Leukapheresis reduced blood viscosity in chronic myelogenous leukemia patients with hyperleukocytosis

Abstract

The effect of leukapheresis on blood viscosity was studied in 7 patients with Philadelphia chromosome positive chronic myelogenous leukemia and extreme hyper leukocytosis (white blood cell counts over 200,000 per µl). All patients had manifestations attributable to leukostasis such as retinal haemorrhage, papilledema, pulmonary infiltrates or phlebitis. A coaxial cylinder viscometer was used to measure the blood viscosity at 37°C and shear rates from 208 to 0.01 sec⁻¹ on paired leukemic blood samples obtained pre- and post-leukapheresis. The leukemic blood viscosity was dependent on leukocrit, total cytocrit and shear rate. The pre-leukapheresis blood viscosity was significantly elevated in 5 patients and 3 of them had viscosity four times higher than normal. Our study documented the presence of blood hyperviscosity associated with hyperleukocytosis not sufficiently compensated by the coexisting anemia in patients with chronic myelogenous leukemia, particularly those of younger age or in blast crisis. Leukapheresis resulted in temporary cytoreduction, decreased the blood viscosity, and probably helped to ameliorate leukostasis.