scholarly journals Serum Has Higher Proportion of Janus Kinase 2 V617F Mutation Compared to Paired EDTA-Whole Blood Sample: A Model for Somatic Mutation Quantification Using qPCR and the 2-∆∆Cq Method

Diagnostics ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 153 ◽  
Author(s):  
Gustavo Barcelos Barra ◽  
Ticiane Henriques Santa Rita ◽  
Ana Luisa Santa Cruz Almeida ◽  
Rafael Henriques Jácomo ◽  
Lídia Freire Abdalla Nery
Keyword(s):  
Whole Blood ◽  
Mutant Allele ◽  
Myeloproliferative Neoplasms ◽  
Jak2 V617f ◽  
Absolute Quantification ◽  
Janus Kinase ◽  
Molecular Diagnostic ◽  
Janus Kinase 2 ◽  
Cq Method ◽  
V617f Mutation

Detection of the Janus Kinase-2 (JAK2) V617F mutation is a diagnostic criterion for myeloproliferative neoplasms, and high levels of mutant alleles are associated with worse outcomes. This mutation is usually tested on blood DNA by allele-specific qPCR (AS-qPCR) and measured using absolute quantification. However, some automated DNA extractions co-extracts of PCR inhibitors from blood and qPCR absolute quantification need increased efforts in order to maintain standard curves. JAK2 V617F can also be detected in serum using droplet digital PCR (ddPCR), a specimen with less inhibitors and favorable to automated extractions, but ddPCR instruments are not wide available as qPCR thermocyclers. Here, we evaluate whether JAK2 V617F could be accurately quantified by AS-qPCR using the 2-∆∆Cq method on blood DNA and validate the assay using gold-standard molecular diagnostic protocols. Next, we apply the validated method to assess if the mutation could be reliably detected/quantified in serum. JAK2 V617F could be quantified by AS-qPCR using the 2-∆∆Cq method—the assay was highly accurate (bias of 1.91%) compared to a commercial kit, highly precise (total CV% of 0.40%, 1.92%, 11.12% for samples with 93%, 54%, and 2.5% of mutant allele), highly sensitive (limit of detection of 0.15%), and demonstrated a linear detection response from 1.1% to 99.9%. Serum presented a higher mutant allele burden compared to the paired whole blood (mean of 4%), which allows for an increased JAK2 mutant detection rate and favors increased JAK2 V617F high-throughput analysis.

Should We Screen for Janus Kinase 2 V617F Mutation in Cerebral Venous Thrombosis?

2017 ◽  
Vol 44 (3-4) ◽  
pp. 97-104 ◽  
Author(s):  
Matthias Lamy ◽  
Paola Palazzo ◽  
Pierre Agius ◽  
Jean Claude Chomel ◽  
Jonathan Ciron ◽  
...  
Keyword(s):  
Venous Thrombosis ◽  
Cerebral Venous Thrombosis ◽  
Myeloproliferative Neoplasms ◽  
Jak2 V617f ◽  
Janus Kinase ◽  
Jak2 V617f Mutation ◽  
Janus Kinase 2 ◽  
Jak2 Mutation ◽  
Venous Thromboembolic Events ◽  
V617f Mutation

Background: The presence of Janus Kinase 2 (JAK2) V617F mutation represents a major diagnostic criterion for detecting myeloproliferative neoplasms (MPN) and even in the absence of overt MPN, JAK2 V617F mutation is associated with splanchnic vein thrombosis. However, the actual prevalence and diagnostic value of the JAK2 V617F mutation in patients with cerebral venous thrombosis (CVT) are not known. The aims of this study were to assess the prevalence of JAK2 V617F mutation in a large group of consecutive CVT patients, to detect clinical, biological, and radiological features associated with the mutation, and to determine the long-term venous thrombosis recurrence rate in CVT patients with JAK2 mutation but without overt MPN in order to recommend the best preventive treatment. Methods: This was a prospective study conducted on consecutive patients with a first-ever radiologically confirmed CVT. JAK2 V617F mutation analysis was assessed in all the study subjects. JAK2 V617F-positive patients were followed up to detect new venous thrombotic events. Results: Of the 125 included subjects, 7 were found to have JAK2 V617F mutation (5.6%; 95% CI 2.3-11.2). Older age (p = 0.039) and higher platelet count (p = 0.004) were independently associated with JAK2 V617F positivity in patients without overt MPN. During a mean follow-up period of 59 (SD 46) months, 2 JAK2 V617F-positive patients presented with 4 new venous thromboembolic events. Conclusions: Screening for the JAK2 V617F mutation in CVT patients seems to be useful even in the absence of overt MPN and/or in the presence of other risk factors for CVT because of its relatively high prevalence and the risk of thrombosis recurrence.

