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BackgroundCOVID-19 severity is mainly related to lung impairment. However, preexisting patient characteristics and biomarkers at admission associated with this event are not precisely known.MethodsWe report 205 patients admitted for a proven COVID-19 in our institution between March 7 and April 22, 2020, particularly their comorbidities, respiratory severity, immune profile, and metabolic profile.FindingsMedian age was 70 years [interquartile range (IQR) 25-75: 60;79]; 115 (56·1%) patients were men. Oxygen supplementation of >2L/min was required in 107 patients (52·2%) after a median time of 8 days [IQR: 6;10] after the first symptoms; 67 (32·7%) patients were admitted to the intensive care unit (ICU), almost exclusively due to severe hypoxia. Patients requiring >2L/min oxygen therapy and/or ICU admission were older and more frequently males, with a significantly higher body mass index (BMI), a significantly higher total cholesterol (TC) / HDL cholesterol ratio, and higher triglycerides. They also had higher plasma levels of C-reactive protein (CRP) and interleukin 6 (IL-6); IL-6 >20 ng/L and CRP >70 mg/L were significantly associated with ICU admission and/or (for patients with a decision of limitation of life-support therapy) death. Higher BMI and TC/HDL-c ratio were associated with higher CRP and IL-6 levels. Steroid therapy was performed in 61 patients; while its clinical impact was inconclusive due to heterogeneous situations, IL-6 levels decreased significantly more in these patients.InterpretationSevere COVID-19 mostly relates to late-onset pneumonia associated with preexisting metabolic syndrome markers and a surge in inflammatory markers, allowing the early identification of at-risk patients.FundingThis work was supported by Foundation University of Grenoble Alpes.

Diffuse large B‐cell lymphoma (DLBCL) is a clinically heterogeneous entity, in which the first‐line treatment currently consists of an immuno‐chemotherapy regimen (R‐CHOP). However, around 30% of patients will not respond or will relapse. Overexpression of c‐MYC or p53 is frequently found in DLBCL, but an association with prognosis remains controversial, as for other biomarkers previously linked with DLBCL aggressivity (CD5, CD23, or BCL2). The aim of this study was to explore the expression of these biomarkers and their correlation with outcome, clinical, or pathological features in a DLBCL cohort. Immunohistochemical (c‐MYC, p53, BCL2, CD5, and CD23), morphological (‘starry‐sky’ pattern [SSP]), targeted gene panel sequencing by next‐generation sequencing (NGS), and fluorescence in situ hybridisation analyses were performed on tissue microarray blocks for a retrospective cohort of 94 R‐CHOP‐treated de novo DLBCL. In univariate analyses, p53 overexpression (p53high) was associated with unfavourable outcome (p = 0.04) and with c‐MYC overexpression (p = 0.01), whereas c‐MYC overexpression was linked with an SSP (p = 0.004), but only tended towards an inferior prognosis (p = 0.06). Presence of a starry‐sky morphology was found to be correlated with better survival in p53high DLBCL (p = 0.03) and/or c‐MYC‐positive DLBCL (p = 0.002). Furthermore, NGS data revealed that these three variables were associated with somatic mutations (PIM1, TNFRSF14, FOXO1, and B2M) involved in B‐cell proliferation, survival, metabolism, and immune signalling. Taken together, these results show that the SSP pattern seems to be a protective factor in high‐risk DLBCL subgroups and highlight cell death as a built‐in failsafe mechanism to control tumour growth.

IntroductionSuspicion 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 analysisThe 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 disseminationAn 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 numberNCT04399018.

Suspicion of myelodysplastic syndromes (MDS) is the most common reason for bone marrow aspirate in elderly patients. This study aimed to prospectively validate the accuracy for flow cytometric analysis of peripheral blood neutrophil myeloperoxidase expression in ruling out MDS. We enrolled 62 consecutive patients who were referred for suspected MDS, based on medical history and peripheral blood cytopenia. The accuracy of intra-individual robust coefficient of variation (RCV) for peripheral blood neutrophil myeloperoxidase expression was assessed with a prespecified 30% threshold. Cytomorphological evaluation of bone marrow aspirate performed by experienced hematopathologists confirmed MDS in 23 patients (prevalence, 37%), unconfirmed MDS in 32 patients (52%, including 3 patients with idiopathic cytopenia of undetermined significance (ICUS)), and was uninterpretable in 7 patients (11%). The median intra-individual RCV values for neutrophil myeloperoxidase expression in peripheral blood were 37.4% (range, 30.7-54.1), 29.2% (range, 28.1-32.1), and 29.1% (range, 24.7-37.8) for patients with confirmed suspicion of MDS, ICUS, and unconfirmed suspicion of MDS, respectively (P

Leukemic cells display some alterations in metabolic pathways, which play a role in leukemogenesis and in patients’ prognosis. To evaluate the characteristics and the impact of this metabolic reprogramming, we explore the bone marrow samples from 54 de novo acute myeloid leukemia (AML) patients, using an untargeted metabolomics approach based on proton high-resolution magic angle spinning-nuclear magnetic resonance. The spectra obtained were subjected to multivariate statistical analysis to find specific metabolome alterations and biomarkers correlated to clinical features. We found that patients display a large diversity of metabolic profiles, according to the different AML cytologic subtypes and molecular statuses. The link between metabolism and molecular status was particularly strong for the oncometabolite 2-hydroxyglutarate (2-HG), whose intracellular production is directly linked to the presence of isocitrate dehydrogenase mutations. Moreover, patients’ prognosis was strongly impacted by several metabolites, such as 2-HG that appeared as a good prognostic biomarker in our cohort. Conversely, deregulations in phospholipid metabolism had a negative impact on prognosis through 2 main metabolites (phosphocholine and phosphoethanolamine), which could be potential aggressiveness biomarkers. Finally, we highlighted an overexpression of glutathione and alanine in chemoresistant patients. Overall, our results demonstrate that different metabolic pathways could be activated in leukemic cells according to their phenotype and maturation levels. This confirms that metabolic reprogramming strongly influences prognosis of patients and underscores a particular role of certain metabolites and associated pathways in AML prognosis, suggesting common mechanisms developed by leukemic cells to maintain their aggressiveness even after well-conducted induction chemotherapy.

