Journal of Blood Disorders & Transfusion

European vs. 2015-World Health Organization clinical molecular and pathological classification of myeloproliferative neoplasms

4^th International Conference on Blood Malignancies & Treatment

April 18-19, 2016 Dubai, UAE

J J Michiels

Goodheart Institute, The Netherlands

Posters & Accepted Abstracts: J Blood Disord Transfus

Abstract:

The BCR/ABL fusion gene or the Ph1-chromosome in the t(9;22)(q34;q11) exerts a high tyrokinase activity, which is the cause of chronic myeloid leukemia (CML). The 1990 Hannover Bone Marrow Classification separated CML from the myeloproliferative disorders essentialthrombocythemia (ET), polycythemia vera (PV) and chronic megakaryocytic granulocytic myeloproliferation (CMGM). The 2006-2008 European Clinical Molecular and Pathological (ECMP) criteria discovered 3 variants of thrombocythemia: ET with features of PV (prodromal PV), �??true�?� ET and ET associated with CMGM. The 2008 World Health Organization (WHO)-ECMP and 2014 WHO-CMP classifications defined three phenotypes of JAK2V617F mutated ET: normocellular ET (WHO-ET), hypercelluar ET due to increased erythropoiesis (prodromal PV) and ET with hypercellular megakaryocytic-granulocytic myeloproliferation. The JAK2V617F mutation load in heterozygous WHO-ET is low and associated with normal life expectance. The hetero/homozygous JAK2V617F mutation load in PV and myelofibrosis is related to myeloproliferative neoplasm (MPN) disease burden in terms of symptomatic splenomegaly, constitutional symptoms, bone marrow hypercellularity and myelofibrosis. JAK2 exon 12 mutated MPN presents as idiopathic eryhrocythemia and early stage PV. According to 2014 WHO-CMP criteria, JAK2 wild type MPL515 mutated ET is the second distinct thrombocythemia featured by clustered giant megakaryocytes with hyperlobulated stag-horn-like nuclei, in a normocellular bone marrow consistent with the diagnosis of �??true�?� ET. JAK2/MPL wild type, calreticulin mutated hypercellular ET appears to be the third distinct thrombocythemia characterized by clustered large immature dysmorphic megakaryocytes and bulky (bulbous) hyperchromatic nuclei consistent with CMGM or primary megakaryocytic granulocytic myeloproliferation.

Biography :

Email: goodheartcenter@upcmail.nl