Hematocrit dependence of erythrocyte aggregation

We studied hematocrit, erythrocyte aggregation index and plasma fibrinogen level in 19 healthy subjects. We measured erythrocyte aggregation both on native blood and on washed erythrocytes resuspended in their own autologous plasma or serum. We found a significant negative linear correlation between hematocrit and the erythrocyte aggregation index on native blood whereas we found a significant negative polynomial (quadratic) correlation between hematocrit and erythrocyte aggregation on erythrocyte suspensions. Moreover we found a significant positive correlation between plasma fibrinogen levels and the erythrocyte aggregation index. Methodological and clinical aspects of these findings are discussed.