Microarray analysis reveals distinct immune signatures in BCR?ABL positive and negative myeloproliferative neoplasms

Background: BCR?ABL mutation on the Philadelphia chromosome is the key driver of chronic myeloid leukemia (CML) pathogenesis. However, there are certain cases of myeloproliferative neoplasms (MPN) wherein no inherent driver mutation is detected resulting in clinical phenotype. It is important to identify key genes and pathways in driving the disease. The aim of the study was to use a gene-based omics approach to molecularly characterize these mutation-positive and negative cases to further strengthen diagnostics and precision medicine. Methods: A microarray profiling was done on CD34 positive cells isolated from two BCR?ABL positive and five BCR?ABL negative samples. JAK2V617F mutation testing was also done to rule out the presence of any other mutation in the latter group. The fold change cut-off was taken as �5 with p?0.5 for significant genes. The gene network and pathway analysis were done using DAVID and STRING software. Results: The genes upregulated in BCR?ABL negative samples were shown to be involved in immune regulation, signal transduction and T- and B-cell signalling. The protein-protein interaction network of upregulated genes in these samples were enriched for various immunomodulatory genes such as HLADP, HLADQ , IL7R, CCR7, CD3 subtypes. These genes further formed a network with signal transduction genes such as LCK, FYN, RAG1, DOCK1, AKT3, SMAD3, LEF1. Conclusion: The results suggested a modulation of immune response genes and its subsequent effect on oncogenic signalling in BCR?ABL negative samples as compared to BCR?ABL positive samples. The protein network analysis was enriched for genes involved in Src, TGF-beta and PI3K-AKT pathway contributing to the proliferation of neoplastic clone.

Influencia de la carga alélica del JAK2V617F en pacientes cubanos con trombocitemia esencial y mielofibrosis primaria / Influence of JAK2V617F allelic burden in Cuban patients with essential thrombocythemia and primary myelofibrosis

Introducción: La frecuencia de la mutación JAK2V617F se estima entre el 50 y 60 por ciento en pacientes con trombocitemia esencial y mielofibrosis primaria. El 30 por ciento de los pacientes con policitemia vera y mielofibrosis primaria. Entre 2-4 por ciento de los pacientes con trombocitemia esencial presentan pérdida de heterocigosidad. Objetivos: Evaluar la influencia de la carga alélica de la mutación JAK2V617F y su relación con variables clínico-hematológicas en el diagnóstico de estas enfermedades en pacientes cubanos. Métodos: Se realizó un estudio retrospectivo, descriptivo y longitudinal en el Instituto de Hematología e Inmunología entre 2010 y 2020. Se incluyeron todos los pacientes con sospecha de trombocitemia esencial y mielofibrosis primaria con muestras de ADN válidas. Se les cuantificó la carga alélica de la mutación por PCR en tiempo real. Resultados: Se detectó la mutación en 66,7 por ciento de los diagnosticados con trombocitemia esencial y mielofibrosis primaria. El 62,5 por ciento de los pacientes con mielofibrosis primaria fueron homocigotos a la mutación, mientras que en la trombocitemia esencial solo el 20,8 por ciento. La diferencia de medias de cargas alélicas entre ambas enfermedades fue estadísticamente significativa. No se encontraron diferencias significativas en la comparación de las variables clínicas y hematológicas en estas enfermedades ni asociación con la carga alélica con excepción de las plaquetas en la mielofibrosis primaria. Conclusiones: El estudio estuvo limitado por la escasa muestra de pacientes, pero se corresponde con otras investigaciones que sostienen el concepto de que la presentación fenotípica de las neoplasias mieloproliferativasestá influenciada por la carga mutacional del JAK2V617F(AU)

