Deformability of red cells and splenectomy in hemolytic anemias

Abstract

The flexibility of human erythrocytes is caused by three properties: membrane flexibility, fluidity of the interior of the cells and a surplus of cell surface area versus cell volume due to the biconcave form. These factors permit them to assume any desired shape without changing their volume. If the fluidity of the cell interior or the surplus of cell surface is reduced, the “conformation instability” of the erythrocyte will decrease. In this overview the connection between rigidity and accelerated destruction of the erythrocytes in congenital hemolytic anemias will be discussed. Although alterations of rheological properties of the erythrocytes are due to different reasons, the mechanism of hemolysis is identical in nearly all congenital hemolytic anemias. The rigid cells are sequestered in the spleen, because of their inability to pass the small slits between the adventitial cells of the venous sinuses. After splenectomy the survival time of erythrocytes increases because the rigid cells no longer are sequestered at the same rate by the rest of the reticuloendothelial system.