JAK2 Mutation Research Articles

Thrombotic Prediction Model Based on Epigenetic Regulator Mutations in Essential Thrombocythemia Patients Using Survival Analysis in Recurrent Events.

Essential thrombocythemia (ET) involves the proliferation of megakaryocytes and platelets and is associated with an increased risk of thrombosis. We aimed to evaluate thrombotic risks in patients with epigenetic regulator mutations and generate a model to predict thrombosis in ET. This cohort study enrolled patients aged > 15 years diagnosed with ET at the Songklanakarind Hospital between January 2002 and December 2019. Twenty-five targeted gene mutations, including somatic driver mutations (JAK2, CALR, MPL), epigenetic regulator mutations (TET2, DNMT3A, IDH1, IDH2, TET2, ASXL1, EZH2, SF3B1, SRSF2) and other genes relevant to myeloid neoplasms, were identified using next-generation sequencing. Thrombotic events were confirmed based on clinical condition and imaging findings, and thrombotic risks were analyzed using five survival models with the recurrent event method. Ninety-six patients were enrolled with a median follow-up of 6.91 years. Of these, 15 patients experienced 17 arterial thrombotic events in total. Patients with JAK2 mutation and IDH1 mutation had the highest frequency of thrombotic events with somatic driver mutations (17.3%) and epigenetic regulator mutations (100%). The 10-year thrombosis-free survival rate was 81.3% (95% confidence interval: 72.0-91.8%). IDH1 mutation was a significant factor for thrombotic risk in the multivariate analysis for all models. The Prentice, William, and Peterson (PWP) gap-time model was the most appropriate prediction model. The PWP gap-time model was a good predictive model for thrombotic risk in patients with ET. IDH1 mutation was significant risk factors for thrombosis; however, further studies with a larger sample size should confirm this and provide more insight.

Genomic classification and outcomes of young patients with polycythemia vera and essential thrombocythemia according to the presence of splanchnic vein thrombosis and its chronology

To elucidate the role of splanchnic vein thrombosis (SVT) and genomic characteristics in prognosis and survival, we compared patients with polycythemia vera (PV) or essential thrombocythemia (ET) presenting SVT at diagnosis (n = 69, median age 43 years) or during follow-up (n = 21, median age 46 years) to a sex- and age-matched control group of PV/ET without SVT (n = 165, median age 48 years). The majority of patients presenting with SVT at diagnosis were classified as myeloproliferative neoplasm with heterozygous JAK2 mutation (87% of cases vs. 69% in PV/ET control group, p < 0.05), characterized by low JAK2 allele burden and no high-risk mutations. Despite this lower molecular complexity, patients presenting with SVT showed a higher risk of death (HR 3.0, 95% CI 1.5-6.0, p = 0.003) and lower event-free survival (HR 3.0, 95% CI 1.9–4.8, p < 0.001) than age- and sex-matched PV/ET controls. In patients presenting with SVT, molecular high-risk was associated with increased risk of venous re-thrombosis (HR 5.8, 95% CI 1.4–24.0, p = 0.01). Patients developing SVT during follow-up were more frequently allocated in molecular high-risk than those with SVT at diagnosis (52% versus 13%, p < 0.05). In the whole cohort of patients, molecular classification identified PV/ET patients at higher risk of disease progression whereas DNMT3A/TET2/ASXL1 mutations were associated with higher risk of arterial thrombosis. In conclusion, clinical and molecular characteristics are different in PV/ET patients with SVT, depending on whether it occurs at diagnosis or at follow-up. Molecular characterization by NGS is useful for assessing the risk of thrombosis and disease progression in young patients with PV/ET.

Idiopathic erythrocytosis: a germline disease?

