Leukocytosis Can Predict Thrombotic Events in Myelofibrosis

Abstract Thrombotic events are the main complication of Philadelphia-negative chronic myeloproliferative neoplasms (MPN). In polycythemia vera (PV) and essential thrombocythemia (ET), risk factors for thrombosis are well established, such as age greater than 60 years and previous thrombosis. However, the role of JAK2 V617F mutation and leukocytosis at diagnosis as risk factor for thrombosis is still controversial. Our aim was to identify factors related to the risk for thrombotic events in the studied population.This study is a retrospective non-interventional cohort. All of the analyses were performed using the database of 142 patients with MPN regularly followed at the Hematology Division (at UNIFESP-SP) from 1992 to 2014. Diagnosis was established according to WHO criteria. We analyzed the JAK2 V617F mutation, hemoglobin (g/dL), hematocrit (%), white blood cells (x109/L) and platelets (x109/L) at the diagnosis and DIPSS-Plus risk score (International Working Group for Myelofibrosis Research and Treatment, 2009). These variables were associated with thrombotic event at any time.Of the 142 patients, 54 had diagnosis of PMF, 28 of PV, 33 of ET and 27 of post-essential thrombocythaemic myelofibrosis (post ET MF) or post-polycythaemic myelofibrosis (post-PV MF). This last group was included in myelofibrosis group for statistical purposes. Thrombotic events were more frequent in PV patients (39.2%), followed by ET (33.3%), and PMF (20.9%). From those which JAK2 mutation was obtained, it was positive in 92.4% of PV patients, 62% of PMF and 50% of ET. In none of the three groups, the presence of JAK2 V617F mutation was related to increased risk of thrombosis. In myelofibrosis, leukocytosis was higher among thrombotic patients (median of 13.7 in thrombotic group versus 9.7x 109/L; p 0.0379). None of the other parameters, hemoglobin, hematocrit, platelets and DIPSS-Plus were statistically significant. In ET, the hemoglobin level at diagnosis was significantly higher in the presence of thrombosis (mean of 14.57 in thrombotic group against 13.03 g/dL in the non-thrombotic one, p 0.0428). The other parameters, hematocrit, white blood cells and platelets were not relevant. The median WBC in the thrombotic group was 9.4 and in the non-thrombotic one 9.3 x109/L. Finally, in polycythemia vera, none of the variables were related to thrombosis. Among the studied population, leukocytosis was increased in patients with thrombotic event in MF. Thus, monitoring leukocyte count in MF is essential to predict thrombosis risk and should be further studied in order to define therapeutic goals in these patients. Disclosures No relevant conflicts of interest to declare.

Download Full-text

Analysis of JAK2 V617F Mutation and Its Clinical Significance in Patients with Thrombocythemia and Other Myeloproliferative Neoplasms in Chinese

Blood ◽

10.1182/blood.v118.21.4687.4687 ◽

2011 ◽

Vol 118 (21) ◽

pp. 4687-4687

Author(s):

Yue Xu ◽

Changxin Yin ◽

Han He ◽

Lingling Shu ◽

Fuqun Wu ◽

...

Keyword(s):

Polycythemia Vera ◽

Essential Thrombocythemia ◽

Conflicts Of Interest ◽

Myeloproliferative Neoplasms ◽

Jak2 V617f ◽

Jak2 V617f Mutation ◽

Jak2 Mutation ◽

Western Countries ◽

Arms Pcr ◽

V617f Mutation

Abstract Abstract 4687 JAK2 mutation is commonly found in Philadelphia-negative myeloproliferative neoplasms (MPNs). In Western countries, this mutation is found in approximately 96 percent of people with polycythemia vera, half of individuals with essential thrombocythemia or primary myelofibrosis. We used the method of amplification refractory mutation PCR (ARMS-PCR) to investigate MPN patients in China. We focused our study on patients with essential thrombocythemia (ET). ARMS-PCR was used to detect JAK2 V617F mutation in the bone barrow (BM) or peripheral blood of 37 MPN patients, which consisting of 7 ET, 5 polycythemia vera (PV), 5 chronic myeloid leukemia (CML), 5 chronic idiopathic myelofibrosis (CIMF), as well as 15 suspected MPNs. 17 cases of JAK2 V617F mutation (45.9%) were found in 37 patients, including 4 ET (57.1%), 4 PV (80.0%), 3 CIMF (60.0%), 6 suspected MPNs (40.0%). We did not find JAK2 V617F in the patients with CML. Our results indicated that the frequency of JAK2 V617F mutation in bcr/abl-negative MPNs in Chinese is similar to that in MPN patients in Western countries. At the same time, ARMS-PCR can distinguish the mutation is heterozygous or homozygous. Most patients were heterozygous for JAK2 but only a few were homozygous. In conclusion, our study showed that JAK2 V617F mutation frequency in Chinese MPN patients is similar to that in patients with this disorder in the West. It is the major molecular genetic abnormality in bcr-abl negative MPN and it can be used for diagnosis of MPN in China. Disclosures: No relevant conflicts of interest to declare.

