Monoclonal antibody against platelet thrombospondin decreases erythrocyte aggregation rate

Abstract

The effect of thrombospondin, a major glycoprotein in the platelet a-granule, on the erythrocyte aggregation rate was investigated. Venous blood was sampled from 8 healthy male volunteers and anticoagulated with 1.1 mg/ml EDTA(K₂). The erythrocyte aggregation rate of each blood sample was measured with a whole-blood erythrocyte aggregometer before and after incubation with murine monoclonal antibody against human platelet thrombospondin. After 15 min incubation, the erythrocyte aggregation rate exhibited a significant decrease to 0.055 ± 0.022/s, representing 71.9 ± 8.7% of the control value (0.075 ± 0.028/s) (p < 0.0005). The results obtained suggest that thrombospondin may participate in the control of erythrocyte aggregability in the circulating blood.