Clujul Medical 4 - Clujul Medical - Iuliu Haţieganu

Clujul Medical 2008 vol. LXXXI – nr.4 442
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New issues in essential thrombocythemia diagnosis and pathogenesis in Jak2
era
LAURA URIAN, L. PETROV
Summary
Essential thrombocythemia, polycythemia vera and myelofibrosis with myeloid metaplasia
constitute the CLASSIC bcr-abl negative myeloproliferative disorders. Each of these disorders represent a
stem cell derived clonal myeloproliferation. Unlike with cases of chronic myeloid leukaemia in which the
bcr-abl mutation is invarably detected, current diagnosis of essential thrombocythemia is based on a
consensus driven set of clinical and laboratory criteria. In 2005 an activating jak2 mutation – jakV617F
was demonstrated in all 3 classic myeloproliferative disorders, the mutational frequency in essential
thrombocythemia was estimated at 50 % and offers opportunity for refining current diagnoses and
pathogenesis. In essential thrombocythemia, JAK2 V617F has been associated with higher levels of
haemoglobin and leukocyte count, higher risk of transformation into polycythemia vera and advanced age
at diagnosis. In contrast the specific mutation has not an effect on survival, thrombosis risk or leukemic
transformation rate.
Keywords: essential thrombocythemia, mutation JAK2V617F, bleeding, thrombosis.