Changes in erythrocyte microrheology in patients with psoriasis.

Erythrocyte deformability (ED), the ability of red blood cells to change shape during flow in the microcirculation, is the basic rheological property of erythrocytes. It is determined by the surface area to volume ratio, viscoelastic properties of the membrane, and intracellular viscosity. The aim of the present study was to determine changes in erythrocyte microrheology in patients with psoriasis. The whole red cell deformability was measured by flow-channel diffractometry. To assess the contribution of different factors influencing changes in ED, measurements were also made of the biophysical state of the phospholipid bilayer, using an osmotic haemolysis technique, and internal viscosity, using electron paramagnetic resonance spectroscopy. The results showed a significant decrease in ED in patients with psoriasis in comparison with controls, and suggested that the main cause of this may be alterations in intracellular viscosity and membrane viscoelastic behaviour.