Kooperativer Bibliotheksverbund

In: Blood, American Society of Hematology, Vol. 122, No. 21 ( 2013-11-15), p. 502-502

Abstract: Follicular lymphoma (FL) is a B-cell lymphoma whose cytogenetic hallmark is the translocation t(14;18)(q32;q21) which juxtaposes the BCL2 oncogene to the immunoglobulin heavy chain locus (IGHV). FLs maintain key features of normal germinal center reactions, such as ongoing somatic hypermutation (SHM) of IGHV genes and selection for a functional B-cell receptor. SHM is mediated by activation-induced cytidine deaminase (AID) leading to single nucleotide exchange in IGHV genes and to a much lesser extent in non-IG genes. It was our objective to investigate the clonal evolution of t(14,18) FL from primary to relapse tumors simultaneously on several genetic and epigenetic levels. Methods We studied paired primary and relapsed tumors from 33 patients with t(14;18)-positive FL (76 samples: 25 pairs; 6 trios and 2 quadruples). In a core set of 19 patients we performed Sanger and next generation sequencing of the clonal VHDHJH rearrangements of the IGHV locus. We performed deep sequencing of 9 genes (BCL2, BCL6, MYC, RHOH, PAX5, IRF4, C2TA, REL and PIM1) targeted by aberrant SHM (aSHM) in lymphoma for 69 FL samples including the complete core set. We furthermore analyzed mutations in the coding regions of 10 candidate driver genes of lymphomagenesis (BCL2, MLL2, CREBBP, TNFRSF14, EZH2, EP300, MEF2B, BCL6, MYC, TP53) by deep sequencing. In addition to genetic analyses, evolutionary patterns of DNA-methylation were addressed by Illumina 27k arrays. Results We found strong evidence for ongoing selection against replacement mutations in the IGHV genes both in complementarity determining regions and framework regions, consistent with ongoing dependence of FL on a functional B-cell receptor and stimulation by antigens. Using mean normalized Hamming distance as a quantitative measure for the evolutionary divergence of paired samples (IGHV-divergence) and analyzing phylogenetic trees we classified the patterns of evolution into 3 categories: “No Evolution” (shared IGHV sequences in primary and relapse tumors), “Sequential Evolution” (relapse sequences emerge out of primary ones), “Divergent Evolution” (sequences of primary and relapse sample appear disjoint). We observed a mutation frequency of 62.0 per 100 kb in aSHM targets. These mutations were strongly enriched at the WRCY/RGYW target motifs characteristic for the SHM/AID machinery (OR=3.4; p 〈 0.001). The most frequently altered locus was BCL2 affected in 68 of 69 samples (with 315.3 mutations per 100 kb) likely due to the recombination of the translocated allele into the IGH locus. We detected 197 single nucleotide variants (SNV) affecting the candidate driver genes (4.4 mutations per 100 kb) of which 145 were protein-changing. The genes most frequently affected were CREBBP (52 SNVs in 43/69 samples) and MLL2 (54 in 39/69). High incidence of CREBBP mutations and the high mutated allele frequencies of these mutations suggest that CREBBP deregulation is an early event in FL lymphomagenesis. We defined the aSHM-divergence as the proportion of observed aSHM mutations not present in both samples and found a significant correlation between the IGHV-divergence and the aSHM-divergence in the non-IG aSHM targets (r=0.724 [0.40-0.88]). We calculated a measure for divergence in DNA-methylation within patients by the proportion of all paired CpGs showing a methylation difference of at least 25%. DNA-methylation-divergence was found to correlate with IGHV-divergence (r=0.516 [0.24-0.72] ) indicating that evolutionary divergence also affects the level of DNA-methylation. Conclusion Our observations demonstrate correlated evolutionary changes on all genomic and epigenomic levels in FL. This process most likely originates from an ongoing germinal center reaction with a functional BCR driving FL cells, sustaining a continuously active AID-machinery leading to addition of IGHV-mutations and to aberrant mutations in non-IG aSHM-target sites. The drifts in DNA-methylation patterns might be a consequence of additional mutations found in histone modifying genes such as CREBBP. The individual pattern of tumor evolution is likely to impact prognosis and clinical decision making which needs to be investigated in larger series. (Acknowledgment: BMBF/PTJ 0315452) Disclosures: No relevant conflicts of interest to declare.

