primary myelofibrosis

The pathogenesis of acquired myeloperoxidase (MPO) deficiency, a rare phenomenon observed in patients with Philadelphia chromosome-negative myeloproliferative neoplasms (MPN), is unknown. MPO is a glycoprotein chaperoned by Calreticulin (CALR) in the endoplasmic reticulum. Mutations inCALRare frequently found in patients with myelofibrosis (MF) and essential thrombocythemia (ET) with nonmutatedJanuskinase 2(JAK2). We hypothesized that acquired MPO deficiency in MPN could be associated with the presence ofCALRmutations. A cohort of 317 MPN patients (142 polycythemia vera (PV), 94 ET and 81 MF) was screened for MPO deficiency. MPO deficiency was observed in 6/81 MF patients (7.4%), but not in PV or ET patients. Susceptibility to infections had been documented in 2/6 (33%) MPO deficient patients. Five out of six patients with MPO deficiency carried a homozygousCALRmutation and were also deficient in eosinophilic peroxidase (EPX). In contrast, one MF patient with aJAK2-V617F mutation an...

The Janus kinase 2 mutation, JAK2617V>F, is myeloid neoplasm-specific; its presence excludes secondary polycythemia, thrombocytosis, or bone marrow fibrosis from other causes. Furthermore, JAK2617V>F or a JAK2 exon 12 mutation is present in virtually all patients with polycythemia vera (PV), whereas JAK2617V>F also occurs in approximately half of patients with essential thrombocythemia (ET) or primary myelofibrosis (PMF). Therefore, JAK2 mutation screening holds the promise of a decisive diagnostic test in PV while being complementary to histology for the diagnosis of ET and PMF; the combination of molecular testing and histologic review should also facilitate diagnosis of ET associated with borderline thrombocytosis. Accordingly, revision of the current World Health Organization (WHO) diagnostic criteria for PV, ET, and PMF is warranted; JAK2 mutation analysis should be listed as a major criterion for PV diagnosis, and the platelet count threshold for ET diagnosis can be l...

BACKGROUND AND OBJECTIVES Detection of chromosomal abnormalities in myeloproliferative disorders is important for proper diagnosis of these disorders. This study has investigated the presence of JAK2 mutation (V617F) in Egyptian patients with myeloproliferative disorders referred to National Cancer institute, Cairo University. METHODS The study involved 110 cases of Philadelphia negative Myeloproliferative diseases (MPDs), 70 cases with Polycythemia Vera (PV), 24 cases with Essential Thrombocytosis (ET) and 16 cases with Idiopathic Myelofibrosis (IMF) and 20 cases as a control group which represented as; (10 cases with secondary erythrocytosis, 1 case with reactive thrombocytosis, 4 cases as normal control and 5 as Philadelphia positive Chronic Myeloid Leukemia cases), they were collected from National Cancer Institute (NCI) over 3 years. We used ARMS technique for mutation detection. RESULTS The frequency of the V617F JAK2 mutation was highest in patients with PV where 56 out of 70...

Clonal architecture in myeloproliferative neoplasms (MPNs) is poorly understood. Here we report genomic analyses of a patient with primary myelofibrosis (PMF) transformed to secondary acute myeloid leukemia (sAML). Whole genome sequencing (WGS) was performed on PMF and sAML diagnosis samples, with skin included as a germline surrogate. Deep sequencing validation was performed on the WGS samples and an additional sample obtained during sAML remission/relapsed PMF. Clustering analysis of 649 validated somatic single-nucleotide variants revealed four distinct clonal groups, each including putative driver mutations. The first group (including JAK2 and U2AF1), representing the founding clone, included mutations with high frequency at all three disease stages. The second clonal group (including MYB) was present only in PMF, suggesting the presence of a clone that was dispensable for transformation. The third group (including ASXL1) contained mutations with low frequency in PMF and high fr...

Bone marrow fibrosis is a central pathological feature and World Health Organization major diagnostic criterion of myelofibrosis. Although bone marrow fibrosis is seen in a variety of malignant and non-malignant disease states, the deposition of reticulin and collagen fibrosis in the bone marrow of patients with myelofibrosis is believed to be mediated by the myelofibrosis hematopoietic stem/progenitor cell, contributing to an impaired microenvironment favoring malignant over normal hematopoiesis. Increased expression of inflammatory cytokines, lysyl oxidase, transforming growth factor-β, impaired megakaryocyte function, and aberrant JAK-STAT signaling have all been implicated in the pathogenesis of bone marrow fibrosis. A number of studies indicate that bone marrow fibrosis is an adverse prognostic variable in myeloproliferative neoplasms. However, modern myelofibrosis prognostication systems utilized in risk-adapted treatment approaches do not include bone marrow fibrosis as a pro...

