Leucocyte numbers and quality: their effect on viscosity.

Leucocyte suspension viscosity was measured using cells from a number of leukaemias. Samples from individuals with acute myelomonocytic and myeloid leukaemias, and chronic myelogenous and chronic lymphatic leukaemias were examined for their viscosity and flow properties. Leucocytes were suspended in native plasma and the effect of variable leucocyte numbers in the ranges seen in some leukaemias (100-600 x 10(9)/l) examined at different shear stresses. The effect of MCV was also determined in relation to viscosity. The results showed an increasing order of viscosity from the leucocytes of chronic lymphatic leukaemia through chronic myelogenous and acute myeloid leukaemia to the acute myelomonocytic variety. This bears some relation to the mean corpuscular volume, but confirms the fact that at high numbers of cells, patients with acute myelomonocytic, and to a lesser extent the myeloid leukaemias, are at considerable risk of blood hyperviscosity.