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and aggressive leukemia for which we developed a nationwide network to collect data from new cases diagnosed in France. In a retrospective, observational study of 86 patients (2000-2013), we described clinical and biological data focusing on morphologies and immunophenotype. We found expression of markers associated with plasmacytoid dendritic cell origin (HLA-DRhigh, CD303+, CD304+, and cTCL1+) plus CD4 and CD56 and frequent expression of isolated markers from the myeloid, B-, and T-lymphoid lineages, whereas specific markers (myeloperoxidase, CD14, cCD3, CD19, and cCD22) were not expressed. Fifty-one percent of cytogenetic abnormalities impact chromosomes 13, 12, 9, and 15. Myelemia was associated with an adverse prognosis. We categorized chemotherapeutic regimens into 5 groups: acute myeloid leukemia (AML)–like, acute lymphoid leukemia (ALL)–like, lymphoma (cyclophosphamide, doxorubicin, vincristine, and prednisone [CHOP])–like, high-dose methotrexate with asparaginase (Aspa-MTX) chemotherapies, and not otherwise specified (NOS) treatments. Thirty patients received allogeneic hematopoietic cell transplantation (allo-HCT), and 4 patients received autologous hematopoietic cell transplantation. There was no difference in survival between patients receiving AML-like, ALL-like, or Aspa-MTX regimens; survival was longer in patients who received AML-like, ALL-like, or Aspa-MTX regimens than in those who received CHOP-like regimens or NOS. Eleven patients are in persistent complete remission after allo-HCT with a median survival of 49 months vs 8 for other patients. Our series confirms a high response rate with a lower toxicity profile with the Aspa-MTX regimen, offering the best chance of access to hematopoietic cell transplantation and a possible cure.

Follicular lymphoid hyperplasia induced by dasatinib is an entity recently described. It is sometimes difficult to rule out the diagnostic of small B-cell lymphoma. Usually, the node is swollen, with follicular architecture conserved, composed by germinal centers with variable size and shape, with a hight number of mitoses and tingible bodies macrophages inside. Follicular lymphoid hyperplasia is isolated or associated with multiple reactive patterns. The immunohistochemical profil of germinal centers is CD20+, CD10+, BCL6+, BCL2-. Swollen node disappears in a short time after dasatinib discontinuation. Clinicians and pathologists need to be aware of this entity, so as not to avoid mistakenly suspect lymphoma when lymphadenopathy occurs in a patient with chronic myeloid leukemia treated with dasatinib.

Simple Summary CYCLON is a nuclear protein, which has been associated with disease progression and treatment resistance in DLBCL, the most common form of aggressive B-cell lymphoma, but also represents a predictive factor of refractory disease and relapse for immuno-chemotherapy-treated DLBCL patients. The molecular mechanisms related to this unstructured protein remain largely uncharacterized. Here, we performed a mass-spectrometry-based identification of the CYCLON protein interactome that suggested it could exert nucleolar functions related to cell proliferation. Among the CYCLON oncogenic network, we performed an immunohistochemical evaluation of the multi-functional nucleolar protein NPM1 in a DLBCL cohort and showed that CYCLON/NPM1 concomitant expression delineates a poor prognosis subgroup of patients. Multivariate survival analyses demonstrated that specific sub-cellular localizations of CYCLON and NPM1 represent independent novel predictors specifically associated with refractory DLBCL. Abstract R-CHOP immuno-chemotherapy significantly improved clinical management of diffuse large B-cell lymphoma (DLBCL). However, 30–40% of DLBCL patients still present a refractory disease or relapse. Most of the prognostic markers identified to date fail to accurately stratify high-risk DLBCL patients. We have previously shown that the nuclear protein CYCLON is associated with DLBCL disease progression and resistance to anti-CD20 immunotherapy in preclinical models. We also recently reported that it also represents a potent predictor of refractory disease and relapse in a retrospective DLBCL cohort. However, only sparse data are available to predict the potential biological role of CYCLON and how it might exert its adverse effects on lymphoma cells. Here, we characterized the protein interaction network of CYCLON, connecting this protein to the nucleolus, RNA processing, MYC signaling and cell cycle progression. Among this network, NPM1, a nucleolar multi-functional protein frequently deregulated in cancer, emerged as another potential target related to treatment resistance in DLBCL. Immunohistochemistry evaluation of CYCLON and NPM1 revealed that their co-expression is strongly related to inferior prognosis in DLBCL. More specifically, alternative sub-cellular localizations of the proteins (extra-nucleolar CYCLON and pan-cellular NPM1) represent independent predictive factors specifically associated to R-CHOP refractory DLBCL patients, which could allow them to be orientated towards risk-adapted or novel targeted therapies.