scholarly journals Megakaryocytic morphology in Janus kinase 2 V617F positive myeloproliferative neoplasm

2017 ◽  
Vol 06 (02) ◽  
pp. 075-078
Author(s):  
Shuchi Ghai ◽  
Sharada Rai
Keyword(s):  
Bone Marrow ◽  
Myeloproliferative Neoplasms ◽  
Myeloproliferative Neoplasm ◽  
Jak2 V617f ◽  
Janus Kinase ◽  
Jak2 V617f Mutation ◽  
Fisher Exact Test ◽  
Janus Kinase 2 ◽  
Bone Marrow Biopsies ◽  
V617f Mutation

Abstract Context: Alterations in megakaryocyte morphology are the hallmark of myeloproliferative neoplasms (MPNs). These neoplasm are also associated with Janus kinase 2 (JAK2) V617F mutation in nearly 95% patients with polycythemia vera (PV), 40% patients of essential thrombocythemia (ET) and 50% patients of myelofibrosis (MF). The utility of megakaryocyte morphology in these disorders in correlation with JAK2 V617F remains unresolved. Aims: The aim of the study was to assess the morphology of megakaryocytes in bone marrow aspirates (BMAs) and bone marrow biopsies of patients of BCR-ABL negative MPNs with JAK2 V617F mutation. Settings and Design: This study was a retrospective and prospective, hospital-based study undertaken for a period ranging from January 2011 to April 2015. Subjects and Methods: Assessment of morphological features of megakaryocytes in 15 BMAs and their respective biopsies which included seven cases of PV, three cases of ET, and five cases of MF with JAK2 V617F mutation. Statistical Analysis Used: Chi-square test and Fisher exact test were used to compare the different features of megakaryocytes. Software version SPSS 13.0 was used. Results: Megakaryocytes in ET were found to have characteristically large size with staghorn multinucleated nuclei and exhibiting large amount of cytoplasm. MF showed dense clustering of megakaryocytes with staghorn nucleus along with sinusoidal dilatation and intrasinusoidal hematopoiesis. PV showed loose and dense clustering of megakaryocytes with a predominance of cloud-like nuclei. Few of the megakaryocytic morphologic features showed overlap between MF and PV and between ET and early MF. Conclusions: Megakaryocytic morphology can aid in the accurate diagnosis of the different subcategories of MPNs. This would help in categorization of clinically suspicious patients of JAK2 V617F negative patients.

Screening JAK2 Exon 12 in JAK2 V617F Negative Patients with Myeloproliferative Disorders Reveals a New Splice Site Mutation

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 5238-5238
Author(s):  
C. Bento ◽  
A. Estevinho ◽  
I. Rapado ◽  
S. Grande ◽  
H. Matos ◽  
...  
Keyword(s):  
Splice Site ◽  
Genomic Dna ◽  
Mutant Allele ◽  
Splice Site Mutation ◽  
Jak2 V617f ◽  
Janus Kinase ◽  
Site Mutation ◽  
Mutational Status ◽  
Low Levels ◽  
V617f Mutation