Introduction: The frequency of the JAK2V617F mutation is estimated to be between 50 percent and 60 percent in patients with essential thrombocythemia and primary myelofibrosis. 30 percent of patients with polycythemia vera and primary myelofibrosis and 2-4 percent of patients with essential thrombocythemia show loss of heterozygosity. Objectives: To evaluate the influence of the allelic load of the JAK2V617F mutation in the diagnosis of these diseases in Cuban patients and its relationship with clinical-hematological variables. Methodology: A retrospective, descriptive and longitudinal study was carried out at the Institute of Hematology and Immunology between 2010 and 2020. All patients with suspected essential thrombocythemia and primary myelofibrosis with valid DNA samples were included. The allelic load of the mutation was quantified by real-time PCR. Results: The mutation was detected in 66.7 percent of those diagnosed with essential thrombocythemia and primary myelofibrosis. 62.5 percent of the patients with primary myelofibrosis were homozygous for the mutation, while in essential thrombocythemia only 20.8 percent. The difference in mean allelic loads between both diseases was statistically significant. No significant differences were found in the comparison of clinical and hematological variables in these diseases or association with allelic load, with the exception of platelets in primary myelofibrosis. Conclusions: The study was limited by the small sample of patients, but it corresponds to other investigations that support the concept that the phenotypic presentation of myeloproliferative neoplasms is influenced by the mutational load of JAK2V617F(AU)

Progress of BCR-ABL fusion gene and JAK2 V617F mutation double-positive myeloproliferative neoplasms / 白血病·淋巴瘤

Myeloproliferative neoplasms (MPN) are a group of clonal disorders of hematopoietic stem cells, and JAK2 V617F gene mutation is the main basis for the diagnosis of MPN. Previous studies have shown that BCR-ABL fusion gene and JAK2 V617F gene mutation are mutually exclusive in MPN patients, but in recent years, patients with a double mutation of both genes are often reported. The article synthesizes the relevant domestic and foreign literature in recent years, and reviews the BCR-ABL fusion gene and JAK2 V617F mutation double-positive MPN.

Clinical Correlation of Lactate Dehydrogenase Activity with JAK2V617F and FLT3 Mutations in Myeloproliferative Disorders and Acute Myeloid Leukemia: Indian Population

Background: Lactate dehydrogenase (LDH) play main role in the cell damage.Previous study has shown elevated level in acute leukemia and myeloproliferative disorders. Molecular markers specifically for JAK2V617F mutation in myeloproliferative disorders (MPDs) and FLT3 mutations in acute myeloid leukemia patients (AML) are well known for clinical practice. But, still only few reports have shown the correlation of LDH activity with molecular markers in Hematological Malignancy. Therefore, aim of study is to correlate LDH activity with established specific molecular markers in MPDs and AML. Methods:10 healthy individuals, 50 patients with MPDs and 50 patients with AML were included for the study. Serum LDH was performed by autoanalyser. The JAK2V617F mutations is analyse from blood by Real time PCR and FLT3 ITD/D835 mutations are analysed from blood by PCR-RFLP respectively. Statistical analysis was done by SPSS statistical software. Results: LDH Activity were higher in MPDs and AML as compared with healthy individual. Mean LDH activity was higher in FLT3 ITD/D835 positive mutation and JAK2V617F positive mutation in AML and MPDs respectively was observed. Conclusion: High LDH activity with Positive frequency of FLT3 ITD/D835 mutation in Acute Myeloid Leukemia and Positive frequency of JAK2V617F mutation in Myeloproliferative Disorders were observed.

Correlation analysis on JAK2V617F mutation and clinical features in patients with myeloproliferative neoplasms and its clinical significance / 吉林大学学报(医学版)

Objective: To investigate the distribution of JAK2V617F mutation in the patients with myeloproliferative neoplasms (MPN), to explore the association between JAK2V617F mutation and the clinical features of MPN, and to clarify its clinical significance in the diagnosis and treatment of the MPN patients. Methods: A total of 170 patients with MPN were selected as the subjects and divided into true polycythemia (PV) group (n=68), primary thrombocytopenia (ET) group (n=88) and primary myelofibrosis (PMF) group (n=14). The JAK2V617F mutations in 170 patients with MPN were detected by allele-specific PCR (AS-PCR). The differences in gender, age, white blood cell count, hemoglobin, platelet count, prothrombin time (PT), activated partial thromboplastin time (APTT), D-dimer, whether complicated with splenomegaly and thromboembolism of the JAK2V617F mutant-type and wild-type patients in each group were analyzed. Results: The total mutation rate of JAK2V617F mutation in 170 patients with MPN was 68. 2% (116/170), and the mutation rates in PV, ET, and PMF groups were 72. 1% (49/68), 68. 1% (60/88), and 50. 0% (7/14), respectively. The JAK2V617F mutation rate in PV group was higher than those in the other two groups, but there were no statistical differences (P = 0. 281). Compared with wild type group, the age of onset, the white blood cell and platelet counts of the PV patients with JAK2V617F mutation were significantly increased (P

