JAK2V617F Mutation In Patients Research Articles

Central Retinal Vein Occlusion as the Debut of a Chronic Myeloproliferative Neoplasm

Introduction. Most retinal vascular diseases are associated with systemic risk factors such as hypertension, diabetes mellitus, age and smoking. However, in their absence, further examination is required to identify possible hematological disorders.Purpose. Improve the diagnostic and management scheme for patients with occlusion of the central retinal vein or its branches.Materials and methods. A clinical case of the onset of polycythemia vera with the central retinal vein occlusion is described. As part of the study, a molecular genetic analysis was carried out to identify the driver mutation JAK2V617F in peripheral blood as a screening diagnosis of Ph-negative chronic myeloproliferative neoplasms (CMN), a cytological, cytogenetic study of bone marrow aspirate and a morphological study of bone marrow trephine biopsy.Results. A mutant allele of the JAK2V617F gene with a diagnostically significant allele load of 14.61 % was determined in a patient hospitalized in the ophthalmology department with a diagnosis of central retinal vein occlusion (CRVO) of the right eye. The patient was referred for further examination to the Moscow City Hematology Center of Botkin City Clinical Hospital, where, aſter examination, the diagnosis was established: True polycythemia.Discussion. CMN are a group of tumor diseases of hematopoietic tissue characterized by malignant transformation of bone marrow stem cells with their subsequent clonal proliferation. Cytogenetic and molecular genetic disorders play a significant role in the pathogenesis of chronic CMN. True polycythemia, essential thrombocytemia, primary myelofibrosis belong to the group of classical Ph-negative CMP, Thrombotic, vascular and hemorrhagic complications are the most common causes of death in patients with this pathology.Conclusion. Previously, various ophthalmological manifestations and symptoms have been described in patients with CMN. The observed complications are diverse and oſten secondary to the pathognomonic hematological disorders for these diseases. It is worth considering the clinical value of molecular genetic analysis to detect the JAK2V617F mutation in patients with central retinal vein occlusion for early diagnosis of CMN and timely administration of appropriate therapy.

The value of searching for the JAK2 V617F mutation in patients with deep vein thrbosis

The value of searching for the JAK2 V617F mutation in patients with deep vein thrbosis

JAK2 V617F Mutation in Patients with Thrombosis

Background: Thrombosis is a major disorder with serious complications. The JAK2V617F mutation results in constitutive phosphorylation of JAK2 and activation of the cellular proliferation cascade.
 The present study aimed to clarify the prevalence of JAK2V617F mutation in patients with thrombosis.
 Subjects and Methods: This case-control study was conducted on 60 subjects subdivided into 2 groups: 30 healthy subjects as a control group (Group I) and 30 patients diagnosed with thrombosis (Group II). All subjects were subjected to full history taking, and clinical examination and investigated for Molecular detection of JAK2V617F mutation, FV (Factor V Leiden) – PTH (Prothrombin), and MTHFR (Methylene tetrahydro-folate reductase).
 Results: There was a statistically significant difference among the studied groups as regards the JAK2V617F mutation (P value < 0.05, odds ratio = 41.216, 95% C.I. 95% = 2.302 - 738.034, relative risk = 25, 95% C.I. 95% = 1.547– 404.012). This mutation was more significantly associated with venous thrombosis than arterial thrombosis (P = < 0.05).
 Conclusion: This study showed a significant association between JAK2V617F mutation and thrombosis with more significant evidence in the venous than the arterial thrombosis.

