Clinical outcomes of ruxolitinib treatment in 595 intermediate-1 risk patients with myelofibrosis: The RUX-MF Real-World Study.

BACKGROUND: Ruxolitinib (RUX) is a JAK1/2 inhibitor approved for the therapy of myelofibrosis (MF) based on clinical trials including only intermediate2-high risk (INT2/HIGH) patients. However, RUX is commonly used in intermediate-1 (INT1) patients, with scarce information on responses and outcome. METHODS: The authors investigated the benefit of RUX in 1055 MF patients, included in the "RUX-MF" retrospective study. RESULTS: At baseline (BL), 595 (56.2%) patients were at INT1-risk according to DIPSS (PMF) or MYSEC-PM (SMF). The spleen was palpable at <5 cm, between 5 and 10 cm, and >10 cm below costal margin in 5.9%, 47.4%, and 39.7% of patients, respectively; 300 (54.1%) were highly symptomatic (total symptom score ≥20). High-molecular-risk (HMR) mutations (IDH1/2, ASXL-1, SRSF2, EZH2, U2AF1Q157) were detected in 77/167 patients. A total of 101 (19.2%) patients had ≥1 cytopenia (Hb < 10 g/dL: n.36; PLT <100 x 109/L: n = 43; white blood cells <4 x 109/L: n = 40). After 6 months on RUX, IWG-MRT-defined spleen and symptoms response rates were 26.8% and 67.9%, respectively. In univariate analysis, predictors of SR at 6 months were no HMR mutations odds ratio [OR], 2.0, p = .05], no cytopenia (OR, 2.10; p = .01), and blasts <1% (OR, 1.91; p = .01). In multivariate analysis, absence of HMR maintained a significant association (OR, 2.1 [1.12-3.76]; p = .01). CONCLUSIONS: In INT1 patients, responses were more frequent and durable, whereas toxicity rates were lower compared to INT2/high-risk patients. Presence of HMR mutations, cytopenia, and peripheral blasts identified less-responsive INT1 patients, who may benefit for alternative therapeutic strategies.

Erythrocytosis and CKD: A Review.

Erythrocytosis or polycythemia is defined as an increase in red blood cell concentration above the age- and sex-specific normal levels. Unlike anemia, which is very common in patients with chronic kidney disease (CKD), erythrocytosis is less frequent but requires specific understanding by health care professionals in order to provide the best care. Erythrocytosis, especially when undiagnosed and untreated, can lead to serious thrombotic events and higher mortality. Classic causes of erythrocytosis associated with CKD include cystic kidney diseases, kidney or other erythropoietin-secreting neoplasms, high-altitude renal syndrome, overdosage of erythropoietin-stimulating agents, androgen therapy, heavy smoking, chronic lung disease, obstructive sleep apnea, IgA nephropathy, post-kidney transplant erythrocytosis, renal artery stenosis, and congenital etiologies. After ruling out the common acquired causes of erythrocytosis and/or in the presence of suggestive parameters, primary erythrocytosis or polycythemia vera (PV) should be considered, and patients should be screened for JAK2V617F somatic mutation. The newest entity inducing erythrocytosis is linked to the use of sodium/glucose cotransporter 2 (SGLT2) inhibitors that hypothetically activate hypoxia-inducible factor 2α (HIF-2α) and in some cases unmask PV. This Review focuses on the pathogenesis, renal manifestations and management of PV, the pathophysiology of erythrocytosis induced by SGLT2 inhibitors and the relevance of timely JAK2 mutation screening in these patients.

Predictive significance of high neutrophil ratio for thrombosis in myeloproliferative neoplasms: JSH-MPN-R18 subanalysis.