Polycythemia Vera (PV) is typically caused by V617F or exon 12 JAK2 mutations. Little is known about Polycythemia cases where no JAK2 variants can be detected, and no other causes identified. This condition is defined as idiopathic erythrocytosis (IE). We evaluated clinical-laboratory parameters of a cohort of 56 IE patients and we determined their molecular profile at diagnosis with paired blood/buccal-DNA exome-sequencing coupled with a high-depth targeted OncoPanel to identify a possible underling germline or somatic cause. We demonstrated that most of our cohort (40/56: 71.4%) showed no evidence of clonal hematopoiesis, suggesting that IE is, in large part, a germline disorder. We identified 20 low mutation burden somatic variants (Variant allelic fraction, VAF, < 10%) in only 14 (25%) patients, principally involving DNMT3A and TET2. Only 2 patients presented high mutation burden somatic variants, involving DNMT3A, TET2, ASXL1 and WT1. We identified recurrent germline variants in 42 (75%) patients occurring mainly in JAK/STAT, Hypoxia and Iron metabolism pathways, among them: JAK3-V722I and HIF1A-P582S; a high fraction of patients (48.2%) resulted also mutated in homeostatic iron regulatory gene HFE-H63D or C282Y. By generating cellular models, we showed that JAK3-V722I causes activation of the JAK-STAT5 axis and upregulation of EPAS1/HIF2A, while HIF1A-P582S causes suppression of hepcidin mRNA synthesis, suggesting a major role for these variants in the onset of IE.Graphical abstract

One thousand patients with essential thrombocythemia: the Florence-CRIMM experience

We describe 1000 patients with essential thrombocythemia seen at the Center Research and Innovation of Myeloproliferative Neoplasms (CRIMM), Florence, Italy, between 1980 and 2023: median age 59 years (18–95), females 65%, JAK2/CALR/MPL-mutated 66%/19%/4%, triple-negative (TN) 11%. Extreme thrombocytosis (ExT, platelets ≥1000 × 109/L) in 16%, leukocytosis (leukocytes >11 × 109/L) in 16%, and at least one cardiovascular risk factor in 52% of cases. JAK2-mutated patients were older (median 62 years) and CALR-mutated and TN (53 years for both) younger (p < 0.001). Female gender clustered with TN (76%) and JAK2 (67%) vs CALR (46%) mutations (p < 0.001). ExT clustered with CALR (type-2 more than type-1), TN and MPL, and leukocytosis with JAK2 mutation (p < 0.001). In multivariable analysis, risk factors for arterial thrombosis-free survival were age ≥60 years (HR 2.0; p < 0.001) and JAK2 mutation (HR 1.3; p = 0.02) with borderline significance for male gender (p = 0.08) and cardiovascular risk factors (p = 0.08); for venous thrombosis-free survival, JAK2 mutation (HR 1.9; p = 0.03) with borderline significance for venous thrombosis history (p = 0.07); for overall survival, older age (p < 0.001), male gender (HR 1.9; p < 0.001), absolute neutrophil count (ANC) ≥ 8 × 109/L (HR 1.8; p = 0.01), absolute lymphocyte count (ALC) < 1.7 × 109/L (HR 1.2; p = 0.03); for myelofibrosis-free survival, CALR mutation (HR 2.7; p < 0.001, particularly for CALR type 1/1-like, HR 3.3) and MPL mutation (HR 3.9; p = 0.001); for leukemia-free survival, older age (p = 0.03). Cytoreductive therapy appeared to mitigate both venous (HR 0.3; p = 0.01) and arterial thrombosis (HR 4; p = 0.04); there was a trend for aspirin in preventing arterial thrombosis recurrence. The current study provides real-world observations in essential thrombocythemia, representing a valid source document for interpreting current literature and planning future studies.

