Study of the factors affecting blood viscosity in patients with thromboangiitis obliterans. A preliminary report.

Hematocrit values, plasma fibrinogen levels, and erythrocyte deformability are well-recognized factors affecting blood viscosity. We studied the incidence of abnormalities in these factors among 17 patients suffering from thromboangiitis obliterans (Buerger's disease) compared with 14 normal age- and sex-matched control subjects. Hematocrit values and fibrinogen levels were higher, whereas the erythrocyte filterability index was lower among the patients with Buerger's disease (p less than 0.001). Incubation of washed erythrocytes from these patients with control plasma of blood type AB produced an improvement of the filterability index (p less than 0.005). Our findings suggest that patients suffering from Buerger's disease show, in addition to the well-recognized arterial lesions, an abnormality in the factors affecting blood viscosity. This may contribute to a worsening of the clinical manifestations. Evidence is presented suggesting that a plasmatic factor may be responsible for the impaired erythrocyte filterability.