COVID-19 is caused by the human pathogen severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and has resulted in widespread morbidity and mortality. CD4+ T cells, CD8+ T cells and neutralizing antibodies all contribute to control SARS-CoV-2 infection. However, heterogeneity is a major factor in disease severity and in immune innate and adaptive responses to SARS-CoV-2. We performed a deep analysis by flow cytometry of lymphocyte populations of 125 hospitalized SARS-CoV-2 infected patients on the day of hospital admission. Five clusters of patients were identified using hierarchical classification on the basis of their immunophenotypic profile, with different mortality outcomes. Some characteristics were observed in all the clusters of patients, such as lymphopenia and an elevated level of effector CD8+CCR7- T cells. However, low levels of T cell activation are associated to a better disease outcome; on the other hand, profound CD8+ T-cell lymphopenia, a high level of CD4+ and CD8+ T-cell activation and a high level of CD8+ T-cell senescence are associated with a higher mortality outcome. Furthermore, a cluster of patient was characterized by high B-cell responses with an extremely high level of plasmablasts. Our study points out the prognostic value of lymphocyte parameters such as T-cell activation and senescence and strengthen the interest in treating the patients early in course of the disease with targeted immunomodulatory therapies based on the type of adaptive response of each patient.

International audience; CD30 transmembrane receptor, a member of the tumor necrosis factor receptor family, is expressed in different lymphomas. Brentuximab vedotin (BV), a CD30 monoclonal antibody (Ab)-drug conjugate, is effective in CD30-positive lymphomas. However, the response to BV is not always correlated to CD30 expression detected by immunohistochemistry (IHC). The objectives of this study were to standardize and evaluate CD30 intensity by flow cytometry (FCM) in non-Hodgkin's lymphomas. Twelve centers analyzed 161 cases on standardized cytometers using normalized median fluorescence intensity (nMFI30) of three different Abs, of which one clone can recognize the same epitope as BV. FCM distinguished four groups of cases: negative group (n = 110) which showed no expression with the three clones; high positive group (n = 13) which gave nMFI30 > 5% with all tested clones; dim positive group (n = 17) which showed nMFI30 > 1% with all tested clones and

Background High-grade B-cell lymphoma with rearrangements of MYC and BCL2 and/or BCL6 is an aggressive mature B-cell neoplasm, whereas B-lymphoblastic lymphoma is immature cell proliferation, with a frequent positivity for terminal deoxynucleotidyl transferase. The transformation of a low-grade follicular lymphoma into a lymphoblastic neoplasm expressing terminal deoxynucleotidyl transferase is a very rare event. Case presentation A 55-year-old Caucasian man was followed for a grade 1–2 follicular lymphoma carrying a t(14;18) IGH/BCL2+ and was initially treated with R-CHOP. The follicular lymphoma presented two relapses. In the third relapse, the patient had multiple lymphadenopathy and ascites, which motivated a retroperitoneal biopsy and an ascitic tap. These samples were analyzed by histological, cytological, flow cytometric, cytogenetic, and molecular assessments. The patient died of a multiple organ dysfunction syndrome 2 weeks after his third relapse. The biopsy revealed a diffuse proliferation made up of two types of tumor cells: centroblasts (Bcl-6-positive) and immature cells (terminal deoxynucleotidyl transferase-positive). Flow cytometric analysis confirmed the immature phenotype, with an expression of terminal deoxynucleotidyl transferase, combined with a loss of membrane immunoglobulins. The cytogenetic analysis performed on the ascites revealed a clonal evolution characterized by a t(8;22)(q24;q11) MYC+ translocation not previously detected in follicular lymphoma. Fluorescence in situ hybridization confirmed the double rearrangement of the BCL2 and MYC genes. Polymerase chain reactions and sequencing were used to study the clonal relationship between follicular lymphoma and the secondary tumors. The IGVH gene rearrangement revealed a unique clonal rearrangement involving an IGVH4–59 subset in all three specimens. Conclusion These findings suggest a clonal relationship between the two types of lymphoma cells. Furthermore, they support the transformation of an acute follicular lymphoma into a composite lymphoma combining a high-grade B-cell lymphoma and a lymphoblastic neoplasm expressing terminal deoxynucleotidyl transferase. This case report highlights the possible transformation of follicular lymphoma into a highly aggressive and immature proliferation.

Neoplasms involving plasmacytoid dendritic cells (pDC) include blastic pDC neoplasms (BPDCN) and other pDC proliferations, where pDC are associated with myeloid malignancies: most frequently chronic myelomonocytic leukemia (CMML) but also acute myeloid leukemia (AML), hereafter named pDC-AML. We aimed to determine the reactive or neoplastic origin of pDC in pDC-AML, and their link with the CD34+ blasts, monocytes or conventional DC (cDC) associated in the same sample, by phenotypic and molecular analyses (targeted next-generation sequencing, 70 genes). We compared 15 pDCAML at diagnosis with 21 BPDCN and 11 normal pDC from healthy donors. CD45low CD34+ blasts were found in all cases (10-80% of medullar cells), associated with pDC (4-36%), monocytes in 14 cases (1-10%) and cDC (two cases, 4.8-19%). pDC in pDC-AML harbor a clearly different phenotype from BPDCN: CD4+ CD56– in 100% of cases, most frequently CD303+, CD304+ and CD34+; lower expression of cTCL1 and CD123 with isolated lymphoid markers (CD22/CD7/CD5) in some cases, suggesting a prepDC stage. In all cases, pDC, monocytes and cDC are neoplastic since they harbor the same mutations as CD34+ blasts. RUNX1 is the most commonly mutated gene: detected in all AML with minimal differentiation (M0-AML) but not in the other cases. Despite the low number of cases, the systematic association between M0-AML, RUNX1 mutations and an excess of pDC is puzzling. Further evaluation in a larger cohort is required to confirm RUNX1 mutations in pDC-AML with minimal differentiation and to investigate whether it represents a proliferation of blasts with macrophage and DC progenitor potential.

