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1.
PLoS One ; 19(1): e0296758, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38198473

RESUMO

OBJECTIVES: Cytomegalovirus (CMV) is frequently detected in lung and/or blood samples of patients with Pneumocystis jirovecii pneumonia (PJP), although this co-detection is not precisely understood. We aimed to determine whether PJP was more severe in case of CMV detection. METHODS: We retrospectively included all patients with a diagnosis of PJP between 2009 and 2020 in our centre and with a measure of CMV viral load in blood and/or bronchoalveolar lavage (BAL). PJP severity was assessed by the requirement for intensive care unit (ICU) admission. RESULTS: The median age of the 249 patients was 63 [IQR: 53-73] years. The main conditions were haematological malignancies (44.2%), solid organ transplantations (16.5%), and solid organ cancers (8.8%). Overall, 36.5% patients were admitted to ICU. CMV was detected in BAL in 57/227 patients; the 37 patients with viral load ≥3 log copies/mL were more frequently admitted to ICU (78.4% vs 28.4%, p<0.001). CMV was also detected in blood in 57/194 patients; the 48 patients with viral load ≥3 log copies/mL were more frequently admitted to ICU (68.7% vs 29.4%, p<0.001). ICU admission rate was found to increase with each log of BAL CMV viral load and each log of blood CMV viral load. CONCLUSIONS: PJP is more severe in the case of concomitant CMV detection. This may reflect either the deleterious role of CMV itself, which may require antiviral therapy, or the fact that patients with CMV reactivation are even more immunocompromised.


Assuntos
Síndrome da Imunodeficiência Adquirida , Infecções por Citomegalovirus , Pneumonia por Pneumocystis , Humanos , Pessoa de Meia-Idade , Idoso , Pneumonia por Pneumocystis/diagnóstico , Citomegalovirus , Estudos Retrospectivos , Unidades de Terapia Intensiva , Infecções por Citomegalovirus/complicações , Infecções por Citomegalovirus/diagnóstico
2.
Leuk Res ; 130: 107308, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37230027

RESUMO

Accelerated phase (AP) CML at onset and have poorer prognosis than CP-CML. We hypothesize that off-license use of second generation TKI (TKI2) as front-line therapy might counterbalance this poor prognosis, with limited toxicity. In "real-life" conditions, newly diagnosed patients meeting the ELN cytological criteria for AP-CML or harboring ACA and treated with first-line TKI2 were included in this retrospective multicenter observational study. We enrolled 69 patients [69.5 % male, median age 49.5 years, median follow-up 43.5 months], segregated into hematologic AP [HEM-AP (n = 32)] and cytogenetically defined AP [ACA-AP (n = 37)]. Hematologic parameters were worse in HEM-AP [spleen size (p = 0.014), PB basophils (p < .001), PB blasts (p < .001), PB blasts+promyelocytes (p < .001), low hemoglobin levels (p < .001)]. Dasatinib was initiated in 56 % patients in HEM-AP and in 27 % in ACA-AP, nilotinib in 44 % and 73 % respectively. Response and survival do not differ, regardless of the TKI2: 81 % vs 84.3 % patients achieved CHR, 88 % vs 84 % CCyR, 73 % vs 75 % MMR respectively. The estimated 5-year PFS 91.5 % (95%CI: 84.51-99.06 %) and 5-year OS 96.84 % (95%CI: 92.61-100 %). Only BM blasts (p < 0.001) and BM blasts+promyelocytes (p < 0.001) at diagnosis negatively influenced OS. TKI2 as front-line therapy in newly diagnosed AP-CML induce excellent responses and survival, and counterbalance the negative impact of advanced disease phase.


