Expression of CD33 is a predictive factor for effect of gemtuzumab ozogamicin at different doses in adult acute myeloid leukaemia

It remains unclear in adult acute myeloid leukaemia (AML) whether leukaemic expression of CD33, the target antigen for gemtuzumab ozogamicin (GO), adds prognostic information on GO effectiveness at different doses. CD33 expression quantified in 1583 patients recruited to UK-NCRI-AML17 (younger adults) and UK-NCRI-AML16 (older adults) trials was correlated with clinical outcomes and benefit from GO including a dose randomisation. CD33 expression associated with genetic subgroups, including lower levels in both adverse karyotype and core-binding factor (CBF)-AML, but was not independently prognostic. When comparing GO versus no GO (n=393, CBF-AMLs excluded) by stratified subgroup-adjusted analysis, patients with lowest quartile (Q1) Í33-positivity had no benefit from GO (relapse risk, HR 2.41 (1.27–4.56), P=0.009 for trend; overall survival, HR 1.52 (0.92–2.52)). However, from the dose randomisation (NCRI-AML17, n=464, CBF-AMLs included), 6 mg/m2 GO only had a relapse benefit without increased early mortality in CD33-low (Q1) patients (relapse risk HR 0.64 (0.36–1.12) versus 1.70 (0.99–2.92) for CD33-high, P=0.007 for trend). Thus CD33 expression is a predictive factor for GO effect in adult AML; although GO does not appear to benefit the non-CBF AML patients with lowest CD33 expression a higher GO dose may be more effective for CD33-low but not CD33-high younger adults

Dynamics of the Galactic Bulge using Planetary Nebulae

Evidence for a bar at the center of the Milky Way triggered a renewed enthusiasm for dynamical modelling of the Galactic bar-bulge. Our goal is to compare the kinematics of a sample of tracers, planetary nebulae, widely distributed over the bulge with the corresponding kinematics for a range of models of the inner Galaxy. Three of these models are N-body barred systems arising from the instabilities of a stellar disk (Sellwood, Fux and Kalnajs), and one is a Schwarzschild system constructed to represent the 3D distribution of the COBE/DIRBE near-IR light and then evolved as an N-body system for a few dynamical times (Zhao). For the comparison of our data with the models, we use a new technique developed by Saha (1998). The procedure finds the parameters of each model, i.e. the solar galactocentric distance R_o in model units, the orientation angle phi, the velocity scale (in km/s per model unit), and the solar tangential velocity which best fit the data.Comment: 48 pages (Latex), 30 figures (PS), accepted for pub. in A

Applicability and reproducibility of acute myeloid leukaemia stem cell assessment in a multi-centre setting

Leukaemic stem cells (LSC) have been experimentally defined as the leukaemia-propagating population and are thought to be the cellular reservoir of relapse in acute myeloid leukaemia (AML). Therefore, LSC measurements are warranted to facilitate accurate risk stratification. Previously, we published the composition of a one-tube flow cytometric assay, characterised by the presence of 13 important membrane markers for LSC detection

A Novel Role for PECAM-1 (CD31) in Regulating Haematopoietic Progenitor Cell Compartmentalization between the Peripheral Blood and Bone Marrow

Abstract Although the expression of PECAM-1 (CD31) on vascular and haematopoietic cells within the bone marrow microenvironment has been recognized for some time, its physiological role within this niche remains unexplored. In this study we show that PECAM-1 influences steady state hematopoietic stem cell (HSC) progenitor numbers in the peripheral blood but not the bone marrow compartment. PECAM-1 2/2 mice have higher levels of HSC progenitors in the blood compared to their littermate controls. We show that PECAM-1 is required on both progenitors and bone marrow vascular cells in order for efficient transition between the blood and bone marrow to occur. We have identified key roles for PECAM-1 in both the regulation of HSC migration to the chemokine CXCL12, as well as maintaining levels of the matrix degrading enzyme MMP-9 in the bone marrow vascular niche. Using intravital microscopy and adoptive transfer of either wild type (WT) or PECAM-1 2/2 bone marrow precursors, we demonstrate that the increase in HSC progenitors in the blood is due in part to a reduced ability to migrate from blood to the bone marrow vascular niche. These findings suggest a novel role for PECAM-1 as a regulator of resting homeostatic progenitor cell numbers in the bloo

