BCR-associated factors driving chronic lymphocytic leukemia cells proliferation ex vivo

International audienceA chronic antigenic stimulation is believed to sustain the leukemogenic development of chronic lymphocytic leukemia (CLL) and most of lymphoproliferative malignancies developed from mature B cells. Reproducing a proliferative stimulation ex vivo is critical to decipher the mechanisms of leukemogenesis in these malignancies. However, functional studies of CLL cells remains limited since current ex vivo B cell receptor (BCR) stimulation protocols are not sufficient to induce the proliferation of these cells, pointing out the need of mandatory BCR co-factors in this process. Here, we investigated benefits of several BCR co-stimulatory molecules (IL-2, IL-4, IL-15, IL-21 and CD40 ligand) in multiple culture conditions. Our results demonstrated that BCR engagement (anti-IgM ligation) concomitant to CD40 ligand, IL-4 and IL-21 stimulation allowed CLL cells proliferation ex vivo. In addition, we established a proliferative advantage for ZAP70 positive CLL cells, associated to an increased phosphorylation of ZAP70/SYK and STAT6. Moreover, the use of a tri-dimensional matrix of methylcellulose and the addition of TLR9 agonists further increased this proliferative response. This ex vivo model of BCR stimulation with T-derived cytokines is a relevant and efficient model for functional studies of CLL as well as lymphoproliferative malignancies. Like in most mature lymphoproliferative malignancies, an antigenic stimulation is believed to drive the leukemo-genic process in chronic lymphocytic leukemia (CLL) 1-3. A restricted use of IGHV genes and the existence of ste-reotypic B cell receptor (BCR) on CLL cells 4-6 provides evidence in favor of antigenic stimulation where different microbial antigens, as well as auto-antigens, have been suspected as actors of this chronic stimulation 7. In addition , a chronic BCR self-activation has been shown in subtypes of CLL cells 8. Moreover, several signaling aberrations have been described downstream of the BCR, notably in aggressive CLL with unmutated IGHV (UM-CLL), in which the expression of ZAP70 reinforces BCR responsiveness 9-12. BCR activation, which is essential for the physiological development of lymphocytes 13 would also be indispensable for the survival and proliferation of CLL cells in vivo 2. Accordingly, withdrawal of this stimulation is believed to be responsible for the rapid spontaneous apoptosis of CLL cells ex vivo 14. The cellular consequences of this BCR activation has been extensively studied an

Deep-Learning Assessed Muscular Hypodensity Independently Predicts Mortality in DLBCL Patients Younger Than 60 Years.

[en] BACKGROUND: Muscle depletion (MD) assessed by computed tomography (CT) has been shown to be a predictive marker in solid tumors, but has not been assessed in non-Hodgkin's lymphomas. Despite software improvements, MD measurement remains highly time-consuming and cannot be used in clinical practice. METHODS: This study reports the development of a Deep-Learning automatic segmentation algorithm (DLASA) to measure MD, and investigate its predictive value in a cohort of 656 diffuse large B cell lymphoma (DLBCL) patients included in the GAINED phase III prospective trial (NCT01659099). RESULTS: After training on a series of 190 patients, the DLASA achieved a Dice coefficient of 0.97 ± 0.03. In the cohort, the median skeletal muscle index was 50.2 cm2/m2 and median muscle attenuation (MA) was 36.1 Hounsfield units (HU). No impact of sarcopenia was found on either progression free survival (PFS) or overall survival (OS). Muscular hypodensity, defined as MA below the tenth percentile according to sex, was associated with a lower OS and PFS, respectively (HR = 2.80 (95% CI 1.58-4.95), p < 0.001, and HR = 2.22 (95% CI 1.43-3.45), p < 0.001). Muscular hypodensity appears to be an independent risk factor for mortality in DLBCL and because of DLASA can be estimated in routine practice

SARS-CoV-2 Infection in Patients With Waldenström's Macroglobulinemia: A Multicenter International Cohort Study

The coronavirus disease 2019 (COVID-19) pandemic has represented a huge challenge for vulnerable patients affected with hematological malignancies.1,2 So far, heterogeneous series on patients with lymphoma and COVID-19 have been published with mortality rates ranging from 25% to 40%,3–8 with only limited information about specific neoplasms.Peer reviewe

A French multicentric prospective prognostic cohort with epidemiological, clinical, biological and treatment information to improve knowledge on lymphoma patients: study protocol of the "REal world dAta in LYmphoma and survival in adults" (REALYSA) cohort.