Thrombosis in myeloproliferative neoplasms (MPNs) is an important clinical problem, and risk-stratified management is essential. To identify the clinical characteristics of thrombosis in patients with MPNs, a nationwide multi-institutional retrospective analysis (JSH-MPN-R18) was conducted. The aim of the present study was to perform a sub-analysis of JSH-MPN-R18 findings to clarify the predictive parameters for thrombosis among complete blood count (CBC) results. Among the patients enrolled in JSH-MPN-R18, those with essential thrombocythemia (ET; n = 1152) and polycythemia vera (PV; n = 456) were investigated. We analyzed and compared CBC parameters between patients with and those without any thrombotic events using Welch's T-test. Statistical analyses were performed using the R statistical software. Thrombotic events were observed in 74 patients with ET. In multivariate analysis, only the neutrophil ratio was slightly but significantly higher for ET patients with thrombosis than for those without (p < 0.05). Of note, the absolute neutrophil count (aNeu) was considered a useful predictive tool for thrombosis among patients classified as low-risk according to the revised International Prognostic Score of Thrombosis for Essential Thrombocythemia. Among PV patients, those with thrombosis showed significantly higher hematocrit and aNeu than did those without thrombosis. As a thrombosis-associated factor, the neutrophil ratio was slightly but significantly elevated in patients with ET. This myeloid skew might reflect a higher value of JAK2 V617F allelic frequency in patients with ET with thrombosis; this was not clarified in JSH-MPN-R18. Further accumulation of evidence, including genetic information for JAK2 and other passenger mutations, is warranted.

[How I manage polycythemia]. / Comment j'explore une polyglobulie.

Polycythemia is suspected when hemoglobin and/or hematocrit levels exceed established norms based on gender and age. This biological anomaly can arise from a myeloproliferative neoplasm known as polycythemia vera, or be secondary to excess erythropoietin (EPO) or decreased in plasma volume. Faced with polycythemia, the search for JAK2 mutations and measurement of serum EPO levels can guide toward the etiology. In polycythemia vera, thromboembolic events are the most lethal complications and unfortunately often the initial manifestation of the disease. The condition can also progress to myelofibrosis or acute leukemia. Management aims at reducing the hematocrit below 45 %, in order to limit, but not completely prevent, thrombo-embolic complications. This article elaborates on the clinical considerations around this biological anomaly, relevant complementary examinations, and briefly the therapeutic management.

La polyglobulie est suspectée lorsque le taux d'hémoglobine et/ou d'hématocrite est au-dessus des normes définies selon le sexe et l'âge. Cette anomalie biologique peut survenir à la suite d'une néoplasie myéloproliférative appelée polycythemia vera (PV), être secondaire à un excès d'érythropoïétine (EPO) ou à une diminution du volume plasmatique. Face à une polyglobulie, la recherche de mutations du gène JAK2 et un dosage d'EPO sérique permettront d'orienter vers l'étiologie. En cas de PV, les phénomènes thrombo-emboliques sont les complications les plus léthales et sont malheureusement souvent la première manifestation de la maladie. La maladie peut également évoluer en myélofibrose ou en leucémie aiguë. La prise en charge vise à réduire le taux d'hématocrite en-dessous de 45 %, afin de limiter, sans les empêcher complètement, les complications thrombo-emboliques. Dans cet article, nous développons la réflexion clinique autour de cette anomalie biologique, les examens complémentaires pertinents dans ce domaine et, brièvement, la prise en charge thérapeutique.

The aetiology and burden of myeloproliferative neoplasms in the United Kingdom: the MyelOproliferative neoplasmS: an In-depth case-control (MOSAICC) study protocol.

BACKGROUND: Myeloproliferative neoplasms (MPNs) are a group of haematological malignancies that affect approximately 8 people in every 100,000 individuals in the UK. Little is known about the aetiology of MPNs, as previous studies have been hampered by small sample sizes, thus it is important to understand the cause of MPNs in a larger study to identify prevention strategies and improve treatment strategies. This study aims to determine environmental, lifestyle, genetic and medical causes of MPNs and to assess the relevance of occupational carcinogen exposures and quality of life impacts. METHODS: A UK-wide case-control study of 610 recently diagnosed MPN patients (within 24 months) receiving clinical care at 21 NHS study sites in Scotland, England, Wales and Northern Ireland and 610 non-blood relative/friend controls is underway. Data on occupational and residential history, medical and environmental factors, and quality of life are being collected from the participants via a structured interview and self-complete questionnaires. Clinical data is being provided by the clinical team. Blood, saliva and toenail samples are also being collected for genetic and elemental analysis. Adjusted odds ratios (ORs) and 95% confidence intervals (95%CI) will be calculated using a p < 0.05 to investigate potential risk factors for the MPN clinical and genetic subtypes, and further analyses will be conducted based on the type of data and outcome of interest at a later stage. DISCUSSION: The study design is most effective for investigating the aetiology of rare diseases. The study will enable identification of potential causes of MPNs through in-depth assessment of potential risk factors with potential for longer follow-up of a number of outcomes.

