Numerical-experimental estimation of the deformability of human red blood cells from rheometrical data

TL;DR

This study presents a novel method to estimate the deformability of individual human red blood cells from macro-rheological data, linking suspension viscosity behavior to cell membrane elasticity, aiding clinical diagnosis.

Contribution

The paper introduces an integrated analysis approach that estimates individual RBC deformability from rheological suspension data, a previously unestablished method.

Findings

Estimated membrane shear elasticity matches experimental shear-thinning behavior.

The method successfully links macro-rheological data to individual cell properties.

It enables non-invasive assessment of RBC deformability for clinical applications.

Abstract

The deformability of human red blood cells (RBCs), which comprise almost 99% of the cells in whole blood, is largely related not only to pathophysiological blood flow but also to the levels of intracellular compounds. Therefore, statistical estimates of the deformability of individual RBCs are of paramount importance in the clinical diagnosis of blood diseases. Although the micro-scale hydrodynamic interactions of individual RBCs lead to non-Newtonian blood rheology, there is no established method to estimate individual RBC deformability from the rheological data of RBC suspensions, and the possibility of this estimation has not been proven. To address this issue, we conducted an integrated analysis of a model of the rheology of RBC suspensions, coupled with macro-rheological data of human RBCs suspended in plasma. Assuming a non-linear curve of the relative viscosity of the suspensions as a function of the cell volume fraction, the statistical average of the membrane shear elasticity was estimated for individual intact RBCs or hardened RBCs. Both estimated values reproduced well the experimentally observed shear-thinning non-Newtonian behavior in these suspensions. We hereby conclude that our complementary approach makes it possible to estimate the statistical average of individual RBC deformability from macro-rheological data obtained with usual rheometric tests.