Increasing erythrocyte aggregability with the progressive grades of chronic venous insufficiency: importance and...

Erythrocyte aggregation (EA) has appeared as the most interesting parameter among rheological measurements in chronic venous insufficiency (CVI). We therefore conducted two different kinds of studies to provide further information about the distribution and mechanisms of EA in CVI. We first analysed EA values in 67 patients, classified according to 3 evolutive groups: 27 patients suffering only from subjective symptoms of venous disease (grade 1), 19 patients with varicosis and sapheno-femoral incompetence (grade 2), 21 patients with varicosis and trophic skin changes (grade 3). EA values were also measured in 22 healthy controls. Analysis of EA was performed for equal concentrations of fibrinogen and adjusted for age. EA was significantly higher in CVI. The aggregation index, related to the kinetics of aggregates formation, rose significantly even from grade 1 while compared to controls and rose further with the evolutive grades. The same trend was found with the partial dissociation threshold (i.e. red cells aggregates cohesion). As the measurements were performed at standardized hematocrit and the results expressed after fibrinogen levels adjustment, this suggests the involvement of other factors. We subsequently investigated whether red cells from CVI patients aggregate more than those of controls when suspended in the same medium. The results showed that a cellular factor is unlikely to be involved, and that an interaction between red cells and plasma proteins other than fibrinogen could also explain the increased EA in CVI.