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.

Seven-day storage of single-donor platelets: recovery and survival in an autologous transfusion study.

BACKGROUND: Bacterial screening may effectively reduce the morbidity and mortality risk associated with extended storage of platelets. Platelet viability then becomes the primary determinant of acceptable storage time. This study evaluates the effectiveness of platelets stored in plasma for 7 days. STUDY DESIGN AND METHODS: WBC-reduced, single-donor platelets (n = 24) were collected and stored by standard methods at two sites. Standard in vitro platelet biochemical and functional parameters were monitored over the storage period. On Days 5 and 7 of storage, platelets were alternately labeled with 51Cr and (111)In and returned to the subject, and recovery and survival were determined. RESULTS: Component pH(22 degrees C) was maintained in the range 6.2 to 7.61 through 7 days and did not detrimentally affect either in vitro or in vivo outcomes. In vitro platelet characteristics were adequately maintained over 7 days. Day 5 platelets had better recovery (63.0 +/- 4.36 vs. 53.9 +/- 4.36%, p < 0.0001) and survival (161 +/- 8.1 vs. 133 +/- 8.1 hr, p = 0.006) than Day 7 platelets adjusting for radioisotope, center, and donor effects. CONCLUSION: Although declines in recovery and survival were noted, these are less than used previously to gain licensure of 7-day storage and are unlikely to be clinically significant. Extension of storage to 7 days could be implemented with bacterial screening methods to select out contaminated components without a significant effect on the platelet efficacy compared to 5-day components.

Production of pathogen-inactivated RBC concentrates using PEN110 chemistry: a Phase I clinical study.

BACKGROUND: Despite extensive reductions in risk, donor selection and testing cannot eliminate pathogen transmission. The objective of this study was to evaluate clinically the viability of pathogen-inactivated RBCs. STUDY DESIGN AND METHODS: Twelve healthy subjects each donated two units of blood that were handled as additive system control units or were inactivated using the PEN110 process (INACTINE, V.I. Technologies) in randomized order. PEN110, which inactivates pathogens by reacting with nucleic acid bases, was incubated with RBCs for 6 hours, followed by washing and quenching with sodium thiosulfate. Radiolabeled RBC recovery and survival determinations were undertaken after 28 days of storage; biochemical and hematologic variables were assessed over 42 days. RESULTS: After 28 days, treated units had a 24-hour double-label ((51)Cr/(99m)Tc) recovery (85.0 +/- 5.0%) that was indistinguishable from control units (85.9 +/- 2.7%); the times required for reduction of radioactivity of labeled cells to half the Day 1 activity (T(50)) were similar for both groups (treated, 31.9 +/- 8.2 days; control, 32.9 +/- 3.3 days). No deleterious effects of PEN110 treatment were found on RBC antigens tested. Treatment reduced 2,3-DPG levels by half and slightly lowered pH levels. Throughout the 42-day storage period, treated RBCs had a lower level of lactate production and a trend toward lower glucose consumption. Hemolysis remained below 1 percent; supernatant potassium and ATP levels were lower than those seen in control RBCs. CONCLUSION: PEN110-treated RBCs stored for 28 days meet all critical requirements for therapeutically useful units.