A light scatter based model relating erythrocyte vesiculation to lifetime in circulation

Abstract

Methods for measuring erythrocyte age distribution are not available as a simple analytical tool. Most of them utilize the fluorescence or radioactive isotopes labeling to construct the age distribution and support physicians with aging indices of donor's erythrocytes. The age distribution of erythrocyte may be a useful snapshot of patient state over 120‐days period of life. Previously, we introduced the enhanced assay of erythrocytes with measurement of 48 indices in four categories: concentration/content, morphology, aging and function (10.1002/cyto.a.24554). The aging category was formed by the indices based on the evaluation of the derived age of individual cells. The derived age does not exactly mean the real age of erythrocytes and its evaluation utilizes changes of cellular morphology during a lifespan. In this study, we are introducing the improved methodological approach that allows us to retrieve the derived age of individual erythrocytes, to construct the aging distribution, and to reform the aging category consisting of eight indices. The approach is based on the analysis of the erythrocyte vesiculation. The erythrocyte morphology is analyzed by scanning flow cytometry that measures the primary characteristics (diameter, thickness, and waist) of individual cells. The surface area (S) and sphericity index (SI) are calculated from the primary characteristics and the scattering diagram SI versus S is used in the evaluation of the derived age of each erythrocyte in a sample. We developed the algorithm to evaluate the derived age that provides eight indices in the aging category based on a model using light scatter features. The novel erythrocyte indices were measured for simulated cells and blood samples of 50 donors. We determined the first‐ever reference intervals for these indices.

4π light scattering flow cytometry: enhancing the identification and characterization of individual cells

“…We have demonstrated the SFC's ability to measure 51 indices that characterize erythrocyte morphology and function. 23,25 Additionally, we have measured 21 indices for platelets, allowing for the characterization of platelet morphology and function in relation to hemostasis. 13 Platelet function was assessed through indices that quantify platelet activation, however, there are currently no indices available in the assay for platelet aggregation.…”

Terminal maturation of human reticulocytes to red blood cells by extensive remodelling and progressive liquid ordering of membrane lipids

“…Separate, because the observed decrease in cell volume largely exceeds that obtainable with the release of membrane in the form of small vesicles, thus requiring that cell volume decrease by a different mechanism 50,51,66 . Highly coordinated, in order to maintain a remarkably constant surface-to-volume ratio of the discocyte throughout its circulatory life [68][69][70][71] . The common volume regulatory mechanism for circulating reticulocytes and RBCs may involve mechanosensitive channels and loss of potassium through the Gardos channel 72 .…”