Alterations in erythrocyte rheology in patients with severe peripheral vascular disease: 1. Cell volume dependence of erythrocyte rigidity.

The erythrocyte rigidity of patients suffering from severe peripheral vascular disease (PVD) was measured by a filtration method using 3 microns pore size filters. Filtration pressures for both PVD patients and normal subjects showed a cell volume dependency, and patient filtration pressures were normalized to cell volume to evaluate intrinsic, ie, nonvolume dependent, abnormalities in erythrocyte deformability. A significant (p less than 0.001) increase in cell rigidity was found in 44 of 54 PVD patients in comparison with volume-matched normal controls. No significant difference was found between patient mean corpusculer hemoglobin (MCH) and normal MCH at any given mean corpuscular volume (MCV), indicating that observed increases in erythrocyte rigidity are not attributable to changes in patient MCH. Therefore, the mechanism of increase in erythrocyte rigidity for PVD patients still needs further investigation into such parameters as levels of adenosine triphosphate,2,3-DPG, and membrane fluidity (calcium- and/or protein-binding membrane, cholesterol and phospholipid content of membrane, etc), as well as other aspects of erythrocyte physiology.