BACKGROUND: Age-adjusted lymphoma incidence rates continue to rise in France since the early 80's, although rates have slowed since 2010 and vary across subtypes. Recent improvements in patient survival in major lymphoma subtypes at population level raise new questions about patient outcomes (i.e. quality of life, long-term sequelae). Epidemiological studies have investigated factors related to lymphoma risk, but few have addressed the extent to which socioeconomic status, social institutional context (i.e. healthcare system), social relationships, environmental context (exposures), individual behaviours (lifestyle) or genetic determinants influence lymphoma outcomes, especially in the general population. Moreover, the knowledge of the disease behaviour mainly obtained from clinical trials data is partly biased because of patient selection. METHODS: The REALYSA ("REal world dAta in LYmphoma and Survival in Adults") study is a real-life multicentric cohort set up in French areas covered by population-based cancer registries to study the prognostic value of epidemiological, clinical and biological factors with a prospective 9-year follow-up. We aim to include 6000 patients over 4 to 5 years. Adult patients without lymphoma history and newly diagnosed with one of the following 7 lymphoma subtypes (diffuse large B-cell, follicular, marginal zone, mantle cell, Burkitt, Hodgkin, mature T-cell) are invited to participate during a medical consultation with their hematologist. Exclusion criteria are: having already received anti-lymphoma treatment (except pre-phase) and having a documented HIV infection. Patients are treated according to the standard practice in their center. Clinical data, including treatment received, are extracted from patients' medical records. Patients' risk factors exposures and other epidemiological data are obtained at baseline by filling out a questionnaire during an interview led by a clinical research assistant. Biological samples are collected at baseline and during treatment. A virtual tumor biobank is constituted for baseline tumor samples. Follow-up data, both clinical and epidemiological, are collected every 6 months in the first 3 years and every year thereafter. DISCUSSION: This cohort constitutes an innovative platform for clinical, biological, epidemiological and socio-economic research projects and provides an opportunity to improve knowledge on factors associated to outcome of lymphoma patients in real life. TRIAL REGISTRATION: 2018-A01332-53, ClinicalTrials.gov identifier: NCT03869619

Long-term analysis of the RiBVD phase II trial reveals the unfavorable impact of <i>TP53</i> mutations and hypoalbuminemia in older adults with mantle cell lymphoma; for the LYSA group

Between 2011 and 2012, a phase II trial evaluated the use of the RiBVD (rituximab, bendamustine, velcade and dexamethasone) combination as first-line treatment for mantle cell lymphoma (MCL) patients over the age of 65. We have now re-examined the classic prognostic factors, adding an assessment of TP53 mutation status. Patients (N=74; median age 73 years) were treated with the RiBVD combination. Median progression-free survival (mPFS) was 79 months and median overall survival (mOS) was 111 months. TP53 mutation status was available for 54/74 (73%) patients. TP53 mutations (TP53mt) were found in 12 patients (22.2%). In multivariate analysis, among the prognostic factors (PF) evaluated, only TP53mt and an albumin level (Alb) 3.6 g/dL were independently associated with a shorter mPFS. A hazard ratio (HR) of 3.16 (1.3-9.9, P=0.014) was obtained for TP53mt versus TP53 wild-type (wt), and 3.6 (1.39-9.5, P=0.009) for Alb <3.6 g/dL versus Alb ≥3.6 g/dL. In terms of mOS, multivariate analysis identified three PF: TP53mt (HR: 5.9 [1.77-19.5, P=0.004]), Alb <3.6 g/dL (HR: 5.2 [1.46- 18.5, P=0.011]), and ECOG=2 (HR: 3.7 [1.31-10.6, P=0.014]). Finally, a score combining TP53 status and Alb distinguished three populations based on the presence of 0, 1, or 2 PF. For these populations, mPFS was 7.8 years, 28 months, and 2.5 months, respectively. Our prolonged follow-up confirmed the efficacy of the RiBVD regimen, comparing it favorably to other regimens. TP53mt and hypoalbuminemia emerge as strong PF that can be easily integrated into prognostic scores for older adult patients with MCL