ANTECEDENTES: la mutación JAK2 V617F se ha encontrado en la mayoría de pacientes con neoplasias mieloproliferativas crónicas, por lo que se incluye en los nuevos criterios diagnósticos; sin embargo, pocos estudios las analizan en población latinoamericana, donde no son tan frecuentes.
OBJETIVO: describir las implicaciones clínicas y de pronóstico de la
mutación JAK2 V617F en una cohorte de pacientes con las siguientes
neoplasias mieloproliferativas crónicas: policitemia vera, trombocitemia
esencial y mielofibrosis primaria.
MATERIAL Y MÉTODO: estudio retrospectivo, observacional, analítico
y descriptivo de pacientes con neoplasias mieloproliferativas crónicas
atendidos de 2001 a 2014 que contaran con resultado del estudio para
identificar la mutación JAK2 V617F.
RESULTADOS: se incluyeron 38 pacientes: 55% (n=21) con trombocitemia esencial, 32% (n=12) con mielofibrosis primaria y
13% (n=5) con policitemia vera. JAK2 V617F se reportó en 45% (n=17) de los casos. La ausencia o existencia de JAK2 V617F no influyó en el cuadro clínico inicial. La media de supervivencia general fue de 110.5±15 meses. No se reportaron defunciones en los pacientes sin la mutación analizada (12 años de seguimiento), contra una media de supervivencia de 6.1 años en los portadores de JAK2 V617F (prueba log-rank, p=0.015), aunque al subanalizar la supervivencia de cada neoplasia mieloproliferativa crónica no hubo diferencia significativa.
CONCLUSIONES: la detección de JAK2 V617F facilita el diagnóstico
e incluso se dispone de tratamientos dirigidos a este blanco; sin embargo, en la población mexicana no es tan frecuente su manifestación, por lo que deben ampliarse más las investigaciones al respecto.

Myelofibrosis (MF) is complex at the pathobiologic level and heterogeneous at the clinical level. The advances in molecular characterization of MF provide important insight into the mechanisms driving this chronic myeloid malignancy, refine risk stratification, offer novel therapeutic targets, and serve to measure therapeutic response. Although JAK2 inhibition has been the focus of laboratory and clinical efforts over the last decade, current experimental therapeutic approaches have broadened to include inhibitors of key alternative signaling pathways, epigenetic modulators, anti-fibrotics, and immunotherapies. Based on compelling preclinical rationale, a number of JAK2 inhibitor based combination therapies are now actively being evaluated in the clinic with the goal of disease course modification. The role and timing of hematopoietic stem cell transplant (HSCT) for MF has been challenged with the availability of commercial ruxolitinib and the plethora of experimental treatment opti...

We present the case of a patient with a double transformation during the evolution of chronic hematopoietic malignancy - JAK2 positive chronic myeloproliferative neoplasm; the first transformation had occurred previous to the presentation in our Department, but the second transformation was observed in evolution and it was into a rapidly evolving disease, followed by survival of less than one month. We underline the very poor prognosis -- overall survival of 2.5 years from initial presentation -- a much reduced survival for a chronic myeloproliferative neoplasm, probably due also to multiple associated pathology. Also, the other interesting element of the case is related to the dysfunctional platelets -- hemorrhagic complication at increased platelet count, respectively thrombosis at platelet count under 20000/mmc.

Somatic insertions/deletions in the calreticulin gene have recently been discovered to be causative alterations in myeloproliferative neoplasms. A combination of qualitative and quantitative allele-specific polymerase chain reaction, fragment-sizing, high resolution melting and Sanger-sequencing was applied for the detection of three driver mutations (in Janus kinase 2, calreticulin and myeloproliferative leukemia virus oncogene genes) in 289 cases of essential thrombocythemia and 99 cases of primary myelofibrosis. In essential thrombocythemia, 154 (53%) Janus kinase 2 V617F, 96 (33%) calreticulin, 9 (3%) myeloproliferative leukemia virus oncogene gene mutation-positive and 30 triple-negative (11%) cases were identified, while in primary myelofibrosis 56 (57%) Janus kinase 2 V617F, 25 (25%) calreticulin, 7 (7%) myeloproliferative leukemia virus oncogene gene mutation-positive and 11 (11%) triple-negative cases were identified. Patients positive for the calreticulin mutation were you...

