Abstract
Haemorheologic studies, were performed in 68 patients (pts) with Polycythaemia Vera (PV) under treatment by venesection alone or by cytostatic drugs with or without venesection. PV pts had higher haematocrit (PVC) and elevated whole blood viscosity (WBV) even after reconstitution of blood to 0.45 PCV, in comparison with a control group. MCV and MCH were parallely reduced. In the pts with marked hypochromic microcytosis prolonged erythrocyte filtration times (EFT) were recorded; however this finding seemed better attributable to the larger filtered RBC number than to impaired erythrocyte deformability. The supposed influence of hypochromic microcytosis, due to repeated venesections, on blood viscosity parameters in treated PV pts could not be confirmed. PV pts with “vascular risk” factors had higher values of WBV, plasma viscosity, and fibrinogen. It is concluded that: 1) hypochromic microcytosis is not per se associated with abnormal haemorheological behavior and 2) plasmatic factors greatly contribute to hyperviscosity in treated PV pts.
Get full access to this article
View all access options for this article.