One thousand patients with essential thrombocythemia: the Mayo Clinic experience

We describe 1000 patients with essential thrombocythemia seen at the Mayo Clinic between 1967 and 2023: median age 58 years (18–90), females 63%, JAK2/CALR/MPL-mutated 62%/27%/3%, triple-negative (TN) 8%, extreme thrombocytosis (ExT; platelets ≥1000 × 109/L) 26%, leukocytosis (leukocyte count >11 × 109/L) 20%, and abnormal karyotype 6%. JAK2-mutated patients were older (median 71 years), and CALR mutated (52 years), and TN (50 years) younger (p < 0.01). Female gender clustered with TN (73%) and JAK2 (69%) vs. CALR/MPL (49%/47%) mutations (p < 0.01). ExT clustered with CALR (type-2 more than type-1) and TN and leukocytosis with JAK2 mutation (p < 0.01). In multivariable analysis, risk factors for overall survival were older age (p < 0.01), male gender (HR 1.8), absolute neutrophil count (ANC) ≥ 8 × 109/L (HR 1.6), absolute lymphocyte count (ALC) < 1.7 × 109/L (HR 1.5), hypertension (HR 1.7), and arterial thrombosis history (HR 1.7); for leukemia-free survival, ExT (HR 2.3) and abnormal karyotype (HR 3.1); for myelofibrosis-free survival, ANC ≥ 8 × 109/L (HR 2.3) and MPL mutation (HR 3.9); for arterial thrombosis-free survival, age ≥60 years (HR 1.9), male gender (HR 1.6), arterial thrombosis history (HR 1.7), hypertension (HR 1.7), and JAK2 mutation (HR 1.8); for venous thrombosis-free survival, male gender (HR 1.8) and venous thrombosis history (HR 3.0). Associations between ExT and leukemic transformation and between ANC and fibrotic progression were limited to JAK2-mutated cases. Aspirin therapy appeared to mitigate both arterial (HR 0.4) and venous (HR 0.4) thrombosis risk. HR-based risk models delineated patients with median survivals ranging from 10 years to not reached and 20-year leukemia/myelofibrosis incidences from 3%/21% to 12.8%/49%. The current study provides both novel and confirmatory observations of essential thrombocythemia.

Expression of JAK2 V617F Mutation in BCR - ABL Negative Myeloproliferative Neoplasms

OBJECTIVE: To detect the presence of JAK2V617F mutation in BCR - ABL negative myeloproliferative neoplasms and to stratify high risk patients for targeted therapy.PLACE AND DURATION OF STUDY: Department of Haematology, Armed forces institute of Pathology (AFIP), Rawalpindi, from Dec 2023 to Oct 2023.STUDY DESIGN: Descriptive cross sectional studyMETHODOLOGY: A total of 40 consecutive patients of BCR - ABL 1 negative myeloproliferative disorders were included in the study after being diagnosed according to WHO defined haematological criteria for each disorder and performing bone marrow examination under aseptic measures. Informed consent and ethical approval were obtained from each individual. All patients had their blood samples examined for the G-T point mutation (V617F) in the JAK2 gene located on chromosome 9, utilizing allele-specific real-time qualitative polymerase chain reaction (RT-qPCR). Results were analyzed by using SPSS version 22.RESULTS: Out of total 40 patients included in our study 21(52.5%) had Polycythemia Vera (PV), 15 (37.5%) had Primary myelofibrosis (PMF) and 4 (10%) had Essential thrombocythemia (ET). JAK2 mutation was found in 20 (95.2%) patients of PV, 9 (60%) patients of PMF and 2 (50%) patients of ET with a significant p-value of ˂ 0.001.CONCLUSIONS: JAK2 V617F is a useful clinical marker for establishing diagnosis and separating high risk patients for specific targeted therapy.

Driver mutation zygosity is a critical factor in predicting clonal hematopoiesis transformation risk

