INCREASED WHOLE-BLOOD VISCOSITY ON COOLING IN A PATIENT WITH COLD HEMOAGGLUTININ DISEASE

Whole blood and plasma viscosities were evaluated in a patient with cold hemagglutinin disease at different temperatures and at different shear rates. At 37 and 42.degree. C, whole blood viscosity values, regardless of the shear rate applied, were correspondent to the hematocrit value (31%). The values observed were similar to those noted in a patient with chronic bleeding anemia and an approximately equivalent hematocrit (33%). The same was true for plasma viscosity. At 32.degree. C, whole blood viscosity, regardless of the shear rate, was higher than expected. The values observed were similar to those noted in a normal subject with a clearly higher hematocrit value (44%), and definitely higher than those noted in the chronic anemia patient. Plasma viscosity remained unchanged. In cold hemoagglutinin disease, red cell aggregation and piling are apparently capable of increasing blood viscosity.