(602g) Theoretical and Experimental Verification of Changes In Oxygen Binding Capability of Red Blood Cell Based On Magnetic Susceptibility

Approximately 40% of critically ill individuals receive at least on unit of packed red blood cells, RNC, in the intensive care unit, with a mean of five units per patient; a total of approximately 15 million units a year. However, a significant debate exists with respect to the apparent association of increased morbidity and mortality with old, stored RBC (current standards allow RBC to be up to 45 days old and still transfused). This is referred to in the literature as ?RBC storage lesions?.

While RBC have a number of functions, the most obvious is oxygen transport through the hemoglobin molecule. Interestingly, and theoretically predicted by Linus Pauling in the 1930s, the magnetic susceptibility of the hemoglobin molecule, and correspondingly the RBC, is a function of the oxygenation state of the Heme group: a deoxygenated Heme has a paramagnetic magnetic moment resulting from the existence of unpaired electrons, while oxygenated Heme has a diamagnetic character are a result of paired electrons. This difference in magnetic moments, under specific conditions, can results in detectable difference in RBC induced motion between deoxygenated and oxygenated RBC. Using fundamental relationships, we previously demonstrated that we could predicted, and experimentally verify this induced motion (Zborowski et al. 2003).

In this study, we wish to theoretically and experimentally demonstrate that we can, in fact, detect ?RBC storage lesions? in the ability of the transfusion quality RBC to give up oxygen as the stored blood ages. Potential implications to this overall question will also be discussed.

Zborowski, M., Ostera, G.R., Moore, L.R., Milliron, S., Chalmers, J.J., Schechter, A.N. Red Blood Cell Magnetophoresis, Biophysics Journal, 84:2638-2645. 2003.