Clonal hematopoiesis (CH) can be caused by either single gene mutations (eg point mutations in JAK2 causing CHIP) or mosaic chromosomal alterations (e.g., loss of heterozygosity at chromosome 9p). CH is associated with a significantly increased risk of hematologic malignancies. However, the absolute rate of transformation on an annualized basis is low. Improved prognostication of transformation risk is urgently needed for routine clinical practice. We hypothesized that the co-occurrence of CHIP and mCAs at the same locus (e.g., transforming a heterozygous JAK2 CHIP mutation into a homozygous mutation through concomitant loss of heterozygosity at chromosome 9) might have important prognostic implications for malignancy transformation risk. We tested this hypothesis using our discovery cohort, the UK Biobank (n = 451,180), and subsequently validated it in the BioVU cohort (n = 91,335). We find that individuals with a concurrent somatic mutation and mCA were at significantly increased risk of hematologic malignancy (for example, In BioVU cohort incidence of hematologic malignancies is higher in individuals with co-occurring JAK2 V617F and 9p CN-LOH; HR = 54.76, 95% CI = 33.92–88.41, P < 0.001 vs. JAK2 V617F alone; HR = 44.05, 95% CI = 35.06–55.35, P < 0.001). Currently, the ‘zygosity’ of the CHIP mutation is not routinely reported in clinical assays or considered in prognosticating CHIP transformation risk. Based on these observations, we propose that clinical reports should include ‘zygosity’ status of CHIP mutations and that future prognostication systems should take mutation ‘zygosity’ into account.

Jak2V617F Reversible Activation Shows Its Essential Requirement in Myeloproliferative Neoplasms.

Current JAK inhibitors to treat myeloproliferative neoplasms are ineffective at eradicating mutant cells. We developed an endogenously expressed Jak2V617F dual-recombinase knock-in/knock-out model to investigate Jak2V617F oncogenic reversion in vivo. Jak2V617F deletion abrogates MPN features and depletes disease-sustaining MPN stem cells, suggesting improved Jak2V617F targeting offers the potential for greater therapeutic efficacy. See related commentary by Celik and Challen, p. 701. This article is featured in Selected Articles from This Issue, p. 695.

Approach to the Diagnosis and Management of Essential Thrombocytosis in a Resource-Limited Setting

Essential thrombocytosis (ET) is a myeloproliferative neoplasm (together with polycythemia vera, chronic myelogenous leukemia, and primary myelofibrosis) characterized by clonal proliferation of megakaryocytes, usually due to the presence of JAK2, CALR, or MPL mutations. Whereas a bone marrow aspirate and genetic testing for these mutations are necessary for an accurate diagnosis of ET, in resource-limited settings, these are often either inaccessible or limited by prohibitive costs. A nuanced clinical approach is necessary to diagnose and manage ET in these settings. In this study, we present a case of ET diagnosed and managed in a resource-limited rural setting in Kenya with hydroxyurea and aspirin. We highlight the importance of individualized therapeutic targets, the challenges with dose adjustments in the setting of hydroxyurea-induced neutropenia, and how extrapolated data from the use of hydroxyurea elsewhere may help guide such dose adjustments. Finally, we propose a rationalized approach to treating ET in a resource-limited clinical setting.

Type II mode of JAK2 inhibition and destabilization are potential therapeutic approaches against the ruxolitinib resistance driven myeloproliferative neoplasms.

Ruxolitinib has been approved by the US FDA for the treatment of myeloproliferative neoplasms such as polycythemia vera and primary myelofibrosis. Ruxolitinib will remain a main stay in the treatment of MPN patients due to its effective therapeutic benefits. However, there have been instances of ruxolitinib resistance in MPN patients. As JAK2 is a direct target of ruxolitinib, we generated ruxolitinib-resistant clones to find out the mechanism of resistance. Cell-based screening strategy was used to detect the ruxolitinib-resistant mutations in JAK2. The Sanger sequencing method was used to detect the point mutations in JAK2. Mutations were re-introduced using the site-directed mutagenesis method and stably expressed in Ba/F3 cells. Drug sensitivities against the JAK2 inhibitors were measured using an MTS-based assay. JAK2 and STAT5 activation levels and total proteins were measured using immunoblotting. Computational docking studies were performed using the Glide module of Schrodinger Maestro software. In this study, we have recovered seven residues in the kinase domain of JAK2 that affect ruxolitinib sensitivity. All these mutations confer cross-resistance across the panel of JAK2 kinase inhibitors except JAK2-L983F. JAK2-L983F reduces the sensitivity towards ruxolitinib. However, it is sensitive towards fedratinib indicating that our screen identifies the drug-specific resistance profiles. All the ruxolitinib-resistant JAK2 variants displayed sensitivity towards type II JAK2 inhibitor CHZ-868. In this study, we also found that JAK1-L1010F (homologous JAK2-L983F) is highly resistant towards ruxolitinib suggesting the possibility of JAK1 escape mutations in JAK2-driven MPNs and JAK1 mutated ALL. Finally, our study also shows that HSP90 inhibitors are potent against ruxolitinib-resistant variants through the JAK2 degradation and provides the rationale for clinical evaluation of potent HSP90 inhibitors in genetic resistance driven by JAK2 inhibitors. Our study identifies JAK1 and JAK2 resistance variants against the type I JAK2 inhibitors ruxolitinib, fedratinib, and lestaurtinib. The sensitivity of these resistant variants towards the type II JAK2 inhibitor CHZ-868 indicates that this mode of type II JAK2 inhibition is a potential therapeutic approach against ruxolitinib refractory leukemia. This also proposes the development of potent and specific type II JAK2 inhibitors using ruxolitinib-resistance variants as a prototype.