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood.V122.21.502.502

Language: English

Publisher: American Society of Hematology

Publication Date: 2013

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detail.hit.zdb_id: 80069-7

In: Blood, American Society of Hematology, Vol. 120, No. 9 ( 2012-08-30), p. 1868-1876

Abstract: Quantification of minimal residual disease (MRD) by real-time PCR directed to TCR and Ig gene rearrangements allows a refined evaluation of response in acute lymphoblastic leukemia (ALL). The German Multicenter Study Group for Adult ALL prospectively evaluated molecular response after induction/consolidation chemotherapy according to standardized methods and terminology in patients with Philadelphia chromosome-negative ALL. The cytologic complete response (CR) rate was 89% after induction phases 1 and 2. At this time point the molecular CR rate was 70% in 580 patients with cytologic CR and evaluable MRD. Patients with molecular CR after consolidation had a significantly higher probability of continuous complete remission (CCR; 74% vs 35%; P 〈 .0001) and of overall survival (80% vs 42%; P = .0001) compared with patients with molecular failure. Patients with molecular failure without stem cell transplantation (SCT) in first CR relapsed after a median time of 7.6 months; CCR and survival at 5 years only reached 12% and 33%, respectively. Quantitative MRD assessment identified patients with molecular failure as a new high-risk group. These patients display resistance to conventional drugs and are candidates for treatment with targeted, experimental drugs and allogeneic SCT. Molecular response was shown to be highly predictive for outcome and therefore constitutes a relevant study end point. The studies are registered at www.clinicaltrials.gov as NCT00199056 and NCT00198991.

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood-2011-09-377713

Language: English

Publisher: American Society of Hematology

Publication Date: 2012

detail.hit.zdb_id: 1468538-3

detail.hit.zdb_id: 80069-7

In: Blood, American Society of Hematology, Vol. 120, No. 21 ( 2012-11-16), p. 788-788