Dural Venous Sinus Thrombosis and Papilledema Related to JAK2 Mutation: A Case Series.

BACKGROUND: Dural venous sinus thrombosis (DVST) is an important cause of papilledema. Patients diagnosed with DVST should undergo work-up for underlying hypercoagulable state, including genetic causes. One important prothrombotic mutation is in the JAK2 gene, which is a driver of myeloproliferative neoplasms including polycythemia vera (PV). We aimed to determine the prevalence of JAK2 mutation in patients in presenting to neuro-ophthalmology clinic with DVST and papilledema. METHODS: Retrospective case series of patients seen in a tertiary neuro-ophthalmology practice who presented with papilledema due to DVST and were investigated for presence of JAK2 mutation. RESULTS: Four out of 15 patients with DVST (26%) were found to have JAK2 V617F mutation which led to subsequent diagnosis of PV in 2. One additional patient had a known diagnosis of essential thrombocytosis. We describe the clinical presentation of these four patients with papilledema and JAK2 mutation. CONCLUSIONS: A significant proportion of patients with papilledema secondary to DVST will harbor mutations in the JAK2 gene. Clinicians should be aware of this mutation as early testing will facilitate timely diagnosis and treatment of myeloproliferative disease to improve prognosis and reduce risk of recurrent thrombotic events.

Detection of primary myelofibrosis in blood serum via Raman spectroscopy assisted by machine learning approaches; correlation with clinical diagnosis.

Primary myelofibrosis (PM) is one of the myeloproliferative neoplasm, where stem cell-derived clonal neoplasms was noticed. Diagnosis of this disease is based on: physical examination, peripheral blood findings, bone marrow morphology, cytogenetics, and molecular markers. However, the molecular marker of PM, which is a mutation in the JAK2V617F gene, was observed also in other myeloproliferative neoplasms such as polycythemia vera and essential thrombocythemia. Therefore, there is a need to find methods that provide a marker unique to PM and allow for higher accuracy of PM diagnosis and consequently the treatment of the disease. Continuing, in this study, we used Raman spectroscopy, Principal Components Analysis (PCA), and Partial Least Squares (PLS) analysis as helpful diagnostic tools for PM. Consequently, we used serum collected from PM patients, which were classified using clinical parameters of PM such as the dynamic international prognostic scoring system (DIPSS) for primary myelofibrosis plus score, the JAK2V617F mutation, spleen size, bone marrow reticulin fibrosis degree and use of hydroxyurea drug features. Raman spectra showed higher amounts of C-H, C-C and C-C/C-N and amide II and lower amounts of amide I and vibrations of CH3 groups in PM patients than in healthy ones. Furthermore, shifts of amides II and I vibrations in PM patients were noticed. Machine learning methods were used to analyze Raman regions: (i) 800 cm-1 and 1800 cm-1, (ii) 1600 cm-1-1700 cm-1, and (iii) 2700 cm-1-3000 cm-1 showed 100 % accuracy, sensitivity, and specificity. Differences in the spectral dynamic showed that differences in the amide II and amide I regions were the most significant in distinguishing between PM and healthy subjects. Importantly, until now, the efficacy of Raman spectroscopy has not been established in clinical diagnostics of PM disease using the correlation between Raman spectra and PM clinical prognostic scoring. Continuing, our results showed the correlation between Raman signals and bone marrow fibrosis, as well as JAKV617F. Consequently, the results revealed that Raman spectroscopy has a high potential for use in medical laboratory diagnostics to quantify multiple biomarkers simultaneously, especially in the selected Raman regions.

