Paraproteinemia: blood hyperviscosity and clinical manifestations.

Abstract

A B S T R A C T Many of the clinical features of paraproteinemia result from impairment of blood flow through the vascular tree because of blood hyperviscosity. Studies were carried out in 65 patients with serum paraproteins (31 with IgG, 25 with IgM, and 9 with IgA) to examine the relationship between the blood viscosity and the frequency of selected clinical features. The blood and plasma viscosities were measured at low rates of shear. Blood hyperviscosity was present in 91% of the patients and plasma hyperviscosity in 75% of the patients. In each of the three immunoglobulin classes both the blood and plasma viscosities increased logarithmically with the paraprotein concentration being greatest in the case of IgM. In addition, the relationship between the hematocrit and the logarithm of blood viscosity tended to be linear at any given protein concentration. In patients with very high levels of paraprotein the blood viscosity was modified by low hematocrits; the latter was below 30 in 70% of patients in whom the concentration of paraprotein was above 4 g/100 ml. The prevalence of clinical complications involving the retinal circulation, the peripheral vascular system, and the central nervous system increased markedly with increasing blood viscosity, measured at 0.18 s-1. One or more of these regions was affected in greater than 80% of patients with blood viscosity above 60 centipoise and in less than 23% ofpatients with blood viscosity below 40 centipoise. These observations illustrate the complex relationship between blood viscosity, concentration of paraprotein, immunoDr. M. A.

Biosynthesis of Immunoglobulin in Human Immunoproliferative Diseases

“…Plasma volume was some times derived from nomograms for height, weight and haematocrit. In patients with hy perviscosity who have expanded plasma volume [14], this method may underesti mate plasma volume with some degree of false underestimation of TCM. However, this situation arose in very few patients.…”

Plasma Exchange

“…Cryoglobulin and paraprotein may both be associated with an elevation of viscosity (McGrath and Penny, 1976;McGrath and Penny, 1978). Plasma factors, apart from fibrinogen, may also affect red-cell deformability (Braasch, 1974;Dodds et al, 1979).…”

Non-surgical management of peripheral vascular disease: a review.

“…'9 Increased viscosity due to paraproteinaemia will occasionally give rise to peripheral vascular symptoms, and these may regress with treatment. 40 Polycythaemia rubra vera is an occasional cause of peripheral vascular symptoms,41 but more commonly secondary polycythaemia and pseudopolycythaemia will be found.42 Improvement may be expected to accompany a reduced packed cell volume in all these groups using simple dilution techniques43 and phlebotomy, but it is unlikely that reducing the packed cell volume to abnormally low concentrations will offer any satisfactory practical long-term improvement. Many drugs used to treat peripheral vascular disease have been recently shown to decrease blood viscosity, but clinical trials have failed to show any benefit from these agents.44 Even the red cell itself appears to be abnormally rigid in peripheral vascular disease45 and drugs said to alter this are available,46 although evidence of their benefit to the ischaemic limb is not.…”