Essential thrombocythaemia: a single institution experience of 16 years.

This presentation is a clinical narrative and long term follow up (6-16 years) of 21 prospectively studied patients with essential thrombocythaemia (ET) in Kuwait. The median age (55.9 years) is younger than reported by others. Two patients were below the age of 40 years with one of them presenting as post-polycytheamia ET at 16 years of age. Twelve patients (57.1 %) remained asymptomatic throughout the period of follow up. Four patients complained of erythromelalgia, three (19 %) suffered from thrombotic episodes and only one (4.3 %) had excessive bleeding. Four patients presented with splenomegaly. Intensity of thrombocytosis or duration of very high platelet count had no relationship with these complications. Two patients transformed to post-ET myelofibrosis and one patient developed chronic myeloid leukaemia (CML). None transitioned to acute leukaemia. All patients are still alive after follow up for 6-16 years. Janus kinase 2 mutation was positive in eight (38 %) patients. It had no bearing on transition of our ET patients to post-ET myelofibrosis or CML. Platelet aggregation tests were performed in 14 patients. Six (42.9 %) showed defective response to ADP. Only one of these patients suffered from bleeding. All patients were given aspirin (81 mg/day). Cyto-reductive therapy with hydroxyurea was taken by six (42.9 %) subjects. Two patients who were treated with anagrelide and one with alpha-interferon did not continue treatment for long.