TLR2 Derangements Likely Play a Significant Role in the Inflammatory Response and Thrombosis in Patients with Ph(-) Classical Myeloproliferative Neoplasm.

We investigated the role of toll-like receptors (TLRs) in inflammatory pathways in Philadelphia chromosome-negative myeloproliferative neoplasms (Ph(-)MPNs). TLR2 expression was increased in ET, PV, and MPN (grouped as (PV + (ET) + MF)), whereas TLR4 was elevated only in MPN. TLR3, 7, and 9 were not elevated. Cultured monocyte-derived dendritic cells and plasma assays in TLR2-elevated patients were found to secrete more cytokines than those from TLR2-normal patients. These facts suggest that TLR2 is the major inflammatory pathways in MPN. We also measured S100A9 and reactive oxygen species (ROS), revealing increased S100A9 in PV, MF, and MPN, while ROS were only increased in MF. These data suggests that MPNs initially involve TLR2, with minor contributions from TLR4, and with S100A9, leading to ROS formation, JAK2 mutation, and progression to MF or leukemia. Furthermore, patients with JAK2 mutations or leukocytosis exhibited higher TLR2 expression. In leukocyte-platelet interactions, cells from MPN patients displayed a stronger response to a TLR2 agonist than TLR4 agonist. A TLR2 inhibitor (but not a TLR4 inhibitor) attenuated this response. Thrombosis incidence was higher in TLR2-elevated patients (29%) than in TLR2-normal patients (19%). These findings suggest that TLR2 likely contributes to thrombosis in MPN.

An Approach to the Investigation of Thrombocytosis: Differentiating between Essential Thrombocythemia and Secondary Thrombocytosis.

Thrombocytosis is a common reason for referral to Hematology. Differentiating between secondary causes of thrombocytosis and essential thrombocythemia (ET) is often clinically challenging. A practical diagnostic approach to identify secondary thrombocytosis could reduce overinvestigation such as next generation sequencing (NGS) panel. All adult patients with thrombocytosis (≥450 × 109/L) who underwent molecular testing at a single tertiary care centre between January 1, 2018 and May 31, 2021 were evaluated. Clinical and laboratory variables were compared between patients with secondary thrombocytosis vs. ET. Clinical variables included smoking, thrombosis, splenectomy, active malignancy, chronic inflammatory disease, and iron deficiency anemia. Laboratory variables included complete blood count (CBC), ferritin, and myeloid mutations detected by NGS. The overall yield of molecular testing was 52.4%; 92.1% of which were mutations in JAK2, CALR, and/or MPL. Clinical factors predictive of ET included history of arterial thrombosis (p < 0.05); active malignancy, chronic inflammatory disease, splenectomy, and iron deficiency were associated with secondary thrombocytosis (p < 0.05). A diagnosis of ET was associated with higher hemoglobin, mean corpuscular volume (MCV), red cell distribution width (RDW), and mean platelet volume (MPV), while secondary thrombocytosis was associated with higher body mass index, white blood cells, and neutrophils (p < 0.01). A practical approach to investigating patients with persistent thrombocytosis based on clinical characteristics such as active malignancy, chronic inflammatory disease, splenectomy, and iron deficiency may assist in accurately identifying patients more likely to have secondary causes of thrombocytosis and reduce overinvestigation, particularly costly molecular testing.

