| 1. |
- Arribas, AJ, et al.
(author)
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Genome-wide promoter methylation of hairy cell leukemia
- 2019
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In: Blood advances. - : American Society of Hematology. - 2473-9537 .- 2473-9529. ; 3:3, s. 384-396
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Journal article (peer-reviewed)abstract
- Classic hairy cell leukemia (HCL) is a tumor of mature clonal B cells with unique genetic, morphologic, and phenotypic features. DNA methylation profiling has provided a new tier of investigation to gain insight into the origin and behavior of B-cell malignancies; however, the methylation profile of HCL has not been specifically investigated. DNA methylation profiling was analyzed with the Infinium HumanMethylation27 array in 41 mature B-cell tumors, including 11 HCL, 7 splenic marginal zone lymphomas (SMZLs), and chronic lymphocytic leukemia with an unmutated (n = 7) or mutated (n = 6) immunoglobulin gene heavy chain variable (IGHV) region or using IGHV3-21 (n = 10). Methylation profiles of nontumor B-cell subsets and gene expression profiling data were obtained from public databases. HCL had a methylation signature distinct from each B-cell tumor entity, including the closest entity, SMZL. Comparison with normal B-cell subsets revealed the strongest similarity with postgerminal center (GC) B cells and a clear separation from pre-GC and GC cellular programs. Comparison of the integrated analysis with post-GC B cells revealed significant hypomethylation and overexpression of BCR–TLR–NF-κB and BRAF-MAPK signaling pathways and cell adhesion, as well as hypermethylation and underexpression of cell-differentiation markers and methylated genes in cancer, suggesting regulation of the transformed hairy cells through specific components of the B-cell receptor and the BRAF signaling pathways. Our data identify a specific methylation profile of HCL, which may help to distinguish it from other mature B-cell tumors.
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| 2. |
- Arruda, Lucas C. M., et al.
(author)
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Impact of gamma delta T cells on clinical outcome of hematopoietic stem cell transplantation : systematic review and meta-analysis
- 2019
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In: Blood Advances. - : American Society of Hematology. - 2473-9529 .- 2473-9537. ; 3:21, s. 3436-3448
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Research review (peer-reviewed)abstract
- Allogeneic hematopoietic stem cell transplantation (HSCT) using alpha beta T-/B-cell-depleted grafts recently emerged as a transplant strategy and highlighted the potential role of gamma delta T cells on HSCT outcomes. Our aim was to scrutinize available evidence of gamma delta T-cell impact on relapse, infections, survival, and acute graft-versus-host disease (aGVHD). We performed a systematic review and meta-analysis of studies assessing gamma delta T cells in HSCT. We searched PubMed, Web of Science, Scopus, and conference abstracts from inception to March 2019 for relevant studies. We included all studies that assessed gamma delta T cells associated with HSCT. Data were extracted independently by 2 investigators based on strict selection criteria. A random-effects model was used to pool outcomes across studies. Primary outcome was disease relapse. We also assessed infections, survival, and aGVHD incidence. The review was registered with PROSPERO (CRD42019133344). Our search returned 2412 studies, of which 11 (919 patients) were eligible for meta-analysis. Median follow-up was 30 months (interquartile range, 22-32). High gamma delta T-cell values after HSCT were associated with less disease relapse (risk ratio [RR], 0.58; 95% confidence interval [95% CI], 0.40-0.84; P = .004; I-2 = 0%), fewer viral infections (RR, 0.59; 95% CI, 0.43-0.82; P < .002; I-2 = 0%) and higher overall (HR, 0.28; 95% CI, 0.18-0.44; P < .00001; I-2 = 0%) and disease-free survivals (HR 0.29; 95% CI, 0.18-0.48; P < .00001; I-2 = 0%). We found no association between high gd T-cell values and aGVHD incidence (RR, 0.72; 95% CI, 0.41-1.27; P = .26; I-2 = 0%). In conclusion, high gd T cells after HSCT is associated with a favorable clinical outcome but not with aGVHD development, suggesting that gd T cells have a significant effect on the success of HSCT. This study was registered with PROSPERO as #CRD42019133344.
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| 3. |
- Asimomitis, G, et al.