Background Studies of normal bone marrow (BM) cell composition by flow cytometry are scarce. Presently, we aimed to quantify 14 cell subsets from infants to elderly patients. Methods Cell subsets in BM samples from 180 individuals without morphologically abnormal leukocytes were analyzed using a single combination of eight antibodies: CD3/CD10/CD38/CD19/CD36/CD16/CD34/CD45. Results By comparison with the Holdrinet score, we first validated the immature granulocyte/neutrophil (IGRA/N) ratio as a readily obtainable criterion of BM sample purity in 145 cases. Then, the 115 highly pure samples were selected (IGRA/N ≥ 1.2) and analyzed according to age group. CD34+ myeloblasts became progressively more infrequent with age: median 1.4% in infancy to 0.5% in the elderly. Neutrophils increased: 10.7% to 22.8%; all other myeloid subsets, IGRA, eosinophils, basophils and monocytes remained stable: respectively 40.3% to 46.7%, 2.0% to 2.8%, 0.2% to 0.3%, and 4.4% to 5.0% throughout life. Erythroblasts were lower in children (8.4% to 10.3%) than in adults (12.5% to 15.1%). For lymphoid cells, hematogones and transitional B-cells decreased: 15.5% to 0.6% and 3.6% to 0.1%, respectively; mature lymphocytes remained stable: B-cells: 1.4% to 2.8%, T-cells: 5.8% to 8.7%, and NK-cells: 0.7% to 1.4%. Plasma cells varied slightly: 0.1% to 0.5%. Differences of about 40% were seen in moderately pure (IGRA/N: 0.5 to 1.2) BM samples. Conclusion We thus provide the first values for 14 myeloid and lymphoid subsets characterizing BM cell composition in 5 age ranges. They should provide important information when screening patients for hematological disorders or abnormal bone marrow development. © 2018 International Clinical Cytometry Society.

La proteine S100A8 est deregulee dans de nombreux types de cancer. Dans les leucemies aigues myeloides (LAM), son expression intracellulaire est associee a un pronostic defavorable. Bien qu’elle puisse etre secretee et qu’elle exerce une activite d’alarmine, le role extracellulaire de la proteine S100A8 dans la niche hematopoietique reste meconnu. Nous avons mesure la proteine S100A8 par technique ELISA chez 78 plasmas medullaires, dont 50 LAM. La concentration en S100A8 ([S100A8]) est significativement plus elevee chez les patients atteints de LAM que chez les patients sains ou presentant des etats pre-leucemiques (syndrome myeloproliferatif, syndrome myelodysplasique). Dans les LAM, nous montrons que la [S100A8] est significativement associee a la leucocytose. Fait interessant, la [S100A8] est fortement correlee avec le pourcentage de monocytes mais negativement correlee avec le pourcentage de blastes medullaires. Ce lien entre la [S100A8] et monocytes a ete confirme par la correlation avec le pourcentage de cellules CD36+ CD64+ CD14+ determine par immunophenotypage. De plus, la [S100A8] est plus elevee dans la leucemie aigue monocytaire et myelomonocytaire (LAM4/5) que dans les autres sous-types de FAB. En analyse multivariee, la [S100A8] est principalement exprimee lorsque les blastes exprimaient des marqueurs monocytaires CD11c+, CD4+, CD3- ou CD117-. Pour confirmer l’origine monocytaire de la proteine S100A8, nous avons mesure par cytometrie en flux la proteine S100A8 intracellulaire dans les blastes, les lymphocytes, les PNN, les promonocytes et les monocytes de patients atteints de LAM. Les blastes CD34+ expriment peu de S100A8 intracellulaire. La proteine S100A8 est significativement plus exprimee par les monocytes et les promonocytes, confirmant par une seconde approche l’origine monocytaire de la S100A8 dans les LAM. Pour finir, nous avons etudie l’impact pronostique de la [S100A8] qui semble associee a une diminution de la survie globale dans les LAM4/M5. En conclusion, nos travaux caracterisent la secretion de S100A8 dans les plasmas medullaires et son role dans la leucemogenese.

International audience; Suspicion of myelodysplastic syndromes is one of the commonest reasons for bone marrow aspirate in elderly patients presenting with persistent peripheral blood cytopenia of unclear etiology. A peripheral blood assay that accurately rules out myelodysplastic syndromes would have major benefits. The diagnostic accuracy of the intraindividual robust coefficient of variation for neutrophil myeloperoxidase expression measured by flow cytometric analysis in peripheral blood was evaluated in a retrospective derivation study (44 myelodysplastic syndrome cases and 44 controls) and a prospective validation study (68 consecutive patients with suspected myelodysplastic syndromes). Compared with controls, myelodysplastic syndrome cases had higher median robust coefficient of variation values for neutrophil myeloperoxidase expression (40.2% versus 30.9%, P

International audience; 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 4 (P=0.05) and a hepcidin:ferritin ratio 2000 pg/mL and a hepcidin:ferritin ratio

Flow cytometry is broadly used for the identification, characterization, and monitoring of hematological malignancies. However, the use of clinical flow cytometry is restricted by its lack of reproducibility across multiple centers. Since 2006, the EuroFlow consortium has been developing a standardized procedure detailing the whole process from instrument settings to data analysis. The FranceFlow group was created in 2010 with the intention to educate participating centers in France about the standardized instrument setting protocol (SOP) developed by the EuroFlow consortium and to organise several rounds of quality controls (QCs) in order to evaluate the feasibility of its application and its results. Here, we report the 5 year experience of the FranceFlow group and the results of the seven QCs of 23 instruments, involving up to 19 centers, in France and in Belgium. The FranceFlow group demonstrates that both the distribution and applicability of the SOP have been successful. Intercenter reproducibility was evaluated using both normal and pathological blood samples. Coefficients of variation (CVs) across the centers were