Assuntos
Leucemia Mielogênica Crônica BCR-ABL Positiva , Humanos , Masculino , Pessoa de Meia-Idade , Feminino , Mesilato de Imatinib , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Dasatinibe/uso terapêutico , Pirimidinas , Resultado do Tratamento , Inibidores de Proteínas Quinases/uso terapêutico
3.
Cells ; 12(4)2023 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-36831325

RESUMO

The bone marrow niche plays an increasing role in the pathophysiogenesis of myelodysplastic syndromes. More specifically, mesenchymal stromal cells, which can secrete extracellular vesicles and their miRNA contents, modulate the fate of hematopoietic stem cells leading to leukemogenesis. Extracellular vesicles can mediate their miRNA and protein contents between nearby cells but also in the plasma of the patients, being potent tools for diagnosis and prognostic markers in MDS. They can be targeted by antisense miRNA or by modulators of the secretion of extracellular vesicles and could lead to future therapeutic directions in MDS.


Assuntos
Vesículas Extracelulares , MicroRNAs , Síndromes Mielodisplásicas , Humanos , MicroRNAs/genética , Medula Óssea/metabolismo , Síndromes Mielodisplásicas/genética , Células-Tronco Hematopoéticas/metabolismo , Vesículas Extracelulares/metabolismo
4.
EJHaem ; 3(4): 1091-1099, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36467818

RESUMO

Myelodysplastic syndromes (MDS) are a heterogeneous group of clonal hematological disorders. Treatment options are classified and defined by prognostic risk based on the International Prognostic Scoring System (IPSS) and, more recently, the revised IPSS (IPSS-R). The treatment goal for lower-risk MDS is to correct cytopenias or their consequences, with the goal of maintaining or improving quality of life. Erythropoiesis-stimulating agents (ESAs) play an important role in treating anemia. Individuals with MDS who have a 5q deletion are particularly sensitive to treatment with lenalidomide; however, this comprises the minority of patients with MDS. Luspatercept was recently approved in the United States and the European Union for the treatment of ESA-refractory MDS with ring sideroblasts. Research into new treatment options, especially after ESA failure, is needed. In this review, we will focus on the current therapeutic options for MDS-related anemia.

5.
BMJ Open ; 12(10): e065850, 2022 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-36207039

RESUMO

INTRODUCTION: Suspicion of myelodysplastic syndromes (MDS) is the most common reason for bone marrow aspirate in elderly patients. Peripheral blood neutrophil myeloperoxidase expression quantified by flow cytometric analysis might rule out MDS for up to 35% of patients referred for suspected disease, without requiring bone marrow aspiration. Yet laboratory-developed liquid antibody cocktails have practical limitations, because of lack of standardisation and poor stability. This research project aims to estimate the level of agreement and comparative accuracy between a single-use flow cytometry tube of lyophilised reagents (BD Lyotube Stain 468) and its laboratory-developed liquid reagent counterpart in quantifying peripheral blood neutrophil myeloperoxidase expression, among adult patients referred for suspected MDS. METHODS AND ANALYSIS: The MPO-MDS-Develop project is a cross-sectional diagnostic accuracy study of two index tests by comparison with a reference standard in consecutive unselected adult patients conducted at a single university hospital. Flow cytometry analysis of peripheral blood samples will be performed by independent operators blinded to the reference diagnosis, using either Lyotube Stain 468 or laboratory-developed liquid reagent cocktail. The reference diagnosis of MDS will be established by cytomorphological evaluation of bone marrow aspirate by two independent haematopathologists blinded to the index test results. Morphologic assessment will be complemented by bone marrow flow cytometric score, karyotype and targeted next-generation sequencing panel of 43 genes, where relevant. The target sample size is 103 patients. ETHICS AND DISSEMINATION: An institutional review board (Comité de Protection des Personnes Sud Est III, Lyon, France) approved the protocol prior to study initiation (reference number: 2020-028-B). Participants will be recruited using an opt-out approach. Efforts will be made to release the primary results within 6 months of study completion. TRIAL REGISTRATION NUMBER: NCT04399018.