(author)
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Patient-specific MDS-RS iPSCs define the mis-spliced transcript repertoire and chromatin landscape of SF3B1-mutant HSPCs
- 2022
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In: Blood advances. - : American Society of Hematology. - 2473-9537 .- 2473-9529. ; 6:10, s. 2992-3005
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Journal article (peer-reviewed)abstract
- SF3B1K700E is the most frequent mutation in myelodysplastic syndrome (MDS), but the mechanisms by which it drives MDS pathogenesis remain unclear. We derived a panel of 18 genetically matched SF3B1K700E- and SF3B1WT-induced pluripotent stem cell (iPSC) lines from patients with MDS with ring sideroblasts (MDS-RS) harboring isolated SF3B1K700E mutations and performed RNA and ATAC sequencing in purified CD34+/CD45+ hematopoietic stem/progenitor cells (HSPCs) derived from them. We developed a novel computational framework integrating splicing with transcript usage and gene expression analyses and derived a SF3B1K700E splicing signature consisting of 59 splicing events linked to 34 genes, which associates with the SF3B1 mutational status of primary MDS patient cells. The chromatin landscape of SF3B1K700E HSPCs showed increased priming toward the megakaryocyte- erythroid lineage. Transcription factor motifs enriched in chromatin regions more accessible in SF3B1K700E cells included, unexpectedly, motifs of the TEA domain (TEAD) transcription factor family. TEAD expression and transcriptional activity were upregulated in SF3B1-mutant iPSC-HSPCs, in support of a Hippo pathway-independent role of TEAD as a potential novel transcriptional regulator of SF3B1K700E cells. This study provides a comprehensive characterization of the transcriptional and chromatin landscape of SF3B1K700E HSPCs and nominates novel mis-spliced genes and transcriptional programs with putative roles in MDS-RS disease biology.
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| 4. |
- Asquith, Nathan L., et al.
(author)
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Fibrin protofibril packing and clot stability are enhanced by extended knob-hole interactions and catch-slip bonds
- 2022
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In: Blood Advances. - : American Society of Hematology. - 2473-9529 .- 2473-9537. ; 6:13, s. 4015-4027
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Journal article (peer-reviewed)abstract
- Fibrin polymerization involves thrombin-mediated exposure of knobs on one monomer that bind to holes available on another, leading to the formation of fibers. In silico evidence has suggested that the classical A:a knob-hole interaction is enhanced by surrounding residues not directly involved in the binding pocket of hole a, via noncovalent interactions with knob A. We assessed the importance of extended knob-hole interactions by performing biochemical, biophysical, and in silico modeling studies on recombinant human fibrinogen variants with mutations at residues responsible for the extended interactions. Three single fibrinogen variants, yD297N, yE323Q, and yK356Q, and a triple variant yDEK (yD297N/yE323Q/yK356Q) were produced in a CHO (Chinese Hamster Ovary) cell expression system. Longitudinal protofibril growth probed by atomic force microscopy was disrupted for yD297N and enhanced for the yK356Q mutation. Initial polymerization rates were reduced for all variants in turbidimetric studies. Laser scanning confocal microscopy showed that yDEK and yE323Q produced denser clots, whereas yD297N and yK356Q were similar to wild type. Scanning electron microscopy and light scattering studies showed that fiber thickness and protofibril packing of the fibers were reduced for all variants. Clot viscoelastic analysis showed that only yDEK was more readily deformable. In silico modeling suggested that most variants displayed only slip-bond dissociation kinetics compared with biphasic catch-slip kinetics characteristics of wild type. These data provide new evidence for the role of extended interactions in supporting the classical knob-hole bonds involving catch-slip behavior in fibrin formation, clot structure, and clot mechanics.
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| 5. |
- Au, A. E., et al.
(author)
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Proinflammatory microenvironment promotes lymphoma progression in mice with high megakaryocyte and TPO levels
- 2023
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In: Blood Advances. - : American Society of Hematology. - 2473-9529 .- 2473-9537. ; 7:8, s. 1560-1571
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Journal article (peer-reviewed)abstract
- Platelets have been shown to enhance the survival of lymphoma cell lines, but it is unclear if they play a role in lymphoma. Here we investigate a potential role for platelets and/or megakaryocytes in Eµ-myc lymphoma progression. Eµ-myc tumour cells were transplanted into recipient wild-type control mice, Mpl-/-, or TpoTg mice, which exhibit normal, low and high platelet and megakaryocyte counts, respectively. Transplanted TpoTg mice exhibited enhanced lymphoma progression with increased WBC counts, spleen and lymph node weights and enhanced liver infiltration when compared to wild-type. Conversely, tumour bearing Mpl-/- mice presented with reduced WBC counts, lymph node weights and less liver infiltration when compared to wild-type. Utilizing a Mpl-deficient thrombocytopenic immunocompromised mouse model, our results were confirmed with the human NHL GRANTA cell line. While we found that platelets and platelet released molecules supported Eµ-myc tumour cell survival in vitro, pharmacological inhibition of platelet function or anticoagulation in Eµ-myc transplanted wild-type mice did not improve disease outcome. Furthermore, transient platelet depletion or sustained Bcl-xL dependent thrombocytopenia did not alter lymphoma progression. Cytokine analysis of the bone marrow fluid microenvironment revealed increased levels of the proinflammatory molecule interleukin (IL)-1 in TpoTg mice, whereas levels were lowered in Mpl-/- mice. Moreover, RNA sequencing of blood-resident Eµ-myclymphoma cells from TpoTgand wild-type mice after tumour transplant revealed upregulation of hallmark gene sets associated with inflammatory response in TpoTg mice. We propose that a pro-inflammatory microenvironment in TpoTgmice promoted lymphoma progression.