Association of JAK2V617F mutation with thrombosis in Indian patients with Philadelphia negative chronic myeloproliferative neoplasms

Background: It is still a matter of debate regarding the association of JAK2V617F mutation with thrombosis in BCR-ABL negative CMPN patients. The role of JAK2V617F mutation in increasing the thrombotic risk in CMPNs is yet unequivocal. Aims: To clarify the contribution of JAK2V617F mutation in thrombosis in CMPN patients. Settings and Design: This retrospective study was done to evaluate role of JAK2V617F mutation in thrombosis in CMPNs. Materials and Methods: 65 CMPN patients (PV, ET and PMF) were analyzed for JAK2V617F mutation using ARMS-PCR and detailed history of thrombosis was recorded in these patients. Statistical Analysis: P values were 2 tailed, and statistical significance was set at P < 0.05. Results: 46/65 were males and 19/65 were females [M: F: 2.4:1] with median age 46 years [range, 14-80 years]. Patients had median Hb 15.6 g/dl [range, 5.1-20.3], median TLC 10.7 × 109/l [range 2.4-216] and platelet count 360 × 109/l [range, 20-1859]. 32 were JAK2V617F positive and 33 were negative for this mutation. On comparing the prevalence of thrombosis in JAK2V617F positive patients with JAK2V617F negative patients, we observed that 20/32 (62.5%) JAK2V617F positive patients had thrombosis as compared to 16/33 (48%) in JAK2V617F negative patients (P = 0.04). We observed significant association of JAK2V617F mutation with thrombosis, however no association of this mutation with thrombosis was observed among the JAK2V617F negative patients. Conclusion: Our study suggests that JAK2V617F mutation may increase the risk of thrombosis in CMPNs. This finding could lead to risk stratification, setting up the treatment strategy in CMPNs.

Philadelphia-negative myeloproliferative neoplasms as disorders marked by cytokine modulation

ABSTRACT Background: Cytokines are key immune mediators in physiological and disease processes, whose increased levels have been associated with the physiopathology of hematopoietic malignancies, such as myeloproliferative neoplasms. Methods: This study examined the plasma cytokine profiles of patients with essential thrombocythemia, primary myelofibrosis, polycythemia vera and of healthy subjects, and analyzed correlations with JAK2 V617F status and clinical-hematological parameters. Results: The proinflammatory cytokine levels were increased in myeloproliferative neoplasm patients, and the presence of the JAK2 V617F mutation was associated with high IP-10 levels in primary myelofibrosis patients. Conclusions: Essential thrombocythemia, primary myelofibrosis, and polycythemia vera patients exhibited different patterns of cytokine production, as revealed by cytokine network correlations. Together, these findings suggest that augmented cytokine levels are associated with the physiopathology of myeloproliferative neoplasms.

The JAK2 V617F Mutation in Chronic Myeloid Leukaemia within a BCR-ABL Positive Cohort of Beninese Patients

Chronic myelogenous leukaemia (CML) is an acquired myeloproliferative disorder (MPD) characterized by a chromosomal abnormality (the Philadelphia chromosome) that causes the chimeric BCR-ABL oncogene. An acquired genetic mutation in exon 12 of the JAK2 tyrosine kinase gene leading to a substitution of a valine for a phenylalanine (V617F) has been described as the most common form of CML for those who test negative for the Philadelphia (Ph) chromosome. According to World Health Organization (WHO) classifications (2008), the JAK2 V617F mutation and the BCR-ABL translocation are mutually exclusive for Ph(-) and Ph (+) MP, respectively. We studied the JAK2 V617F mutation in Ph+ myeloid leukaemia in a cohort of 27 Beninese patients. The ARMS multiplex PCR technique was used to identify the JAK2 V617F mutation in all patients. Most of the patients were diagnosed as in the chronic phase (88.9%) of the disease, and all of them were carriers of the Philadelphia chromosome and considered Ph (+). No patients with the BCR/ABL translocation carried the JAK2 V617F mutation. JAK2 V617F is specific to Philadelphia gene negative MP.

