JAK2(V617F) positive early stage myeloproliferative disease (essential thrombocythemia) as the cause of portal vein thrombosis in two middle-aged women: therapeutic implications in view of the literature.
MPLW515L mutation was found to be harbored in only one of 102 patients, who had essential thrombocythemia (ET, 1.0%) and was not detected in patients with polycythemia vera (PV), idiopathic myelofibrosis (IMF), and chronic myelogenous leukemia (CML).
CD34(+) cell JAK2(V617F) clonal dominance, defined as coherence between the CD34(+) cell and neutrophil JAK2(V617F) allele burdens, was present in 24% of ET, 56% of PV, and 93% of PMF patients, and was independent of the CD34(+) cell JAK2(V617F) genotype.
JAK2 DNA mutational analysis was done on diagnostic bone marrow samples obtained from 88 patients with Down's syndrome-associated acute lymphoblastic leukaemia; and 216 patients with sporadic acute lymphoblastic leukaemia, Down's syndrome-associated acute megakaryoblastic leukaemia, and essential thrombocythaemia.
JAK2 mutational status assessment was valuable to distinguish two populations of patients with ET, showing distinctive hematologic and clinical features.
JAK2V617F-positive latent essential thrombocythemia and splanchnic vein thrombosis: the role of bone marrow biopsy for the diagnosis of myeloproliferative disease.
TET2 mutations were mainly observed (10 of 12) in patients with primary myelofibrosis or patients with polycythemia vera or essential thrombocythemia who secondarily evolved toward myelofibrosis or acute myeloid leukemia.
MPL(W515L) was found in 3% of ET and 8% of PMF, with a significantly higher percentage of mutated alleles in fibrotic than prefibrotic PMF (median, 78% MPL(W515L) alleles; p<0.05).
JAK2 and MPL mutations appear to exert a phenotype-modifying effect and are distinctly associated with polycythemia vera, essential thrombocythemia and primary myelofibrosis; the corresponding mutational frequencies are approximately 99, 55 and 65% for JAK2 and 0, 3 and 10% for MPL mutations.
Thrombospondin-1 (TSP-1) in primary myelofibrosis (PMF) - a megakaryocyte-derived biomarker which largely discriminates PMF from essential thrombocythemia.
VEGF expression parallelled VEGFR-1 and resulted increased in Ph- MPNs (NCs: 0.08±0.04; ET: 0.13±0.06; PV: 0.29±0.2; PMF: 0.31±0.15) and higher in post-polycythaemic myelofibrosis and in the fibrotic stage of PMF than in the non-fibrotic phases of both diseases.
JAK2 inhibition in polycythemia vera (PV) and essential thrombocythemia (ET) for this class of agents appears promising to reduce myeloproliferations, symptoms, and perhaps prevent thrombohemorrhagic events.
JAK2 and MPL mutations also occur in essential thrombocythemia (ET) and primary myelofibrosis (PMF), but their diagnostic value is limited by suboptimal sensitivity and specificity.
Janus kinase-2 (JAK2) is mutated in a high proportion of patients with polycythemia vera and in a smaller number with essential thrombocythemia and primary myelofibrosis.