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| 6. |
- Baech, J, et al.
(author)
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Risk of diabetes and the impact on preexisting diabetes in patients with lymphoma treated with steroid-containing immunochemotherapy
- 2022
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In: Blood advances. - : American Society of Hematology. - 2473-9537 .- 2473-9529. ; 6:15, s. 4427-4435
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Journal article (peer-reviewed)abstract
- First-line treatments for lymphomas often include high doses of prednisolone, but the risks of new-onset diabetes mellitus (DM) or worsening of preexisting DM following treatment with cyclic high dose corticosteroids is unknown. This cohort study matched non-Hodgkin lymphoma (NHL) patients treated with steroid-containing immunochemotherapy (ie, R-CHOP[-like] and R-CVP) between 2002 and 2015 to individuals from the Danish population to investigate the risks of new-onset DM. For patients with preexisting DM, the risks of insulin dependency and anthracycline-associated cardiovascular diseases (CVDs) were assessed. In total, 5672 NHL patients and 28 360 matched comparators were included. Time-varying incidence rate ratios (IRRs) showed increased risk of DM in the first year after treatment compared with matched comparators, with the highest IRR being 2.7. The absolute risks were higher among patients in the first 2 years, but the difference was clinically insignificant. NHL patients with preexisting DM had increased risks of insulin prescriptions with 0.5-, 5-, and 10-year cumulative risk differences of insulin treatment of 15.3, 11.8, and 6.0 percentage units as compared with the DM comparators. In a landmark analysis at 1 year, DM patients with lymphoma had decreased risks of insulin dependency compared with comparators. Time-varying IRRs showed a higher CVD risk for NHL patients with DM as compared with comparators in the first year after treatment. NHL patients treated with steroid-containing immunochemotherapy regimens have a clinically insignificant increased risk of DM in the first year following treatment, and patients with preexisting DM have a temporary increased risk of insulin prescriptions and CVD.
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| 7. |
- Bang, Benedicte, et al.
(author)
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A somatic UBA2 variant preceded ETV6-RUNX1 in the concordant BCP-ALL of monozygotic twins
- 2022
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In: Blood Advances. - : American Society of Hematology. - 2473-9529 .- 2473-9537. ; 6:7, s. 2275-2289
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Journal article (peer-reviewed)abstract
- Genetic analysis of leukemic clones in monozygotic twins with concordant acute lymphoblastic leukemia (ALL) has proved a unique opportunity to gain insight into the molecular phylogenetics of leukemogenesis. Using whole-genome sequencing, we characterized constitutional and somatic single nucleotide variants/insertion-deletions (indels) and structural variants in a monozygotic twin pair with concordant ETV6-RUNX1(+) B-cell precursor ALL (BCP-ALL). In addition, digital PCR (dPCR) was applied to evaluate the presence of and quantify selected somatic variants at birth, diagnosis, and remission. A shared somatic complex rearrangement involving chromosomes 11, 12, and 21 with identical fusion sequences in leukemias of both twins offered direct proof of a common clonal origin. The ETV6-RUNX1 fusion detected at diagnosis was found to originate from this complex rearrangement. A shared somatic frameshift deletion in UBA2 was also identified in diagnostic samples. In addition, each leukemia independently acquired analogous deletions of 3 genes recurrently targeted in BCP-ALLs (ETV6, ATF7IP, and RAG1/RAG2), providing evidence of a convergent clonal evolution only explained by a strong concurrent selective pressure. Quantification of the UBA2 deletion by dPCR surprisingly indicated it persisted in remission. This, for the first time to our knowledge, provided evidence of a UBA2 variant preceding the well-established initiating event ETV6-RUNX1. Further, we suggest the UBA2 deletion exerted a leukemia predisposing effect and that its essential role in Small Ubiquitin-like Modifier (SUMO) attachment (SUMOylation), regulating nearly all physiological and pathological cellular processes such as DNA-repair by nonhomologous end joining, may hold a mechanistic explanation for the predisposition.
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| 8. |
- Basar, R, et al.
(author)
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Large-scale GMP-compliant CRISPR-Cas9-mediated deletion of the glucocorticoid receptor in multivirus-specific T cells
- 2020
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In: Blood advances. - : American Society of Hematology. - 2473-9537 .- 2473-9529. ; 4:14, s. 3357-3367
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Journal article (peer-reviewed)abstract
- Virus-specific T cells have proven highly effective for the treatment of severe and drug-refractory infections after hematopoietic stem cell transplant (HSCT). However, the efficacy of these cells is hindered by the use of glucocorticoids, often given to patients for the management of complications such as graft-versus-host disease. To address this limitation, we have developed a novel strategy for the rapid generation of good manufacturing practice (GMP)–grade glucocorticoid-resistant multivirus-specific T cells (VSTs) using clustered regularly interspaced short palindromic repeats (CRISPR)–CRISPR-associated protein 9 (Cas9) gene-editing technology. We have shown that deleting the nuclear receptor subfamily 3 group C member 1 (NR3C1; the gene encoding for the glucocorticoid receptor) renders VSTs resistant to the lymphocytotoxic effect of glucocorticoids. NR3C1-knockout (KO) VSTs kill their targets and proliferate successfully in the presence of high doses of dexamethasone both in vitro and in vivo. Moreover, we developed a protocol for the rapid generation of GMP-grade NR3C1 KO VSTs with high on-target activity and minimal off-target editing. These genetically engineered VSTs promise to be a novel approach for the treatment of patients with life-threatening viral infections post-HSCT on glucocorticoid therapy.