Methodological developments in proteomic analysis for the discovery and validation of biomarkers in B-cells lymphoid malignancies in adults

Le développement actuel très rapide des différentes approches « omiques » génère un grand nombre de biomarqueurs potentiels, en particulier dans le domaine de la cancérologie.L’analyse protéomique par spectrométrie de masse a particulièrement bénéficié des progrès technologiques récents qui ont permis la mise au point de nouvelles approches quantitatives globales ou ciblées. Néanmoins, peu de biomarqueurs potentiels finissent par être concrètement utilisés en pratique clinique, nécessitant l’optimisation des différentes étapes de leur développement.Dans la continuité des travaux ayant abouti à l’identification de biomarqueurs diagnostiques dans les hémopathies lymphoïdes B, ce travail de thèse a permis le développement d’une méthode d’analyse protéomique ciblée pour la vérification et la validation de nouveaux biomarqueurs potentiels. La possibilité d’appliquer des stratégies quantitatives globales à un très grand nombre d’échantillons a pu être démontrée. L’application de ces stratégies quantitatives globales à du tissu ganglionnaire provenant de lymphomes agressifs a permis d’identifier des biomarqueurs potentiellement associés à une résistance au traitement. Enfin,le mode de préparation tube-gel, facilitant l’étude d’un grand nombre d’échantillons, a été validé pour la réalisation d’analyses protéomiques différentielles.The current development of new « omics » technologies has led to the discovery of a large number of potential biomarkers, particularly in the field of oncology. Proteomics analysis bymass spectrometry have particularly benefited from these technological advances with the development of new global or targeted quantitative approaches. Nevertheless, only a few numbers of potential biomarkers are finally used in clinical practice, requiring further optimization of the development process. Following the initial identification of biomarkers in the diagnosis of lymphoid malignancies performed previously, this thesis has allowed the development of a targeted proteomics method that can be used for the validation of new potential biomarkers. The ability of analysing a large number of samples with a global quantitative approach has also been demonstrated. The application of these global quantitative strategies on lymph node tissue of aggressive lymphoma has permitted the identification of potential new biomarkers associated with chemorefractoriness. Lastly, a tube-gel protocol facilitating the analysis of a large number of samples has been validated for differential proteomics studies

Methodological developments in proteomic analysis for the discovery and validation of biomarkers in B-cells lymphoid malignancies in adults