Expression of socs1 and shp1 in JAK2V617F mutation positive myeloproliferative neoplasms and regulation effect of ruxolitinib / 第二军医大学学报

Objective To analyze the relationship between the JAK2V617F mutation and the expressions of phosphorylated Janus kinase 2 (p-JAK2), suppressor of cytokine signaling 1 (SOCS1), and SH2-containing protein tyrosine phosphatase 1 (SHP1) in JAK2V617F mutation positive myeloproliferative neoplasm (MPN) tissues, and to investigate the effects of JAK2 inhibitor ruxolitinib on regulating the proliferation of JAK2V617F mutation positive human erythroleukemia cell lines HEL and the expressions of SOCS1 and SHP1 in HEL cells. Methods A total of 48 patients with JAK2V617F mutation positive MPN (MPN group) and 24 patients with anemia (control group) in Hebei General Hospital and The First People’s Hospital of Baoding from Jul. 2012 to Aug. 2016 were enrolled in this study. The protein expressions of p-JAK2, SOCS1 and SHP1 in bone marrow biopsies (BMBs) were detected by immunohistochemistry. The correlations between JAK2V617F mutation level and the protein expressions of SOCS1 and SHP1 were analyzed by Spearman rank correlation analysis. HEL cells were treated with ruxolitinib at different concentrations (50, 100, 250, 500 and 1 000 nmol/L), and the viability of cells was determined by CCK-8 assay. The JAK2V617F mutation levels in MPN tissues and HEL cells and the mRNA expressions of JAK2, SOCS1 and SHP1 in HEL cells were detected by qPCR. The protein expressions of JAK2, SOCS1 and SHP1 in HEL cells were detected by Western blotting analysis. Results The ratio of JAK2V617F/JAK2 was (57.33±20.82)% in the MPN group and was zero in the control group. The protein expressions of p-JAK2, SOCS1 and SHP1 in BMBs of MPN patients were significantly different from those in the control group (all P0.01). The protein expressions of SOCS1 and SHP1 were negatively correlated with the mutation level of JAK2V617F (r＝－0.648, －0.692; P0.05). The expressions of SOCS1 and SHP1 in MPN patients with JAK2V617F/JAK250% were significantly higher than those in MPN patients with JAK2V617F/JAK2≥50% (P0.01), while the expression of p-JAK2 was significantly lower than that in MPN patients with JAK2V617F/JAK2≥50% (P0.01). After treatment with 250 nmol/L ruxolitinib for 24 h, 48 h, and 72 h, the viabilities of HEL cells were (60.06±3.87)%, (52.05±2.88)%, and (36.43±2.01)%, respectively. With the increase of ruxolitinib concentrations, the mRNA and protein expressions of JAK2 and the protein expression of p-JAK2 were gradually decreased (P0.01, P0.05), while the mRNA and protein expressions of SOCS1 and SHP1 were gradually increased (all P0.01). Conclusion Ruxolitinib can inhibit the expressions of JAK and the phosphorylation of JAK in HEL cells, enhance the expressions of SOCS1 and SHP1, and reduce the viability of HEL cells.

Clinical significances of JAK2 mutation in patients with polycythemia vera / 中国肿瘤临床

Polycythemia vera (PV) is a myeloproliferative neoplasm (MPN) characterized by overproduction of red blood cells. The pathogenesis of PV is not completely understood. However, studies report that it may be associated with the gain-of-function somatic mutation of JAK2 and that the JAK2 mutation provides a molecular diagnostic standard for PV. JAK2 mutation and allele mutation bur-den are useful for predicting clinical features and courses. The discovery of JAK2 mutation has promoted the development of molecu-lar-targeted therapy, such as the JAK2 inhibitor, ruxolitinib, a drug with superior therapeutic effect and safety that is used in clinical practice. The JAK2 allele mutation burden is closely associated with leukocytosis and progression to myelofibrosis (MF). A high JAK2 al-lele mutation burden may be a risk factor for poor prognosis. This article briefly reviews the clinical significance of the JAK2 mutation in patients with PV.

