Blood Viscosity in Waldenström’s Macroglobulinemia

Erythrocytes and plasma proteins contribute to viscosity of blood. Therefore, blood viscosity was measured in 16 persons with macroglobulinemia with a cone-plate viscometer at defined shear rates. In each person a significant correlation (p < 0.001) was found between hematocrit and the logarithm of blood viscosity. The regression equation of this relationship in each patient was used to calculate the blood viscosity at several hematocrits. The blood viscosity at a given shear rate and constant hematocrit was significantly correlated (p < 0.001) with the plasma macroglobulin concentration in g/100 ml. The plasma of patients with macroglobulinemia is a non-Newtonian fluid, but at a given shear rate the plasma viscosity is a function of the macroglobulin concentration. These observations allowed the construction of an equation for calculation of blood viscosity in patients with macroglobulinemia when the hematocrit and plasma macroglobulin concentrations are known.