Direct oral anticoagulants (DOACs) have been approved to treat and prevent thrombotic events. However, they are not yet labeled for use in patients with active cancers. Myeloproliferative neoplasms ...(MPNs) are clonal chronic disorders with a high incidence of thrombotic events, for which low-dose aspirin (LDA) is the standard drug treatment. We analyzed efficacy and safety of DOACs prescription in patients treated for MPNs. An MPN database, the OBENE registry, was established at our institution. We collected biological and clinical data from diagnosis to last follow-up for every patient included in this study. Thrombotic and hemorrhagic events and hematologic evolutions were categorized as major events in the database. Of the 760 MPN patients in the OBENE registry, 25 (3.3%) were treated with a DOAC. Median follow-up duration was 2.1 years (0.12–4.3 years). The reasons for prescribing DOACs were atrial fibrillation and thrombotic events for 13 and 12 patients, respectively. We only observed one thrombotic event (4%) and three major hemorrhagic events (12%). A case–control study did not detect a significant difference in thrombotic or hemorrhagic events in patients treated with LDA and DOACs. These preliminary results suggest that DOACs may be highly efficient and safe for use in MPN patients.
To study the role of the JAK2-V617F mutation in leukemic transformation, we examined 27 patients with myeloproliferative disorders (MPDs) who transformed to acute myeloid leukemia (AML). At MPD ...diagnosis, JAK2-V617F was detectable in 17 of 27 patients. Surprisingly, only 5 of 17 patients developed JAK2-V617F–positive AML, whereas 9 of 17 patients transformed to JAK2-V617F–negative AML. Microsatellite analysis in a female patient showed that mitotic recombination was not responsible for the transition from JAK2-V617F–positive MPD to JAK2-V617F–negative AML, and clonality determined by the MPP1 polymorphism demonstrated that the granulocytes and leukemic blasts inactivated the same parental X chromosome. In a second patient positive for JAK2-V617F at transformation, but with JAK2-V617F–negative leukemic blasts, we found del(11q) in all cells examined, suggesting a common clonal origin of MPD and AML. We conclude that JAK2-V617F–positive MPD frequently yields JAK2-V617F–negative AML, and transformation of a common JAK2-V617F–negative ancestor represents a possible mechanism.
We have previously described the safety and efficacy of pegylated interferon-α2a therapy in a cohort of 62 patients with myeloproliferative neoplasm-associated myelofibrosis followed in centers ...affiliated to the French Intergroup of Myeloproliferative neoplasms. In this study, we report their long-term outcomes and correlations with mutational patterns of driver and non-driver mutations analyzed by targeted next generation sequencing. The median age at diagnosis was 66 years old, the median follow-up since starting pegylated interferon was 58 months. At the time of analysis, 30 (48.4%) patients were alive including 16 still being treated with pegylated interferon. The median survival of patients with intermediate and high-risk prognostic Lille and dynamic International Prognostic Scoring System scores treated with pegylated interferon was increased in comparison to that of historical cohorts. In addition, overall survival was significantly correlated with the duration of pegylated interferon therapy (70
30 months after 2 years of treatment,
<10
).
allele burden was decreased by more than 50% in 58.8% of patients and two patients even achieved complete molecular response. Next-generation sequencing analyses performed in 49 patients showed that 28 (57.1%) of them carried non-driver mutations. The presence of at least one additional mutation was associated with a reduction of both overall and leukemia-free survival. These findings in a large series of patients with myelofibrosis suggest that pegylated interferon therapy may provide a survival benefit for patients with intermediate- or high-risk Lille and dynamic International Prognostic Scoring System scores. It also reduced the
allele burden in most patients. These results further support the use of pegylated interferon in selected patients with myelofibrosis.
Acquired von Willebrand syndrome (AVWS) is a rare bleeding disorder that usually mimics type 1 or 2A von Willebrand disease (VWD).
Can AVWS mimic the phenotype of type 2B VWD?
A 64-year-old male ...patient presented with thrombocytopenia, normal routine hemostasis results, and normal VWF antigen and factor VIII levels but reduced von Willebrand factor (VWF) activity (31 IU/dL). The ristocetin-induced platelet aggregation test showed paradoxical aggregation at low doses of ristocetin, suggesting type 2B VWD, but no deleterious sequence variation was found in either the VWF or GP1BA genes, compatible with AVWS. Serum protein electrophoresis revealed a monoclonal immunoglobulin G antibody.
This AVWS with a 2B phenotype VWD was probably related to a monoclonal immunoglobulin G antibody causing a VWF conformational change, resulting in increased affinity to platelet glycoprotein-Ib. In the event of surgery or bleeding, treatment with vonicog alfa seems to be the best option for this patient.
•Acquired von Willebrand syndrome can mimic type 2B von Willebrand disease.•A patient with thrombocytopenia and bleeding symptoms was required to undergo a prostate biopsy.•Monoclonal immunoglobulin G causes von Willebrand factor conformational change, resulting in type 2B acquired von Willebrand syndrome.•Recombinant von Willebrand factor concentrate has been shown to be more effective than intravenous immunoglobulin.
Since the discovery of spliceosome mutations in myeloid malignancies, abnormal pre-mRNA splicing, which has been well studied in various cancers, has attracted novel interest in hematology. However, ...despite the common occurrence of spliceosome mutations in myelo-proliferative neoplasms (MPN), not much is known regarding the characterization and mechanisms of splicing anomalies in MPN. In this article, we review the current scientific literature regarding “splicing and myeloproliferative neoplasms”. We first analyse the clinical series reporting spliceosome mutations in MPN and their clinical correlates. We then present the current knowledge about molecular mechanisms by which these mutations participate in the pathogenesis of MPN or other myeloid malignancies. Beside spliceosome mutations, splicing anomalies have been described in myeloproliferative neoplasms, as well as in acute myeloid leukemias, a dreadful complication of these chronic diseases. Based on splicing anomalies reported in chronic myelogenous leukemia as well as in acute leukemia, and the mechanisms presiding splicing deregulation, we propose that abnormal splicing plays a major role in the evolution of myeloproliferative neoplasms and may be the target of specific therapeutic strategies.
In this study, we have addressed how Lyn kinase signaling mediates nilotinib-resistance by quantitative phospho-proteomics using Stable Isotope Labeling with Amino acid in Cell culture. We have found ...an increased tyrosine phosphorylation of 2 additional tyrosine kinases in nilotinib-resistant cells: the spleen tyrosine kinase Syk and the UFO family receptor tyrosine kinase Axl. This increased tyrosine phosphorylation involved an interaction of these tyrosine kinases with Lyn. Inhibition of Syk by the inhibitors R406 or BAY 61-3606 or by RNA interference restored the capacity of nilotinib to inhibit cell proliferation. Conversely, coexpression of Lyn and Syk were required to fully induce resistance to nilotinib in drug-sensitive cells. Surprisingly, the knockdown of Syk also strongly decreased tyrosine phosphorylation of Lyn and Axl, thus uncovering interplay between Syk and Lyn. We have shown the involvement of the adaptor protein CDCP-1 in resistance to nilotinib. Interestingly, the expression of Axl and CDCP1 were found increased both in a nilotinib-resistant cell line and in nilotinib-resistant CML patients. We conclude that an oncogenic signaling mediated by Lyn and Syk can bypass the need of Bcr-Abl in CML cells. Thus, targeting these kinases may be of therapeutic value to override imatinib or nilotinib resistance in CML.
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