Abstract: Abstract 788 Background. Real-Time Quantitative (RQ) PCR-based MRD detection using tumor-specific primers derived from the immunoglobulin heavy chain variable region (IGH) is an established disease monitoring tool with high predictive value in ALL, MCL and MM. It is highly sensitive and has been standardized in the context of international cooperative groups such as the European Scientific Foundation for Laboratory Hematooncology (ESLHO). However it has some limitations, including marker identification failure, particularly in hypermutated tumors and false negatives due to clonal evolution, particularly in ALL. IGH-based next-generation sequencing (NGS) might overcome some of these limitations and further increase sensitivity, specificity, accuracy and reproducibility. We have thus performed a head to head comparison of the two methods on diagnostic (DG) and post-treatment follow-up (FU) samples on a panel of 55 patients. Patients and Methods. Overall, 381 samples (215 bone marrow, 166 peripheral blood; 62 DG, 319 FU) were collected from 55 patients (15 ALL, 30 MCL, 10 MM) in which RQ-PCR based MRD analysis had been performed in the context of prospective clinical trials. IGH-based RQ-PCR was carried out as previously described [Ladetto et al, BBMT 2000; Brüggemann et al, Blood 2006], according to the criteria of the European Study Group on MRD detection [van der Velden et al, Leukemia 2007] , at two experienced MRD laboratories (Kiel, DE, 238 samples; Torino, IT, 143 samples). NGS was performed at the Sequenta facilities in San Francisco, CA, USA. Using universal primer sets, we amplified IGH variable, diversity, and joining gene segments from genomic DNA. Amplified products were sequenced to obtain a high degree of coverage (14 reads per each IGH molecule) and analyzed using standardized algorithms for clonotype determination. Tumor-specific clonotypes were identified for each patient based on their high-frequency in DG sample and then quantitated in FU samples. A quantitative and standardized measure of clone level among all leukocytes was determined using internal reference DNA. NGS analysis was performed independently and data were blinded until comparison. Comparability of MRD results by RQ-PCR and NGS was assessed by means of bivariate correlations between methods analysis (software R 2.15.1 package irr). Discordances were classified as follows: a positive/negative discordance was defined as major when the positive result was 〉 1 E-05 and minor when ≤1 E-05; a quantitative discordance was defined as the presence of two positive results with a quantitative discrepancy 〉 1 log. Results. 51 pts (93%) were evaluable with at least one tool (RQ-PCR 45, NGS 49), 43 (78%) with both and 4 (7%) with none. Disease-specific success rates are shown in Tab. 1. Overall, 333 samples (87%) were evaluated with at least one tool (RQ-PCR 282, NGS 319) and 268 (70%) with both. The latter group was thus comparable in terms of MRD output. A correlation analysis between RQ-PCR and NGS results is shown in Fig. 1. Overall a significant concordance was observed (p 〈 0.001, R=0.791). 210/268 (78%) samples had an optimal level of concordance. Of these 99 were MRD negative and 111 MRD positive. Major discordances were 17 (6,3%) with NGS overestimating compared to RQ-PCR in 11 samples and underestimating in 6; minor discordances were 23 (8,6%) with NGS overestimating in 5 samples and underestimating in 18; quantitative discordances were 18 (6,7%) with NGS overestimating in 14 cases and underdestimating in 4. In 2 ALL clonal evolution hampered straightforward MRD assessment in one of both methods. In one case IGH RQ-PCR underestimated MRD while a second RQ-PCR marker (TCRD) led to results comparable to NGS. In a second case NGS did not detect the tumor clone identified at diagnosis due to loss of the complete IGHV at relapse whereas the preceeding IGHDJ was preserved and detected by RQ-PCR targeting the preserved DJ region. Conclusions. NGS is a feasible tool for IGH-based MRD monitoring in ALL, MCL and MM, in selected cases reaching similar sensitivities compared to standardized RQ-PCR. Good concordance was seen in the vast majority of cases. However, disease-specific pitfalls (clonal evolution, somatic hypermutations, frequency of complete IGH rearrangements) have to be considered for both methods and prospective comparative analysis of unselected cases is required to verify the clinical impact of NGS-based MRD assessment. Disclosures: No relevant conflicts of interest to declare.

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood.V120.21.788.788

Language: English

Publisher: American Society of Hematology

Publication Date: 2012

detail.hit.zdb_id: 1468538-3

detail.hit.zdb_id: 80069-7

In: Blood, American Society of Hematology, Vol. 114, No. 26 ( 2009-12-17), p. 5400-5401

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood-2009-09-243741

Language: English

Publisher: American Society of Hematology

Publication Date: 2009

detail.hit.zdb_id: 1468538-3

detail.hit.zdb_id: 80069-7

In: physica status solidi (a), Wiley, Vol. 213, No. 3 ( 2016-03), p. 610-619

Abstract: Three‐dimensional (3D) assemblies of nanostructures are gaining more and more attention during the recent years as promising systems to increase the integration density in microelectronic devices. Here we present the fabrication of large areas of 3D nanowire networks (NWNWs) of antimony for thermoelectric applications by electrodeposition in etched ion‐track membranes. The synthesis parameters have been investigated and optimized to achieve mechanically stable and free‐standing NWNWs without a supporting matrix. A cross‐plane method for the complete steady state thermoelectric characterization of an embedded nanowire assembly (NWA) is also introduced, which enables the measurements of Seebeck‐coefficient, cross‐plane thermal conductivity, and electrical resistance of the NWA, and can also be applied to thin films. First results of the thermoelectric properties of Sb NWA are presented.