A case of ischemic stroke with hemorrhagic transformation associated with essential thrombocythemia and JAK-2 V617F mutation.

BACKGROUND: Essential thrombocythemia (ET) is a rare cause of stroke. The V617F mutation in the Janus kinase 2 (JAK2) gene is one of the most typical mutations in ET and has been shown to be a risk factor for stroke, especially in younger people. However, to date, there have been few reports of intracranial thrombotic and hemorrhagic complications in patients with ET. Herein, we present a case of JAK2 gene mutation-associated ET in a patient who developed both ischemic and hemorrhagic stroke, and discuss potential underlying mechanisms. CASE PRESENTATION: A 45-year-old Chinese male presented to our center with gradually developing weakness of the right limbs for 3 months. A computed tomography scan of the brain showed an area of infarction with hemorrhage in the left subcortical and corona radiata regions. High-resolution magnetic resonance imaging revealed a thrombosis on the surface of the atherosclerotic plaque. Digital subtraction angiography revealed an insect bite-like change in the C1 branch of the left internal carotid artery, which caused up to 50% stenosis. Blood tests showed continued elevation of the platelet and white blood cell counts. After consultation with a hematologist, a bone marrow biopsy was performed, which revealed proliferative bone marrow changes with numerous megakaryocytes and proliferative but mature granulocytes. Further genetic testing revealed a positive JAK2-V617F mutation. Therefore, the diagnosis of ET was confirmed according to the World Health Organization (WHO) 2016 diagnostic criteria. Finally, we decided to administer aspirin and hydroxyurea. The patient remained stroke free and the platelet levels were normal throughout the 1-year follow-up period. CONCLUSIONS: JAK2 mutations affect the proliferation and differentiation of blood cells through the JAK, signal transducer and activator of transcription pathway, which leads to changes in platelets and macrophages, and an increase in neutrophil extracellular traps, which may explain the patient's ischemic and hemorrhagic changes. Further investigation of the underlying mechanisms may change the treatment strategy for such patients in the future.

JAK2 inhibition in JAK2V617F-bearing leukemia cells enriches CD34+ leukemic stem cells that are abolished by the telomerase inhibitor GRN163L.

The activating-mutation of JAK2V617F drives the development of myeloproliferative neoplasms (MPNs). Several JAK2 inhibitors such as ruxolitinib and gandotinib (LY2784544) currently in clinical trials and, provide improvements in MPNs including myelofibrosis. However, JAK2 inhibitors are non-curative and murine experiments show that JAK2 inhibitors don't eradicate MPN stem cells and it is currently unclear how they escape. We thus determined the effect of the specific JAK2V617F inhibitor LY2784544 on leukemic stem (CD34+) cells (LSCs) using the JAK2V617F-bearing erythroleukemia cell line HEL. The LY2784544 treatment caused a transient proliferation inhibition and apoptosis of HEL cells, but a recovery occurred within a week. Thereafter, the continuous LY2784544 exposure induced the accumulation of CD34+ LSCs, and the CD34+ cells increased from 2% to >90% by week 9, which was accompanied by increased clonogenic potentials. LY2784544 was capable of stimulating CD34 expression even in CD34- HEL cells, which indicated cellular de-differentiation. A significantly enhanced expression of the stem cell factor KLF4 was observed in LY2784544-treated HEL cells. Inhibiting KLF4 expression attenuated LY2784544-mediated accumulation of CD34+ LSCs. Moreover, the telomerase inhibitor GRN163L abolished the LY2784544-effect. JAK2 inhibitors thus cause enrichment of LSCs and are unlikely to cure MPN as a monotherapy. Simultaneously targeting JAK2V617F and KLF4 or telomerase may be a novel strategy for MPN therapy, which should be of significance both biologically and clinically.

Concomitant and noncanonical JAK2 and MPL mutations in JAK2V617F- and MPLW515 L-positive myelofibrosis.

