The influence of fractions of abnormal erythrocytes on aggregation.

Erythrocytes with abnormal shapes and deformability reduce cell aggregation and hence sedimentation. It is not known what influence small fractions of these abnormal cells have on the sedimentation behaviour of normal cells. We have used three different methods to alter erythrocyte properties (glutaraldehyde, heat treatment, and metabolic depletion). The admixture of such cells in increasing fractions to normal cells affected the sedimentation behaviour in three different ways. Heat-treated erythrocytes decreased the sedimentation proportionally. Small fractions of glutaraldehyde-treated cells increased the sedimentation, which was explained by a pro-aggregatory change of surface properties by glutaraldehyde. With 50% or more glutaraldehyde-treated cells sedimentation was inhibited, which was due to excessive formation of aggregates occupying the entire tube. The presence of small fractions of echinocytes produced by metabolic depletion decreased cell sedimentation disproportionally, which was explained by an inability of spiculated cells to form aggregates with normal erythrocytes. These results indicate that erythrocyte sedimentation is affected by fraction of abnormal cells in a complex way. Many diseases are characterized by fractions of abnormal erythrocytes. Our results may, therefore, contribute to a better understanding of these conditions.