Platelet activation and erythrocyte aggregation rate in patients with cerebral infarction

We measured the platelet activation and the rate of erythrocyte aggregation simultaneously employing venous blood from 31 patients with cerebral infarction during the acute phase (less than 7 days after onset) and 73 patients with cerebral infarction during the chronic phase (more than 1 month after onset.). The degree of platelet activation was estimated from the levels of plasma beta-thromboglobulin (BTG), platelet factor 4 (PF4), and thrombospondin (TSP). The erythrocyte aggregation rate was examined using the whole-blood erythrocyte aggregometer developed by us (Am. J. Physiol. 251, H1205-H1210, 1986) with concomitant measurement of the fibrinogen concentration. The mean values of the erythrocyte aggregation rate, plasma BTG, PF4, TSP and fibrinogen concentration at the acute phase of cerebral infarction were statistically significantly (P<0.05) higher than those at the chronic phase of cerebral infarction or in the control group. Multiple regression analysis revealed that fibrinogen, BTG and TSP were main factors contributing to the enhanced erythrocyte aggregation rate at the acute phase of cerebral infarction, but fibrinogen was the sole contributing factor at the chronic phase of cerebral infarction. We conclude that the platelet activation, erythrocyte aggregation rate and fibrinogen concentration were closely correlated with each other in patients with cerebral infarction during the acute phase.