A comparison of methods for the study of platelet hyperfunction in thromboembolic disorders.

To gain insight into the interrelationship of various methods for the study of platelet hyperfunction, we compared plasma beta-thromboglobulin (beta-TG), circulating platelet aggregates (CPA), and ADP-induced platelet aggregation in 119 patients with thromboembolic disorders and 28 control subjects. CPA correlated fairly well with beta-TG, suggesting that both methods measure similar in vivo platelet activation and aggregation. CPA had an excellent correlation with platelet survival half-time. In contrast, there was a poor correlation between in vitro platelet aggregation and CPA or beta-TG. These results confirm the notion that both CPA and beta-TG procedures are suitable for determination of in vivo platelet activation whereas platelet aggregation technique has serious limitations to test in vivo platelet activity. In order to have an accurate assessment of platelet hyperfunction, a battery of tests are needed.