Plasma Levels of β-Thromboglobulin and Platelet Factor 4 in Relation to the Venous Platelet Concentration

Abstract

The plasma levels of β -thromboglobulin (β-TG) and platelet factor 4 (PF-4) were determined in patients with various hematologic malignancies, and the results were related to simultaneously determined venous platelet counts. All studied patients were in a steady state. The plasma β-TG concentrations were determined on 69 occasions and the values ranged from 0 to 82 ng/ml. In 33 instances, the venous platelet countwas < 25 × 10⁹/l and in two thirds of these samples β-TG was undedectable. The highest values for plasma β-TG were found in patients with the highest venous platelet counts. A highly significant correlation (r = 0.77, p < 0.001) between the values forplasma β-TG and venous platelet count was present. The plasma concentrations for PF-4 ranged from 0 to 50 ng/ml. Similarly, there was a highly significant relationship (r = 0.78, p < 0.001) between the values for PF-4 and venous platelet concentration. We conclude, if the plasma levels of β-TGand PF-4 are used as markers of platelet activation in vivo, it is necessary to simultaneously consider the platelet concentration in the collected blood.