Polycythemia vera and management of the thrombotic risk: an update

Polycythemia vera (PV) is a chronic Philadelphia-negative myeloproliferative neoplasm caused by JAK2 mutation and characterized predominantly by the overproduction of red blood cells. The current treatment strategies of PV are based on periodic phlebotomies aimed at preventing thrombotic events associated with increased hematocrit levels. Additional therapies to mitigate the thrombotic burden, which represents the most important predictor of reduced survival in PV patients, include cytoreductive therapies, low-dose aspirin, and systemic anticoagulation. This concise review summarizes the current knowledge on the management of the thrombotic risk in PV patients.

JAK2, CALR, and MPL Mutation Profiles in Colombian patients with BCR-ABL Negative Myeloproliferative Neoplasms.

Among the chronic myeloproliferative neoplasms (MPNs) not associated with BCR-ABL mutations are polycythemia vera, primary myelofibrosis, and essential thrombocythemia. These diseases are caused by mutations in genes, such as the JAK2, MPL, and CALR genes, which participate in regulating the JAK-STAT signaling pathway. This study aimed to establish the frequencies of mutations in the JAK2, MPL, and CALR genes in a group of Colombian patients with a negative clinical diagnosis of BCR-ABL chronic myeloproliferative neoplasms. The JAK2 V617F and MPL W515K mutations and deletions or insertions in exon 9 of the CALR gene were analyzed in 52 Colombian patients with polycythemia vera, primary myelofibrosis, and essential thrombocythemia. The JAK2V617F mutation was carried by 51.9% of the patients, the CALR mutation by 23%, and the MPL mutation by 3.8%; 23% were triple-negative for the mutations analyzed. In these neoplasms, 6 mutation types in CALR were identified, one of which has not been previously reported. Additionally, one patient presented a double mutation in both the CALR and JAK2 genes. Regarding the hematological results for the mutations, significant differences were found in the hemoglobin level, hematocrit level, and platelet count among the three neoplasms. Thus, this study demonstrates the importance of the molecular characterization of the JAK2, CALR and MPL mutations in Colombian patients (the genetic context of which remains unclear in the abovementioned neoplasms) to achieve an accurate diagnosis, a good prognosis, adequate management, and patient survival.

Concurrent diagnosis of Sjogren’s syndrome and polycthemia vera: a rare co-existence

Primary Sjogren's Syndrome(pSS) is a chronic autoimmune disease and focal lymphocytic infiltration of the exocrine glands is the key pathological feature (1). Polycythemia vera(PV) is a chronic myeloproliferative disorder characterized by JAK-2 mutations and increased red blood cell mass(2,3). Autoimmune diseases and hematological malignancies can often be observed together. Patients with SS are at a higher risk of developing lymphoproliferative diseases mainly low-grade B-cell lymphomas and predominantly marginal zone lymphoma. Moreover, PV can rarely be presented with paraneoplastic events including small vessel vasculitis (2). However, PV and pSS co-existence had never been reported. We here want to present a case of concurrently diagnosed PV and pSS.

Molecular markers as possible efficacy predictors of targeted therapy for myelofibrosis: single-center study

