Abstract

This chapter discusses the possible molecular origin of red blood cell aggregation. It also discusses the methods typically used to measure Red blood cells (RBC) aggregation and to quantify single-cell adhesion strength. The chapter presents the impact of aggregation on the bulk blood viscosity and the pathophysiological factors involved in RBC aggregation, including the case of sickle cell anemia. The change in blood microstructure due to aggregation disruption is accompanied by a strong viscosity drop from approximately 100 to 10 cP. The aggregation force has been found to decrease with the interaction area while the disaggregation decreases with the same parameter. There are two unique RBC characteristics that are primarily responsible for this non-Newtonian behavior: RBC deformability and RBC aggregation. In addition to its effects on blood viscosity, RBC aggregation has been shown to directly modulate vascular reactivity.