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| 9. |
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| 10. |
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| 11. |
- Bergsten, E, et al.
(author)
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Stem cell transplantation for children with hemophagocytic lymphohistiocytosis: results from the HLH-2004 study
- 2020
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In: Blood advances. - : American Society of Hematology. - 2473-9537 .- 2473-9529. ; 4:15, s. 3754-3766
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Journal article (peer-reviewed)abstract
- We report the largest prospective study thus far on hematopoietic stem cell transplantation (HSCT) in hemophagocytic lymphohistiocytosis (HLH), a life-threatening hyperinflammatory syndrome comprising familial/genetic HLH (FHL) and secondary HLH. Although all patients with HLH typically need intensive anti-inflammatory therapy, patients with FHL also need HSCT to be cured. In the international HLH-2004 study, 187 children aged <18 years fulfilling the study inclusion criteria (5 of 8 diagnostic criteria, affected sibling, or molecular diagnosis in FHL-causative genes) underwent 209 transplants (2004-2012), defined as indicated in patients with familial/genetic, relapsing, or severe/persistent disease. Five-year overall survival (OS) post-HSCT was 66% (95% confidence interval [CI], 59-72); event-free survival (EFS) was 60% (95% CI, 52-67). Five-year OS was 81% (95% CI, 65-90) for children with a complete response and 59% (95% CI, 48-69) for those with a partial response (hazard ratio [HR], 2.12; 95% CI, 1.06-4.27; P = .035). For children with verified FHL (family history/genetically verified, n = 134), 5-year OS was 71% (95% CI, 62-78) and EFS was 62% (95% CI, 54-70); 5-year OS for children without verified FHL (n = 53) was significantly lower (52%; 95% CI, 38-65) (P = .040; HR, 1.69; 95% CI, 1.03-2.77); they were also significantly older. Notably, 20 (38%) of 53 patients without verified FHL had natural killer cell activity reported as normal at diagnosis, after 2 months, or at HSCT, suggestive of secondary HLH; and in addition 14 (26%) of these 53 children had no evidence of biallelic mutations despite having 3 or 4 FHL genes analyzed (natural killer cell activity not analyzed after 2 months or at HSCT). We conclude that post-HSCT survival in FHL remains suboptimal, and that the FHL diagnosis should be carefully investigated before HSCT. Pretransplant complete remission is beneficial but not mandatory to achieve post-HSCT survival. This trial was registered at www.clinicaltrials.gov as #NCT00426101.
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| 12. |
- Bonfiglio, Silvia, et al.
(author)
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BTK and PLCG2 remain unmutated in one-third of patients with CLL relapsing on ibrutinib
- 2023
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In: Blood Advances. - : American Society of Hematology. - 2473-9529 .- 2473-9537. ; 7:12, s. 2794-2806
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Journal article (peer-reviewed)abstract
- Patients with chronic lymphocytic leukemia (CLL) progressing on ibrutinib constitute an unmet need. Though Bruton tyrosine kinase (BTK) and PLCG2 mutations are associated with ibrutinib resistance, their frequency and relevance to progression are not fully understood. In this multicenter retrospective observational study, we analyzed 98 patients with CLL on ibrutinib (49 relapsing after an initial response and 49 still responding after ≥1 year of continuous treatment) using a next-generation sequencing (NGS) panel (1% sensitivity) comprising 13 CLL-relevant genes including BTK and PLCG2. BTK hotspot mutations were validated by droplet digital polymerase chain reaction (ddPCR) (0.1% sensitivity). By integrating NGS and ddPCR results, 32 of 49 relapsing cases (65%) carried at least 1 hotspot BTK and/or PLCG2 mutation(s); in 6 of 32, BTK mutations were only detected by ddPCR (variant allele frequency [VAF] 0.1% to 1.2%). BTK/PLCG2 mutations were also identified in 6 of 49 responding patients (12%; 5/6 VAF <10%), of whom 2 progressed later. Among the relapsing patients, the BTK-mutated (BTKmut) group was enriched for EGR2 mutations, whereas BTK-wildtype (BTKwt) cases more frequently displayed BIRC3 and NFKBIE mutations. Using an extended capture-based panel, only BRAF and IKZF3 mutations showed a predominance in relapsing cases, who were enriched for del(8p) (n = 11; 3 BTKwt). Finally, no difference in TP53 mutation burden was observed between BTKmut and BTKwt relapsing cases, and ibrutinib treatment did not favor selection of TP53-aberrant clones. In conclusion, we show that BTK/PLCG2 mutations were absent in a substantial fraction (35%) of a real-world cohort failing ibrutinib, and propose additional mechanisms contributing to resistance.
