The predictive value of vascular risk factors and gender for the development of thrombotic complications in essential thrombocythemia.

The impact of the cardiovascular risk factors smoking, hypertension, hypercholesterolemia, and diabetes mellitus on the risk of thrombotic complications was evaluated retrospectively in 132 patients with essential thrombocythemia (ET). The median age at diagnosis was 51 years, and the median follow-up time was 65 months. Sixty-three out of 132 patients (48%) had one or more vascular risk factors, whereas 69 patients (52%) had no risk factors.

Development of erythrocytosis in the course of essential thrombocythemia.

Erythrocytosis is not a feature of essential thrombocythemia (ET); this is the most important difference between ET and polycythemia vera (PV). Transformation of ET to PV has only rarely been described. We have reviewed the blood cell counts of 170 ET patients with a median follow-up of 63 months (range 11-313).

Essential thrombocythemia at diagnosis: causes of diagnostic evaluation and presence of positive diagnostic findings.

The reasons for diagnostic evaluation and the clinical and laboratory data at diagnosis of 170 patients with essential thrombocythemia (ET) were studied retrospectively. The age distribution was 19-88 years (median 52 years), and 52 patients were under the age of 45 years. In 111 patients (65%) thrombocytosis was a chance finding, but the past history of 37 of these patients revealed symptoms known to be related to ET.

Long-term bone marrow cultures in polycythaemia vera and essential thrombocythaemia.

Bone marrow samples of 8 patients with essential thrombocythaemia and three patients with polycythaemia vera were cultured in long-term bone marrow cultures. The production of non-adherent cells and colony-forming unit-granulocyte-macrophage harvested weekly did not differ from that of 29 healthy bone marrow transplant donors. There was a trend towards less complete stromal confluence in patients with a myeloproliferative disease.