Platelet PDGF and TGF-β Levels in Myeloproliferative Disorders.

Myeloproliferative disorders mainly including essential thrombocythemia, polycythemia vera, chronic myeloid leukemia and myelofibrosis with myeloid metaplasia are clonal myeloproliferative diseases in which myelofibrosis is commonly observed. The pathogenesis of myelofibrosis still remains unclear. However it was proposed that an inappropriate release of PDGF from either megakaryocytes in bone marrow or platelets in circulation might promote medullary fibrosis. Recently the role of another peptide growth factor, namely TGF-β, in the fibrotic process was emphasized. This review will focus on the different studies aimed at the evaluation of intraplatelet PDGF and TGF-β content in patients with the various MPD, and outline the salient results lending support to the potential role of PDGF and TGF-β in the promotion of myelofibrosis.