable through frozen storage and preparation for transfusion. Rejuvenation promoted significant metabolic reprogramming, including the reactivation of energy-generating and antioxidant pathways (the pentose phosphate pathway and glutathione homeostasis), salvage reactions, cofactor reservoirs, and membrane lipid recycling.

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.