Blood rheology and sickle cell anemia

This review explores the involvement of blood rheological properties in sickle cell anemia. After outlining some basic hemodynamic and hemorheological principles, we define blood viscosity and its main determinants-hematocrit, plasma viscosity, red blood cell deformability and aggregation. This first part concludes with a discussion of the relationship between blood viscosity and vascular response, including the F & aring;hr ae us and F & aring;hr ae us-Lindqvist effects typical of micro-circulation. The second part explores how blood rheology is implicated in sickle cell anemia, detailing the cellular and molecular determinants of hemorheological abnormalities, such as the effects of fetal hemoglobin, a-thalassemia, glucose-6-phosphate dehydrogenase deficiency, (3S haplotypes, ion channels and membrane transporters, oxidative stress, nitric oxide, and red blood cell mitochondrial retention.