STAT3 mutation impacts biological and clinical features of T-LGL leukemia

STAT3 mutations have been described in 30-40% of T-large granular lymphocyte (T-LGL) leukemia patients, leading to STAT3 pathway activation. Considering the heterogeneity of the disease and the several immunophenotypes that LGL clone may express, the aim of this work was to evaluate whether STAT3 mutations might be associated with a distinctive LGL immunophenotype and/or might be indicative for specific clinical features.Our series of cases included a pilot cohort of 101 T-LGL leukemia patients (68 CD8+/CD4- and 33 CD4+/CD8\ub1) from Padua Hematology Unit (Italy) and a validation cohort of additional 20 patients from Rennes Hematology Unit (France).Our results indicate that i) CD8+ T-LGL leukemia patients with CD16+/CD56- immunophenotype identify a subset of patients characterized by the presence of STAT3 mutations and neutropenia, ii) CD4+/CD8\ub1 T-LGL leukemia are devoid of STAT3 mutations but characterized by STAT5b mutations, and iii) a correlation exists between STAT3 activation and presence of Fas ligand, this molecule resulting highly expressed in CD8+/CD16+/CD56- patients. Experiments with stimulation and inhibition of STAT3 phosphorylation confirmed this relationship. In conclusion, our data show that T-LGL leukemia with specific molecular and phenotypic patterns is associated with discrete clinical features contributing to get insights into molecular bases accounting for the development of Fas ligand-mediated neutropenia

LGL leukemia: from pathogenesis to treatment

International audienceLarge granular lymphocyte (LGL) leukemia has been recognized by the World Health Organization classifications amongst mature T-cell and natural killer (NK) cell neoplasms. There are 3 categories: chronic T-cell leukemia and NK-cell lymphocytosis, which are similarly indolent diseases characterized by cytopenias and autoimmune conditions as opposed to aggressive NK-cell LGL leukemia. Clonal LGL expansion arise from chronic antigenic stimulation, which promotes dysregulation of apoptosis, mainly due to constitutive activation of survival pathways including Jak/Stat, MapK, phosphatidylinositol 3-kinase-Akt, Ras-Raf-1, MEK1/extracellular signal-regulated kinase, sphingolipid, and nuclear factor-κB. Socs3 downregulation may also contribute to Stat3 activation. Interleukin 15 plays a key role in activation of leukemic LGL. Several somatic mutations including Stat3, Stat5b, and tumor necrosis factor alpha-induced protein 3 have been demonstrated recently in LGL leukemia. Because these mutations are present in less than half of the patients, they cannot completely explain LGL leukemogenesis. A better mechanistic understanding of leukemic LGL survival will allow future consideration of a more targeted therapeutic approach than the current practice of immunosuppressive therapy

NK subtype of Large Granular Leukemia

International audienceLes leucémies à grands lymphocytes granuleux (LGL) sont des syndromes lymphoprolifératifs rares caractérisés par une expansion clonale de lymphocytes T ou natural killer (NK) dans 85 et 15 % des cas, respectivement. De manière intéressante, les leucémies LGL-T et -NK ont une physiopathologie commune et des présentations clinique et biologique similaires. Ce syndrome lymphoprolifératif est caractérisé par des cytopénies et une association fréquente à des maladies ou à des manifestations auto-immunes. Il s’agit d’une pathologie d’évolution indolente permettant, dans la plupart des cas, d’opter pour une stratégie d’abstention-surveillance au diagnostic. Néanmoins, la majorité des patients requerront l’initiation d’un traitement au cours du suivi. Les cellules NK étant dépourvues de récepteur des lymphocytes T (TCR), l’obtention d’une preuve de clonalité dans les leucémies à LGL-NK est difficile. Ce point est crucial, compte tenu de possibles expansions réactionnelles dans des contextes d’infections virales ou de pathologies dysimmunitaires. La démarche diagnostique a été facilitée par les progrès réalisés ces dernières années dans la compréhension de la physiopathologie et l’identification récente de mutations récurrentes. Dans cette revue, nous aborderons la physiopathologie des leucémies LGL-NK, nous présenterons les récents progrès réalisés dans les stratégies diagnostiques avant d’aborder la prise en charge thérapeutique