Prevalence of the JAK2V617F Mutation in Patients with Ischemic Stroke

Introduction: Patients with the Philadelphia negative myeloproliferative neoplasms (MPN) have an increased risk of thromboembolic events, ischemic cerebrovascular events in particular. The somatic mutation JAK2V617F is associated with MPN with a prevalence of 96% in polycythemia vera (PV), 55% in essential thrombocythemia (ET), and 65% in primary myelofibrosis (PMF). The JAK2V617F mutation is found to be an independent risk factor for thrombosis in patients with MPN. However, whether the JAK2V617F mutation is a risk factor for arterial thrombosis in the absence of an MPN diagnosis is still uncertain. The sensitivity of the assay used for detection is crucial when assessing the presence of the JAK2V617F mutation. A higher sensitivity enables detection of lower allele burdens. This is illustrated by the varying prevalences (0.1-3.1%) in background population studies. In the Danish population study GESUS of approximately 20.000 individuals, the JAK2V617F mutation was detected by droplet digital PCR (ddPCR) with an assay sensitivity of 0.009%. The GESUS study found a JAK2V617F prevalence of 3.1%. Similarly, prevalence studies of JAK2V617F mutation in stroke have varying detection limits from 0.01-5% mutant alleles. The vast majority of these studies are retrospective studies in younger subpopulations of stroke patients. We aimed to investigate the prevalence of the JAK2V617F mutation in a prospective design of consecutively enrolled unselected patients with ischemic stroke or transient ischemic attack by the highly sensitive ddPCR. Method: We recruited 90 consecutive patients with ischemic stroke or transient ischemic attack during admission at the Department of Neurology, Zealand University Hospital, Denmark. A blood sample was taken within 7 days of the onset of symptoms and screened for the JAK2V617F mutation by ddPCR. Patients unable to give informed consent were excluded from the study. Results: Out of 90 patients (mean age 71, range 46-92; female 37%) with ischemic stroke or transient ischemic attack, the JAK2V617F mutation was found in 11 patients (12.2%). Allele burdens ranged from 0.0021 to 24. All 11 patients suffered an ischemic stroke. Six out of 11 patients with the JAK2V617F mutation had elevated blood cell levels i.e. erythrocytosis, thrombocytosis, and/or leukocytosis at the time of recruitment. Only three patients had continuously elevated blood cell levels after 1 month. Patient no. 6 with a JAK2V617F mutation allele burden of 34% had blood cell levels meeting the diagnostic criteria for MPN and was diagnosed with ET. Patient no. 2 had a JAK2V617F allele burden of 14% and increased levels of hemoglobin and platelet count, which both normalized spontaneously after 1 month. The patient was referred for a hematological workup and was found to have mild splenomegaly and a bone marrow biopsy showing myeloproliferative features. In light of the normal blood cell parameters, patient no. 2 was diagnosed with MPN-U. The patients with a JAK2V617F mutation are presented in table 1. Additional data will be presented at ASH. Conclusion and implications: The present study reveals a JAK2V617F mutation prevalence (12.2%) in a stroke population that is substantially higher compared to the background population (GESUS) in the same region of Denmark, using the same assay. The GESUS study showed a JAK2V617F mutationprevalence of 3.1% and for individuals above age 60 a prevalence of 4.1%. Given the fact that the JAK2V617F mutation is present in patients with and without cytosis, our results highly suggest that the JAK2V617F mutation per se is a thrombogenic factor in ischemic stroke. This calls for an exploration of the pathophysiological mechanisms and potential treatments to prevent future thrombotic events in individuals with and without cytosis. Table legend: Clinical and paraclinical characteristics of ischemic stroke patients with the JAK2V617F mutation. IS, ischemic stroke; TIA, transient ischemic attack; HTN, hypertension; HLP, hyperlipidemia; AF, atrial fibrillation; IHD, ischemic heart disease; DM2, diabetes mellitus type 2; Hb, hemoglobin; PLT, platelet count; WBC, white blood cells. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

PTPN1 Deficiency Accelerates the Progression to Myelofibrosis in JAK2V617F-Driven Myeloproliferative Neoplasm

The deletion of chromosome 20q (del20q) is frequently associated with myeloid malignancies including myeloproliferative neoplasms (MPN), myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). The del20q cytogenetic abnormality was observed most frequently in patients with myelofibrosis (MF). However, the key target genes within 20q involved in the pathogenesis of myelofibrosis has remained elusive. We previously reported that PTPN1 gene encoding protein tyrosine phosphatase non-receptor type 1 is a potential tumor suppressor within 20q in MPN/MF (Jobe et al. Leukemia 2017). The del20q involving PTPN1 deletion was more commonly found in MPN/MF in comparison to other myeloid neoplasms. We also observed significant co-occurrence of del20q involving PTPN1 deletion with JAK2V617F mutation in patients with MF. So, we hypothesize that PTPN1 deficiency may cooperate with JAK2V617F in the pathogenesis of MF. In this study, we investigated the effects of heterozygous and homozygous PTPN1 deletion in JAK2V617F-induced MPN using a conditional PTPN1 knockout allele and a JAK2V617F knock-in mouse model of MPN. We previously reported the generation of a conditional JAK2V617F knock-in mouse. Mice expressing heterozygous JAK2V617F (JAK2VF/+) exhibit a PV-like MPN characterized by increase in red blood cells (RBC), white blood cells (WBC), neutrophils and platelets in the peripheral blood. Heterozygous deletion of PTPN1 significantly increased WBC, neutrophil and platelet counts but reduced RBC and hemoglobin levels in JAK2VF/+ mice. Flow cytometric analysis showed that heterozygous deletion of PTPN1 significantly increased myeloid (Gr-1+Mac-1+) and megakaryocytic (CD41+CD61+) precursors in the BM and spleens of PTPN1-deficient JAK2VF/+ mice compared with JAK2VF/+ mice. Additionally, deletion of PTPN1 significantly increased hematopoietic stem cells and myeloid progenitors in the BM and spleens of PTPN1-deficient JAK2VF/+ mice compared to JAK2VF/+ mice. Spleen weight was significantly increased in JAK2VF/+ mice, while deletion of PTPN1 further enhanced splenomegaly in PTPN1-deficient JAK2VF/+ mice. Furthermore, deletion of PTPN1 significantly enhanced bone marrow fibrosis in JAK2VF/+mice. Homozygous deletion of PTPN1 resulted in more robust and accelerated development of lethal myelofibrosis in JAK2VF/+ mice. The cooperative effects of JAK2V617F and PTPN1 deficiency in myelofibrotic transformation is associated with increased production of proinflammatory cytokines including IL-1beta, IL-6 and TGF-beta. We also observed enhanced activation of STAT1, STAT3, ERK1/2 and NF-kB in PTPN1-deficient JAK2VF/+ mice bone marrow compared with JAK2VF/+ or WT mice bone marrow. CRISPR/Cas9-mediated deletion of PTPN1 also resulted in enhanced activation of these signaling molecules and increased proliferation in JAK2V617F-positive mouse and human hematopoietic cells. Furthermore, deletion of PTPN1 significantly reduced ruxolitinib sensitivity against JAK2V617F-positive hematopoietic cells, suggesting that del20q involving PTPN1 deletion may cause ruxolitinib resistance in MPN. Overall, this study demonstrates that PTPN1 is an important target in del20q-associated MPN, and deficiency of PTPN1 collaborates with JAK2V617F in the progression to myelofibrosis.

