Age-related changes in deformability of human erythrocytes

Abstract

The present study was designed to further the characterization of age- related changes in the deformability of human erythrocytes. The top (approximately young) and bottom (approximately old) 10% fractions of density-separated red cells from ten normal donors were subjected to graded levels of shear stress in a rheoscope. Measurements were made of steady-state elongation (cells tank treading in a state of dynamic equilibrium) and the time course of shape recovery following abrupt cessation of shear. In parallel with the rheologic experiments, several physical and chemical properties were assayed to determine correlates of mechanical properties. These included mean cell volume, mean corpuscular hemoglobin concentration, type A1 hemoglobin, glucosylation of membrane proteins, and membrane phospholipid and protein concentration. The microrheologic observations revealed that only about 90% of the old cells retained their capacity to tank tread. However, the tank-treading cells elongated less than their younger counterparts at corresponding levels of shear stress, thus demonstrating a reduced level of deformability. Further analysis of the data indicates that increases in membrane viscosity and elastic modulus along with a significant loss in excess surface area contribute to the limitation of the ability of the older cells to change shape.

Donor Age and Red Cell Age Contribute to the Variance in Lorrca Indices in Healthy Donors for Next Generation Ektacytometry: A Pilot Study

“…It is generally accepted that aging and senescence of RBCs results in loss of deformability (Linderkamp and Meiselman, 1982;Sutera et al, 1985;Chasis et al, 1989;Lutz et al, 1992;Bor-Kucukatay et al, 2005;McNamee et al, 2019). Information on the changes in RBC deformability during transformation from reticulocytes to young and mature cells is controversial.…”

Dynamics of erythrocytes in oscillatory shear flows: effects of S/V ratio

“…43 Another study shows that during the aging process of RBC there is a 2.4% decrease in volume but a 18% decrease in surface area so that the sphericity index of old cells rises to around 0.9 if the original value is 0.75. 25 The value of the sphericity index can be much larger in diseased cells. For instance, in cells affected by hereditary spherocytosis the shape approaches a sphere.…”

“…For example, during in vivo aging both the surface area and the internal volume of a RBC decrease in a way so that the S/V ratio decreases as well and the cell shape becomes more spherical. 25 The deformability of a red cell in quasi-static or dynamic loads is primarily determined by three factors: the shear stiffness of the membrane, the internal viscosity, and the S/V ratio. Among these factors, the membrane stiffness is included in the capillary number C a .…”

A Flow Induced Autoimmune Response and Accelerated Senescence of Red Blood Cells in Cardiovascular Devices

“…Poor RBC deformability has long been recognized for both senescent and mechanically traumatized RBCs. Working independently, Sutera and Shiga observed the flow of density separated, older cells in the rheoscope and reported increased stiffness 49,50 and many groups have found decreased deformability after non-physiologic shear of a non-segregated population of RBCs. Stiff red blood cells are challenged by the small dimensions of the trabeculated surfaces in the spleen.…”