Le développement actuel très rapide des différentes approches « omiques » génère un grand nombre de biomarqueurs potentiels, en particulier dans le domaine de la cancérologie.L’analyse protéomique par spectrométrie de masse a particulièrement bénéficié des progrès technologiques récents qui ont permis la mise au point de nouvelles approches quantitatives globales ou ciblées. Néanmoins, peu de biomarqueurs potentiels finissent par être concrètement utilisés en pratique clinique, nécessitant l’optimisation des différentes étapes de leur développement.Dans la continuité des travaux ayant abouti à l’identification de biomarqueurs diagnostiques dans les hémopathies lymphoïdes B, ce travail de thèse a permis le développement d’une méthode d’analyse protéomique ciblée pour la vérification et la validation de nouveaux biomarqueurs potentiels. La possibilité d’appliquer des stratégies quantitatives globales à un très grand nombre d’échantillons a pu être démontrée. L’application de ces stratégies quantitatives globales à du tissu ganglionnaire provenant de lymphomes agressifs a permis d’identifier des biomarqueurs potentiellement associés à une résistance au traitement. Enfin,le mode de préparation tube-gel, facilitant l’étude d’un grand nombre d’échantillons, a été validé pour la réalisation d’analyses protéomiques différentielles.The current development of new « omics » technologies has led to the discovery of a large number of potential biomarkers, particularly in the field of oncology. Proteomics analysis bymass spectrometry have particularly benefited from these technological advances with the development of new global or targeted quantitative approaches. Nevertheless, only a few numbers of potential biomarkers are finally used in clinical practice, requiring further optimization of the development process. Following the initial identification of biomarkers in the diagnosis of lymphoid malignancies performed previously, this thesis has allowed the development of a targeted proteomics method that can be used for the validation of new potential biomarkers. The ability of analysing a large number of samples with a global quantitative approach has also been demonstrated. The application of these global quantitative strategies on lymph node tissue of aggressive lymphoma has permitted the identification of potential new biomarkers associated with chemorefractoriness. Lastly, a tube-gel protocol facilitating the analysis of a large number of samples has been validated for differential proteomics studies

Développements méthodologiques en analyse protéomique pour la découverte et la validation de biomarqueurs dans les hémopathies lymphoïdes B de l'adulte

The current development of new « omics » technologies has led to the discovery of a large number of potential biomarkers, particularly in the field of oncology. Proteomics analysis bymass spectrometry have particularly benefited from these technological advances with the development of new global or targeted quantitative approaches. Nevertheless, only a few numbers of potential biomarkers are finally used in clinical practice, requiring further optimization of the development process. Following the initial identification of biomarkers in the diagnosis of lymphoid malignancies performed previously, this thesis has allowed the development of a targeted proteomics method that can be used for the validation of new potential biomarkers. The ability of analysing a large number of samples with a global quantitative approach has also been demonstrated. The application of these global quantitative strategies on lymph node tissue of aggressive lymphoma has permitted the identification of potential new biomarkers associated with chemorefractoriness. Lastly, a tube-gel protocol facilitating the analysis of a large number of samples has been validated for differential proteomics studies.Le développement actuel très rapide des différentes approches « omiques » génère un grand nombre de biomarqueurs potentiels, en particulier dans le domaine de la cancérologie.L’analyse protéomique par spectrométrie de masse a particulièrement bénéficié des progrès technologiques récents qui ont permis la mise au point de nouvelles approches quantitatives globales ou ciblées. Néanmoins, peu de biomarqueurs potentiels finissent par être concrètement utilisés en pratique clinique, nécessitant l’optimisation des différentes étapes de leur développement.Dans la continuité des travaux ayant abouti à l’identification de biomarqueurs diagnostiques dans les hémopathies lymphoïdes B, ce travail de thèse a permis le développement d’une méthode d’analyse protéomique ciblée pour la vérification et la validation de nouveaux biomarqueurs potentiels. La possibilité d’appliquer des stratégies quantitatives globales à un très grand nombre d’échantillons a pu être démontrée. L’application de ces stratégies quantitatives globales à du tissu ganglionnaire provenant de lymphomes agressifs a permis d’identifier des biomarqueurs potentiellement associés à une résistance au traitement. Enfin,le mode de préparation tube-gel, facilitant l’étude d’un grand nombre d’échantillons, a été validé pour la réalisation d’analyses protéomiques différentielles

Valeur de l'allogreffe de cellules souches hématopoïétiques à conditionnement atténué en traitement de consolidation de la première rémission complète d'une leucémie aiguë myéloblastique (analyse des resultats du protocole LAM 2001 chez les patients âgés de 51 à 60 ans avec un donneur familial HLA identique.)

STRASBOURG-Medecine (674822101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF