Evolution of adverse changes in stored RBCs
Elliott Bennett-Guerrero, Tim H Veldman, Allan Doctor, Marilyn J Telen, Thomas L Ortel, T Scott Reid, Melissa A Mulherin, Hongmei Zhu, Raymond D Buck, Robert M Califf, Timothy J McMahon, Elliott Bennett-Guerrero, Tim H Veldman, Allan Doctor, Marilyn J Telen, Thomas L Ortel, T Scott Reid, Melissa A Mulherin, Hongmei Zhu, Raymond D Buck, Robert M Califf, Timothy J McMahon
Abstract
Recent studies have underscored questions about the balance of risk and benefit of RBC transfusion. A better understanding of the nature and timing of molecular and functional changes in stored RBCs may provide strategies to improve the balance of benefit and risk of RBC transfusion. We analyzed changes occurring during RBC storage focusing on RBC deformability, RBC-dependent vasoregulatory function, and S-nitrosohemoglobin (SNO-Hb), through which hemoglobin (Hb) O(2) desaturation is coupled to regional increases in blood flow in vivo (hypoxic vasodilation). Five hundred ml of blood from each of 15 healthy volunteers was processed into leukofiltered, additive solution 3-exposed RBCs and stored at 1-6 degrees C according to AABB standards. Blood was subjected to 26 assays at 0, 3, 8, 24 and 96 h, and at 1, 2, 3, 4, and 6 weeks. RBC SNO-Hb decreased rapidly (1.2 x 10(-4) at 3 h vs. 6.5 x 10(-4) (fresh) mol S-nitrosothiol (SNO)/mol Hb tetramer (P = 0.032, mercuric-displaced photolysis-chemiluminescence assay), and remained low over the 42-day period. The decline was corroborated by using the carbon monoxide-saturated copper-cysteine assay [3.0 x 10(-5) at 3 h vs. 9.0 x 10(-5) (fresh) mol SNO/mol Hb]. In parallel, vasodilation by stored RBCs was significantly depressed. RBC deformability assayed at a physiological shear stress decreased gradually over the 42-day period (P < 0.001). Time courses vary for several storage-induced defects that might account for recent observations linking blood transfusion with adverse outcomes. Of clinical concern is that SNO levels, and their physiological correlate, RBC-dependent vasodilation, become depressed soon after collection, suggesting that even "fresh" blood may have developed adverse biological characteristics.
Conflict of interest statement
Conflict of interest statement: E.B.-G., A.D., M.J.T., T.L.O., and T.J.M. received grant support from NITROX LLC (www.nitrox.com) to perform this study; A.D. received less than $10,000 as consulting fees or paid advisory board for NITROX LLC and iNO Therapeutics and received grant support from iNO Therapeutics. T.H.V. and T.S.R. (formerly an employee of Cato Research Ltd., which coordinated and did data management for this study) were employees of NITROX LLC during the study; R.D.B. was compensated for this work through StatWorks, Inc., which was contracted by NITROX LLC to perform the statistical analyses; R.M.C. is a founder of and has a significant equity interest in NITROX LLC; T.J.M. is coinventor of U.S. Patent 6,916,471, 2005 “Red blood cells loaded with S-nitrosothiols and uses therefore.”
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Source: PubMed