Characteristics of patients with cerebral sinus venous thrombosis and JAK2 V617F mutation.

Janus kinase 2 (JAK2-V617F) mutations can cause thrombocytosis, polycythemia and hyper viscosity leading to cerebral sinus venous thrombosis (CSVT). However, data regarding the characteristics and prevalence of JAK2-V617F mutation in patients with CSVT are currently lacking. We aimed to evaluate the characteristics of CSVT patients that carry the JAK2 mutation. Data of consecutive patients with CSVT, admitted to three large academic medical centers between 2010 and 2020, were retrospectively studied. Demographics, clinical presentations, radiological and clinical outcome parameters were compared between carriers of the JAK2-V617F mutation and controls. Out of 404 patients diagnosed with CSVT, 26 patients (6.5%) were carriers of the mutation. JAK2 mutation carriers more often had thrombocytosis (54% vs. 1%, p < 0.001). Furthermore, carriers of the JAK2 mutation less often had involvement of the transverse sinus (50% vs. 68%, p = 0.021). Finally, patients with the JAK2 mutation were more prone to have intracerebral hemorrhage (ICH, 31% vs. 17%, p = 0.044), but there was no significant difference between groups in terms of mortality nor functional outcome. JAK2 mutation is not uncommon in patients with CSVT and should be routinely screened for in this population. CSVT in JAK2 mutation carriers may have a tendency toward involving specific venous sinuses and is associated with a higher rate of ICH but similar overall prognosis.

Janus kinase 2 (JAK2V617F) mutations in patients with splanchnic vein thrombosis, a single centre experience

JAK2V617F mutation is recurrent in polycythaemia vera and essential thrombocythaemia, which are myeloproliferative neoplasms (MPNs) frequently associated with arterial and venous thromboembolism. It also reported as a marker for occult MPN in patients with splanchnic venous thrombosis. We evaluate frequency of JAK2V617F and CALR mutations in patients’ samples presenting with splanchnic vein thrombosis that are sent to Clinical Referral Haematology Laboratory, Hospital Ampang, the tertiary referral laboratory offering both tests within Ministry of Health Malaysia. We retrospectively investigated JAK2V617F mutations samples from years 2016–2020 with presenting history of splanchnic vein thrombosis confirmed by ultrasound or computed tomography (CT) imaging. JAK2V617F mutation analysis was done by amplification refractory mutation system (ARMS) PCR and CALR mutation analysis by high resolution melting (HRM). There was a total of 93 patients (47 men and 46 women) during 2016 and 2020. 16 patients were found to have the JAK2V617 mutation, and the remaining were negative for JAK2V617F and CALR mutation. Of note, we found that patients with JAK2 V617F mutation presented with higher total white blood cell count and platelet count than those without mutation (p<0.05). Despite thrombosis being a common manifestation of MPN, the role of screening JAK2V617F mutations in all patients presenting with splanchnic vein thrombosis without other features of MPN is unclear. However, the significance of this mutation screening provides an accurate diagnosis and further understanding of the role of JAK2V617F mutation in thrombosis has a great potential for future development of therapeutics intervention.