Type of Medium: Online Resource

ISSN: 1862-6300 , 1862-6319

URL: Issue

URL: Article

DOI: 10.1002/pssa.v213.3

DOI: 10.1002/pssa.201532616

Language: English

Publisher: Wiley

Publication Date: 2016

detail.hit.zdb_id: 1481091-8

detail.hit.zdb_id: 208850-2

In: Blood, American Society of Hematology, Vol. 136, No. Supplement 1 ( 2020-11-5), p. 37-38

Abstract: Introduction: In T-ALL, in contrast to BCP-ALL, molecular subgroups are less well defined. Molecular subgroups are based on aberrant expression of oncogenes often resting upon structural aberrations (chromosomal translocation, copy number variations, point mutations). So far, comprehensive studies on molecular subgroups have been predominantly performed in pediatric patients. The clinical relevance of molecular characteristics is not taken into account for risk stratification and targeted therapeutic options for T-ALL patients are limited. Risk stratification is mainly based on immunophenotype and MRD response. Thus, in the German Multicenter Study Group for Adult ALL (GMALL) protocols early and mature T-ALL and molecular failure after first consolidation are high risk features. Whole RNA transcriptome sequencing (RNAseq) enables molecular subgroup allocation profiles with potential prognostic relevance. Herein, we investigated a large cohort of 161 adult T-ALL patients with RNAseq for molecular subgroups and their clinical implication. Patients and methods : RNAseq data (Illumina HiSeq 4000, 100 or 125 bp paired-end, average read count ~30 million reads/sample) were generated from 161 adult T-ALL patients from diagnostic bone marrow samples. For 84 of these T-ALL patients, we additionally investigated DNA methylation using Infinium 450k methylation bead arrays and mutation status using deep targeted DNA sequencing with a gene panel consisting of 206 genes (HiSeq 1500, 100 bp paired-end, average ~800 reads/bp). All patients were treated likewise within pediatric inspired protocols of the GMALL. Clinical follow up and outcome data were available for 129 patients aged between 18 and 55 years. Results: Based on oncogene expression, we could assign molecular subgroups to 160 out of the 161 T-ALL patients: HOXA: n=37 (23%), TLX1: n=37 (23%), TAL/LMO: n=33 (20%), LYL1/LMO2: n=31 (19%), TLX3: n=17 (11%) , NKX2-1: n=4 (2%), TAL2: n=1 (1%). Among others, gene fusion events incorporating TAL1 (n=16), HOXA (n=6), TLX1 (n=14), TLX3 (n=2) and NKX2 (n=2) were detected as underlying mechanisms. Age distribution revealed more TAL/LMO in the younger population (16-25 years: 35% versus & gt;35 years: 3%; p=0.001) and more LYL1/LMO2 and HOXA in the older patients (16-25 years: 23% vs. & gt;35 years: 40%; n.s.). DNA methylation analyses for 84 of the 161 patients support the molecular classification with four distinct subgroups demonstrating a homogenous methylation profile for the TLX1 driven subgroup (methylation cluster M3, n=30). In contrast, methylation cluster M2 (n=21) showed a hypomethylation in CpG islands and comprises the majority of TAL/LMO positive cases (19/21) including all samples with STIL-TAL1 fusions. M1 (n=25) and M4 (n=7) clusters comprised TLX3 (mainly cluster M1, 8/10), HOXA and LYL1/LMO2 cases. Mutation analysis showed a high rate of NOTCH1 (n=71%) mutations in the TLX1 subgroup and an increased rate of mutations in the JAK/STAT pathway (n=29%) and epigenetic regulators (n=50%) in HOXA and LYL1/LMO2 subgroups. Regarding clinical outcome, 126 out of 129 (98%) patients achieved a morphologically complete remission (CR), two patients failed CR, one patient died during induction therapy. Regarding MRD response, 12% of the investigated T-ALL patients showed a molecular failure after consolidation. Noteworthy, we found a molecular CR for 28/30 (93%) patients in the TLX1 subgroup, but only 11/19 (58%) respectively 2/6 (33%) in the HOXA and the LYL1/LMO2 subgroup. This finding results in exceptional five year-overall survival (5y-OS) of 93% in TLX1 patients. Together with the NKX2-1 subgroup (n=4, with 100% 5y-OS), these patients build a prognostically favourable risk group in the overall cohort (94% 5y-OS versus 76% in TAL-LMO patients versus 62% in all other subgroups, p=0.007). This result could not only be found in the overall cohort, but also within the already good risk subgroup of thymic T-ALL patients (93% vs. 75%, p=0.02). Conclusion: This is to our knowledge the largest cohort of adult T-ALL patients characterized by RNAseq on molecular level. Our findings point towards an age dependent distribution of molecular subgroups contributing to age-dependent outcome differences. Patients with TLX1 reveal a molecular subgroup with extraordinary good prognosis. Within thymic T-ALL, the subgroup of patients without TLX1 (~53%) has an inferior but still good prognosis. Disclosures Fiedler: Gilead: Other: support for meeting attendance; Jazz Pharmaceuticals: Honoraria, Other: support for meeting attendance; Abbvie: Membership on an entity's Board of Directors or advisory committees; Morphosys: Consultancy, Honoraria; Celgene: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Honoraria; ARIAD/Incyte: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Other: support for meeting attendance, Patents & Royalties, Research Funding; Daiichi Sankyo: Other: support for meeting attendance. Alakel:Pfizer: Consultancy. Schwartz:AMGEN: Other: personal fees and non-financial support; Novartis: Other: personal fees and non-financial support; Jazz Pharmaceuticals: Other: personal fees and non-financial support; Pfizer: Other: personal fees ; BTG Intl Inc: Other: personal fees ; Gilead Sciences: Other: personal fees and non-financial support ; MSD Sharp & Dohme: Other: personal fees ; Basilea: Other: non-financial suppor. Müller-Tidow:Pfizer: Research Funding, Speakers Bureau; Daiichi Sankyo: Research Funding; Janssen-Cilag GmbH: Speakers Bureau; BiolineRx: Research Funding. Brüggemann:Regeneron: Research Funding; Affimed: Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria; Incyte: Consultancy; Roche: Consultancy; Celgene: Consultancy. Goekbuget:Servier: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Gilead: Consultancy; Erytech: Consultancy; Kite: Consultancy; Jazz: Consultancy, Research Funding.

