Red Cell

In this book, world-renowned experts in the field of hematopoietic cell transplantation examine a range of issues and controversies relating to apheresis, with the aim of identifying current trends and best practices. Readers will find up-to-date guidance on donor evaluation, CD34+ cell mobilization strategies, options and selection of apheresis device, anticoagulation techniques in apheresis, the role of prediction algorithms in determining procedure eligibility and length, and the prevention and management of complications.

The rheology of dense red blood cell suspensions is investigated via computer simulations based on the lattice Boltzmann, the immersed boundary, and the finite element methods. The red blood cells are treated as extended and deformable particles immersed in the ambient fluid. In the first part of the work, the numerical model and strategies for stress evaluation are discussed. In the second part, the behavior of the suspensions in simple shear flow is studied for different volume fractions, particle deformabilities, and shear rates. Shear thinning behavior is recovered. The existence of a shear-induced transition from a tumbling to a tank-treading motion is demonstrated. The transition can be parameterized by a single quantity, namely the effective capillary number. It is the ratio of the suspension stress and the characteristic particle membrane stress. At the transition point, a strong increase in the orientational order of the red blood cells and a significant decrease of the particle diffusivity are observed. However, the average cell deformation shows no signature of the transition.