A Murine Model with JAK2V617F Expression in Both Hematopoietic Cells and Vascular Endothelial Cells Recapitulates the Key Features of Human Myeloproliferative Neoplasm

IntroductionAlthough murine models have provided unequivocal evidence that the JAK2V617F mutation is able to cause myeloproliferative neoplasms (MPNs), there is significant heterogeneity in disease phenotypes between different murine models and none has been able to recapitulate both the myeloproliferative phenotype and cardiovascular pathology seen in patients with MPNs. In addition, these murine models were mostly followed for less than 3-9 months and how aging affects MPN disease progression has not been studied. Endothelial cells (ECs) are an essential component of the hematopoietic niche, and they have been shown to express the JAK2V617F mutation in patients with MPNs. In this study, we investigated how MPN progresses in the JAK2V617F-bearing vascular niche during aging.MethodsJAK2V617F Flip-Flop (FF1) mice (which carry a Cre-inducible human JAK2V617F gene driven by the human JAK2 promoter) were crossed with Tie2-cre mice to express JAK2V617F specifically in all hematopoietic cells (including HSPCs) and vascular ECs (Tie2FF1).ResultsThe Tie2FF1 mice developed essential thrombocythemia to primary myelofibrosisdisease transformation with extramedullary splenic hematopoiesis during 18-month follow up. No evidence of leukemia transformation was observed in the Tie2FF1 mice. (Figure 1)Hematopoietic colony formation assays, flow cytometry analysis, and in vitro culture experiments revealed that there was a loss of both HSPC number and HSPC function in the marrow of old Tie2FF1 mice during aging, mimicking the advanced phases of myelofibrosis. In contrast, the spleen of old Tie2FF1 mice was able to maintain the expansion of JAK2V617F mutant hematopoiesis during aging and MPN disease progression. (Figure 2)These differences between marrow and spleen hematopoiesis in the old Tie2FF1 mice prompted us to investigate how aging affects the JAK2V617F mutant hematopoiesis differently in the marrow and spleen. We found that, although the JAK2V617F mutant HSCs (Lin -cKit +Sca1 +CD150 +CD48 -) from old Tie2FF1 mice were more proliferative than wild-type HSCs in both the marrow and spleen, mutant marrow HSCs were more apoptotic and senescent than wild-type HSCs in the marrow while mutant spleen HSCs were relatively protected in the spleen. Examination of the hematopoietic vascular niche revealed that marrow ECs (CD45 -CD31 +) were significantly decreased in old Tie2FF1 mice compared to age-matched control mice; in contrast, spleen ECs were significantly expanded and less senescent in old Tie2FF1 mice compared to control mice. Therefore, the different vascular niche function of the marrow and spleen could contribute to the decreased marrow hematopoiesis and expanded splenic hematopoiesis we have observed in the Tie2FF1 mice during aging. (Figure 3)Previously, we reported that the Tie2FF1 mice developed spontaneous heart failure with thrombosis, vasculopathy, and cardiomyopathy at 20wk of age. Here, we followed the cardiovascular function of Tie2FF1 mice during aging. At 18mo of age, the Tie2FF1 mice continued to demonstrate a phenotype of dilated cardiomyopathy with a moderate but significant decrease in left ventricular ejection fraction and an increase in left ventricular volume and mass compared to age-matched control mice. Histology examination revealed spontaneous thrombosis in the right ventricle, pulmonary arteries, both main (epicardial) coronary arteries and scattered coronary arterioles (microvessels) in the old Tie2FF1 mice, while age-matched Tie2-cre control mice had no evidence of spontaneous thrombosis in their heart or lungs. Despite these cardiovascular dysfunctions, there was no difference in body weight nor was there any increased incidence of sudden death between the old Tie2FF1 mice and control mice. These findings suggested that there was a persistent but compensated cardiomyopathy and heart failure in the Tie2FF1 mice during aging. (Figure 4)ConclusionCompared to other MPN murine models reported so far, the Tie2FF1 mice is the first MPN murine model that faithfully recapitulated almost all the key features of the human MPN diseases. Considering the presence of the JAK2V617F mutation in microvascular ECs isolated from patients with MPNs and the recapitulation of all the key features of human MPN diseasesby the Tie2FF1 mice, the roles of endothelial dysfunction in the hematologic and cardiovascular pathogenesis of MPN shall be further investigated. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Clonal Hematopoiesis and JAK2V617F Mutations in Patients With Cardiovascular Disease

Clonal Hematopoiesis and JAK2V617F Mutations in Patients With Cardiovascular Disease

JAK2 V617F Prevalence Study: Associations in the General Population and Vascular Disease Populations