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| 13. |
- Borg Hammer, Anne Sofie, et al.
(author)
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Hypodiploidy has unfavorable impact on survival in pediatric acute myeloid leukemia : An I-BFM Study Group collaboration
- 2023
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In: Blood Advances. - : American Society of Hematology. - 2473-9529 .- 2473-9537. ; 7:6, s. 1045-1055
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Journal article (peer-reviewed)abstract
- Hypodiploidy, defined as modal numbers (MNs) 45 or lower, has not been independently investigated in pediatric acute myeloid leukemia (AML) but is a well-described high-risk factor in pediatric acute lymphoblastic leukemia. We aimed to characterize and study the prognostic impact of hypodiploidy in pediatric AML. In this retrospective cohort study, we included children below 18 years of age with de novo AML and a hypodiploid karyotype diagnosed from 2000 to 2015 in 14 childhood AML groups from the International Berlin-Frankfurt-Münster (I-BFM) framework. Exclusion criteria comprised constitutional hypodiploidy, monosomy 7, composite karyotype, and t(8;21) with concurring sex chromosome loss. Hypodiploidy occurred in 81 patients (1.3%) with MNs, 45 (n = 66); 44 (n = 10) and 43 (n = 5). The most frequently lost chromosomes were chromosome 9 and sex chromosomes. Five-year event-free survival (EFS) and overall survival (OS) were 34% and 52%, respectively, for the hypodiploid cohort. Children with MN≤44 (n = 15) had inferior EFS (21%) and OS (33%) compared with children with MN = 45 (n = 66; EFS, 37%; OS, 56%). Adjusted hazard ratios (HRs) were 4.9 (P = .001) and 6.1 (P = .003). Monosomal karyotype or monosomy 9 had particular poor OS (43% and 15%, respectively). Allogeneic stem cell transplantation (SCT) in first complete remission (CR1) (n = 18) did not mitigate the unfavorable outcome of hypodiploidy (adjusted HR for OS was 1.5; P = .42). We identified pediatric hypodiploid AML as a rare subgroup with an inferior prognosis even in the patients treated with SCT in CR1.
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| 14. |
- Bruck, O, et al.
(author)
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Immune profiles in acute myeloid leukemia bone marrow associate with patient age, T-cell receptor clonality, and survival
- 2020
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In: Blood advances. - : American Society of Hematology. - 2473-9537 .- 2473-9529. ; 4:2, s. 274-286
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Journal article (peer-reviewed)abstract
- The immunologic microenvironment in various solid tumors is aberrant and correlates with clinical survival. Here, we present a comprehensive analysis of the immune environment of acute myeloid leukemia (AML) bone marrow (BM) at diagnosis. We compared the immunologic landscape of formalin-fixed paraffin-embedded BM trephine samples from AML (n = 69), chronic myeloid leukemia (CML; n = 56), and B-cell acute lymphoblastic leukemia (B-ALL) patients (n = 52) at diagnosis to controls (n = 12) with 30 immunophenotype markers using multiplex immunohistochemistry and computerized image analysis. We identified distinct immunologic profiles specific for leukemia subtypes and controls enabling accurate classification of AML (area under the curve [AUC] = 1.0), CML (AUC = 0.99), B-ALL (AUC = 0.96), and control subjects (AUC = 1.0). Interestingly, 2 major immunologic AML clusters differing in age, T-cell receptor clonality, and survival were discovered. A low proportion of regulatory T cells and pSTAT1+cMAF− monocytes were identified as novel biomarkers of superior event-free survival in intensively treated AML patients. Moreover, we demonstrated that AML BM and peripheral blood samples are dissimilar in terms of immune cell phenotypes. To conclude, our study shows that the immunologic landscape considerably varies by leukemia subtype suggesting disease-specific immunoregulation. Furthermore, the association of the AML immune microenvironment with clinical parameters suggests a rationale for including immunologic parameters to improve disease classification or even patient risk stratification.
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| 15. |
- Brynjólfsson, Siggeir Fannar, et al.
(author)
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Long-lived plasma cells in human bone marrow can be either CD191(+) or CD19(-)
- 2017
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In: Blood Advances. - : American Society of Hematology. - 2473-9529 .- 2473-9537. ; 1:13, s. 835-838
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Journal article (peer-reviewed)abstract
- Long-lived plasma cells secreting vaccinia-specific antibodies are detected in human bone marrow >35 years after the eradication of smallpox. Long-lived plasma cells secreting vaccinia-specific antibodies are still able to express the B-lymphocyte antigen CD19.