Clinical Implications of Quantitative JAK2 V617F Analysis using Droplet Digital PCR in Myeloproliferative Neoplasms

BACKGROUND: JAK2 V617F is the most common mutation in myeloproliferative neoplasms (MPNs) and is a major diagnostic criterion. Mutation quantification is useful for classifying patients with MPN into subgroups and for prognostic prediction. Droplet digital PCR (ddPCR) can provide accurate and reproducible quantitative analysis of DNA. This study was designed to verify the correlation of ddPCR with pyrosequencing results in the diagnosis of MPN and to investigate clinical implications of the mutational burden. METHODS: Peripheral blood or bone marrow samples were obtained from 56 patients newly diagnosed with MPN or previously diagnosed with MPN but not yet indicated for JAK2 inhibitor treatment between 2012 and 2016. The JAK2 V617F mutation was detected by pyrosequencing as a diagnostic work-up. The same samples were used for ddPCR to determine the correlation between assays and establish a detection sensitivity cut-off. Clinical and hematologic aspects were reviewed. RESULTS: Forty-two (75%) and 46 (82.1%) patients were positive for JAK2 V617F by pyrosequencing and ddPCR, respectively. The mean mutated allele frequency at diagnosis was 37.5±30.1% and was 40.7±31.2% with ddPCR, representing a strong correlation (r=0.9712, P < 0.001). Follow-up samples were available for 12 patients, including eight that were JAK2 V617F-positive. Of these, mutational burden reduction after treatment was observed in six patients (75%), consistent with trends of hematologic improvement. CONCLUSIONS: Quantitative analysis of the JAK2 V617F mutation using ddPCR was highly correlated with pyrosequencing data and may reflect the clinical response to treatment.

Performance evaluation of the automated SNPs analyzer for the detection of JAK2 V617F mutation / 中华检验医学杂志

Objective To test and evaluate the JAK2 gene V617F mutation in patients with myeloproliferative tumors based on i-densy IS-5320 platform according to ISO15189 accreditation requirements.Methods Instrument performance verification.Selected from December 2014 to February 2017, 20 cases of JAK2 V617F mutation positive peripheral blood samples from Huashan Hospital of the Shanghai FuDan University Medical College and 20 cases of peripheral blood samples with negative JAK2V617F mutation.The Realtime PCR with TaqMan MGB probe was selected as the control method to verify and evaluate the accuracy of testing JAK 2 V617F mutation on i-densy IS-5320 platform.Whole blood samples were used to evaluate the reproducibility , cross-contamination and anti-interference ability of this platform.The ability of mutation load was verified by detecting mixtures of human erythnoleukemia cells and colorectal cancer cell HCT116 with 12 different proportions.Results I-densy IS-5320 platform and TaqMan MGB probe real-time fluorescence quantitative PCR show the same result .The within-run reproducibility and between-run reproducibility are both 100%.There is no observed contamination .High bilirubin and high triglyceride blood samples have no obvious interference on mutation detection .The mutation ratio with a load as low as 0.25%could be tested stably by i-densy IS-5320 platform.The detecting peak of melting curve can reflect the ratio of JAK2 V617F mutation to some extent.Conclusions I-densy IS-5320 can detect the mutation of JAK2 V617F gene in the whole blood directly.It has high sensitivity, accuracy and stability, and is easy to operate, and also can reflect the mutation load of JAK2 V617F, which could meet the clinical requirements for the detection of mutations.

Implicancia pronóstica de características basales en trombocitopenia esencial / Prognostic implication of basal characteristics in essential thrombocythemia