Introduction Clonal hematopoiesis (CH) is defined as an expansion of blood stem cell clones that bear advantageous somatic mutations. JAK2V617F is not only the most common mutation association with MPN, it is the fifth most common lesion implicated in CH. While the JAK2V617F positive MPN are rare diseases, CH occurs at relatively common rates in the aging population. CH carriers, and in particular JAK2V617F CH carriers, similar to MPN patients, are at increased risk of developing blood cancers, and arterial and venous thromboses. While many large-scale general population studies have examined prevalence of JAK2V617F CH, a comprehensive assessment of associations to disease has not been performed. Methods We identified all published studies that evaluated the prevalence of the JAK2V617F and CALR exon 9 mutations in the general population and in vascular disease risk populations. We used PUBMED, EMBASE, and SCOPUS databases. Two reviewers independently performed study selection and extracted study characteristics. Studies were included if they met the following criteria : analysis of JAK2/CALR mutations was performed according commonly accepted criteria and study inclusion of at least 40 patients. Results We identified 5793 abstracts/manuscripts that met our search criteria. After title/abstract review, 104 manuscripts were included in the meta-analysis (Figure 1). Thirteen of these studies examined the prevalence of JAK2V617F and CALR exon 9 mutations in a general, unselected population. Among 546,504 participants included in these studies, 1,850 (0.34%) were positive for the JAK2V617F mutation. In contrast, 32 out of 19,958 (0.16%) were positive for CALR exon 9 mutations. In the general population, the JAK2V617F mutation was most commonly associated with male sex, increased age, and smoking. Three studies reported increased blood counts, predominantly platelets and white blood cells. Four studies noted an increased risk of MPN or hematologic cancer in those with the JAK2V617F mutation. The JAK2V617F mutation was associated with an increased risk of venous thrombosis in 3 studies and ischemic heart disease/MI in 2 studies. JAK2V617F variant allele fraction (VAF) when reported ranged 0.004% to 86%. The prevalence of the JAK2V617F in patients with venous or arterial vasculopathy was examined in 91 studies with a total of 35,982 participants. Of these, 26,279 individuals had a history of thrombotic disease and 8,944 were controls. Of the participants with a history of any type of vascular disease, 1,279 (4.9%) were noted to have the JAK2V617F mutation with VAF, when reported, ranging from 0.2-96.2%. On subgroup analysis, patients with splanchnic vein thrombosis had the highest prevalence of the JAK2V617F mutation (18.7%) followed by patients with ischemic stroke (8.5%) and cerebral vein thrombosis (6.0%) (Table 1). The prevalence of the JAK2V617F mutation in patients with DVT/PE and peripheral arterial disease (PAD) was 1.6% and 3.1% respectively. The prevalence of JAK2V617F among all of the vascular disease subsets was substantially higher than the control populations. Similarly, the prevalence of CALR was noted to be high in studies of splanchnic vein thrombosis and cerebral vein thrombosis. (Table 2). Conclusions JAK2V617F and CALR mutations are associated with alterations of blood counts and thrombosis. Even at very low VAF, JAK2V617F is a thrombosis risk factor in the general population and is over-represented in populations with thrombosis. In every thrombosis group, the prevalence in JAK2V617F in thrombosis patients was higher than that in the control population, suggesting the JAK2V617F mutation may contribute to both arterial and venous thrombotic risk, whether in the MPN or CH population context. Disclosures Naik: Elsevier: Consultancy; Rigel: Research Funding. Moliterno:Pharmessentia: Consultancy; MPNRF: Research Funding.

PCR đặc hiệu allele tích hợp công nghệ amplification refractory mutation system (Dsa-Pcr-Arms) phát hiện đột biến jak2 v617f và Carl trên bệnh nhân có hội chứng tăng sản tủy

BIDIRECTIONAL ALLELE SPECIFIC PCR INTEGRATED WITH AMPLIFICATION REFRACTORY MUTATION SYSTEM –(DSA-PCR-ARMS) FOR ANALYZING CARL AND JAK2 V617F MUTATIONS IN PATIENTS WITH MYELOPROLIFERATIVE NEOPLASM Bachground: Jak2 V617F and CARLmutation arerecognized as essential molecular genetic markers in diagnostic definition of myeloid proliferative neoplasm (MPN). Objective: to establish an income relevant Allele-specific-PCR-ARMS (DSA-PCR-ARMS) assays to identify Jak2 V617F, CARL mutations in MPN patients. Subjects: 64 MPN patients’ samples, one V617F positive referrance samples and one CALR mutant positive sample. Methods: dilution series of 100%, 50%, 25%, 5%, 0,5% and 0% mutant alleles were created as pseudo-samples establish the detection limits and the technical specificity of DSA-PCR-ARMS assays in identifying the mentioned genetics markers. Result: Our approach can detect presence of 0.5 % V617F mutant DNA fragment; beside that just by one gel-based PCR reaction, we can differentiate the deletion/insertion CARL carriers from the wild type counterpart. By applying our approachesto a study cohort of 50 MPN cases, a sensitivity of 64% and specificity of 100% was recorded for our Jak2 V617F detection assay and we also detected 3 CARL mutation case amongst the 10 V617F negative cases. Conclusion: The in-house of Jak2 V617F/CARL mutation detection protocols have been successfully established in our hospital. Key words: Jak2 V617F, CARL, myeloid proliferative neoplasm (MPN).