Download Full-text

CRISPR/Cas12a-Based Ultrasensitive and Rapid Detection of JAK2 V617F Somatic Mutation in Myeloproliferative Neoplasms

Biosensors ◽

10.3390/bios11080247 ◽

2021 ◽

Vol 11 (8) ◽

pp. 247

Author(s):

Miaomiao Chen ◽

Chunhua Zhang ◽

Zhiqing Hu ◽

Zhuo Li ◽

Menglin Li ◽

...

Keyword(s):

Detection System ◽

Myeloproliferative Neoplasms ◽

Cost Effective ◽

Jak2 V617f ◽

Jak2 V617f Mutation ◽

Minimum Detectable Concentration ◽

Lateral Flow Strip ◽

Whole Process ◽

Detectable Concentration ◽

V617f Mutation

The JAK2 V617F mutation is a major diagnostic, therapeutic, and monitoring molecular target of Philadelphia-negative myeloproliferative neoplasms (MPNs). To date, numerous methods of detecting the JAK2 V617F mutation have been reported, but there is no gold-standard diagnostic method for clinical applications. Here, we developed and validated an efficient Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR associated protein 12a (Cas12a)-based assay to detect the JAK2 V617F mutation. Our results showed that the sensitivity of the JAK2 V617F/Cas12a fluorescence detection system was as high as 0.01%, and the JAK2 V617F/Cas12a lateral flow strip assay could unambiguously detect as low as 0.5% of the JAK2 V617F mutation, which was much higher than the sensitivity required for clinical application. The minimum detectable concentration of genomic DNA achieved was 0.01 ng/μL (~5 aM, ~3 copies/μL). In addition, the whole process only took about 1.5 h, and the cost of an individual test was much lower than that of the current assays. Thus, our methods can be applied to detect the JAK2 V617F mutation, and they are highly sensitive, rapid, cost-effective, and convenient.

Download Full-text

The study of Jak2 V617F mutation in polycythemia vera with zebrafish model

Cell Research ◽

10.1038/cr.2008.231 ◽

2008 ◽

Vol 18 (S1) ◽

pp. S141-S141

Author(s):

Alvin CH Ma ◽

Alice MS Cheung ◽

Alister C Ward ◽

Wing-Yan Au ◽

Yok-Lam Kwong ◽

...

Keyword(s):

Polycythemia Vera ◽

Jak2 V617f ◽

Jak2 V617f Mutation ◽

Zebrafish Model ◽

V617f Mutation

Download Full-text

Splanchnic venous thrombosis in JAK2 V617F mutation positive myeloproliferative neoplasms – long term follow-up of a regional case series

Thrombosis Journal ◽

10.1186/s12959-018-0187-z ◽

2018 ◽

Vol 16 (1) ◽

Cited By ~ 3

Author(s):

Graeme Greenfield ◽

Mary Frances McMullin

Keyword(s):

Venous Thrombosis ◽

Myeloproliferative Neoplasms ◽

Case Series ◽

Jak2 V617f ◽

Jak2 V617f Mutation ◽

Long Term Follow Up ◽

V617f Mutation

Download Full-text

Critical requirement for Stat5 in a mouse model of polycythemia vera

Blood ◽

10.1182/blood-2011-03-345215 ◽

2012 ◽

Vol 119 (15) ◽

pp. 3539-3549 ◽

Cited By ~ 77

Author(s):

Dongqing Yan ◽

Robert E. Hutchison ◽

Golam Mohi

Keyword(s):

Polycythemia Vera ◽

Blood Cells ◽

Myeloproliferative Neoplasms ◽

White Blood Cells ◽

Strong Support ◽

Primary Myelofibrosis ◽

Blood Parameters ◽

Critical Function ◽

Critical Requirement ◽

Multiple Signaling

The JAK2V617F mutation has been identified in most cases of Ph-negative myeloproliferative neoplasms (MPNs) including polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). Expression of JAK2V617F results in constitutive activation of multiple signaling molecules/pathways. However, the key signaling downstream of JAK2V617F required for transformation and induction of MPNs remains elusive. Using a mouse genetic strategy, we show here that Stat5 is absolutely required for the pathogenesis of PV induced by Jak2V617F. Whereas expression of Jak2V617F in mice resulted in all the features of human PV, including an increase in red blood cells, hemoglobin, hematocrit, white blood cells, platelets, and splenomegaly, deletion of Stat5 in the Jak2V617F knockin mice normalized all the blood parameters and the spleen size. Furthermore, deletion of Stat5 completely abrogated erythropoietin (Epo)–independent erythroid colony formation evoked by Jak2V617F, a hallmark feature of PV. Re-expression of Stat5 in Stat5-deficient Jak2V617F knockin mice completely rescued the defects in transformation of hematopoietic progenitors and the PV phenotype. Together, these results indicate a critical function for Stat5 in the pathogenesis of PV. These findings also provide strong support for the development of Stat5 inhibitors as targeted therapies for the treatment of PV and other JAK2V617F-positive MPNs.

