The influence of iron-deficient indices on whole blood viscosity in polycythaemia.

The relationship of the red-cell indices, packed-cell volume (PCV) and plasma viscosity to whole-blood viscosity was examined in 18 patients with polycythaemia. Sixteen were examined again following a course of venesection. The results were analysed by multiple regression analysis which allowed the effects of individual variables to be independently assessed. A reduction of the MCH or MCV was associated with increased whole-blood viscosity especially at low-shear rates. It is concluded that the reduced size of iron-deficient cells results in increased cell-cell interaction causing an increase in whole-blood viscosity.