Assuntos
Síndromes Mielodisplásicas , Neutrófilos , Adulto , Idoso , Estudos Transversais , Citometria de Fluxo/métodos , Humanos , Indicadores e Reagentes , Síndromes Mielodisplásicas/diagnóstico , Neutrófilos/metabolismo , Peroxidase
6.
Br J Haematol ; 194(2): 336-343, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34151423

RESUMO

Despite a moderate prevalence in low-risk myelodysplastic syndromes (MDS) and chronic myelomonocytic leukaemia (CMML), thrombocytopenia remains a risk of severe bleeding and therapeutic options are still limited. There are only a few studies with eltrombopag (ELT), a thrombopoietin receptor agonist, in those patients. In this retrospective multicentre study, ELT was used in 50 patients with MDS and 11 with CMML, with no excess of marrow blasts and platelet counts of <50 × 109 /l in a 'real-life' situation. Platelet response occurred in 47 (77%) patients. The median (range) duration of response was 8 (0-69) months. None of the eight still responders who discontinued ELT had relapsed, at a median (range) of 16 (6-23) months after ELT discontinuation. Although 36% of the patients were anti-coagulated or anti-aggregated only 10% of patients had Grade ≥3 bleeding events. Thrombotic events were observed in six (10%) patients, who all but one had a medical history of arterial or venous thrombosis. Progression to acute myeloid leukaemia occurred in four (7%) patients. In this first 'real-life' study, ELT was effective and generally well tolerated in patients with MDS/CMML without excess blasts.


Assuntos
Benzoatos/uso terapêutico , Hidrazinas/uso terapêutico , Leucemia Mielomonocítica Crônica/tratamento farmacológico , Síndromes Mielodisplásicas/tratamento farmacológico , Pirazóis/uso terapêutico , Receptores de Trombopoetina/agonistas , Trombocitopenia/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , Plaquetas/efeitos dos fármacos , Feminino , França/epidemiologia , Humanos , Leucemia Mielomonocítica Crônica/epidemiologia , Masculino , Síndromes Mielodisplásicas/epidemiologia , Estudos Retrospectivos , Trombocitopenia/epidemiologia
7.
Am J Hematol ; 96(1): 80-88, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33108024

RESUMO

The value of pretransplant splenectomy in patients with myelofibrosis (MF) is subject to debate, since the procedure may preclude subsequent allogeneic hematopoietic cell transplantation (allo-HCT). To determine the impact of pretransplant splenectomy on the incidence of allo-HCT, we conducted a comprehensive retrospective study of all patients with MF for whom an unrelated donor search had been initiated via the French bone marrow transplantation registry (RFGM) between 1 January 2008 and 1 January 2017. Additional data were collected from the patients' medical files and a database held by the French-Language Society for Bone Marrow Transplantation and Cell Therapy (SFGM-TC). We used a multistate model with four states ("RFGM registration"; "splenectomy"; "death before allo-HCT", and "allo-HCT") to evaluate the association between splenectomy and the incidence of allo-HCT. The study included 530 patients from 57 centers. With a median follow-up time of 6 years, we observed 81 splenectomies, 99 deaths before allo-HCT (90 without splenectomy and nine after), and 333 allo-HCTs (268 without splenectomy and 65 after). In a bivariable analysis, the hazard ratio [95% confidence interval (CI)] for the association of splenectomy with allo-HCT was 7.2 [5.1-10.3] in the first 4 months and 1.18 [0.69-2.03] thereafter. The hazard ratio [95% CI] for death associated with splenectomy was 1.58 [0.79-3.14]. These reassuring results suggest that splenectomy does not preclude allo-HCT in patients with MF.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Mielofibrose Primária , Sistema de Registros , Esplenectomia , Aloenxertos , Intervalo Livre de Doença , Feminino , França/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Mielofibrose Primária/mortalidade , Mielofibrose Primária/terapia , Taxa de Sobrevida
11.
Free Radic Biol Med ; 146: 107-118, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31626946