Download Full-text

Increased risk of heparin induced thrombocytopenia and thrombosis in patients with essential thrombocythemia carrying the homozygous JAK2 V617F mutation

Journal of Thrombosis and Thrombolysis ◽

10.1007/s11239-018-1773-4 ◽

2018 ◽

Vol 47 (1) ◽

pp. 155-156 ◽

Cited By ~ 1

Author(s):

Roberto Castelli ◽

Paolo Gallipoli ◽

Riccardo Schiavon ◽

Thomas Teatini ◽

Giorgio Lambertenghi Deliliers ◽

...

Keyword(s):

Essential Thrombocythemia ◽

Jak2 V617f ◽

Jak2 V617f Mutation ◽

Heparin Induced Thrombocytopenia ◽

Increased Risk ◽

V617f Mutation

Download Full-text

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

Turkish Journal of Biochemistry ◽

10.1515/tjb-2018-0054 ◽

2019 ◽

Vol 44 (4) ◽

pp. 492-498

Author(s):

Gonca Gulbay ◽

Elif Yesilada ◽

Mehmet Ali Erkurt ◽

Harika Gozukara Bag ◽

Irfan Kuku ◽

...

Keyword(s):

Blood Cell ◽

Essential Thrombocythemia ◽

Myeloproliferative Neoplasms ◽

Hematological Parameters ◽

Jak2 V617f ◽

Primary Myelofibrosis ◽

Myeloproliferative Disorders ◽

Jak2 V617f Mutation ◽

V617f Mutation ◽

The Difference

AbstractObjectiveDetection ofJAK2V617F in myeloproliferative neoplasms (MPNs) is very important in both diagnosis and disease progression. In our study, we investigated the frequency ofJAK2V617F mutation in patients with myeloproliferative disorders.MethodsWe 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.ResultsIn our patients were determined 22.6%JAK2V617F mutation. 33.3% in women, 19.2% in men have been positive forJAK2V617F mutation. In our studyJAK2V617F 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)] betweenJAK2V617F positive andJAK2V617F negative patients.ConclusionsInvestigation 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.

Download Full-text

Relation between JAK2 (V617F) mutation status, granulocyte activation, and constitutive mobilization of CD34+ cells into peripheral blood in myeloproliferative disorders

Blood ◽

10.1182/blood-2005-09-3826 ◽

2006 ◽

Vol 107 (9) ◽

pp. 3676-3682 ◽

Cited By ~ 164

Author(s):

Francesco Passamonti ◽

Elisa Rumi ◽

Daniela Pietra ◽

Matteo G. Della Porta ◽

Emanuela Boveri ◽

...

Keyword(s):

Polycythemia Vera ◽

Gene Dosage ◽

Jak2 V617f ◽

Myeloproliferative Disorders ◽

Jak2 V617f Mutation ◽

Disease Category ◽

Mutation Status ◽

Cell Counts ◽

Cd34 Cells ◽

V617f Mutation

We studied the relationship between granulocyte JAK2 (V617F) mutation status, circulating CD34+ cells, and granulocyte activation in myeloproliferative disorders. Quantitative allele-specific polymerase chain reaction (PCR) showed significant differences between various disorders with respect to either the proportion of positive patients (53%-100%) or that of mutant alleles, which overall ranged from 1% to 100%. In polycythemia vera, JAK2 (V617F) was detected in 23 of 25 subjects at diagnosis and in 16 of 16 patients whose disease had evolved into myelofibrosis; median percentages of mutant alleles in these subgroups were significantly different (32% versus 95%, P < .001). Circulating CD34+ cell counts were variably elevated and associated with disease category and JAK2 (V617F) mutation status. Most patients had granulocyte activation patterns similar to those induced by administration of granulocyte colony-stimulating factor. A JAK2 (V617F) gene dosage effect on both CD34+ cell counts and granulocyte activation was clearly demonstrated in polycythemia vera, where abnormal patterns were mainly found in patients carrying more than 50% mutant alleles. These observations suggest that JAK2 (V617F) may constitutively activate granulocytes and by this means mobilize CD34+ cells. This exemplifies a novel paradigm in which a somatic gain-of-function mutation is initially responsible for clonal expansion of hematopoietic cells and later for their abnormal trafficking via an activated cell progeny.

Download Full-text