Haema 2012; 3(1): 89-98
by Georgios Georgiou, Vasiliki Mpartzi
Research Laboratory of APPK
Abstract
The myeloproliferative neoplasms are clonal diseases characterized by overproduction of mainly mature cells. In 2008 the World Health Organization (WHO) classified myeloproliferative neoplasms (MPN) in specific categories. This new classification system was the result of the discovery of specific genetic lesions found in MPNs: JAK2 and MPL gene mutations. The detection of these lesions is applicable to everyday clinical practice as an integral component of the diagnostic approach to these diseases. After the discovery of these mutations, it became apparent that the pathogenesis of the various MPNs is much more complex. All MPNs are clonal diseases with the initial damage occurring to the primitive hematopoietic cell, causing cell overproduction, due to increased sensitivity or complete independence from the influence of cytokines. The last few years several mutations in various genes have been detected in MPNs: mutations in TET2, ASXL1, CBL, IDH, etc. The involvement of these mutations in the initial pathogenesis of MPN is not known; unknown is also whether the combination of different mutations can lead to different phenotypic expression (eg a particular combination of mutations leads to polycythemia vera, another combination leads to essential thrombocythaemia etc). It remains to be shown whether this complex genetic abnormalities in MPNs can be useful in clinical practice with regard to the differential diagnosis, but also in targeted therapy.