RESUMO

Reactive oxygen species (ROS) produced in hematopoietic stem cells (HSCs) are involved in the balance between quiescence, self-renewal, proliferation and differentiation processes. However the role of NOX enzymes on the early stages of hematopoietic differentiation is poorly investigated. For that, we used induced pluripotent stem cells (iPSCs) derived from X-linked Chronic Granulomatous Disease (X0CGD) patients with deficiency in NOX2, and AR220CGD patients with deficiency in p22phox subunit which decreases NOX1, NOX2, NOX3 and NOX4 activities. CD34+ hematopoietic progenitors were obtained after 7, 10 and 13 days of iPS/OP9 co-culture differentiation system. Neither NOX expression nor activity was found in Wild-type (WT), X0CGD and AR220CGD iPSCs. Although NOX2 and NOX4 mRNA were found in WT, X0CGD and AR220CGD iPSC-derived CD34+ cells at day 10 and 13 of differentiation, NOX4 protein was the only NOX enzyme expressed in these cells. A NADPH oxidase activity was measured in WT and X0CGD iPSC-derived CD34+ cells but not in AR220CGD iPSC-derived CD34+ cells because of the absence of p22phox, which is essential for the NOX4 activity. The absence of NOX4 activity and the poor NOX-independent ROS production in AR220CGD iPSC-derived CD34+ cells favored the CD34+ cells production but lowered their hematopoietic potential compared to WT and X0CGD iPSC-derived CD34+ cells. In addition we found a large production of primitive AR220CGD iPSC-derived progenitors at day 7 compared to the WT and X0CGD cell types. In conclusion NOX4 is the major NOX enzyme involved in the early stages of hematopoietic differentiation from iPSCs and its activity can modulate the production, the hematopoietic potential and the phenotype of iPSC-derived CD34+.


Assuntos
Doença Granulomatosa Crônica , Transplante de Células-Tronco Hematopoéticas , Células-Tronco Pluripotentes Induzidas , Diferenciação Celular , Doença Granulomatosa Crônica/genética , Humanos , NADPH Oxidase 4/genética , NADPH Oxidases/genética , Espécies Reativas de Oxigênio
12.
Ann Hematol ; 99(1): 21, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31788722

RESUMO

This article was originally published without an Open Access but due to the authors final decision to opt for Open Choice this correction was created.

13.
Ann Hematol ; 99(1): 7-19, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31650290

RESUMO

Myelodysplastic syndromes (MDS) are hematopoietic stem cell malignancies associated with an erythroid maturation defect, resulting in anemia. Treatments for MDS include erythropoiesis-stimulating agents (ESAs). The identification of prognostic markers is important to help predict response and improve outcomes. Various scoring systems have been developed to help predict response to ESAs. Despite limitations in its assessment, serum erythropoietin (sEPO) level is an important predictor of hematologic response to ESAs in patients with lower-risk MDS. Numerous studies have reported significantly lower sEPO levels among responders versus non-responders. Furthermore, treatment response is significantly more likely among those with sEPO levels below versus those above various cutoffs. Other prognostic indicators for response to ESAs include lower transfusion requirement, fewer bone marrow blasts, higher hemoglobin, lower serum ferritin, lower-risk MDS, and more normal cytogenetics. Studies of other MDS therapies (e.g., lenalidomide and luspatercept) have also reported that lower sEPO levels are indicative of hematologic response. In addition, lower sEPO levels (up to 500 IU/L) have been included in treatment algorithms for patients with lower-risk MDS to define whether ESAs are indicated. Lower sEPO levels are predictive of hematologic response-particularly to ESAs. Further, clinical trials should use sEPO thresholds to ensure more homogeneous cohorts.


Assuntos
Receptores de Activinas Tipo II/uso terapêutico , Eritropoetina/sangue , Fragmentos Fc das Imunoglobulinas/uso terapêutico , Lenalidomida/uso terapêutico , Síndromes Mielodisplásicas/sangue , Síndromes Mielodisplásicas/tratamento farmacológico , Proteínas Recombinantes de Fusão/uso terapêutico , Células da Medula Óssea/metabolismo , Células da Medula Óssea/patologia , Feminino , Ferritinas/sangue , Hemoglobinas/metabolismo , Humanos , Masculino , Síndromes Mielodisplásicas/diagnóstico , Síndromes Mielodisplásicas/patologia , Prognóstico , Fatores de Risco
14.
Biol Blood Marrow Transplant ; 25(12): 2366-2374, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31326611