Sequential genotyping for phenotype-driver mutations in JAK2 (exon 14), CALR (exon 9), and MPL (exon 10) is recommended in patients with myeloproliferative neoplasms. Yet, atypical JAK2- and MPL-mutations were described in some triple-negative patients. Whether noncanonical and/or concomitant JAK2- and MPL-mutations exist in myelofibrosis (MF) regardless of phenotype-driver mutations is not yet elucidated. For this, next-generation sequencing (NGS) was performed using blood genomic DNA from 128 MF patients (primary MF, n = 93; post-ET-MF, n = 18; post-PV-MF, n = 17). While no atypical JAK2- or MPL-mutations were seen in 24 CALR-positive samples, two JAK2-mutations [c.3323A > G, p.N1108S; c.3188G > A, p.R1063H] were detected in two of the 21 (9.5%) triple-negative patients. Twelve of the 82 (14.6%) JAK2V617F-positive cases had coexisting germline JAK2-mutations [JAK2R1063H, n = 6; JAK2R893T, n = 1; JAK2T525A, n = 1] or at least one somatic MPL-mutation [MPLY591D, n = 3; MPLW515 L, n = 2; MPLE335K, n = 1]. Overall, MPL-mutations always coexisted with JAK2V617F and/or other MPL-mutations. None of the JAK2V617F plus a second JAK2-mutation carried a TET2-mutation but all patients with JAK2V617F plus an MPL-mutation harbored a somatic TET2-mutation. Four genomic clusters could be identified in the JAK2V617F-positive cohort. Cluster-I (10%) (noncanonical JAK2mutated (mut) + TET2wildtype (wt) ) were younger and had less proliferative disease compared with cluster-IV (5%) (TET2mut + MPLmut ). In conclusion, recurrent concomitant classical and/or noncanonical JAK2- and MPL-mutations could be detected by NGS in 15.7% of JAK2V617F- and MPLW515-positive MF patients with genotype-phenotype associations. Many of the germline and/or somatic mutations might act as "Significantly Mutated Genes" contributing to the pathogenesis and phenotypic heterogeneity. A cost-effective NGS-based approach might be an important step towards patient-tailored medicine.

Systemic mastocytosis associated with myelodysplastic/myeloproliferative neoplasms with ring sideroblasts and thrombocytosis: Report of three cases.

The association of systemic mastocytosis with another hematologic neoplasia of myeloid or lymphoid origin is recognized as an advanced subvariant of mastocytosis. Here, we report the association of indolent or smoldering systemic mastocytosis with three cases of myelodysplastic/myeloproliferative neoplasms with ring sideroblasts and thrombocytosis, a recently recognized disease characterized by SF3B1 mutations. The hierarchical pattern of KIT, SF3B1, JAK2, and additional mutations was studied in whole and fractionated subpopulations of peripheral blood cells and whole bone marrow. In two cases, we could demonstrate a multilineage D816V KIT mutation, involving all myeloid lineages in one patient and also the lymphoid series in the other. Two patients displaying both SF3B1 and V617F JAK2 mutations had a very poor prognosis. Another patient bearing SF3B1, but not V617F JAK2 mutation, had a favorable response to erythropoietin treatment and long survival.

Recurrent ischaemic cerebrovascular events as presenting manifestations of myeloproliferative neoplasms.

BACKGROUND AND PURPOSE: Myeloproliferative neoplasms (MPNs) - polycythemia vera, essential thrombocythemia and primary myelofibrosis - are associated with increased risk for ischaemic cerebrovascular events (ICVEs). Due to their low prevalence, MPNs often remain undiagnosed as the cause of ICVEs. METHODS: Case records at the University of Tübingen between 2014 and 2017 were screened to identify patients with MPN-related ICVEs. Clinical features, brain imaging, laboratory findings, applied treatments and neurological outcomes were assessed. RESULTS: In all, 3318 patients with ICVEs were identified, and amongst them 17 patients with MPN-related ICVEs were included in a retrospective study. In 58% of these patients, ICVEs were the first manifestation of the underlying MPN; 24% presented with transient ischaemic attack and 76% with ischaemic stroke. Potentially concurrent ICVE etiologies were noted in 70% of the patients. The majority (94%) of patients were positive for the JAK2 V617F mutation, whilst in 29% recurrent ICVEs (range two to three) were noted prior to MPN diagnosis. Early MPN diagnosis and management was the only significant prognostic factor for ICVE recurrence (P < 0.001). DISCUSSION: Evidence is provided that, although rare, MPNs represent an underdiagnosed cause of recurrent ICVEs. High clinical awareness is warranted to identify an underlying MPN in patients presenting with sustained, abnormal blood count findings. Clinical algorithms for prompt MPN diagnosis and initiation of MPN treatment (e.g. cytoreductive therapy, phlebotomy) are required. As MPN management comprises a significant protective factor against ICVE recurrence, induction of MPN treatment should be regarded as an integral component of secondary stroke prevention in MPN-associated ICVEs.