Toward a Better Classification System for NK-LGL Disorders

International audienceLarge granular lymphocytic leukemia is a rare lymphoproliferative disorder characterized by a clonal expansion of T-lineage lymphocyte or natural killer (NK) cells in 85 and 15% of cases respectively. T and NK large granular leukemia share common pathophysiology, clinical and biological presentation. The disease is characterized by cytopenia and a frequent association with autoimmune manifestations. Despite an indolent course allowing a watch and wait attitude in the majority of patients at diagnosis, two third of the patient will eventually need a treatment during the course of the disease. Unlike T lymphocyte, NK cells do not express T cell receptor making the proof of clonality difficult. Indeed, the distinction between clonal and reactive NK-cell expansion observed in several situations such as autoimmune diseases and viral infections is challenging. Advances in our understanding of the pathogenesis with the recent identification of recurrent mutations provide new tools to prove the clonality. In this review, we will discuss the pathophysiology of NK large granular leukemia, the recent advances in the diagnosis and therapeutic strategies

Ruxolitinib for refractory large granular lymphocyte leukemia

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Patients Participating in Nasogastric Tube Insertion through Hypnoanalgesia during High-dose Chemotherapy-induced Aplasia

International audienceThe insertion of a nasogastric (NG) tube is often a difficult experience for both patients and caregivers. This often results in a high failure rate of NG insertion. This pilot study aimed to evaluate the effectiveness, tolerance, and acceptability of hypnoanalgesia to assist self-insertion of an NG tube. Patients undergoing high-dose chemotherapy for autologous or allogeneic hematopoietic stem cell transplantation (HSCT) or acute leukemia and with high risk of aplasia were included in the study. A total of 38 patients were included during 6 consecutive months. They all achieved successful NG tube self-insertion. The NG tube remained in place during hospitalization in 32 cases for an average duration of 15 days. Six patients rejected the NG tube during vomiting but they all voluntarily attempted it again later on and succeeded. The discomfort related to NG-tube insertion was mild. This pilot study suggests that NG tube self-insertion assisted by hypnoanalgesia may be effective, well-accepted, and well-tolerated in patients. These promising findings will need further confirmation

Joint Model of Iron and Hepcidin During the Menstrual Cycle in Healthy Women

International audienceHepcidin regulates serum iron levels, and its dosage is used in differential diagnostic of iron-related pathologies. We used the data collected in the HEPMEN (named after HEPcidin during MENses) study to investigate the joint dynamics of serum hepcidin and iron during the menstrual cycle in healthy women. Ninety menstruating women were recruited after a screening visit. Six fasting blood samples for determination of iron-status variables were taken in the morning throughout the cycle, starting on the second day of the period. Non-linear mixed effect models were used to describe the evolution of iron and hepcidin. Demographic and medical covariates were tested for their effect on model parameters. Parameter estimation was performed using the SAEM algorithm implemented in the Monolix software. A general pattern was observed for both hepcidin and iron, consisting of an initial decrease during menstruation, followed by a rebound and stabilising during the second half of the cycle. We developed a joint model including a menstruation-induced decrease of both molecules at the beginning of the menses and a rebound effect after menses. Iron stimulated the release of hepcidin. Several covariates, including contraception, amount of blood loss and ferritin, were found to influence the parameters. The joint model of iron and hepcidin was able to describe the fluctuations induced by blood loss from menstruation in healthy non-menopausal women and the subsequent regulation. The HEPMEN study showed fluctuations of iron-status variables during the menstrual cycle, which should be considered when using hepcidin measurements for diagnostic purposes in women of child-bearing potentia

Molecular mechanisms underlying transformation of large granular lymphocytic leukemia to high-grade T-cell lymphoma

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