RESUMO

Therapy-related myelodysplastic syndrome (t-MDS) after autologous stem cell transplantation (ASCT) is a rare complication with no curative option. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) may be considered for eligible patients and has been understudied in t-MDS. We report 47 consecutive patients with t-MDS after an ASCT who underwent allo-HSCT with a median age of 58 years (range, 30 to 71 years) at transplantation and a median follow-up of 22 months (range, 0.7 to 107). The median overall survival (OS) was 6.9 months (95% confidence interval [CI], 0 to 19 months). OS rates were 45% (29% to 60%) and 30% (15% to 45%) at 1 and 3 years after transplantation, respectively. On univariate analysis, prior therapy for t-MDS before allo-HSCT (P = .02) and mismatched donors (P = .004) were associated with poor OS. Three-year nonrelapse mortality (NRM) and relapse rates were 44% (25% to 63%) and 41% (22% to 61%), respectively. Mismatched donors (P < .001) were associated with higher NRM and a high-risk MDS (P = .008) with a higher relapse risk. On multivariate analysis, HLA mismatch was associated with higher NRM (hazard ratio, 6.21; 95% CI, 1.63 to 23.62; P = .007). In conclusion, our results suggest that one third of the patients who develop t-MDS after an ASCT for lymphoma are cured after an allo-HSCT. The use of mismatched donors with standard graft-versus-host disease prophylaxis should be avoided in such an indication for allo-HSCT. It will be worthwhile to see if the implementation of cyclophosphamide post-transplantation will improve the outcome with mismatched donors.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Linfoma , Síndromes Mielodisplásicas , Segunda Neoplasia Primária , Doadores não Relacionados , Aloenxertos , Autoenxertos , Intervalo Livre de Doença , Linfoma/mortalidade , Linfoma/terapia , Síndromes Mielodisplásicas/mortalidade , Síndromes Mielodisplásicas/terapia , Segunda Neoplasia Primária/mortalidade , Segunda Neoplasia Primária/terapia , Sistema de Registros , Estudos Retrospectivos , Sociedades Médicas , Taxa de Sobrevida
15.
Blood Adv ; 3(12): 1868-1880, 2019 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-31221660

RESUMO

Chronic myelomonocytic leukemia (CMML) is a myeloid hematological malignancy with overlapping features of myelodysplastic syndromes (MDSs) and myeloproliferative neoplasms (MPNs). The knowledge of the role of the tumor microenvironment (TME), particularly mesenchymal stromal cells (MSCs), in MDS pathogenesis is increasing. Generally, cancer is associated with a procoagulant state participating in tumor development. Monocytes release procoagulant, tissue factor (TF)-bearing microparticles. We hypothesized that MSCs and clonal monocytes release procoagulant extracellular vesicles (EVs) within the CMML TME, inducing a procoagulant state that could modify hematopoietic stem cell (HSC) homeostasis. We isolated and cultured MSCs and monocytes from CMML patients and MSCs from healthy donors (HDs). Their medium EVs and small EVs (sEVs) were collected after iterative ultracentrifugations and characterized by nanoparticle tracking analysis. Their impact on hemostasis was studied with a thrombin generation assay and fibrinography. CMML or HD HSCs were exposed to sEVs from either CMML or HD MSCs. CMML MSC sEVs increased HD HSC procoagulant activity, suggesting a transfer of TF from the CMML TME to HD HSCs. The presence of TF on sEVs was shown by electron microscopy and western blot. Moreover, CMML monocyte EVs conferred a procoagulant activity to HD MSCs, which was reversed by an anti-TF antibody, suggesting the presence of TF on the EVs. Our findings revealed a procoagulant "climate" within the CMML environment related to TF-bearing sEVs secreted by CMML MSCs and monocytes.