The discovery of the JAK2V617F mutation has made the diagnosis of polycythemia vera (PV) much easier, but the pathogenesis of PV is still incompletely understood. In particular, it is not yet elucidated how a single mutation can be found in multiple myeloproliferative ...

Primary myelofibrosis (PMF) is a myeloproliferative neoplasm which is a precursor to myeloid leukemia. Dysmegakaryopoiesis and extramedullary hematopoiesis characterize PMF, which is also associated with bone marrow (BM) stromal alterations marked by fibrosis, neoangiogenesis and osteomyelosclerosis. In particular, contributions to PMF from mesenchymal stromal cells (MSC) have been suggested by mouse studies, but evidence in humans remains lacking. In this study, we show that BM MSC from PMF patients exhibit unique molecular and functional abnormalities distinct from other myeloproliferative neoplasms and these abnormalities are maintained stably ex vivo in the absence of leukemic cells. PMF-MSC overexpressed heparin-binding cytokines, including pro-inflammatory TGF-β1 and osteogenic BMP-2, as well as glycosaminoglycans such as heparan sulfate and chondroitin sulfate. Transcriptome and functional analyses revealed alterations in MSC differentiation characterized by an increased oste...

Molecular genetics may influence outcome for patients with myelofibrosis. To determine the impact of molecular genetics on outcome after allogeneic stem cell transplantation, we screened 169 patients with primary myelofibrosis (n = 110), post-ET/PV myelofibrosis (n = 46), and myelofibrosis in transformation (n = 13) for mutations in 16 frequently mutated genes. The most frequent mutation was JAK2V617F (n = 101) followed by ASXL1 (n = 49), calreticulin (n = 34), SRSF2 (n = 16), TET2 (n = 10), U2AF1 (n = 11), EZH2 (n = 7), MPL (n = 6), IDH2 (n = 5), IDH1 (n = 4), and CBL (n = 1). The cumulative incidence of non-relapse mortality (NRM) at 1 year was 21% and of relapse at 5 years 25%. The 5-year progression-free and overall survival (PFS and OS) was 52% and 56%, respectively. In a multivariate analysis CALR mutation was an independent factor for lower NRM (hazard ratio (HR) 0.415, p = 0.05), improved PFS (HR 0.393, p = 0.01), and OS (HR 0.448, p = 0.03). ASXL1 and IDH2 mutations were in...

Patients with myeloproliferative neoplasms (MPNs) including polycythemia vera, essential thrombocythemia, and myelofibrosis, are faced with oppressive symptom profiles that compromise daily functioning and quality of life. Among these symptoms, sexuality-related symptoms have emerged as particularly prominent and largely unaddressed. In the current study, the authors evaluated how sexuality symptoms from MPN relate to other patient characteristics, disease features, treatments, and symptoms. A total of 1971 patients with MPN (827 with essential thrombocythemia, 682 with polycythemia vera, 456 with myelofibrosis, and 6 classified as other) were prospectively evaluated and patient responses to the Myeloproliferative Neoplasm Symptom Assessment Form (MPN-SAF) and the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC-QLQ C30) were collected, along with information regarding individual disease characteristics and laboratory data. Sexu...

Purpose We evaluated the efficacy and safety of momelotinib, a potent and selective Janus kinase 1 and 2 inhibitor (JAKi), compared with ruxolitinib, in JAKi-naïve patients with myelofibrosis. Patients and Methods Patients (N = 432) with high risk or intermediate-2 risk or symptomatic intermediate-1 risk myelofibrosis were randomly assigned to receive 24 weeks of treatment with momelotinib 200 mg once daily or ruxolitinib 20 mg twice a day (or per label), after which all patients could receive open-label momelotinib. The primary end point was a ≥ 35% reduction in spleen volume at 24 weeks of therapy. Secondary end points were rates of symptom response and effects on RBC transfusion requirements. Results A ≥ 35% reduction in spleen volume at week 24 was achieved by a similar proportion of patients in both treatment arms: 26.5% of the momelotinib group and 29% of the ruxolitinib group (noninferior; P = .011). A ≥ 50% reduction in the total symptom score was observed in 28.4% and 42.2%...