Respiratory tract Candida spp. colonization is associated with more frequent bacterial ventilator-associated pneumonia (VAP). However, this colonization could be causally related to VAP or simply reflect the immune paralysis associated with multiple organ failure. To prospectively evaluate the relationship between Candida spp. colonization and bacterial VAP in mechanically ventilated patients with multiple organ failure. Patients receiving mechanical ventilation for > 4 days and presenting multiple organ failure were included. Tracheal colonization with Candida spp. was evaluated at inclusion (day 0, D0) and every 4 days until extubation. Quantitative proximal and tracheal cultures were performed at each VAP episode. Monocyte human leukocyte antigen-DR isotype (mHLA-DR) expression and the ratio of polymononuclear leukocytes to lymphocytes were used to evaluate immunoparalysis at D0 and D7. The relationship between fungal colonization and VAP was modelled using cause-specific models for repeated events with adjustment for time-dependent confounders and immune factors. A total of 213 patients, with a median age of 64, simplified acute physiology score II (SAPS II) score 55 and sequential organ failure assessment (SOFA) score 10, mainly admitted for medical reasons (n = 197, 92%), were enrolled in 2012–2015. The median ICU stay was 24 days and the mortality rate was 32% (69 cases). Median mHLA-DR was 5916 Ab-bound/cell [3863–8934]; median lymphocyte count, 0.9Giga/L [0.6–1.3]; neutrophil-to-lymphocyte ratio, 10.9 [6.5–19.7]. Overall, 146 cases (68.5%) had tracheal colonization with Candida spp. An episode of VAP occurred (either for the first or only time) in 62 (29.1%) cases 5.5 days (median) after D0; a second episode occurred in 12 (5.6%) cases, 15.5 days (median) after D0. After adjustment, bronchial colonization with Candida was not associated with VAP [adjusted cause-specific hazard ratio = 0.98 (0.59–1.65), p = 0.95]. In patients with mechanical ventilation for more than 4 days and multiple organ failure, bronchial colonization with Candida spp. was not associated with VAP, even after adjustment for immune function.

Background Bone marrow analysis by flow cytometry is part of the routine diagnosis of hematological disorders in medical laboratories. Differential leukocyte count and identification of abnormal cell subsets is currently performed through morphological examination on bone marrow smears by skilled cytologists. In this work, we propose a single 8-color tube for providing equivalent information, using flow cytometry. Methods 99 bone marrow samples were classified into 2 groups, (i) 51 samples, obtained from either healthy donors (n = 4) or patients with various diseases at diagnosis or during remission that did not present a hematological malignancy (n = 47), and (ii) 48 pathological samples with quantitative and/or qualitative abnormalities. A panel of eight antibodies-CD3-FITC/CD10-PE/CD38-PerCP-Cy5.5/CD19-PECy7/CD36-APC/CD16-APC-H7/CD34-BV421/CD45-V500-was tested to identify the main cell subsets at different stages of maturation using a FACSCanto-II analyzer. Results We first proposed a strategy of sequential gating leading to the identification of 14 leukocyte subsets, that is, erythroblasts, monocytes, B-lymphoid cells from hematogones to plasma-cells (5 subsets), T- and NK-cells, polymorphonuclear cells (neutrophils, eosinophils, and basophils), myeloblasts and other immature granular cells. This approach was validated by comparing flow cytometry and microscopic morphological examination, both in cases of normal and abnormal samples. Interestingly, cell identification, and numeration by flow cytometry was easy to perform and highly reproducible. Conclusion A very simple, rapid, and reproducible flow cytometric approach, using a combination of eight antibodies allows determination of the cellular composition of bone marrow with high precision. © 2016 International Clinical Cytometry Society.

A working group initiated within the French Cytometry Association (AFC) was developed in order to harmonize the application of multiparameter flow cytometry (MFC) for myeloid disease diagnosis in France. The protocol presented here was agreed-upon and applied between September 2013 and November 2015 in six French diagnostic laboratories (University Hospitals of Saint-Etienne, Grenoble, Clermont-Ferrand, Nice, and Lille and Institut Paoli-Calmettes in Marseille) and allowed the standardization of bone marrow sample preparation and data acquisition. Three maturation databases were developed for neutrophil, monocytic, and erythroid lineages with bone marrow from "healthy" donor individuals (individuals without any evidence of a hematopoietic disease). A robust method of analysis for each myeloid lineage should be applicable for routine diagnostic use. New cases can be analyzed in the same manner and compared against the usual databases. Thus, quantitative and qualitative phenotypic abnormalities can be identified and those above 2SD compared with data of normal bone marrow samples should be considered indicative of pathology. The major limitation is the higher variability between the data achieved using the monoclonal antibodies obtained with the methods based on hybridoma technologies and currently used in clinical diagnosis. Setting criteria for technical validation of the data acquired may help improve the utility of MFC for MDS diagnostics. The establishment of these criteria requires analysis against a database. The reduction of investigator subjectivity in data analysis is an important advantage of this method.

INTRODUCTION: Erythropoiesis stimulating agents (ESA) are generally the first line of treatment of anaemia in lower risk myelodysplastic syndrome (MDS) patients. We prospectively investigated the predictive value of somatic mutations, and biomarkers of ineffective erythropoiesis including flow cytometry RED score, serum GDF-15, and hepcidin levels. METHODS: Inclusion criteria were: ESA naive, IPSS low or intermediate-1 MDS with Hemoglobin (Hb) level< 10g/dL. Patients received epoetin zeta 40 000 IU/week and erythroid response (HI-E, IWG 2006 criteria) was assessed at W12. sEPO level, iron parameters and hepcidin, flow cytometry (FC) Ogata and Red Score (RS), GDF-15, and molecular analysis by NGS were determined at baseline. RESULTS: 70 patients were included. Median age was 78 years. There were 22 RCMD, 19 RCUD, 14 RARS, 4 RAEB-1, 6 CMML, 2 del 5q-, 3 unclassifiable, R-IPSS was 13 very low, 47 low, 9 intermediate and high. Twenty patients were transfusion-dependent. HI-E was 48% and median duration of response was 26 months. At baseline, non-responders had significantly higher FC Red Score, lower hepcidin/ferritin ratio, lower IPSS. In multivariate analysis, only RS>4 at T0 (p=0.05) and hepcidin/ferritin 2000 pg/ml and hepcidin/ferritin

