Essential thrombocythemia in young adults: Major thrombotic complications and complications during pregnancy - A follow-up study in 68 patients

Objectives: Although essential thrombocythemia (ET) is usually primarily co nsidered a disorder of middle age, it has been observed in children and you ng adults. However, the real risk for thrombosis in these patients has not been clearly established. Design: Prospective analysis of consecutive patie nts younger than 40 at the time of the diagnosis of ET and followed in our department between 1980 and 1998. Subjects: Sixty-eight patients (28 males and 40 females, median follow-up 99.14 months) affected by ET diagnosed in agreement with the Polycythemia Vera Study Group criteria. Interventions: A symptomatic ET patients were not treated. In contrast, patients with associ ated atherosclerotic risk factors, microvascular disturbances, or a previou s major arterial thrombosis were given acetyl salicylic acid (ASA 100 mg/da y). Only patients with major thrombotic complications and a platelet count >1,000 x 10(9)/L received cytoreductive therapy. Outcome measures: (1) to e valuate thrombotic complications in young patients with ET, (2) to relate t hrombotic risk to the presence of general atherosclerotic risk factors, and (3) to adopt treatment, and (4) to report the outcome of the pregnancies m onitored in our population. Results: Fifteen patients had major thrombosis, 11 of which were the presenting features of ET. No rethrombosis has been o bserved. Only one patient with thrombotic complications was under efficient treatment. Atherosclerotic risk factors are more common in patients with m ajor arterial thrombosis than in asymptomatic subjects. Thirteen normal bab ies were delivered our of 16 pregnancies, 6 of the pregnant women were on A SA therapy. Conclusions: Most thrombosis in young ET patients occurred at t he time of the diagnosis, and venous thrombotic events represent one-third of total thrombosis. Cardiovascular risk factors seem to be concurrent stim uli for arterial thrombosis in ET. The thrombotic complication rate was 2.6 /100 patients/year ASA reduces microvascular disturbances, thrombosis, and rethrombosis and possibly reduces obstetric complications in women with ET.