88% (46/52) of the patients with PV, 47% (39/81) with ET, and 77% (8/11) with PMF were positive for JAK2V617F, while more than 35% of the individuals were JAK2 V617F-negative, confirming a high prevalence of this abnormality in MPNs, more frequently with a low mutated allele burden, similar to what has been reported in other Western countries, despite differences among methods used to detect this mutation.
Primary myelofibrosis (PMF) is a myeloproliferative disorder characterized by bone marrow fibrosis or dysmegakaryocytes, extramedullary hematopoiesis, and the presence of JAK2 mutations.
Primary myelofibrosis or myelofibrotic transformation preceded all 7 JAK2-mutant but only 1 of 9 JAK2 wild-type AMLs (P = .001), implying that JAK2-mutant AML is preceded by mutation(s) that give rise to a "myelofibrosis" phenotype.
Primary myelofibrosis (PMF) is a myeloproliferative neoplasm (MPN) characterized by stem cell-derived clonal myeloproliferation that is often but not always accompanied by JAK2, CALR, or MPL mutations; additional disease features include bone marrow stromal reaction including reticulin fibrosis, abnormal cytokine expression, anemia, hepatosplenomegaly, extramedullary hematopoiesis (EMH), constitutional symptoms, cachexia, leukemic progression, and shortened survival.
Primary Myelofibrosis (PMF) is a myeloproliferative disorder associated with JAK2V617F, Calreticulin (CALR) indels, and MPLW515L/K mutations activating the tyrosine kinase JAK2 and its downstream signaling pathway.
JAK2V617F-positive ET/PV and CIMF should be distinguished from wild-type JAK2 ET, rare cases of PV, and CIMF, and should be evaluated during life-long follow-up.
Janus kinase 2 (V617F) mutation status, signal transducer and activator of transcription-3 phosphorylation and impaired neutrophil apoptosis in myelofibrosis with myeloid metaplasia.
JAK2(V617F), a mutant of tyrosine kinase JAK2, is found in most patients with polycythemia vera (PV) and a substantial proportion of patients with idiopathic myelofibrosis or essential thrombocythemia.
JAK2(V617F) failed to induce polycythemia in recipients after deletion of Stat5a/b, although the loss of STAT5 did not prevent the development of myelofibrosis.
JAK2V617F mutations were detected in 6 of the 28 patients with bone marrow fibrosis presenting at the time of diagnosis and 2 of the 7 patients with bone marrow fibrosis developing in the course of disease, significantly higher than the control group patients.
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.
JAK2-positive cutaneous myelofibrosis presenting as sclerosing extramedullary hematopoietic tumors on the scalp: case presentation and review of the literature.
JAK2 is mutated (V617F) in more than 90 % of patients with polycythemia vera (PV) and approximately 60 % of patients with essential thrombocythemia (ET) or primary myelofibrosis (PMF).
JAK2 inhibitor monotherapy is effective in reducing splenomegaly and symptom burden in the majority of treated patients with myelofibrosis, but LT can still occur.