Filtration of washed erythrocytes in atherosclerosis and diabetes mellitus

A positive-pressure filtration technique, using 5 µm pore-size Nuclepore filters, was used to study erythrocyte deformability in 47 atherosclerotic patients (compared with 25 controls) and 55 diabetics (compared with 37 controls). The effects of hyperproteinaemia, which caused significant increases in plasma viscosity and whole-blood viscosity in the atherosclerotic patients, and which can also impair erythrocyte filtration, were eliminated by washing the erythrocytes. The leucocytosis of diabetes mellitus, which can also impair erythrocyte filtration, was corrected for by adjusting the filtration results to a standard leucocyte count of 7.5 × 10 9 /l. After elimination of these extrinsic variables, the filterability of atherosclerotic and diabetic erythrocytes, from out-patients in the steady state, was not significantly different from that of control erythrocytes.