Abstract Background. The identification of the somatic mutation V617F in exon 14 of the Janus kinase 2 gene (JAK2) has simplified the diagnosis of many patients affected with typical chronic myeloproliferative diseases (MPDs). In patients without the V617F the molecular basis of MPD are still unclear but, recently, mutations in exon 12 of the JAK2 gene have been identified in a minority of patients, associated with a selective increase in erythropoiesis resulting in polycythemia vera (PV) or idiopathic erythrocytosis (IE) (Scott et al, NEJM 2007). Aim. To determine the JAK2 exon 12 mutational status in a group of JAK2 V617F negative patients with PV or IE. Methods. Genomic DNA was extracted from peripheral blood leukocytes from 85 MPD patients (PV or IE) included in the present study. All the samples were tested for JAK2 V617F mutation by allele specific polymerase chain reaction (ASO-PCR) and those negative for V617F mutant allele were subjected to real time quantitative PCR (RQ-PCR) using hybridization probes. Subsequently, all JAK2 V617F negative samples by both ASO-PCR and RQ-PCR where subjected to direct sequencing to exclude JAK2 exon 12 mutations. Results. JAK2 V617F was positive in 78 (91.7%) of the 85 patients, however, in two of these patients the V617F mutation was only detected upon subjecting genomic DNA to RQ-PCR which revealed low levels of the mutant allele, 2.65 % and 3.98%. Analysis of the JAK2 exon 12 in the seven JAK2 V617F negative patients detected three previously described mutations: a duplication (V536-1546) and two deletions (H539-K540del+542K and R541-E543 delinsK)and a previously unreported splice site mutation detected in intron 12 (IVS12nt6 T-C). To our knowledge this was the first description of intronic mutations in the JAK2 gene. No mutations were detected in the remaining 3 (3.6%) patients. Conclusions. In this cohort study JAK2 mutations were observed in 82 (96,5%), of the 85 patients, of these 78 (95.12%) had the V617F allele. In two cases V617F was detected at low levels (2.65% and 3.98%) only by RQ-PCR, highlighting the need for sensitive techniques to detect somatic mutations. One of the patients, a young male with erythrocytosis and low serum Epo levels, revealed a previously unreported splicing mutation (IVS12 nt6: T-C). This study illustrates the heterogeneity at the DNA level in PV patients which may assist in better understanding the genotype and phenotype relationship in MPD patients and assist in further delineating the role of JAK2 in these disorders.

scholarly journals Analysis of JAK2 V617F mutation in Tunisian patients with myeloproliferative neoplasms

2021 ◽  
Vol 19 ◽  
pp. 205873922110065
Author(s):  
Soumaya Chadi ◽  
Tarak Dhaouadi ◽  
Imen Sfar ◽  
Hela Baccouche ◽  
Rym Nabli ◽  
...  
Keyword(s):  
Mutant Allele ◽  
Myeloproliferative Neoplasms ◽  
Direct Sequencing ◽  
Jak2 V617f ◽  
Primary Myelofibrosis ◽  
Jak2 V617f Mutation ◽  
Pcr Rflp ◽  
Tunisian Patients ◽  
Healthy Control ◽  
V617f Mutation

We aimed to investigate the prevalence of the JAK2 V617F mutation in Tunisian patients with myeloproliferative neoplasms (MPN) and to look for possible associations with diseases’ presentation. In this context, JAK2 V617F polymorphism was detected by PCR-RFLP and direct sequencing in 213 MPN patients (109 with polycythemia vera (PV), 93 with essential thrombocythemia (ET) and 11 with primary myelofibrosis (PMF)), 77 unclassified patients with thrombosis (UPT) and 95 healthy control subjects. The JAK2 V617F mutant allele was present by either PCR-RFLP or direct sequencing in 158 (74.17%) MPN patients while all UPT and controls were negative. Besides, the JAK2 V617F mutation was significantly more frequent in patients with PV 98 (89.9%) than in ET 54 (58.1%) and PMF 6 (54.5%) groups, p < 0.001. Analytic results in MPN patients showed significant associations between the JAK2 SNP and both hemoglobin levels (16.29 ± 3 vs 13.01 ± 3.65) and hematocrit (52.99 ± 8.34 vs 45.37 ± 10.94), p < 0.001 and p < 0.001, respectively. In addition, in the ET subgroup thrombosis was significantly more frequent in patients carrying the V617F mutation (16, (29.6%) vs 3, (7.7%)), p = 0.01. In ET patients, the V617F mutation seems to be predictive of thrombosis occurrence.

scholarly journals JAK2-V617F mutation in patients with myeloproliferative neoplasms: Association with FLT3-ITD mutation

2010 ◽  
Vol 138 (9-10) ◽  
pp. 614-618
Author(s):  
Vesna Spasovski ◽  
Natasa Tosic ◽  
Tatjana Kostic ◽  
Sonja Pavlovic ◽  
Milica Colovic
Keyword(s):  
Cell Proliferation ◽  
Myeloproliferative Neoplasms ◽  
Myeloid Cell ◽  
Jak2 V617f ◽  
Signalling Pathway ◽  
Janus Kinase ◽  
Jak2 V617f Mutation ◽  
Polycythaemia Vera ◽  
Jak2 Mutation ◽  
V617f Mutation

