[Increase in erythrocyte and plasma viscosity in patients with atherosclerotic vasculopathy of different sites].

Peripheral atherosclerotic arteriopathies are characterised by increased blood viscosity and, according to some, by a reduction in red blood cell deformability. Red blood cell viscosity was studied in 40 atherosclerosic patients (14 carotid and 26 aortoiliacofemoral lesions). All patients were subjected to the standard diagnostic examination (Doppler velocimetry, etc.). Fifty healthy non-smokers of the same sex and 20 heavy smokers were studied as controls. The viscosity of the whole blood, and plasma and blood fibrinogen were assayed. In studying erythrocyte viscosity, cells poor in leucocytes and platelets suspended in a saline phosphate buffer were employed. The atherosclerotic patients presented significantly higher mean levels of erythrocyte viscosity (p less than 0.01) and the increase in plasma viscosity and blood fibrinogen was also statistically significant. The viscosity of the whole blood was also increased in these patients (p less than 0.001). The increase in blood viscosity in subjects with peripheral arteriopathies therefore appears to be attributable to the plasma and to rheological alterations in the red blood cells.