Validation of previous prognostic models for thrombosis and exploration of modified models in patients with essential thrombocythemia.

OBJECTIVE: We examined the prognostic factors to validate previous prognostic models for survival and thrombosis with large-scale data on Japanese patients with essential thrombocythemia (ET). METHOD: We conducted a study in 352 patients with ET to validate previous prognostic models and search for new prognostic factors. RESULTS: The International Prognostic Score for essential thrombocythemia (IPSET), the conventional risk classification and the International Prognostic Score for thrombosis in essential thrombocythemia (IPSET-T) were confirmed to be reproducible in Japanese patients. However, no significant difference was observed between the low-risk and intermediate-risk categories according to the revised IPSET-T, which does not allow direct comparison of the four risk groups. We reevaluated the risk using a modified revised IPSET-T, which was derived from the revised IPSET-T by scoring the factors as follows: one point for age > 60 years, two points for past history of thrombosis, two points for JAK2 gene mutation-positive; total points of 0 = very low risk, 1 =  low risk, 2 =  intermediate risk, 3 and above = high risk, with significantly different thrombosis-free survival. CONCLUSION: The modified revised IPSET-T has been useful for 4-group stratification to predict a population that requires therapeutic intervention, irrespective of the treatment regimens.

Disease and treatment characteristics of polycythemia vera patients in Belgium: Results from a scientific survey.

OBJECTIVE: The current survey aimed to gather predefined disease parameters and treatment strategies to characterize the polycythemia vera (PV) patient population in Belgium. METHODS: Cross-sectional data from PV patients, seen at least once between May 2014 and May 2015 at 10 sites in Belgium, were collected in aggregated form and analyzed descriptively and quantitatively. RESULTS: Data from 343 PV patients were collected. Of these, 174 (50.7%) were male and 256 (74.6%) were ≥60 years of age. Ninety-two (26.8%) had a prior history of thrombotic events. Considerable proportions of patients had increased hematological parameters (hematocrit > 45% [31.2%], leukocytes > 10 × 109 /L [33.3%], and platelet > 400 × 109 /L [38.2%]). Most patients had non-palpable spleen (284, 87.7%) and no phlebotomies during the past 6 months (197, 57.4%). Low-dose aspirin was given as thrombosis prophylaxis in 249 (72.6%) patients, while 232 (67.6%) received hydroxyurea (HU) as cytoreductive treatment. Forty-one patients (12.0%) were reported as resistant and/or intolerant to HU. Seventeen patients (5.0%) received ruxolitinib in the context of clinical trials. CONCLUSION: This survey provides better insight into the characteristics of Belgian PV patients and currently used treatment strategies. It shows that 232 (67.6%) PV patients continue to receive HU despite being potentially HU-resistant.

Implications of Janus Kinase 2 Mutation in Embolic Stroke of Unknown Source.