Assuntos
Vesículas Extracelulares/metabolismo , Leucemia Mielomonocítica Crônica/patologia , Monócitos/metabolismo , Microambiente Tumoral/imunologia , Fatores de Coagulação Sanguínea/fisiologia , Células Cultivadas , Vesículas Extracelulares/ultraestrutura , Células-Tronco Hematopoéticas/metabolismo , Homeostase/fisiologia , Humanos , Células-Tronco Mesenquimais/metabolismo , Monócitos/patologia , Nanopartículas , Tromboplastina/metabolismo
16.
Haematologica ; 104(3): 497-504, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30287621

RESUMO

Erythropoiesis-stimulating agents are generally the first line of treatment of anemia in patients with lower-risk myelodysplastic syndrome. We prospectively investigated the predictive value of somatic mutations, and biomarkers of ineffective erythropoiesis including the flow cytometry RED score, serum growth-differentiation factor-15, and hepcidin levels. Inclusion criteria were no prior treatment with erythropoiesis-stimulating agents, low- or intermediate-1-risk myelodysplastic syndrome according to the International Prognostic Scoring System, and a hemoglobin level <10 g/dL. Patients could be red blood cell transfusion-dependent or not and were given epoetin zeta 40 000 IU/week. Serum erythropoietin level, iron parameters, hepcidin, flow cytometry Ogata and RED scores, and growth-differentiation factor-15 levels were determined at baseline, and molecular analysis by next-generation sequencing was also conducted. Erythroid response (defined according to the International Working Group 2006 criteria) was assessed at week 12. Seventy patients, with a median age of 78 years, were included in the study. There were 22 patients with refractory cytopenia with multilineage dysplasia, 19 with refractory cytopenia with unilineage dysplasia, 14 with refractory anemia with ring sideroblasts, four with refractory anemia with excess blasts-1, six with chronic myelomonocytic leukemia, two with del5q-and three with unclassifiable myelodysplastic syndrome. According to the revised International Prognostic Scoring System, 13 had very low risk, 47 had low risk, nine intermediate risk and one had high-risk disease. Twenty patients were transfusion dependent. Forty-eight percent had an erythroid response and the median duration of the response was 26 months. At baseline, non-responders had significantly higher RED scores and lower hepcidin:ferritin ratios. In multivariate analysis, only a RED score >4 (P=0.05) and a hepcidin:ferritin ratio <9 (P=0.02) were statistically significantly associated with worse erythroid response. The median response duration was shorter in patients with growth-differentiation factor-15 >2000 pg/mL and a hepcidin:ferritin ratio <9 (P=0.0008 and P=0.01, respectively). In multivariate analysis, both variables were associated with shorter response duration. Erythroid response to epoetin zeta was similar to that obtained with other erythropoiesis-stimulating agents and was correlated with higher baseline hepcidin:ferritin ratio and lower RED score. ClinicalTrials.gov registration: NCT 03598582.


Assuntos
Eritropoese/efeitos dos fármacos , Eritropoetina/uso terapêutico , Ferritinas/sangue , Hepcidinas/sangue , Síndromes Mielodisplásicas/sangue , Síndromes Mielodisplásicas/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , Biomarcadores , Eritropoetina/administração & dosagem , Eritropoetina/efeitos adversos , Feminino , Citometria de Fluxo , Humanos , Ferro/metabolismo , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/diagnóstico , Síndromes Mielodisplásicas/etiologia , Prognóstico , Curva ROC , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/efeitos adversos , Proteínas Recombinantes/uso terapêutico , Resultado do Tratamento
17.
Oncotarget ; 9(19): 14993-15000, 2018 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-29599920