Background. Targeted therapy is the most promising in the treatment of myelofibrosis, but it is necessary to search for the reasons limiting its effectiveness. There are known factors negatively affecting the development of myelofibrosis, but data on their negative impact in the context of targeted therapy are scarce.Aim. Assessing the impact of cytogenetic and genetic abnormalities on the course and therapy results for primary and secondary myelofibrosis during ruxolitinib therapy.Materials and methods. The prospective study included 106 patients with myelofibrosis in the chronic phase (53 (50 %) men and 53 (50 %) women) who received ruxolitinib at the Moscow City Hematology Center, S.P. Botkin City Clinical Hospital. The median age of patients was 62 (18–84) years. The median disease duration before initiation of ruxolitinib therapy was 79 (1–432) months. Before therapy, genetic studies were performed, including next-generation sequencing. The median duration of ruxolitinib therapy was 33 (1–111) months. The influence of the cytogenetic landscape, driver mutations, allele burden of JAK2 (over time) and CALR, additional mutations on the dynamics of symptoms, spleen size, achievement of hematological response, overall survival, progression-free survival, survival without blast crisis and without progression of myelofibrosis with targeted therapy was assessed.Results. The studied genetic factors did not have a significant correlation with hemogram parameters. The hematological response in patients with JAK2 and CALR mutations compared favorably with the response in the groups with the MPL mutation and triple negative status (TNS). Higher hematological response rate was obtained in the group with initially low allele burden &lt;50 % of JAK2 or CALR. Significant differences in 5-year overall survival were found between groups of patients with TNS and JAK2 and CALR mutations (p &lt;0.05); with CALR allele burden &lt;50 % and ³50 % before initiation of ruxolitinib therapy (p = 0.01); the presence or absence of positive dynamics of the JAK2 allele burden during treatment (p &lt;0.05); additional mutations assigned to different pathogenicity groups (p &lt;0.05); with different number of pathogenic mutations (1 or ³2), the presence or absence of pathogenic mutations in the ASXL1 (p = 0.002) and SETBP1 (p = 0.00001) genes. The 5-year progression-free survival was significantly different in cohorts of patients with or without positive dynamics of the JAK2 allelic load during treatment (p &lt;0.05); additional mutations assigned to different pathogenicity groups (p &lt;0.05); with a different number of pathogenic mutations (1 or ³2), the presence or absence of a pathogenic mutation of the SETBP1 gene (p = 0.003). Progression-free survival did not correlate with the type of driver mutation or its absence; however, all patients with TNS died from myelofibrosis progression. Significant differences in 5-year blast crisis-free survival were observed between groups with JAK2 and MPL mutations (p = 0.001), JAK2 and TNS (p = 0.002); difference in 5-year survival without progression of fibrosis – between groups with pathogenic and benign (p = 0.031); uncertain and benign (p = 0.001) mutations.Conclusion. The study identified genetic markers associated with decreased efficacy of ruxolitinib therapy.

Clonal hematopoiesis and its evolution of myeloproliferative neoplasms

The mutations of myeloproliferative neoplasma (MPN) mainly include driver mutations and non-driver mutations. The driver mutations mainly include JAK2 mutations, CALR mutations and MPL mutations and non-driver mutations mainly include ASXL1, DNMT3A, TET2, SF3B1, EZH2, TP53, SRSF2, USAF1, etc. Driver and non-driver mutations and their clonal evolution affect the thrombosis and disease transformation of MPN. Clonal hematopoiesis of MPN can occur decades before diagnosis, even in the fetal stage. After the emergence of clonal hematopoiesis, until the emergence and progression of MPN, gene mutation order, inflammation, interferon therapy affect the disease phenotype and clonal hematopoiesis of MPN. Although great progress has been made in the understanding of MPN clonal hematopoiesis and its evolution with the development of next-generation sequencing, there are still many limitations. In this study, we mainly discuss gene mutations of MPN and their influences on the thrombosis, leukemia and fibrosis transformation, and the influencing factors of clonal evolution, aiming to summarize the influence of clonal hematopoiesis and its evolution on the complications, prognosis and survival of MPN.

Bone Marrow Cancer caused by JAK2 mutations and related treatments

JAK2 V617F, one of the protein mutations, will cause uncontrolled blood production. The mutation leads to a lot of blood and bone marrow diseases, for instance, myeloproliferative neoplasms, myelofibrosis, leukemia et al. Most of these diseases are deadly. Uncontrolled blood cell production might result in leukemia, myelofibrosis, and bone marrow cancer even worse. However, The development of treatments has not been perfected, so mutations in the JAK2 protein still put patients at risk. This article analyzes the mutation principle of JAK2. Many diseases are caused by mutations. At the same time, experiments have confirmed that JAK2 mutations cross-species and do not only occur in humans. In addition, this article explains the treatment options for diseases caused by JAK2 mutations, such as eBM Treatment and Target Therapy. The research provides the stage that concluded the mutant mechanism and the several treatments for the disease caused by the mutation. Although some of the treatments and therapies are not consummated, the future research orientation could be more focused on the clinical study of target therapies like Parental Proteasome Inhibitors.