The role of genetic mutations in cerebral ischemia is not completely understood. Among these genetic variations, Philadelphia-negative gain-of-function mutation in the janus kinase 2 (JAK2) protein leads to overexpression of the genes involved in cell growth and proliferation, and has been linked to development of hematological malignancies, specifically, myeloproliferative neoplasms (MPNs; essential thrombocythemia [ET], polycythemia vera [PV], and primary myelofibrosis). Overt ET and PV are known to induce a prothrombotic state that leads to development of vascular complications, including cerebral arterial or venous thrombosis. Thromboembolism can precede overt presentation of an MPN by 2-3 years. As such, for the selected cases of embolic stroke or cerebrovascular sinus thrombosis with otherwise undetermined source and persistent thrombocytosis or polycythemia, in the absence of a confirmed MPN diagnosis, screening for JAK2 mutation may be reasonable, as early diagnosis and appropriate treatment can influence outcome by preventing recurrent thrombotic events. In this article, we review the literature on the genetics, pathogenesis, clinical manifestations, and treatment of JAK2-associated thrombosis, and present 2 cases of JAK2-associated cerebral arterial infarction and cerebral and systemic venous thromboembolism with otherwise negative etiology workup for stroke.

[Thrombosis in myeloproliferative neoplasms].

Among all types of myeloproliferative neoplasms (MPNs), polycythemia vera (PV) and essential thrombocythemia (ET) require careful management of both thrombosis and hemostasis. One recent concern associated with MPNs is the JAK2 mutation (V617F). This mutation is essential for MPN pathology, but it has also garnered attention for its association with thrombosis. Several studies have reported the mechanisms underlying the onset of thrombosis in both PV and ET and have also discussed the association between JAK2 mutations and thrombotic tendencies. Arterial thrombosis is a common clinical symptom that is associated with the diagnosis and course of both PV and ET. Particularly, cerebral infarction has been identified as the leading cause of death in patients with untreated PV. Notably, PV and ET are also associated with a high incidence of venous thromboembolism (VTE). The occurrence of this type of thrombosis at atypical sites, such as cerebral venous sinus thrombosis and splanchnic vein thrombosis (SVT), is not uncommon. Generally, patients with PV and ET have good life expectancy; their treatment essentially focuses on dealing with thrombosis and bleeding. Phlebotomy may be used for treating patients with PV; however, low-dose aspirin is used to prevent the onset of arterial thrombosis. For patients with a history of VTE, oral anticoagulants are commonly prescribed to prevent recurrence.

JAK2 V617F MUTATION SCANNING IN PATIENTS WITH ADRENAL INCIDENTALOMA.

OBJECTIVE: Adrenal incidentaloma are lesions which are stated incidentally by imaging methods when there is no suspicion of any disease in adrenal gland. Inappropriate Jak2 signaling causes some solid and hematological malignancies. But the Jak2 mutation has not been previously evaluated with regard to adrenal tumors. In this study, we aimed to positivity of the Jak2 mutation in patients with non functioning adrenal incidentaloma (NFAI). METHODS: 45 (38 female-7 male) patients, who were followed due to NFAI at Tepecik Training and Research Hospital, Department of Endocrinology and Internal Medicine between February 2014 and March 2015, and 45 (31 female-14 male) healthy controls were included in the study. RESULTS: The average age was 54.02±11.7 years and 38 patients were female, 7 were men. All patients underwent the following analyses for excluding a functioning adrenal mass, overnight dexamethasone suppression test, 24 hour urinary metanephrine and normetanephrine, plasma aldosterone/ renin activity ratio. Jak2 mutation of the patients who were diagnosed as NFAI was all negative. CONCLUSION: We could not identify the JAK2 gene mutation positivity in any sample. Since other possible mechanisms may throw fresh light on the etiology of adrenal incidentaloma, further clinical studies are needed on this subject.

Correlation between JAK2 allele burden and pulmonary arterial hypertension and hematological parameters in Philadelphia negative JAK2 positive myeloproliferative neoplasms. An Egyptian experience.

