Program: Oral and Poster Abstracts
Session: 401. Basic Science and Clinical Practice in Blood Transfusion: Poster II
We analyzed the morphological, biochemical, metabolic, and bio-mechanical characteristics of erythrocytes stored in optimal blood bank conditions for 6 donors, at Day 3, 21, 28, 35 and 42 of the storage period. This longitudinal study of parameters such as mean corpuscular volume, intracellular ATP level, hemolysis, osmotic fragility, deformability and the plasma levels of ions and metabolites has highlighted a great inter-donor variability in the storage lesion process. Moreover, Imagestream analysis of front views of sharp, single cells revealed a subpopulation of small erythrocytes. The “projected surface area” distribution on normalized frequency plots was bimodal in 5 of 6 concentrates, showing a well-demarcated subpopulation of less than 62 µm2. The proportion of this sub-population increased with storage from 0.5-3.4% at D3 to 4-23.5% at D42 (p<0.05). These cells displayed a low fluorescence staining in the EMA-binding test, a diagnostic test for hereditary spherocytosis. With a more detailed morphological analysis we could determine that this sub-population corresponds to a mix of echinocytes III, spherocytes and sphero-echinocytes (Bessis classification). These results have been confirmed by differential interference phase contrast microscopy (DIC) observations, carried out in parallel, as a gold standard of our imaging flow cytometry study. Indeed, we found a very good correlation between the proportion of small erythrocytes detected in imaging flow cytometry and the echinocytes III, sphero- and spheroechino-cytes detected by DIC (correlation coefficient= 0.84).
These morphological alterations have been considered irreversible (Berezina et al., 2002) and are reminiscent of those associated with mechanical clearance of erythrocytes in the spleen of patients with hereditary spherocytosis (Mohandas et al., 2008). We hypothesize that these storage-induced small erythrocytes correspond to the subpopulation of “damaged” erythrocytes that are rapidly cleared after transfusion. Confirmation of these findings using ex-vivo perfusion of human spleens and observational studies in transfused patients would support the use of imaging flow cytometry to predict transfusion yield.
Disclosures: No relevant conflicts of interest to declare.
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