Introduction. An acquired somatic mutation V617F in Janus kinase 2 gene (JAK2) is the cause of uncontrolled proliferation in patients with myeloproliferative neoplasms. It is known that uncontrolled myeloid cell proliferation is also provoked by alteration in other genes, e.g. mutations in receptor tyrosine kinase FLT3 gene. FLT3 represents the most frequently mutated gene in acute myeloid leukaemia. Interestingly, mutated FLT3- ITD (internal tandem duplication) protein is a member of the same signalling pathway as JAK2 protein, the STAT5 signalling pathway. STAT5 activation is recognized as important for selfrenewal of haematopoetic stem cells. Objective. The aim of this study was the detection of JAK2- V617F mutation in patients with myeloproliferative neoplasms. Additionally, we investigated the presence of FLT3-ITD mutation in JAK2-V617F-positive patients in order to shed the light on the hypothesis of a similar role of these two molecular markers in haematological malignancies. Methods. Using allele-specific PCR, 61 patients with known or suspected diagnosis of myeloproliferative neoplasms were tested for the presence of JAK2-V617F mutation. Samples that were positive for JAK2 mutation were subsequently tested for the presence of FLT3-ITD mutation by PCR. Results. Eighteen of 61 analysed patients were positive for JAK2-V617F mutation. Among them, 8/18 samples were diagnosed as polycythaemia vera, and 10/18 as essential thrombocythaemia. None of JAK2-V617F-positive patient was positive for FLT3-ITD mutation. Conclusion. This study suggests that one activating mutation is sufficient for aberrant cell proliferation leading to malignant transformation of haematopoetic stem cell.

scholarly journals Prevalence of the JAK2 V617F Mutation in Patients with Peripheral Arterial Disease

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3165-3165
Author(s):  
Elena Kinz ◽  
Klaus Gasser ◽  
Axel Muendlein ◽  
Andreas Leiherer ◽  
Michael Steurer ◽  
...  
Keyword(s):  
Mutant Allele ◽  
Myeloproliferative Neoplasms ◽  
Jak2 V617f ◽  
Arterial Disease ◽  
Jak2 V617f Mutation ◽  
Allele Burden ◽  
Cell Counts ◽  
V617f Mutation ◽  
Artery Disease ◽  
Peripheral Arterial

Abstract Introduction: The acquired JAK2 V617F mutation is common in patients with myeloproliferative neoplasms and increases thrombotic risk. We previously showed that JAK2 V617F is also found in healthy subjects as well as in patients with coronary artery disease (0.6% and 1.3%, respectively). Peripheral arterial disease (PAD) is an important manifestation of diffuse atherosclerosis and PAD patients are at exceptionally high risk for cardiovascular events, showing a worse prognosis than that of patients with coronary artery disease Due to the close relation of the JAK2 V617F mutation to thrombotic events we hypothesized that this mutation may play an important role in the risk management of PAD patients. However, prevalence of JAK2 V617F or of occult myeloproliferative neoplasms is unknown in PAD patients. Methods: In the present study we determined the prevalence of JAK2 V617F in a cohort of 287 patients with sonographically proven PAD. JAK2 mutational status from 997 age-matched healthy people was available from a previous study. JAK2 V617F screening and quantification of allele burden in both cohorts was performed with allele-specific quantitative real-time PCR. Results: From a total of 287 PAD patients samples, 9 (3.1%) were tested positive for JAK2 V617F mutation corresponding to a 5-fold, highly significant increase compared with healthy people (p<0.001). Mutant allele burden of JAK2 V617F positive samples was ranging between 0.2% and 96.2% (median=0.75%). Generally, our study showed no significant association of the JAK2 V617F mutation with abnormal blood cell counts. However, the patient with the highest mutant allele burden showed elevated hemoglobin values (> 18.5 g/dL) indicating polycythemia vera (PV). Conclusion: We conclude that the prevalence of JAK2 V617F mutation is significantly increased in PAD patients compared to the general population. For this reason mutation analysis should be considered in PAD patients with abnormal blood cell counts to identify occult myeloproliferative neoplasms and to adjust therapeutic treatment, possibly reducing the risk of future vascular complications. Disclosures No relevant conflicts of interest to declare.

scholarly journals Prevalence of the Janus kinase 2 V617F mutation in Philadelphia-negative myeloproliferative neoplasms in a Portuguese population

2017 ◽  
Vol 7 (4) ◽  
pp. 370-376 ◽  
Author(s):  
Ana Paula Azevedo ◽  
Susana N. Silva ◽  
Alice Reichert ◽  
Fernando Lima ◽  
Esmeraldina Júnior ◽  
...  
Keyword(s):  
Myeloproliferative Neoplasms ◽  
Janus Kinase ◽  
Janus Kinase 2 ◽  
Portuguese Population ◽  
V617f Mutation

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

Biosensors ◽  
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.

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