DIAGNOSTIC VALUE OF JAK2 V617F MUTATIONAL SCREENING IN PATIENTS WITH BUDD-CHIARI SYNDROME

Background: The diagnosis of underlying myeloproliferative neoplasms (MPNs) is often problematic in patients with Budd Chiari syndrome (BCS). A clonal mutation in JAK2 tyrosine kinase (JAK2V617F) occurs in a high proportion of patients with MPNs and is of use in the characterization of occult MPNs in BCS. Aim of the work: Detection of JAK2 V617F mutation in patients with BCS and its value in detection of occult MPNs. Patients and Methods: This study was carried out on fifty seven newly diagnosed Budd Chiari syndrome patientswho were attending tropical department in Ain Shams University Hospitals during the period from July 2017 to July 2018.Detection of JAK2V617F mutation was done by real time polymerase chain reaction. Results: Out of the studied 57 BCS patients, JAK2 V617F mutation was detected in 12 patients (21.1%) {10 (83.3%) were heterozygous and 2(16.7%) were homozygous for mutation}, while 45 patients (78.9%) were negative.On comparing JAK2 V617F positive and negative groups, there was a highly statistically significant relation regarding MPNs diagnosis, where all JAK2 V617F positive patients were diagnosed as MPNs of whom 7 (58.3%) had overtpresentation and 5(41.7%) had occult presentation, while in JAK2 V617F negative patients only 2 were diagnosed overt MPNs (p=0.001). Conclusion: In conclusion the JAK2 V617F mutation is an acquired mutation that can be used for diagnosis of latent MPNs presenting with thrombotic events, thus it is recommended to include JAK2 V617F gene analysis in the research panel for BCS patients.

Evaluation of the JAK2 V617F gene mutation in myeloproliferative neoplasms cases: a one-center study from Eastern Anatolia

Abstract Objective Detection of JAK2 V617F in myeloproliferative neoplasms (MPNs) is very important in both diagnosis and disease progression. In our study, we investigated the frequency of JAK2 V617F mutation in patients with myeloproliferative disorders. Methods We retrospectively reviewed the records of 720 patients (174 females and 546 males) who were tested for JAK2 V617F mutation from January 2007 to December 2017. Results In our patients were determined 22.6% JAK2 V617F mutation. 33.3% in women, 19.2% in men have been positive for JAK2 V617F mutation. In our study JAK2 V617F present in 48.6% of essential thrombocythemia, 80.5% of polycythemia rubra vera (PV), 47.5% of primary myelofibrosis, 10% of MPNs, unclassifiable, 0.8% of others. We also investigated the difference in hematological parameters [white blood cell, hemoglobin (Hb), hematocrit (HCT), red blood cell distribution widths (RDW) and platelets count (PLT)] between JAK2 V617F positive and JAK2 V617F negative patients. Conclusions Investigation of the JAK2 V617F mutation is very important in cases of MPNs. In our study JAK2 V617F mutation was higher in PV, essential thrombocythemia, and primary myelofibrosis patients. However, there were significant differences in Hb, HCT, RDW and PLT levels in mutation-positive patients.

Jak2v617f Mutation in Patients With Myeloproliferative Diseases And Those With Ischemic Heart Disease With Normal Coronary Angiography

Jak2v617f Mutation in Patients With Myeloproliferative Diseases And Those With Ischemic Heart Disease With Normal Coronary Angiography

JAK2V617F detection and allele burden measurement in saliva vs. peripheral blood in patients with myelofibrosis

We previously demonstrated that peripheral blood (PB) is a reliable source for testing JAK2V617F mutation in patients with myelofibrosis (MF); saliva has also been tested to detect such mutation, however its diagnostic accuracy as compared to PB has not been validated.In this study, we prospectively tested 167 patients with MF for JAK2V617F mutation, using both saliva and PB collected at the same time from each patient. The concordance between the 2 sources was 96%, with a sensitivity of 100% and a specificity of 90%. The only factor associated with false positivity on saliva was ongoing transfusion dependency.JAK2V617F testing using saliva is a simple, non-invasive, and potentially a more reliable method than PB for measuring JAK2 status and assessing V617F allelic burden in patients with transfusion dependency.