Features of immune mediated diseases in JAK2 (V617F)-positive myeloproliferative neoplasms and the potential therapeutic role of JAK inhibitors

ObjectiveThe Janus Kinase (JAK) 2 (V617F) mutation is the most frequently detected in myeloproliferative neoplasms (MPN). JAK2(V617F) mutation displays a pro-inflammatory phenotype that may be associated to a higher risk of immune mediated diseases (IMIDs), thromboembolic complications or other cancers. We aimed to evaluate the prevalence and main features of both rheumatic and non-rheumatic IMIDs in a cohort of MPNs patients with JAK2 (V617F) mutation. MethodsStudy of all patients diagnosed with MPNs and JAK2 (V617F) mutation at a tertiary hospital in Northern Spain from 2004 to 2022. We focused on patients with rheumatic IMIDs to assess the time from IMIDs diagnosis to the detection of JAK2V617F mutation, the clinical course and severity of the disease, potential thrombotic complications, malignancies and therapeutic response. Results130 patients (73 men/57 women; mean age, 70.1 ± 14.5 years) were identified. Fifty-four (41.5 %) patients were diagnosed with at least one IMID. The prevalence of rheumatic IMIDs was 7.7 % (n = 10), including rheumatoid arthritis (n = 4), polymyalgia rheumatica (n = 3), Sjögren syndrome (n = 1), antiphospholipid syndrome (n = 1) and autoinflammatory syndrome with WDR1 mutation (n = 1). Thrombotic complications were observed in 4 of these 10 patients. The clinical course of the rheumatic IMID was mild in most cases and responded to conventional immunosuppressive therapy. One patient was successfully treated with Baricitinib, a JAK1/JAK2 inhibitor. ConclusionsA high prevalence of rheumatic IMIDs is observed in patients with MPNs and JAK2 (V617F) mutation. JAK inhibitors might be a targeted therapy option in these patients.

Compound Angiotrophic Biphasic Myeloid Sarcoma with JAK2 (V617F) and KRAS (G12C) mutations

Introduction. Myeloid sarcomas (MS) are extramedullary manifestations of myeloid neoplasms, associated with conditions like acute myeloid leukemia (AML), myelodysplastic syndromes (MDS), and myeloproliferative neoplasms (MPN). MS presents as tumor masses in various body sites, often expressing myeloid or monocytic markers. This case report details an unusual biphasic MS relapse with a significant “intravascular” component. Materials and methods. A 59-year-old male with a history of JAK2-V617F positive MDS/MPN underwent allogeneic hematopoietic stem cell transplantation and presented with abdominal pain, skin lesions, and systemic symptoms. Biopsy of colonic masses was performed, and subsequent analysis was carried out. Results. The biopsy revealed a neoplasm with solid and intravascular components. The solid part was mainly composed of monocytic lineage cells expressing specific markers, with a small population of myeloid blasts. In contrast, the “intravascular” component was mainly myeloid blasts expressing different markers. Genetic analysis uncovered JAK2 (V617F) and KRAS (G12C) mutations. Despite treatment, the disease progressed, and the patient eventually passed away. Conclusions. Myeloid sarcomas are challenging to diagnose, often being mistaken for large cell lymphomas. They can manifest as isolated extramedullary relapses, with a unique molecular profile. This case stands out due to its biphasic nature, featuring distinct components with differing characteristics, which has not been documented previously in English literature. It underscores the intricate and diverse nature of myeloid sarcomas, emphasizing the need for further research to comprehend their biology and behavior effectively.