Measurable residual disease at induction redefines partial response in acute myeloid leukemia and stratifies outcomes in patients at standard risk without NPM1 mutations

Purpose: We investigated the effect on outcome of measurable or minimal residual disease (MRD) status after each induction course to evaluate the extent of its predictive value for acute myeloid leukemia (AML) risk groups, including NPM1 wild-type (wt) standard risk, when incorporated with other induction response criteria.Methods: As part of the NCRI AML17 trial, 2,450 younger adult patients with AML or high-risk myelodysplastic syndrome had prospective multiparameter flow cytometric MRD (MFC-MRD) assessment. After course 1 (C1), responses were categorized as resistant disease (RD), partial remission (PR), and complete remission (CR) or complete remission with absolute neutrophil count , 1,000/mL or thrombocytopenia , 100,000/mL (CRi) by clinicians, with CR/CRi subdivided by MFC-MRD assay into MRD+ and MRD2. Patients without high-risk factors, including Flt3 internal tandem duplication wt/2NPM1-wt subgroup, received a second daunorubicin/cytosine arabinoside induction; course 2 (C2) was intensified for patients with high-risk factors.Results: Survival outcomes from PR and MRD+ responses after C1 were similar, particularly for good- to standard-risk subgroups (5-year overall survival [OS], 27% RD v 46% PR v 51% MRD+ v 70% MRD2; P , .001). Adjusted analyses confirmed significant OS differences between C1 RD versus PR/MRD+ but not PR versus MRD+. CRi after C1 reduced OS in MRD+ (19% CRi v 45% CR; P = .001) patients, with a smaller effect after C2. The prognostic effect of C2 MFC-MRD status (relapse: hazard ratio [HR], 1.88 [95% CI, 1.50 to 2.36], P , .001; survival: HR, 1.77 [95% CI, 1.41 to 2.22], P , .001) remained significant when adjusting for C1 response. MRD positivity appeared less discriminatory in poor-risk patients by stratified analyses. For the NPM1-wt standard-risk subgroup, C2 MRD+ was significantly associated with poorer outcomes (OS, 33% v 63% MRD2, P = .003;relapse incidence, 89% when MRD+ $ 0.1%); transplant benefit was more apparent in patients with MRD+ (HR, 0.72; 95% CI, 0.31 to 1.69) than those with MRD2 (HR, 1.68 [95% CI, 0.75 to 3.85]; P = .16 for interaction).Conclusion: MFC-MRD can improve outcome stratification by extending the definition of partial response after first induction and may help predict NPM1-wt standard-risk patients with poor outcome who benefit from transplant in the first CR

A Novel Role for PECAM-1 (CD31) in Regulating Haematopoietic Progenitor Cell Compartmentalization between the Peripheral Blood and Bone Marrow

Although the expression of PECAM-1 (CD31) on vascular and haematopoietic cells within the bone marrow microenvironment has been recognized for some time, its physiological role within this niche remains unexplored. In this study we show that PECAM-1 influences steady state hematopoietic stem cell (HSC) progenitor numbers in the peripheral blood but not the bone marrow compartment. PECAM-1−/− mice have higher levels of HSC progenitors in the blood compared to their littermate controls. We show that PECAM-1 is required on both progenitors and bone marrow vascular cells in order for efficient transition between the blood and bone marrow to occur. We have identified key roles for PECAM-1 in both the regulation of HSC migration to the chemokine CXCL12, as well as maintaining levels of the matrix degrading enzyme MMP-9 in the bone marrow vascular niche. Using intravital microscopy and adoptive transfer of either wild type (WT) or PECAM-1−/− bone marrow precursors, we demonstrate that the increase in HSC progenitors in the blood is due in part to a reduced ability to migrate from blood to the bone marrow vascular niche. These findings suggest a novel role for PECAM-1 as a regulator of resting homeostatic progenitor cell numbers in the bloo