Myeloproliferative neoplasms are characterized by a common stem cell-derived clonal proliferation, but are phenotypically diverse. JAK2 is mutated (V617F) in more than 90 % of patients with polycythemia vera (PV) and approximately 60 % of patients with essential thrombocythemia (ET) or primary myelofibrosis (PMF). Pulmonary arterial hypertension (PAH) is a major complication of several hematological disorders. Chronic myeloproliferative disorders associated with PAH have been included in group five for which the etiology is unclear and/or multifactorial. The aim of this study is to screen Egyptian Philadelphia negative JAK2 positive myeloproliferative neoplasm patients for the presence of PAH and its correlation with JAK2 allele burden. We also made a review for correlation of JAK2 allele with hematological parameters comparing our results to others. We enrolled 60 patients with Philadelphia negative myeloproliferative neoplasms. All patients enrolled in the study were subjected to laboratory and imaging workup in the form of CBC, liver, kidney profile, bone marrow examination, abdominal ultrasonography, and transthoracic echocardiography. Our results revealed that 7 patients out of 60 (11.67 %) had pulmonary arterial hypertension, 3 patients with PMF, 2 patients with PRV, and 2 patients with ET, and its correlation with JAK2 allele burden was not statistically significant. Correlation analysis between JAK2 V617F allele burden and other parameters revealed: statistical significant correlation with age, HB, HCT, PLT, UA, LDH, and splenic diameter but insignificant correlation with WBCs and PAH. Pulmonary arterial hypertension prevalence in our study was 11.67 % and no significant correlation with JAK 2 allele burden. Our study is the largest one up to our knowledge that studies the association between its prevalence and JAK2 burden.

Nature and nurture: a case of transcending haematological pre-malignancies in a pair of monozygotic twins adding possible clues on the pathogenesis of B-cell proliferations.

We describe a comprehensive molecular analysis of a pair of monozygotic twins, who came to our attention when one experienced amaurosis fugax and was diagnosed with JAK2+ polycythaemia vera. He (Twin A) was also found to have an asymptomatic B-cell chronic lymphocytic leukaemia (B-CLL). Although JAK2-, Twin B was subsequently shown to have a benign monoclonal B-cell lymphocytosis (MBL). Flow cytometric and molecular analyses of the B-cell compartments revealed different immunoglobulin light and heavy chain usage in each twin. We hypothesized that whole exome sequencing could help delineating the pattern of germline B-cell disorder susceptibility and reveal somatic mutations potentially contributing to the differential patterns of pre-malignancy. Comparing bone marrow cells and T cells and employing in-house engineered integrative analysis, we found aberrations in Twin A consistent with a myeloid neoplasm, i.e. in TET2, RUNX1, PLCB1 and ELF4. Employing the method for detecting high-ranking variants by extensive annotation and relevance scoring, we also identified shared germline variants in genes of proteins interacting with B-cell receptor signalling mediators and the WNT-pathway, including IRF8, PTPRO, BCL9L, SIT1 and SIRPB1, all with possible implications in B-cell proliferation. Similar patterns of IGHV-gene usage to those demonstrated here have been observed in inherited acute lymphoblastic leukaemia. Collectively, these findings may help in facilitating identification of putative master gene(s) involved in B-cell proliferations in general and MBL and B-CLL in particular.

No increase of JAK2 46/1 haplotype frequency in essential thrombocythemia with CALR mutations: Functional effect of the haplotype limited to allele with JAK2V617F mutation but not CALR mutation.

The true frequency of the JAK2 46/1 haplotype in patients of myeloproliferative neoplasms (MPN) with CALR mutations was unknown. Totally 187 MPN cases with diagnosis of polycythemia vera (PV) and essential thrombocythemia (ET) were recruited. The frequency of 46/1 haplotype was significantly higher in JAK2V617F-positive PV (51%, p < 0.001) and ET (41%, p = 0.005) compared to normal controls. The exact location of JAK2V617F mutation was located at the cis-46/1 haplotype in 86.4% (32/37) PV patients and 87.5% (28/32) ET patients, respectively. Among the 51 patients of ET without JAK2V617F mutation, 38 (75%) patients harbored CALR mutations and 3 patients had MPL mutation. The frequency of 46/1 haplotype in the 38 ET patients with CALR mutations was 27%, which is not significantly different from that of normal control (p value = 0.879). Compared to non-46/1 haplotype, the presence of 46/1 haplotype had a trend to have higher white blood cell count in JAK2V617F-mutated PV and ET patients but not in CALR-mutated ET. We conclude that the 46/1 haplotype could have functioning effect but only in the context of JAK2V617F mutation.