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| 16. |
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| 17. |
- Buus, Terkild Brink, et al.
(author)
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Single-cell heterogeneity in Sézary syndrome
- 2018
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In: Blood Advances. - : American Society of Hematology. - 2473-9529 .- 2473-9537. ; 2:16, s. 2115-2126
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Journal article (peer-reviewed)abstract
- Sezary syndrome (SS) is an aggressive leukemic variant of cutaneous T-cell lymphoma (CTCL) with a median life expectancy of less than 4 years. Although initial treatment responses are often good, the vast majority of patients with SS fail to respond to ongoing therapy. We hypothesize that malignant T cells are highly heterogeneous and harbor subpopulations of SS cells that are both sensitive and resistant to treatment. Here, we investigate the presence of single-cell heterogeneity and resistance to histone deacetylase inhibitors (HDACi) within primary malignant T cells from patients with SS. Using single-cell RNA sequencing and flow cytometry, we find that malignant T cells from all investigated patients with SS display a high degree of single-cell heterogeneity at both the mRNA and protein levels. We show that this heterogeneity divides the malignant cells into distinct subpopulations that can be isolated by their expression of different surface antigens. Finally, we show that treatment with HDACi (suberanilohydroxamic acid and romidepsin) selectively eliminates some subpopulations while leaving other subpopulations largely unaffected. In conclusion, we show that patients with SS display a high degree of single-cell heterogeneity within the malignant T-cell population, and that distinct subpopulations of malignant T cells carry HDACi resistance. Our data point to the importance of understanding the heterogeneous nature of malignant SS cells in each individual patient to design combinational and new therapies to counter drug resistance and treatment failure.
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| 18. |
- Cartwright, Ashley, et al.
(author)
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Characterization of large in-frame von Willebrand factor deletions highlights differing pathogenic mechanisms
- 2020
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In: Blood Advances. - 2473-9529 .- 2473-9537. ; 4:13, s. 2979-2990
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Journal article (peer-reviewed)abstract
- Copy number variation (CNV) is known to cause all von Willebrand disease (VWD) types, although the associated pathogenic mechanisms involved have not been extensively studied. Notably, in-frame CNV provides a unique opportunity to investigate how specific von Willebrand factor (VWF) domains influence the processing and packaging of the protein. Using multiplex ligation-dependent probe amplification, this study determined the extent to which CNV contributed to VWD in the Molecular and Clinical Markers for the Diagnosis and Management of Type 1 von Willebrand Disease cohort, highlighting in-frame deletions of exons 3, 4-5, 32-34, and 33-34. Heterozygous in vitro recombinant VWF expression demonstrated that, although deletion of exons 3, 32-34, and 33-34 all resulted in significant reductions in total VWF (P < .0001, P < .001, and P < .01, respectively), only deletion of exons 3 and 32-34 had a significant impact on VWF secretion (P < .0001). High-resolution microscopy of heterozygous and homozygous deletions confirmed these observations, indicating that deletion of exons 3 and 32-34 severely impaired pseudo-Weibel-Palade body (WPB) formation, whereas deletion of exons 33-34 did not, with this variant still exhibiting pseudo-WPB formation similar to wild-type VWF. In-frame deletions in VWD, therefore, contribute to pathogenesis via moderate or severe defects in VWF biosynthesis and secretion.
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| 19. |
- Cartwright, Ashley, et al.
(author)
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Characterization of large in-frame von Willebrand factor deletions highlights differing pathogenic mechanisms
- 2020
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In: Blood Advances. - : Elsevier BV. - 2473-9529 .- 2473-9537. ; 4:13, s. 2979-2990
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Journal article (peer-reviewed)abstract
- Copy number variation (CNV) is known to cause all von Willebrand disease (VWD) types, although the associated pathogenic mechanisms involved have not been extensively studied. Notably, in-frame CNV provides a unique opportunity to investigate how specific von Willebrand factor (VWF) domains influence the processing and packaging of the protein. Using multiplex ligation-dependent probe amplification, this study determined the extent to which CNV contributed to VWD in the Molecular and Clinical Markers for the Diagnosis and Management of Type 1 von Willebrand Disease cohort, highlighting in-frame deletions of exons 3, 4-5, 32-34, and 33-34. Heterozygous in vitro recombinant VWF expression demonstrated that, although deletion of exons 3, 32-34, and 33-34 all resulted in significant reductions in total VWF (P < .0001, P < .001, and P < .01, respectively), only deletion of exons 3 and 32-34 had a significant impact on VWF secretion (P < .0001). High-resolution microscopy of heterozygous and homozygous deletions confirmed these observations, indicating that deletion of exons 3 and 32-34 severely impaired pseudo-Weibel-Palade body (WPB) formation, whereas deletion of exons 33-34 did not, with this variant still exhibiting pseudo-WPB formation similar to wild-type VWF. In-frame deletions in VWD, therefore, contribute to pathogenesis via moderate or severe defects in VWF biosynthesis and secretion.