A randomised comparison of CPX-351 and FLAG-Ida in adverse karyotype AML and high-risk MDS: the UK NCRI AML19 trial

Liposomal daunorubicin and cytarabine (CPX-351) improves overall survival (OS) compared to 7+3 chemotherapy in older patients with secondary acute myeloid leukaemia (AML); to date there have been no randomized studies in younger patients. The high-risk cohort of the UK NCRI AML19 trial (ISRCTN78449203) compared CPX-351 with FLAG-Ida in younger adults with newly-diagnosed adverse cytogenetic AML or high-risk myelodysplastic syndromes (MDS). 189 patients were randomized (median age 56y). By clinical criteria 49% had de novo AML, 20% secondary AML and 30% high risk MDS. MDS-related cytogenetics were present in 73% of patients, with complex karyotype in 49%. TP53 was the most commonly mutated gene, in 43%. Myelodysplasia-related gene mutations were present in 75 patients (44%). The overall response rate (CR + CRi) after course two was 64% and 76% for CPX-351 and FLAG-Ida (OR:0.54, 95%CI 0.28-1.04, p=0.06). There was no difference in OS (13.3 months vs 11.4 months, HR:0.78, 95%CI 0.55-1.12, p=0.17) or event-free survival (HR:0.90, 95%CI 0.64-1.27, p=0.55) in multivariable analyses. However, relapse-free survival was significantly longer with CPX-351 (median 22.1 vs 8.35 months, HR:0.58, 95% CI 0.36-0.95, p=0.03). There was no difference between the treatment arms in patients with clinically defined secondary AML (HR:1.1, 95%CI 0.52-2.30) or those with MDS-related cytogenetic abnormalities (HR:0.94, 95%CI 0.63-1.40), however an exploratory sub-group of patients with MDS-related gene mutations had significantly longer OS with CPX-351 (median 38.4 vs 16.3 months, HR:0.42, 95%CI 0.21-0.84, heterogeneity p=0.05). In conclusion, OS in younger patients with adverse risk AML/MDS was not significantly different between CPX-351 and FLAG-Ida

Comprehensive genetic dissection of wood properties in a widely-grown tropical tree: Eucalyptus

Background: Eucalyptus is an important genus in industrial plantations throughout the world and is grown for use as timber, pulp, paper and charcoal. Several breeding programmes have been launched worldwide to concomitantly improve growth performance and wood properties (WPs). In this study, an interspecific cross between Eucalyptus urophylla and E. grandis was used to identify major genomic regions (Quantitative Trait Loci, QTL) controlling the variability of WPs. Results: Linkage maps were generated for both parent species. A total of 117 QTLs were detected for a series of wood and end-use related traits, including chemical, technological, physical, mechanical and anatomical properties. The QTLs were mainly clustered into five linkage groups. In terms of distribution of QTL effects, our result agrees with the typical L-shape reported in most QTL studies, i.e. most WP QTLs had limited effects and only a few (13) had major effects (phenotypic variance explained > 15%). The co-locations of QTLs for different WPs as well as QTLs and candidate genes are discussed in terms of phenotypic correlations between traits, and of the function of the candidate genes. The major wood property QTL harbours a gene encoding a Cinnamoyl CoA reductase (CCR), a structural enzyme of the monolignol-specific biosynthesis pathway. Conclusions: Given the number of traits analysed, this study provides a comprehensive understanding of the genetic architecture of wood properties in this Eucalyptus full-sib pedigree. At the dawn of Eucalyptus genome sequence, it will provide a framework to identify the nature of genes underlying these important quantitative traits. (Résumé d'auteur

Search for massive resonances in dijet systems containing jets tagged as W or Z boson decays in pp collisions at √s=8 TeV

Peer reviewe

CMS physics technical design report : Addendum on high density QCD with heavy ions

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