Beta-thromboglobulin and platelet factor 4 in polycythemia patients treated by ticlopidine

34 polycythemic patients, in complete or partial stable remission, were studied for beta-thromboglobulin (beta-TG) and platelet factor 4 (PF-4) before, during and after treatment by an antiaggregating agent, ticlopidine, in comparison with 30 untreated patients. The cases with initial high value have an obvious drop, which is still maintained at the 2nd month after treatment, independent of variations of red cell and platelet counts. Any long-term protocol for clinical evaluation of antiaggregating therapy in myelo-proliferative diseases should be founded on evaluation of the markers of platelet function.