Iron accelerates hemoglobin oxidation increasing mortality in vascular diseased guinea pigs following transfusion of stored blood
Jin Hyen Baek, … , Dominik J. Schaer, Paul W. Buehler
Jin Hyen Baek, … , Dominik J. Schaer, Paul W. Buehler
Published May 4, 2017
Citation Information: JCI Insight. 2017;2(9):e93577. https://doi.org/10.1172/jci.insight.93577.
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Research Article Hematology Vascular biology

Iron accelerates hemoglobin oxidation increasing mortality in vascular diseased guinea pigs following transfusion of stored blood

Abstract

Non–transferrin-bound iron (NTBI) and free hemoglobin (Hb) accumulate in circulation following stored RBC transfusions. This study investigated transfusion, vascular disease, and mortality in guinea pigs after stored RBC transfusion alone and following cotransfusion with apo-transferrin (apo-Tf) and haptoglobin (Hp). The effects of RBC exchange transfusion dose (1, 3, and 9 units), storage period (14 days), and mortality were evaluated in guinea pigs with a vascular disease phenotype. Seven-day mortality and the interaction between iron and Hb as cocontributors to adverse outcome were studied. Concentrations of iron and free Hb were greatest after transfusion with 9 units of stored RBCs compared with fresh RBCs or stored RBCs at 1- and 3-unit volumes. Nine units of stored RBCs led to mortality in vascular diseased animals, but not normal animals. One and 3 units of stored RBCs did not cause a mortality effect, suggesting the concomitant relevance of NTBI and Hb on outcome. Cotransfusion with apo-Tf or Hp restored survival to 100% following 9-unit RBC transfusions in vascular diseased animals. Our data suggest that increases in plasma NTBI and Hb contribute to vascular disease–associated mortality through iron-enhanced Hb oxidation and enhanced tissue injury.

Authors

Jin Hyen Baek, Ayla Yalamanoglu, Yamei Gao, Ricardo Guenster, Donat R. Spahn, Dominik J. Schaer, Paul W. Buehler

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Figure 2

Plasma iron and cell-free hemoglobin (Hb) following fresh red blood cell (F-RBC) and stored red blood cell (S-RBC) transfusion in guinea pigs is prevented with infusion of apo-transferrin (apo-Tf) and haptoglobin (Hp), respectively.

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Plasma iron and cell-free hemoglobin (Hb) following fresh red blood cell...
(A and B) Electron microscopy images of donor guinea pig RBCs on storage day 1 and storage day 14, respectively. Scale bars: 5 μm. Original magnification, ×5,000. (C) Maximum plasma non–transferrin-bound iron (NTBI) concentrations (Cmax) were significantly increased following 9-unit transfusion of S-RBCs compared with F-RBCs (n = 10, P = 0.0001), coadministration with apo-Tf significantly decreased NTBI (n = 10, P = 0.0001), while Hp had no effect on plasma NTBI levels. Significant increases in plasma NTBI were also observed following F-RBC transfusion compared with S-RBC + Hp (n = 10, P = 0.0001) and between S-RBC + apo-Tf and S-RBC + Hp (n = 10, P = 0.0001). (D) Plasma apo-Tf concentrations (n = 5) versus time (blue, left axis) and the saturation of infused apo-Tf (n = 5, right gray axis) are shown for qualitative visualization. (E) NTBI plasma concentration versus time areas (AUCs) show no difference between 1, 3, and 9 units of S-RBCs in this model. Transfusion with S-RBCs at 1, 3, and 9 units, and 9 units + Hp significantly increased plasma NTBI compared with 9 units S-RBCs + apo-Tf (n = 10, P = 0.0001). (F) Maximum plasma Hb concentrations (Cmax) increased compared with 9-unit F-RBC transfusion as follows: 9 units F-RBCs versus 9 units S-RBCs (n = 10, P = 0.0140); 9 units F-RBCs versus 9 units S-RBCs + apo-Tf (n = 10, P = 0.0210). While Hp significantly decreased maximum Hb concentrations compared with 9 units S-RBCs (n = 10, P = 0.0151) and 9 units S-RBCs + apo-Tf (n = 10, P = 0.0191). (G) Plasma Hp concentrations (blue, left axis) and mean plasma Hb concentrations (mg/ml) after transfusion with 9 units S-RBCs (red line/area, right axis) are shown to qualitatively demonstrate that Hp exceeds Hb at all time points. Inset is a representative size-exclusion chromatograph showing that all Hb is bound to Hp (red trace represents Hb and blue trace represents Hb-Hp in plasma). All statistical comparisons were made using an ANOVA with a multiple comparisons test. All data are presented as individual values with the mean ± SD.