Platelet and plasma beta thromboglobulin in myeloproliferative syndromes and secondary thrombocytosis.

Elevated plasma beta thromboglobulin (betatg) and decreased intracellular platelet betatg were found in patients with various myeloproliferative disorders. In secondary thrombocytosis, similar, but less marked changes were found. The abnormalities were increased during episodes of clinical thrombosis and could be suppressed in two-thirds of cases by aspirin therapy.