X-inactivation-based clonality analysis and quantitative JAK2V617F assessment reveal a strong association between clonality and JAK2V617F in PV but not ET/MMM, and identifies a subset of JAK2V617F-negative ET and MMM patients with clonal hematopoiesis.
Within this context, elevated CD177 expression is not only a specific feature of PV but may be an indicator of increased erythropoietic activity in thalassaemia syndromes.
Within the 91 patients with normal p50 values, 46 (51%) had secondary erythrocytosis, 13 (14%) polycythemia vera and 32 (35%) idiopathic erythrocytosis.
Within the 91 patients with normal p50 values, 46 (51%) had secondary erythrocytosis, 13 (14%) polycythemia vera and 32 (35%) idiopathic erythrocytosis.
Within the 91 patients with normal p50 values, 46 (51%) had secondary erythrocytosis, 13 (14%) polycythemia vera and 32 (35%) idiopathic erythrocytosis.
Within the 91 patients with normal p50 values, 46 (51%) had secondary erythrocytosis, 13 (14%) polycythemia vera and 32 (35%) idiopathic erythrocytosis.
Within the 91 patients with normal p50 values, 46 (51%) had secondary erythrocytosis, 13 (14%) polycythemia vera and 32 (35%) idiopathic erythrocytosis.
With the use of an in vitro culture system to generate differentiating erythroid cells, we found that erythroblasts derived from patients with PV harboring the JAK2 V617F mutation were able to proliferate and generate higher numbers of mature erythroid cells in the presence of inhibitory signals delivered by CD95 (Fas/Apo-1) and TRAIL receptor stimulation.
While AB and CB, respectively, activated transient or sustained canonical cKIT-signaling, PV showed a non-canonical signaling including increased mTOR and ERK1 and decreased DEPTOR.
While JAK2 inhibitors appear to be promising in PV and ET, they need to be compared with standard therapies, such as hydroxyurea or interferon-based therapies.
When present in a heterozygous state the JAK2-V617F mutation preferentially stimulates megakaryopoiesis and in most cases manifests as essential thrombocythemia (ET), whereas homozygous JAK2-V617F reduces megakaryopoiesis in favor of increased erythropoiesis, resulting in polycythemia vera and/or myelofibrosis.
When marrow cells were separated by velocity sedimentation at unit gravity, most PV clonal granulocyte-macrophage progenitors (CFU-C) (type A G6PD) sedimented between 6.4 and 7.2 mm/h, whereas most residual normal, type B CFU-C sedimented less than or equal to 5.9 mm/h (P = 0.04)., When blood cells were separated over a discontinuous buoyant density gradient, PV clonal CFU-C equilibrated at densities < 1.065 g/ml, whereas residual normal CFU-C were found greater than or equal to 1.065 g/ml (P < 0.01).
We, therefore, screened 52 consecutive patients with polycythemia vera for 12 HH gene mutations, comparing iron status and red cell parameters between patients positive or negative for HH gene mutations.
We used the thrombin generation assay to evaluate the hypercoagulable state according to JAK2(V617F) mutational status in essential thrombocythemia (ET) and polycythemia vera (PV) patients.
We studied the lineage distribution of JAK2 mutations in peripheral blood of 8 polycythemia vera (PV) patients with exon 12 mutations and in 21 PV patients with JAK2-V617F.
We studied samples from 1088 persons with myeloproliferative neoplasms (MPNs) including 421 JAK2(V617F) negative subjects with ET, PMF, polycythemia vera (PV), chronic myeloid leukemia (CML) and hyper-eosinophilic syndrome (HES).
We studied neutrophil CD177 mRNA levels in normal subjects and in 235 patients with Ph-negative chronic myeloproliferative disorders (CMD), including PV, essential thrombocythaemia and myelofibrosis with myeloid metaplasia.
We showed that in vitro the concomitant presence of JAK2(V617F) and TET2 mutations favors clonal polycythemia vera erythroid progenitors in contrast with non-TET2 mutated progenitors.
We show that transplantation of JAK2(V617F)-transduced bone marrow into BALB/c mice induces MPD reminiscent of human PV, characterized by erythrocytosis, granulocytosis, extramedullary hematopoiesis, and bone marrow fibrosis, but not thrombocytosis.
We show that the peripheral CD3<sup>+</sup>CD8<sup>+</sup> T cell pool in PV patients is clearly divided into two discrete populations, a more granular CD3<sup>+</sup>CD8<sup>high</sup> T cell population enriched in effector-memory CD45RA<sup>+</sup> T cells (CD8<sup>+</sup> TEMRA) when compared to CTR (P < 0.001), and a less granular CD3<sup>+</sup>CD8<sup>int</sup> T cell population that is completely absent in the CTR group (78 vs. 0%, P < 0.001) and is a mixture of naïve (CD8<sup>+</sup> T<sub>N</sub>) and CD8<sup>+</sup> TEMRA cells expressing intermediate levels of CD28, i.e., CD3<sup>+</sup>CD8<sup>int</sup>CD28<sup>int</sup>.