The term IMF (Idiopathic Myelofibrosis) refers to a primary bone marrow disease in which the normal haematopoietic bone marrow cells are for unknown reasons replaced by connective tissue. The pathogenesis of the disease has not been clarified yet. We have speculated that the increment of proliferation of bone marrow fibroblasts in IMF may be the consequence of the over-expression of some oncogenes, leading or contributing to the fibrosis via a cell amplification. Thus, we investigated the possible role of the c-myb and B-myb genes in IMF and control bone marrow fibroblasts in different culture conditions to evaluate proliferation parameters in the absence or presence of serum. Using the reverse transcriptase polymerase chain reaction technique, we demonstrated that the kinetics of induction was similar for both c-myb and B-myb during the proliferation of normal bone marrow fibroblasts. When compared to normal controls, cultured IMF fibroblasts showed more elevated values of c-myb and B-myb RNA; furthermore, after a 72 hours stimulation with serum, c-myb and B-myb messages remained relatively high in myelofibrotic fibroblasts. Finally, after serum starvation, c-myb and to a lesser extent B-myb RNA levels remained unusually high in IMF fibroblasts, while under the same experimental conditions c-myb and B-myb messages became virtually undetectable in normal bone marrow fibroblasts. To our knowledge this work represents the first description of an abnormal behavior of these genes in IMF fibroblasts.

Detection of chromosomal abnormalities in myeloproliferative disorders is important for proper diagnosis of these disorders. This study has investigated the presence of JAK2 mutation (V617F) in Egyptian patients with myeloproliferative disorders referred to National Cancer institute, Cairo University. The study involved 110 cases of Philadelphia negative Myeloproliferative diseases (MPDs), 70 cases with Polycythemia Vera (PV), 24 cases with Essential Thrombocytosis (ET) and 16 cases with Idiopathic Myelofibrosis (IMF) and 20 cases as a control group which represented as; (10 cases with secondary erythrocytosis, 1 case with reactive thrombocytosis, 4 cases as normal control and 5 as Philadelphia positive Chronic Myeloid Leukemia cases), they were collected from National Cancer Institute (NCI) over 3 years. We used ARMS technique for mutation detection. The frequency of the V617F JAK2 mutation was highest in patients with PV where 56 out of 70 cases (80%) carried the mutation, followe...

In 2009, the recommendations of the Czech Collaborative Group for Ph- Myeloproliferative Diseases (CZEMP) for diagnosis and treatment of BCR/ABL-negative myeloproliferative diseases (MPD), i.e., essential thrombocythemia (ET), polycythaemia vera (PV) and primary myelofibrosis (PMF) were updated and extended. The present article gives the rationale of the recommendations in full detail. The CZEMP diagnostic criteria for ET and PMF are based on histopathological (HP) findings, which must unconditionally be in line with the given clinical and laboratory characteristics of ET or of a certain stage of PMF, respectively. The platelet count is not decisive for diagnosis. In cases lacking an adequately taken and read HP finding, the Polycythemia Vera Study Group (PVSG) criteria are recommended. The diagnosis of typical PV is based on demonstration of the V617F mutation of the JAK2 gene along with a significant increase of red cell parameters. If these are close to borderline, the demonstrat...

Primary myelofibrosis (PMF) is a myeloproliferative neoplasm characterised by the clonal proliferation of the haematopoietic precursors together with the progressive development of bone marrow fibrosis. This stromal alteration is an important clinical issue and specific prognostic markers are not currently available. In bone marrow biopsies from 58 PMF patients, we explored the methylation pattern of genes encoding cytokines involved in the stromal reaction, namely platelet-derived growth factor-beta (PDGFB), transforming growth factor-beta (TGFB) and basic fibroblast growth factor (FGF2). We also evaluated the methylation profile of the Long Interspersed Nucleotide Element 1 (LINE-1). PDGFB, FGF2 and LINE-1, but not TGFB, were significantly differently methylated in PMF compared to controls. Significantly, PDGFB hypomethylation (<16%) was correlated with a favourable PMF prognosis (grade of marrow fibrosis, p=0.03; International Prognostic Scoring Systems p=0.01 and Dynamic International Prognostic Scoring Systems, p=0.02). Although the basis of the association of PDGFB hypomethylation with favourable prognosis remains to be clarified, we speculate that hypomethylation in PMF could represent the effect of acquired somatic mutations in genes involved in epigenetic regulation of the genome.