OBJETIVO: evaluar asociación entre características basales de Trombocitemia Esencial (TE) y eventos. Materiales-métodos: estudio observacional retrospectivo, datos capturados prospectivamente. Población: adultos con TE confirmada seguidos en CH del IIHEMA. Resultados: 67 pacientes evaluables. Md 68 años. Femenino 44, Masculino 23. Seguimiento Md 6 años. Score riesgo Alto 40, Intermedio 15, Bajo 12. Hematocrito Md 41%. Hemoglobina Md 13.4 g/dL. Leucocitos Md 9.7x109/L. Plaquetas Md 852x109/L. Esplenomegalia 12. Cariotipo normal 40, alterado 5. JAK2 V617F positivo 29/41. BCR/ABL1 negativo 45/45. FRV 40. Eventos: 67. Sangrado, 21 pacientes, presentó asociación con leucocitosis: Md 12.2x109/L en el grupo con sangrado y 8.8x109/L en el grupo sin evento (p=0.003). El 76% del grupo con sangrado y el 36,96% del grupo sin evento tenían leucocitos >10.0x109/L (p= 0.003). Trombocitosis Md 1.204x109/L en el grupo con sangrados y 814.5x109/L en el grupo sin evento (p=0.0098), no alcanzó significación estadística al comparar proporción de pacientes con recuento normal (p=0.46). Tromboembolia, 16 pacientes, se asoció con leucocitosis (Md 11.9x109/L en el grupo con tromboembolia y 9.2x109/L en el grupo sin evento (p=0.02). 75% del grupo con eventos y 41% del grupo sin eventos tenían leucocitos >10.0x109/L (p=0.018)) y con trombocitosis (Md 1.182x109/L en el grupo con tromboembolia y 809x109/L en el grupo sin evento (p=0.04), pero no alcanzó significación estadística al comparar proporción de pacientes con recuento normal (p=0.5)). CONCLUSIÓN: la asociación entre trombocitosis extrema/leucocitosis y sangrado coincidió con la literatura; leucocitosis se asoció a tromboembolia. El JAK2 V617F no mostró asociación: analizaremos prospectivamente aumentando la población para esclarecer asociación y posible rol de terapias dirigidas en esta entidad. (AU)

OBJETIVE: asses association basal characteristics of Essential Trombocitemia (ET) and events. MATERIALS-METHODS: retrospective observational study, data captured prospectively. Population: adults with confirmed ET treated in CH of IHEMA. RESULTS: 67 evaluable patients. Md 68-years-old. Female 44, Male 23. Follow up Md 6 years. Risk Score High 40, Intermeddle 15, Low 12. Hematocrit Md 41%. Hemoglobin Md 13.4 g/dL. Leukocytes Md 9.7x109/L. Platelets Md 852x109/L. Splenomegaly 12. Normal karyotype 40, abnormal 5. JAK2V617F positive 29/41. BCR-ABL1 negative 45/45. Vascular risk factors 40. EVENTS: 67. Bleeding, 21 patients, showed association with leukocytosis: Md 12.2x109/L in the group with bleeding and 8.8x109/L in the group without event (p=0.003). Leukocytes >10.0x109/L was seen in 76% of the group with bleeding versus 36.96% of the group without event (p= 0.003). Thrombocytosis Md 1.204x109/L in the group with bleeding and 814.5x109/L in the group without event (p=0.0098), but did not reach statistical significance when comparing with the proportion of patients with normal counts (p=0.46). Thromboembolism, 16 patients, showed association with both leukocytosis (Md 11.9x109/L in the group with thromboembolism and 9.2x109/L in the group without event (p=0.02). Leukocytosis >10.0x109/L was seen in 75% of the group with events and 41% of the group without event (p=0.018)) and with thrombocytosis (Md 1.182x109/L in the group with thromboembolism and 809x109/L in the group without event (p=0.04), but did not reach statistical significance when comparing with the proportion of patients with normal counts (p=0.5)). CONCLUSION: the association between extreme thrombocytosis/leukocytosis and bleeding was consistent with literature; leukocytosis was associated also with thromboembolism. JAK2 V617F mutated did not show association, we will prospectively analyze increasing the population to clarify its association and possible role of target therapies in this disease. (AU)

Relationship between JAK2-V617F Gene Mutation in Peripheral Blood Mononuclear Cells and Thrombotic Events in Patients with Myeloproliferative Neoplasms / 现代检验医学杂志