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| 20. |
- Casulo, C, et al.
(author)
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Outcomes of older patients with follicular lymphoma using individual data from 5922 patients in 18 randomized controlled trials
- 2021
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In: Blood advances. - : American Society of Hematology. - 2473-9537 .- 2473-9529. ; 5:6, s. 1737-1745
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Journal article (peer-reviewed)abstract
- Limited data exist to describe the clinical features and outcomes for elderly patients with follicular lymphoma (FL). The Follicular Lymphoma Analysis of Surrogacy Hypothesis (FLASH) group performed a prospectively planned pooled analysis of individual patient data from first-line randomized controlled trials (RCTs) and examined associations between age (≤70 vs >70 years), clinical characteristics, and FL outcomes. We identified 18 multicenter clinical RCTs in the FLASH database that enrolled elderly patients (>70 years). Primary end points were early disease outcomes, CR24 and CR30, and progression-free survival (PFS) at 24 months (PFS24). Secondary end points were PFS and overall survival (OS). We identified 5922 previously untreated FL patients from 18 RCTs. Patients age >70 years (vs ≤70 years) more commonly had elevated lactate dehydrogenase, hemoglobin <12 g/dL, ECOG PS ≥2, and elevated β2-microglobulin. Median follow-up was 5.6 years. Patients >70 years did not differ from patients ≤70 years in rates of CR24, CR30, or PFS24. With a median OS of 14.6 years for all patients, median OS was 7.4 and 15.7 years for patients >70 and ≤70 years of age, respectively (hazard ratio = 2.35; 95% confidence interval = 2.03-2.73; P < .001). Age >70 years was a significant predictor of OS and PFS due to higher rates of death without progression, but not PFS24, CR24, or CR30. FL patients >70 years treated on trials have similar early disease outcomes to younger patients. There is no disease-specific outcome difference between age groups. Age alone should not disqualify patients from standard treatments or RCTs.
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| 21. |
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| 22. |
- Chhabra, Saurabh, et al.
(author)
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Myeloablative vs reduced-intensity conditioning allogeneic hematopoietic cell transplantation for chronic myeloid leukemia
- 2018
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In: Blood Advances. - : American Society of Hematology. - 2473-9529 .- 2473-9537. ; 2:21, s. 2922-2936
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Journal article (peer-reviewed)abstract
- Allogeneic hematopoietic cell transplantation (allo-HCT) is a potentially curative treatment of chronic myeloid leukemia (CML). Optimal conditioning intensity for allo-HCT for CML in the era of tyrosine kinase inhibitors (TKIs) is unknown. Using the Center for International Blood and Marrow Transplant Research database, we sought to determine whether reduced-intensity/nonmyeloablative conditioning (RIC) allo-HCT and myeloablative conditioning (MAC) result in similar outcomes in CML patients. We evaluated 1395 CML allo-HCT recipients between the ages of 18 and 60 years. The disease status at transplant was divided into the following categories: chronic phase 1, chronic phase 2 or greater, and accelerated phase. Patients in blast phase at transplant and alternative donor transplants were excluded. The primary outcome was overall survival (OS) after allo-HCT. MAC (n = 1204) and RIC allo-HCT recipients (n = 191) from 2007 to 2014 were included. Patient, disease, and transplantation characteristics were similar, with a few exceptions. Multivariable analysis showed no significant difference in OS between MAC and RIC groups. In addition, leukemia-free survival and nonrelapse mortality did not differ significantly between the 2 groups. Compared with MAC, the RIC group had a higher risk of early relapse after allo-HCT (hazard ratio [HR], 1.85; P = .001). The cumulative incidence of chronic graft-versus-host disease (cGVHD) was lower with RIC than with MAC (HR, 0.77; P = .02). RIC provides similar survival and lower cGVHD compared with MAC and therefore may be a reasonable alternative to MAC for CML patients in the TKI era.
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| 23. |
- Chiodin, G, et al.
