[Clinical applications of beta-thromboglobulin and platelet factor 4 radioimmune assays (author's transl)].

beta-Thromboglobulin (beta-TG) and the anti-heparin activity platelet factor 4 (PF4) were simultaneously assayed by a radioimmune method in 108 subjects, most of whom had already be studied for platelet kinetics. The following data were obtained : while there was no technical cross-reaction, the two assays correlated closely, which indicates that they explore the same physiological phenomena : when controls were chosen at random in a population of wide age range, considerable differences were observed in the results, the values that could be considered excessive in a large percentage of cases, particularly among old, "normal" individuals ; there was no correlation between beta-TG and PF4 values on the one hand platelet destruction rate on the other ; plasma levels of beta-TG and PF4 were significantly higher in patients with vascular diseases and polycythaemia vera than in control but clearly overlapped with the values observed in controls of the same age group. The clinical significance of these data requires, to be assessed, a long-term prospective study aimed at determining whether patients with high beta-TG and PF4 levels present a high risk of thromboembolic complications and whether this risk can be reduced by correcting the biological abnormality with agents altering platelet function.