Objective To analyze the correlation between mutation in JAK2-V617F gene in peripheral blood mononuclear cells and thrombotic events in patients with myeloproliferative.Methods Investigation of thrombosis in 391 patients with MPN,using QRT-PCR to detect JAK2-V617F gene mutation in peripheral blood of patients.Result 105 cases of thrombotic events in 391 MPN patients (26.9％),84 cases of thrombotic events in 273 JAK2-V617F gene mutation positive patients (30.8 ％),however,21 cases of thrombotic events in 118 J AK2-V617F gene mutation negative panents (17.8 ％).The difference between the two groups was statistically significant (x2 =32.30,P＜0.01).In the PV group,45 cases of thrombosis events in JAK2-V617F positive patients (29.2 ％),6 cases of thrombosis events in JAK2-V617F negativepatients (42.9％),there was significant difference between the two groups (x2 =2.13,P＞0.05).In the ET group,18 cases of thrombosis events in JAK2-V617F positive patients (32.2％),9 cases of thrombosis events in JAK2-V617F negative patients (15.8％),there was significant difference between the two groups (x2 =12.32,P＜0.01).In the PMF group,21 cases of thrombosis events in JAK2-V617F posinve patients (33.3 ％),6 cases of thrombosis events in JAK2-V617F negativepatients (12.8 ％),there was significant difference between the two groups (x2 =14.32,P＜0.01).Conclusion JAK2-V617F positive MPN patients were more susceptible to thrombotic events especially in patients with ET and PMF.

The Prevalence of JAK2-V617F Mutation in Sudanese Patients with Chronic Myeloproliferative Neoplasms.

Myeloproliferative neoplasms (MPNs) are clonal malignant diseases that represent a group of conditions including polycythemia vera (PV), essential thrombocythemia (ET), and myelofibrosis (MF). The JAK2-V617F mutation has been described as a frequent genetic event in majority of patients with MPNs. The aim of this study was to determine the frequency of JAK2-V617Fmutation in Sudanese patients with myeloproliferative disorders referred to Isotope Center, and to investigate the differences of laboratory parameters between patients with JAK2-V617F positive myeloproliferative neoplasms (MPNs) and JAK2 wild type MPNs. A total of 259 patients with MPNs; 159 with polycythemia vera (PV), 55 with essential thrombocytosis (ET) and 45 with primary myelofibrosis (PMF), and11 healthy adult individuals were enrolled in this study from March 2013 to November 2015. DNA was isolated from peripheral blood leukocytes by innuPREP kit, and JAK2-V617F mutation gene detected by allele specific PCR. The JAK2-V617F mutation was detected in 71% (184/259) patients with MPNs. The prevalence of the mutation was 81.7% in PV, 56.4% inET, and 51.1% in PMF. Mutation was not detected in 11 healthy adult people. The presence of JAK2-V617F was not associated with Hb level, Hct, or the platelet count for PV and ET, whoever the mutation positively correlated with high Hb (P=.039), Hct (P=.04) in PMF patients, and with high erythrocytes count in PV. The JAK2-V617F mutation can be frequently detected in the Sudanese patients with MPNs.

The relationship between JAK2 V617F mutation and coagulation function in patients with essential thrombocythemia / 白血病·淋巴瘤

Objective To investigate the frequency of JAK2 V617F mutation and JAK2 V617F mutation allele burden in patients with essential thrombocythemia (ET), and explore the relationship between mutation and hematological parameters and coagulation function. Methods The clinical and laboratory parameters of 90 ET patients were analyzed. JAK2 V617F mutation was detected by AS-PCR and the mutation allele burden of JAK2 V617F was detected by qPCR. The correlation between mutation frequency and mutation burden of JAK2 V617F and blood laboratory parameters were investigated in ET. Results JAK2 V617F mutation was found in 50 patients (55.6 %). RBC [(4.67±0.89)×109/L vs (4.04±0.99)×109/L, P =0.003], WBC (11.64±5.20)×109/L vs (9.11±4.11)×109/L, P = 0.014], HCT (0.41±0.07) vs (0.36±0.07), P =0.005) in the JAK2 V617F mutated group were higher than those in the wild-type group. PT in mutated patients was longer than that in wild-type group [(13.18±1.63) s vs (12.02±1.24) s, P = 0.000]. The JAK2 V617F mutation allele burden was (29.91 ±18.63) %. No significant correlation was found between JAK2 V617F mutation allele burden and hematological parameters such as WBC, RBC and Plt (all P>0.05), but the JAK2 V617F mutation allele burden had a significant correlation with FDP (r = 0.456, P = 0.001). Conclusions JAK2 V617F mutation occurs in significant percentage patients with ET. Detection of JAK2 V617F mutation allele burden at diagnosis may play an important role in the early prevention of vascular events.