The JAK2V617F-bearing vascular niche promotes clonal expansion in myeloproliferative neoplasms

The acquired kinase mutation JAK2V617F plays a central role in myeloproliferative neoplasms (MPNs). However, the mechanisms responsible for the malignant hematopoietic stem/progenitor cell (HSPC) expansion seen in patients with MPNs are not fully understood, limiting the effectiveness of current treatment. Endothelial cells (ECs) are an essential component of the hematopoietic niche, and they have been shown to express the JAK2V617F mutation in patients with MPNs. We show that the JAK2V617F-bearing vascular niche promotes the expansion of the JAK2V617F HSPCs in preference to JAK2WT HSPCs, potentially contributing to poor donor cell engraftment and disease relapse following stem cell transplantation. The expression of Chemokine (C-X-C motif) ligand 12 (CXCL12) and stem cell factor (SCF) were upregulated in JAK2V617F-bearing ECs compared to wild-type ECs, potentially accounting for this observation. We further identify that the thrombopoietin (TPO)/MPL signaling pathway is critical for the altered vascular niche function. A better understanding of how the vascular niche contributes to HSPC expansion and MPN development is essential for the design of more effective therapeutic strategies for patients with MPNs.

How the Real-Life Diagnostic and Therapeutic Approach Changed in the Last Two Decades in the Thrombocythemic Patients with Ph- Negative Myeloproliferative Neoplasm. Report on 2388 Subjects of the Registro Italiano Trombocitemie (RIT)

Background: the Registro Italiano Trombocitemie (RIT) was activated mainly to evaluate the diagnosis and therapy appropriateness in the thrombocythemic patients with Ph-negative myeloproliferative neoplasm (MPN) observed in the adhering centers.Objective: to evaluate how the diagnostic and therapeutic approach changed in the RIT patients diagnosed with thrombocythemic MPN in the last two decades.Methods: the RIT centers registered by a web-based system during the years 2005-2014 their thrombocythemic MPN patients, and semesterly updated their follow-up data. For patients diagnosed before 2005, the data on diagnosis and prior follow-up were retrospectively collected. The diagnostic process and the initial treatment (started into the first year after diagnosis) were comparatively analyzed in the patients diagnosed before and after 2005.Results: the RIT centers registered 2629 patients. 2388 of them, object of this analysis, were diagnosed between1995 and 2014: 1098 (46%) in the decade 1995-2004 (Group I), and 1290 (54%) in the decade 2005-2014 (Group II).The diagnostic process in the patients of Group II and Group I included bone marrow biopsy (BMB, performed into 1 year and before any cytoreduction): 85% vs 80%, p <0.001; clonality tests (JAK2 and/or others): 80% vs 9%, p<0.001; cytogenetic evaluation: 55% vs 57%, p 0.58; abdominal echography: 46% vs 41%, p 0.016.The patients of Group II, as compared with those of Group I, showed a similar gender distribution (M/F ratio 0.61 vs 0.65, p 0.452), and had at diagnosis: a higher age (median 60 vs 57 years, p <0.001; age >60 years in 50% vs 45% of cases, p <0.01); a similar rate of prior thrombosis (19% vs 19%), prior hemorrhage (3% vs 4%), CVRFs 69% vs 66%), splenomegaly (25% vs 25%), and hepatomegaly (22% vs 24%); a lower rate of disease-related symptoms (36% vs 40%, p 0.04); a higher rate of comorbidities (55% vs 51%, p 0.03).Moreover, they had: a lower platelet (PLT) count (median 737 vs 775 x 109/L, p <0.001; <600 x 109/L in 22% vs 14% of cases, p <0.001); a similar white blood cell (WBC) count (median 8.6 vs 8.5 x 109/L; >10 x 109/L in 28% vs 26% cases); a similar median levels of hematocrit (HCT %, in females 41.4 vs 41.0; in males 44.7 vs 44.6) and hemoglobin (Hb g/dL, in females 13.8 vs 13.6; in males 15.0 vs 14.9). The BMB, revised according to the WHO 2008 criteria, showed a not different distribution (p 0.21) of ET (64% vs 61%), ep-PMF (16% vs 17%), PMF (3% vs 2%), PV (4% vs 4%), and U-MPN (13% vs 16%. The JAK2 V617F mutation in patients of Group II (at diagnosis) and of Group I (after diagnosis) was found in 62% and in 58% of tested cases (p 0.054), respectively. The patients at high standard thrombotic risk were 58% vs 52%, p 0.004.In the patients of Group II and Group I the distribution of the treatment started into the first year was significantly different (p<0.001): AntiPLT 29% vs 24%, CYT 13% vs 16%, CYT+AntiPLT 49% vs 46%, CYT ± AntiPLT 62% vs 62%, AntiPLT ± CYT 78% vs 69%.The treatment CYT ± AntiPLT was started in the patients at high standard thrombotic risk with a rate of 81% vs 80%, respectively, and in the patients at low standard thrombotic risk in 37% vs 43% of cases, respectively.The initial treatment CYT±AntiPLT was related, in multivariate analysis, both in patients of Group II and Group I, with older age (>60 and 40-60 vs <40 years, p <0.001), higher PLT count (>1000 and 700-1000 vs <700 x 109/L, p <0.001), prior thrombosis (p <0.001), symptoms (p <0.001). Noteworthy, no relationship was found with JAK2 mutation, and WHO diagnosis.Conclusion: in the studied thrombocythemic MPN patients the real-life diagnostic approach was improved after 2005 not only due to the routine use of JAK2 tests, but also due to the higher rate of BMB done (85% vs 80%).The appropriateness of the cytoreductive treatment (CYT±AntiPLT started into one year from diagnosis) remained high in patients at high standard thrombotic risk (over 80% of cases were treated). Concomitantly, the inappropriate use of the cytoreductive drugs in patients at low standard thrombotic risk appreciably decreased (from 43% to 37% of cases). Moreover, it has to be remarked that the therapeutic approach was significantly influenced not only by older age and prior thrombosis, but also by thrombocytosis (PLT count >700 x 109/L), disease-related symptoms, and inconstantly by leukocytosis and CVRFs. [Display omitted] DisclosuresGugliotta:SHIRE Co.: Honoraria. Gugliotta:Bristol Myers Squibb: Consultancy, Honoraria; Novartis: Consultancy, Honoraria.