RESUMO

Myelodysplastic syndromes (MDS) are oligoclonal disorders of the hematopoietic stem cells (HSC). Recurrent gene mutations are involved in the MDS physiopathology along with the medullar microenvironment. To better study the heterogeneity of MDS, it is necessary to create patient derived xenograft (PDX). We have reproduced a PDX model by xenografting HSC (CD34+) and mesenchymal stromal cells (MSC) in NOD/SCID/IL2rγ-/- mice with primary samples from one RAEB2, two RAEB1 and one RARS patients harboring karyotype abnormalities and gene mutations. The average human chimerisms ranged from 59.7% to 0.0175% for the 4 patients. Secondary grafts (G2) were only performed for mice derived from the RAEB2 patient and the average human chimerism was 53.33%. G1 mice 1 and 2, and their derived G2 mice showed less than 20% of medullar blasts whereas mouse 3 and the resulting G2 mice transformed to AML. Clonal architecture was dissected in the different hematopoietic progenitors (HP) harvested from G1 and G2 mice. By direct Sanger sequencing, we found the 4 initial mutations in each HP subpopulation and those mutations had the same variant allele frequency in the CD34+ CD38- HSC from G1 and G2 mice by next generation sequencing (NGS). Targeted NGS analysis done in HSC of mouse 3 did not show any additional driver gene mutations explaining the transformation to AML. To conclude, we have generated a PDX mouse model that perfectly reproduces the MDS founder clone which is stable over time, allowing us to consider this system as a powerful tool to test therapeutic approaches.

18.
Oncotarget ; 8(62): 105510-105524, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-29285268

RESUMO

Anemia is a frequent cytopenia in myelodysplastic syndromes (MDS) and most patients require red blood cell transfusion resulting in iron overload (IO). Deferasirox (DFX) has become the standard treatment of IO in MDS and it displays positive effects on erythropoiesis. In low risk MDS samples, mechanisms improving erythropoiesis after DFX treatment remain unclear. Herein, we addressed this question by using liquid cultures with iron overload of erythroid precursors treated with low dose of DFX (3µM), which corresponds to DFX 5 mg/kg/day, an unusual dose used for iron chelation. We highlight a decreased apoptosis rate and an increased proportion of cycling cells, both leading to higher proliferation rates. The iron chelation properties of low dose DFX failed to activate the Iron Regulatory Proteins and to support iron depletion, but low dose DFX dampers intracellular reactive oxygen species. Furthermore low concentrations of DFX activate the NF-κB pathway in erythroid precursors triggering anti-apoptotic and anti-inflammatory signals. Establishing stable gene silencing of the Thioredoxin (TRX) 1 genes, a NF-κB modulator, showed that fine-tuning of reactive oxygen species (ROS) levels regulates NF-κB. These results justify a clinical trial proposing low dose DFX in MDS patients refractory to erythropoiesis stimulating agents.

19.
Biol Blood Marrow Transplant ; 20(9): 1451-4, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24910381

RESUMO

Acute graft-versus-host disease (aGVHD) still remains the main cause of morbidity and mortality after allogeneic stem cell transplantation. Moreover, patients who did not respond to first-line treatment with glucocorticosteroids have a very poor outcome. Some studies suggested that alemtuzumab (a humanized monoclonal antibody against the CD52 antigen) might be effective for treatment of refractory aGVHD. Here we report a single-center experience with alemtuzumab in refractory gastrointestinal aGVHD. From September 2009 to April 2012 at the Grenoble medical university center, 24 patients who had presented a refractory gastrointestinal aGVHD to corticosteroid, or after another immunosuppressive drug, were retrospectively analyzed. Most patients (n = 19) presented stage 4 gastrointestinal aGVHD. Response to treatment (either complete or partial) was observed in 15 patients (62.4%). The overall survival rate at 1 year for all patients was 33.3% (95% confidence interval [CI], 15.9% to 51.9%) and for responders, 53.3% (95% CI, 26.3% to 74.4%). Two patients died from infection, 5 patients from recurrent GVHD, and 1 from an uncontrolled post-transplant lymphoproliferative disorder.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Antineoplásicos/uso terapêutico , Doença Enxerto-Hospedeiro/tratamento farmacológico , Adulto , Alemtuzumab , Anticorpos Monoclonais Humanizados/administração & dosagem , Antineoplásicos/administração & dosagem , Feminino , Doença Enxerto-Hospedeiro/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
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