The detection and clinical significance of JAK2V617F mutations in myelodysplastic syndrome patients / 中国基层医药

Objective To explore the pathogenesis of myelodysplastic syndrome (MDS)transformation, JAK2V617F mRNA expression levels were compared in peripheral blood of MDS-RA(refractory anemia,RA)and MDS-RAEB(RA with excess blasts,RAEB)patients.Methods JAK2V617F mRNA expression level was detected by fuorescent quantitative polymerase chain reaction(FQ-PCR),and this research reviewed 22 patients diagnosed with MDS,including outpatient and hospitalized patients.20 cases of normal control group were healthy ones.FQ-PCR method was applied to monitor JAK2V617F mRNA expression level in peripheral blood of MDS-RA and MDS-RAEB patients.Results The JAK2V617F gene was not expressed or expressed in healthy subjects,and the copy number was (3 851.96 ±470.46).The patients with MDS-RA(4 631.11 ±3 851.96)was significantly higher than that in healthy subjects(t =3.61,P <0.01);MDS-RAEB patients was (22 545.98 ±11 084.17),and was significantly higher than that in MDS-RA patients(t =4.87,P <0.01).Conclusion JAK2V617F signal transduction can play a role in the pathogenesis and transformation of MDS,and the detection of JAK2-V617F mRNA expression level is use-ful for monitoring progression,judging prognosis and gene regulation therapy of MDS.

Differential diagnosis of masked polycythemia vera and polycythemia vera / 白血病·淋巴瘤

Objective To explore the method for early diagnosis of masked polycythemia vera (mPV) by comparing and analyzing the features of mPV and polycythemia vera (PV). Methods A total of 200 newly diagnosed male patients were collected based on diagnostic criteria, including 100 cases of PV and 100 cases of mPV. Erythropoietin (EPO), neutrophil alkaline phosphatase (NAP) score, bone marrow biopsy (BMB), and JAK2 V617F mutation were evaluated in all cases. After 6 months, hemoglobin (Hb) and JAK2 V617F mutation load were detected in patients without special treatment in two groups during follow-up. Results EPO, NAP score, BMB hematopoietic volume and the number of megakaryocyte had no statistical differences between PV group and mPV group [(3.4 ± 0.7) U/ml vs. (3.2±0.6) U/ml, (276±20) score vs. (278±21) score, (78±10) % vs. (76±9) %, (53±6) vs. (51±5), respectively], while JAK2 V617F mutation load in PV group was higher than that in mPV group[(89.2±9.4) % vs. (78.1±8.6) %, P<0.05]. In mPV patients without special treatment, Hb ≥185 g/L was found in 37 patients after 6 months, and the level of Hb and JAK2 V617F mutation load in these 37 patients reached (194±8) g/L and (90.7±9.1) %, respectively. Conclusions There is no significant difference in EPO, NAP score and BMB between PV and mPV, but the JAK2 V617F mutation load is different. In mPV patients without special treatment, Hb level can reach the typical PV diagnostic criteria after 6 months, meanwhile, JAK2 V617F mutation load is also increased.

Myeloproliferative neoplasms and the JAK/STAT signaling pathway: an overview

ABSTRACTMyeloproliferative neoplasms are caused by a clonal proliferation of a hematopoietic progenitor. First described in 1951 as 'Myeloproliferative Diseases' and reevaluated by the World Health Organization classification system in 2011, myeloproliferative neoplasms include polycythemia vera, essential thrombocythemia and primary myelofibrosis in a subgroup called breakpoint cluster region-Abelson fusion oncogene-negative neoplasms. According to World Health Organization regarding diagnosis criteria for myeloproliferative neoplasms, the presence of the JAK2 V617F mutation is considered the most important criterion in the diagnosis of breakpoint cluster region-Abelson fusion oncogene-negative neoplasms and is thus used as a clonal marker. The V617F mutation in the Janus kinase 2(JAK2) gene produces an altered protein that constitutively activates the Janus kinase/signal transducers and activators of transcription pathway and other pathways downstream as a result of signal transducers and activators of transcription which are subsequently phosphorylated. This affects the expression of genes involved in the regulation of apoptosis and regulatory proteins and modifies the proliferation rate of hematopoietic stem cells.