Assessment of interleukin-10 level and Janus kinase 2 V617F mutation incidence in patients with primary myelofibrosis

Background: Myelofibrosis (MF) is largely documented by an abnormal cytokine expression, which in turn could contribute to bone marrow fibrosis, angiogenesis, and constitutional symptoms. To gain additional pathogenetic insight regarding cytokine phenotype correlations in MF, this study estimated the level of interleukin-10 (IL-10) abnormality and Janus kinase (JAK2 V617F) mutation in primary MF. Objective: The objective of this study was to assess serum IL-10 level and it's relation with the presence of JAK2 V617F mutation in patients with MF. Materials and Methods: JAK2 V617F mutation detection was performed in 32 patients with MF using amplification refractory mutation screening-polymerase chain reaction. IL-10 level was estimated in 36 patients with MF using enzyme-linked immunosorbent assay technique compared to 27 healthy controls who were enrolled for comparison. Results: The study showed higher significant (P ≤ 0.002) increase of IL-10 in patients with MF with cutoff value ≥8.9510 pg/ml and area under the curve value of 0.749 (P Conclusion: JAK2 mutation and IL-10 as anti-inflammatory cytokines may play a role in the pathogenesis and hematological presentation of patients with PMF. High IL-10 level may predict good prognosis in patients with PMF.

Incidence of JAK2V617F Mutation in Patients with Acute Myeloid Leukemia

Incidence of JAK2V617F Mutation in Patients with Acute Myeloid Leukemia

Prevalence of JAK2V617F mutation in deep venous thrombosis patients and its clinical significance as a thrombophilic risk factor: Indian perspective.

Venous thromboembolism is known to be a complex interaction of genetic and acquired factors leading to thrombosis. JAK2V617F mutation is believed to contribute to a thrombophilic phenotype, possibly through enhanced leukocyte-platelet interactions in myeloproliferative neoplasms (MPNs). Several studies have focused on the importance of screening for JAK2V617F mutation in patients with splanchnic venous thrombosis (VT) for the detection of nonovert MPNs. The role of JAK2V617F mutation in VT outside the splanchnic region is still widely unsettled. The primary aim of this study was to find out the prevalence of JAK2V617F mutation in patients with deep venous thrombosis (DVT), its clinical significance as a prothrombotic risk factor, and its possible interactions with other genetic thrombophilic risk factors. A total of 148 patients with idiopathic, symptomatic DVT were evaluated. Median age of presentation was 32 years (range 15-71 years) with a sex ratio of 1.3:1. Overall, the most common genetic prothrombotic factor was factor V Leiden mutation, found in 10.8% (16 of 148) of patients who also showed strong association with increased risk of thrombosis (odds ratio 5.94, confidence interval 1.33-26.4, P = .019). Deficiencies in protein C, protein S, and antithrombin were seen in 8 (5.4%), 10 (6.7%), and 8 (5.4%) patients, respectively. It was observed that the frequency of JAK2V617F mutation was lower in Indian patients, and it also showed weaker association with risk of thrombosis, at least in cases of venous thrombosis outside the splanchnic region.