Background Minimal residual disease (MRD) assessment provides a powerful prognostic factor for therapeutic stratification in acute lymphoblastic leukemia (ALL). Multiparameter flow cytometry (MFC) has the potential for a rapid and sensitive identification of high risk patients. Our group has previously published that MRD levels analyzed by clone specific Ig/TcR-QPCR and MFC were concordant at a sensitivity of 10−4. Here we report the MFC methodological aspects from this multi-center experience. Methods MRD was assessed by MFC in 1030 follow-up samples from 265 pediatric and adult patients with de novo ALL treated in the FRALLE, EORTC, or GRALL clinical trials. MRD assessment as applied by the eight participating MFC laboratories is described in detail regarding cell preparation, leukemia-associated immunophenotype (LAIP) markers and data analysis. Samples were obtained from bone marrow (BM) and peripheral blood (PB). Immunostaining was performed after erythrocyte lysis or Ficoll enrichment. Results This study confirms the applicability of MFC-based MRD assessment in 97% of patients with ALL at the 10−4 cut-off. MRD values after Ficoll enrichment and erythrocyte lysis were found comparable. Higher MRD values were obtained in BM than in PB, especially for B-lineage ALL. Conclusions Measurement of MRD by MFC at the 10−4 cut-off is applicable within a few hours for almost all patients and using a comparable analytical strategy allows for multicenter collaborative studies. The method can be introduced in a strategy aimed at defining the risk of failure of patients with childhood or adult ALL. © 2014 International Clinical Cytometry Society

Introduction: Since the publication of the International Guidelines (Borowitz, 2010; Illingworth, 2018), no study has assessed the long-term evolution of paroxysmal nocturnal hemoglobinuria (PNH) clones using high-resolution flow cytometry. The sole evaluation, performed by Sugimori et al, using a 2-color flow cytometry test, showed the disappearance of PNH clones in 24% of patients with bone marrow (BM) failure over 5 years (Sugimori, 2009). A diagnostic practice harmonization using high-resolution flow cytometry has spread in France since 2013 through an on-going inter-laboratory comparison program (Debliquis, 2015). Thus, our HPNAFC group has been able to initiate a French nation-wide multicenter prospective observational study. Objective: We aimed to assess the evolution of PNH clones over a long term period using mostly high sensitivity test, which is required for minor clone assessment, with validated flow cytometry data. Methods: All patients of any age with a PNH clone or GPI-deficient cells ≥0.01%, newly- or previously-diagnosed, detected in France from February 29th 2016, could be included in this Observatory, provided that the center had validated a PNH flow cytometry quality control. For each patient, the baseline assessment was always considered as the initial PNH clone detection, even if it occurred before the initiation of the Observatory. Thus, this strategy allowed the collection of cases with long-term follow-up. Referent cytometrist of each center included patients in the e-CRF available on the HPNAFC website providing clinical and biological information as well as flow cytometry raw data files. This study was approved by the national research ethics board. Results: As of July 15th 2019, 48 participating flow cytometry laboratories across France have enrolled 356 patients with a PNH clone or GPI-deficient cells ≥ 0.01%. All cases have been carefully reviewed by the 2 principal investigators, who both thoroughly re-examined flow cytometry data and the e-CRF filling that led to the update of roughly one third of the submitted files. This enabled the validation of 200 patients at diagnosis, the remaining 156 being ongoing. One hundred and three of the 200 validated patients displayed at least one follow-up point (more than 3 months apart from the diagnosis) with a clone size determined at diagnosis (see flow chart figure 1A). For 8/103 patients, exchanges with centers are still ongoing. Thus, we were able to assess the evolution of PNH clones of 95 patients with 2 [range: 1-8] follow-up points over a period of 4.1 [0.3-14.2] years, corresponding to 200 validated follow-up points. The patient median age at diagnosis was 40 years old [10-85] with 3 pediatric cases ( Conclusion: This multicenter study based on robust flow cytometry analysis showed no disappearance of PNH clones, including minor ones, over a long period of time, regardless of the clinical manifestations, except for patients who underwent BM transplantation. Moreover, PNH clone size increased in half of patients with BM failure, justifying a long term PNH clone size monitoring, even in these patients. Figure 1 Disclosures Le Garff-Tavernier: Alexion: Consultancy, Honoraria. Pruvot Debliquis:Alexion: Honoraria; Takeda: Honoraria; Pfizer: Honoraria; Gilead: Honoraria; Genzyme: Honoraria. Socie:Alexion: Consultancy. Peffault de Latour:Alexion: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Amgen: Research Funding. Drenou:Alexion: Consultancy, Honoraria. Wagner Ballon:Alexion: Consultancy, Honoraria.

Conversion to belatacept immunosuppression is a therapeutic option for renal-transplant recipients with calcineurin inhibitors (CNI) toxicity, but it associates with high risk of acute rejection. Gradual conversion and serial immune monitoring with urinary chemokine CXCL9 may allow increasing safety of this maneuver. We converted kidney transplant recipients with signs of toxicity to CNI or other immunosuppressive drugs to belatacept over a 2-month period. We monitored renal function, metabolic profile, and circulating lymphocyte subsets. We also quantified urinary CXCL9 over a 12-month follow-up period. Between September 2016 and March 2017, 35 patients were successfully switched to belatacept immunosuppression at 3.3 (1.3-7.2) years after transplant. Two patients had a reversible rise in serum creatinine, associated with acute rejection in one case. Urinary CXCL9 increased before serum creatinine. After conversion, blood pressure and HbA1c significantly declined while eGFR and proteinuria remained stable. The percentage of circulating effector T cells and memory B cells significantly declined. Conversion from CNI to belatacept, in this setting, was feasible and safe, provided it was performed over a 2-month time-period. Monitoring urinary CXCL9 may further increase safety through earlier identification of patients at risk for acute rejection. The procedure associates with improved blood pressure, metabolic profile, and reduced circulating effector T and B cells.