(author)
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High surface IgM levels associate with shorter response to ibrutinib and BTK bypass in patients with CLL
- 2022
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In: Blood advances. - : American Society of Hematology. - 2473-9537 .- 2473-9529. ; 6:18, s. 5494-5504
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Journal article (peer-reviewed)abstract
- Chronic lymphocytic leukemia (CLL) cells have variably low surface IgM (sIgM) levels/signaling capacity, influenced by chronic antigen engagement at tissue sites. Within these low levels, CLL with relatively high sIgM (CLLhigh) progresses more rapidly than CLL with low sIgM (CLLlow). During ibrutinib therapy, surviving CLL cells redistribute into the peripheral blood and can recover sIgM expression. Return of CLL cells to tissue may eventually recur, where cells with high sIgM could promote tumor growth. We analyzed time to new treatment (TTNT) following ibrutinib in 70 patients with CLL (median follow-up of 66 months) and correlated it with pretreatment sIgM levels and signaling characteristics. Pretreatment sIgM levels correlated with signaling capacity, as measured by intracellular Ca2+ mobilization (iCa2+), in vitro (r = 0.70; P < .0001). High sIgM levels/signaling strongly correlated with short TTNT (P < .05), and 36% of patients with CLLhigh vs 8% of patients with CLLlow progressed to require a new treatment. In vitro, capacity of ibrutinib to inhibit sIgM-mediated signaling inversely correlated with pretherapy sIgM levels (r = −0.68; P = .01) or iCa2+ (r = −0.71; P = .009). In patients, sIgM-mediated iCa2+ and ERK phosphorylation levels were reduced by ibrutinib therapy but not abolished. The residual signaling capacity downstream of BTK was associated with high expression of sIgM, whereas it was minimal when sIgM expression was low (P < .05). These results suggested that high sIgM levels facilitated CLL cell resistance to ibrutinib in patients. The CLL cells, surviving in the periphery with high sIgM expression, include a dangerous fraction that is able to migrate to tissue and receive proliferative stimuli, which may require targeting by combined approaches.
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| 24. |
- Daly, J, et al.
(author)
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Targeting hypersialylation in multiple myeloma represents a novel approach to enhance NK cell-mediated tumor responses
- 2022
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In: Blood advances. - : American Society of Hematology. - 2473-9537 .- 2473-9529. ; 6:11, s. 3352-3366
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Journal article (peer-reviewed)abstract
- Abnormal glycosylation is a hallmark of cancer, and the hypersialylated tumor cell surface facilitates abnormal cell trafficking and drug resistance in several malignancies, including multiple myeloma (MM). Furthermore, hypersialylation has also been implicated in facilitating evasion of natural killer (NK) cell–mediated immunosurveillance but not in MM to date. In this study, we explore the role of hypersialylation in promoting escape from NK cells. We document strong expression of sialic acid-derived ligands for Siglec-7 (Siglec-7L) on primary MM cells and MM cell lines, highlighting the possibility of Siglec-7/Siglec-7L interactions in the tumor microenvironment. Interactomics experiments in MM cell lysates revealed PSGL-1 as the predominant Siglec-7L in MM. We show that desialylation, using both a sialidase and sialyltransferase inhibitor (SIA), strongly enhances NK cell–mediated cytotoxicity against MM cells. Furthermore, MM cell desialylation results in increased detection of CD38, a well-validated target in MM. Desialylation enhanced NK cell cytotoxicity against CD38+ MM cells after treatment with the anti-CD38 monoclonal antibody daratumumab. Additionally, we show that MM cells with low CD38 expression can be treated with all trans-retinoic acid (ATRA), SIA and daratumumab to elicit a potent NK cell cytotoxic response. Finally, we demonstrate that Siglec-7KO potentiates NK cell cytotoxicity against Siglec-7L+ MM cells. Taken together, our work shows that desialylation of MM cells is a promising novel approach to enhance NK cell efficacy against MM, which can be combined with frontline therapies to elicit a potent anti-MM response.
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| 25. |
- Doma, Eszter, et al.
(author)
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A robust approach for the generation of functional hematopoietic progenitor cell lines to model leukemic transformation
- 2021
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In: Blood Advances. - : American Society of Hematology. - 2473-9529 .- 2473-9537. ; 5:1, s. 39-53
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Journal article (peer-reviewed)abstract
- Studies of molecular mechanisms of hematopoiesis and leukemogenesis are hampered by the unavailability of progenitor cell lines that accurately mimic the situation in vivo. We now report a robust method to generate and maintain LSK (Lin-, Sca-1+, c-Kit+) cells, which closely resemble MPP1 cells. HPCLSKs reconstitute hematopoiesis in lethally irradiated recipient mice over >8 months. Upon transformation with different oncogenes including BCR/ABL, FLT3-ITD, or MLL-AF9, their leukemic counterparts maintain stem cell properties in vitro and recapitulate leukemia formation in vivo. The method to generate HPCLSKs can be applied to transgenic mice, and we illustrate it for CDK6-deficient animals. Upon BCR/ABLp210 transformation, HPCLSKs Cdk6-/- induce disease with a significantly enhanced latency and reduced incidence, showing the importance of CDK6 in leukemia formation. Studies of the CDK6 transcriptome in murine HPCLSK and human BCR/ABL+ cells have verified that certain pathways depend on CDK6 and have uncovered a novel CDK6-dependent signature, suggesting a role for CDK6 in leukemic progenitor cell homing. Loss of CDK6 may thus lead to a defect in homing. The HPCLSK system represents a unique tool for combined in vitro and in vivo studies and enables the production of large quantities of genetically modifiable hematopoietic or leukemic stem/progenitor cells.
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