[Deformability and aggregability of erythrocytes: significance in clinical biology]

In order to understand blood circulation, knowledge of the rheological properties of blood is required. However the characteristic parameters which must be considered differ according to the circulatory region investigated. A distinction must therefore be made between macrorheological parameters (viscosity, viscoelasticity) and the microrheological parameters (red blood cell deformability and aggregability). In this paper the main determinants of R.B.C. deformability and aggregability are discussed as well as the applications in clinical biology.