International audience; Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and highly aggressiveleukemia for which knowledge on disease mechanisms and effective therapies are currentlylacking. Only a handful of recurring genetic mutations have been identified and none isspecific to BPDCN. In this study, through molecular cloning in an index case that presenteda balanced t(3;5)(q21;q31) and molecular cytogenetic analyses in a further 46 cases, weidentify monoallelic deletion of NR3C1 (5q31), encoding the glucocorticoid receptor (GCR),in 13 of 47 (28%) BPDCN patients. Targeted deep sequencing in 36 BPDCN cases, including10 with NR3C1 deletion, did not reveal NR3C1 point mutations or indels. Haploinsufficiencyfor NR3C1 defined a subset of BPDCN with lowered GCR expression and extremely pooroverall survival (P 5 .0006). Consistent with a role for GCR in tumor suppression, functionalanalyses coupled with gene expression profiling identified corticoresistance and loss-ofEZH2 function as major downstream consequences of NR3C1 deletion in BPDCN.Subsequently, more detailed analyses of the t(3;5)(q21;q31) revealed fusion of NR3C1 to along noncoding RNA (lncRNA) gene (lincRNA-3q) that encodes a novel, nuclear, noncodingRNA involved in the regulation of leukemia stem cell programs and G1/S transition, via E2F.Overexpression oflincRNA-3qwas a consistent feature ofmalignant cells and could be abrogated by bromodomain and extraterminal domain(BET) protein inhibition. Taken together, this work points to NR3C1 as a haploinsufficient tumor suppressor in a subset of BPDCN andidentifies BET inhibition, acting at least partially via lncRNA blockade, as a novel treatment option in BPDCN. (

A precise identification and phenotypic characterization of human B-cell subsets is of crucial importance in both basic research and medicine. In the literature, flow cytometry studies for the phenotypic characterization of B-lymphocytes are mainly focused on the description of a particular cell stage, or of specific cell stages observed in a single type of sample. In the present work, we propose a backbone of 6 antibodies (CD38, CD27, CD10, CD19, CD5 and CD45) and an efficient gating strategy to identify, in a single analysis tube, a large number of B-cell subsets covering the whole B-cell differentiation from precursors to memory and plasma cells. Furthermore, by adding two antibodies in an 8-color combination, our approach allows the analysis of the modulation of any cell surface marker of interest along B-cell differentiation. We thus developed a panel of seven 8-colour antibody combinations to phenotypically characterize B-cell subpopulations in bone marrow, peripheral blood, lymph node and cord blood samples. Beyond qualitative information provided by biparametric representations, we also quantified antigen expression on each of the identified B-cell subsets and we proposed a series of informative curves showing the modulation of seventeen cell surface markers along B-cell differentiation. Our approach by flow cytometry provides an efficient tool to obtain quantitative data on B-cell surface markers expression with a relative easy-to-handle technique that can be applied in routine explorations.

Introduction The CD30 antigen is expressed by a small number of cells in classical Hodgkin lymphoma (HL), by malignant cells in anaplastic large cell lymphoma (ALCL), and in several non-Hodgkin lymphomas (NHL). Brentuximab vedotin (BV), an anti-CD30 monoclonal antibody (Ab) conjugated to chemotherapy, showed its efficacy in HL and ALCL. However, a correlation between response to BV and CD30 expression in NHL is difficult to establish by immunohistochemistry (IHC) since the count of dimly positive cells is difficult to standardize. Flow cytometry (FCM) is a standardizable tool which allows the multiparametric characterization of malignant NHL cells and the quantification of proteins at the cell surface. The objective of this multicentric study is to standardize CD30 expression in NHL by quantitative FCM. Materiel and methods The nine centers used one or two cytometers: BD Biosciences (BD) n=7, Beckman Coulter (BC) n=4. The standardization was conducted using the Euroflow strategy, the same operating procedure and the same reagents. Abs recognizing different CD30 epitopes were: BerH83 (BD), HRS4 (BC) and a specific AC10 (Ancell) similar to BV. If tissue was available, pathologists locally used BerH2 (Dako) for IHC. The CD30 expression was normalized using Mean Fluorescence Intensity (MFI) to MFI CD4 expression and expressed as a percentage (nMFI30). Three cell lines (SUDHL4, K562 and L82) with differential expression of CD30 were shipped to the different laboratories in order to validate the centers using a robust statistical method. Then, NHL cases including anaplastic lymphomas, T lymphomas, and large B cell lymphomas were collected using a website www.mfi30.fr. All FCM Abs were used on available cells when nMFI30 >1% using Ancell Ab. Results On cell lines, all centers obtained similar results: z-scores between -2 to +2. Mean of nMFI30 were SUDHL4 0.1% (SD=0.1), K562 69.8% (SD=16.9), L82 292.9% (SD= 45.7) with BD Abs and 0.6% (SD=0.1), 229.9% (SD= 47.9) and 2053.8 (SD= 282) with BC Abs , respectively, demonstrating that BD and BC Abs are not equivalent. Samples from 82 adult patients were included in the study: peripheral blood (n=39), lymph node suspensions (n=21), bone marrow (n=5) or different tissues (n=17, cerebrospinal, seroma, pleural and ascite fluid, spleen). The diagnoses included diffuse large B-cell lymphoma (DLCBL, n=33 with 4 DLBCL of central nervous system (CNS)), Sezary syndrome (SS, n=14), peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS, n=11), T-cell prolymphocytic leukaemia (T-PLL, n=8), enteropathy-associated T-cell lymphoma (EATL-1, n=2), angio-immunoblastic lymphoma (AITL, n=5), primary effusion lymphoma (PEL, n=1), plasmablastic lymphoma (PBL, n=1), B-lymphoblastic lymphoma (B-LBL, n=1), breast implant associated anaplastic large cell lymphoma (BIA-ALCL, n=1), anaplastic large cell lymphoma (ALCL, n=1), mantle cell lymphoma (n=1), T-cell large granular lymphocyte leukemia (T-LGLL, n=2) and chronic lymphoproliferative disorders of NK cells (CLPD-NK, n=1). Four groups are defined: (1) a negative group (n=60) presents nMFI30 10% with the 3 FCM Abs and positive in IHC (2 ALCL, 1 DLBCL, 1 EATL). This group shows a more intense nMFI30 with BC Ab; (3) a dim positive group (n=8) presents nMFI30 between 1-10% with the 3 FCM Abs. In this group, IHC is negative in 2 out of the 3 tested cases; (4) a discordant group (n=10) presents nMFI30 >1% with at least 1 Ab and discordant with another one. In this group, 8 IHC were tested: 2 IHC positive 1% with Ancell Ab and 1 case shows a high discrepancy between 2 FCM Abs. Regarding lymphoma entities, T-PLL, DLBCL-CNS, and T-LGLL are always negative and the ALCL are positive. Seven out of the 33 DLBCL are in the positive or discordant groups (21%). Conclusion As previously reported in literature using IHC, CD30 is positive in all ALCL, in some DLCBL (20%) and only rarely in other NHL using FCM. Therefore these first results emphasize the feasibility of FCM in CD30 determination and quantification in NHL subtypes and mainly its multicentric standardization. The inclusion of FCM with relevant Abs in clinical trials using BV should be now validated in larger series to better understand clinical results. Figure. Figure. Disclosures Pruvot Debliquis: Alexion: Consultancy, Honoraria; Takeda Oncology: Honoraria. Baseggio:Takeda Oncology: Honoraria. Jacob:Takeda Oncology: Honoraria. Drenou:Takeda Oncology: Honoraria, Research Funding; Alexion: Consultancy, Honoraria.

Adoptive transfer of specific cytotoxic T lymphocytes (CTL) and Cytokine Induced Killer Cells (CIK) following genetic engineering of T-cell receptor zeta hold promising perspective in immunotherapy. In the present work we focused on the mechanisms of anti-tumor action of effectors transduced with an anti-CD19 chimaeric receptor in the context of B-lineage acute lymphoblastic leukemia (B-ALL). Primary B-ALL blasts were efficiently killed by both z-CD19 CTL and z-CD19 CIK effectors. The use of death receptor mediated apoptosis of target cells was excluded since agonists molecules of Fas and TRAIL-receptors failed to induce cell death. Perforin/granzyme pathway was found to be the mechanism of chimaeric effectors mediated killing. Indeed, cytolytic effector molecules perforin as well as granzymes were highly expressed by CTL and CIK. CD19 specific stimulation of transduced effectors was associated with degranulation as attested by CD107 membrane expression and high IFN- and TNF- release. Moreover inhibitors of the perforin-based cytotoxic pathway, Ca 2+-chelating agent EGTA and Concanamycin A, almost completely abrogated B-ALL blast killing. In conclusion we show that the cytolysis response of z-CD19 chimaeric effectors is predominantly mediated via perforin/granzyme pathway and is independent of death receptors signaling in primary B-ALL. Copyright © 2010 David Laurin et al.

Analysis of the T-cell receptor (TCR) repertoire by flow cytometry proved to be relevant for investigating T-cell diversity and detecting reactive cells in blood samples. We used this approach to characterize non-malignant T-lymphocytes in lymph nodes and give insights into their origin. The TCR repertoire of CD4+ and CD8+ T-cells from 81 lymph nodes was analyzed with a four-color flow cytometer using a wide panel of 25 anti-Vbeta monoclonal antibodies. Flow cytometry proved to be a useful and informative technique. We demonstrated a diversified TCR-Vbeta repertoire, and only low level expansions, in 53% of the samples. They involved nearly all Vbeta families, were more frequent in the CD8+ subset of older patients, but were not related to pathology. No evidence could be demonstrated in favor of stimulation by common antigens. Interestingly, the TCR-Vbeta repertoire proved to be very similar in lymph nodes and blood samples. Our results argue that in the cases studied, lymph node enlargement is mainly due to an increased homing of circulating T-cells. They also provide reference values for expression of 25 TCR-Vbeta in lymph nodes, which could serve as a basis for further applications in diagnosis of T-cell lymphoproliferative disorders.

We investigated the possibility that T cells observed in lymph nodes involved by B-non-Hodgkin's lymphomas (B-NHL) may have a direct role in the expression of Mu- or Gamma- heavy chain isotype by autologous malignant B cells. T cells were separated from lymph nodes involved by B-NHL cells expressing either surface IgM (19 cases) or surface IgG (4 cases) and compared to peripheral blood T lymphocytes of healthy subjects (19 cases) for their ability to promote both IgG and IgM secretion in Cowan-activated normal B lymphocytes. The mean values of IgG/IgM ratios obtained under the influence of T cells associated with malignant B cells expressing either surface IgM or surface IgG were not statistically different to that obtained with the help of control T cells (0.60 and 0.62 versus 0.47, respectively). These results do not account for the hypothesis that autologous lymph node T cells may directly affect the expression of the heavy chain isotype by malignant B-NHL cells.