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood-2020-141921

Language: English

Publisher: American Society of Hematology

Publication Date: 2020

detail.hit.zdb_id: 1468538-3

detail.hit.zdb_id: 80069-7

In: MTZ worldwide, Springer Science and Business Media LLC, Vol. 80, No. 7-8 ( 2019-7), p. 100-105

Type of Medium: Online Resource

ISSN: 2192-9114

URL: Article

DOI: 10.1007/s38313-019-0068-2

Language: English

Publisher: Springer Science and Business Media LLC

Publication Date: 2019

In: Blood Advances, American Society of Hematology, Vol. 6, No. 10 ( 2022-05-24), p. 3006-3010

Abstract: Persistence of minimal residual disease (MRD) after induction/consolidation therapy in acute lymphoblastic leukemia is the leading cause of relapse. The GMALL 07/2003 study used MRD detection by real-time quantitative polymerase chain reaction of clonal immune gene rearrangements with 1 × 10−4 as discriminating cutoff: levels ≥1 × 10−4 define molecular failure and MRD-negativity with an assay sensitivity of at least 1 × 10−4 defining complete molecular response. The clinical relevance of MRD results not fitting into these categories is unclear and termed “molecular not evaluable” (MolNE) toward MRD-based treatment decisions. Within the GMALL 07/03 study, 1019 consecutive bone marrow samples after first consolidation were evaluated for MRD. Patients with complete molecular response had significantly better outcome (5-year overall survival [OS] = 85% ± 2%, n = 603; 5-year disease-free survival [DFS] = 73% ± 2%, n = 599) compared with patients with molecular failure (5-year OS = 40% ± 3%, n = 238; 5-year DFS = 29% ± 3%, n = 208), with patients with MolNE in between (5-year OS = 66% ± 4%; 5-year DFS = 52% ± 4%, n = 178). Of MolNE samples reanalyzed using next-generation sequencing (NGS), patients with undetectable NGS-MRD (n = 44; 5-year OS = 88% ± 5%, 5-year DFS = 70% ± 7%) had significantly better outcome than those with positive NGS-MRD (n = 42; 5-year OS = 37% ± 8%; 5-year DFS = 33% ± 8%). MolNE MRD results not just are borderline values with questionable relevance but also form an intermediate-risk group, assignment of which can be further improved by NGS.

Type of Medium: Online Resource

ISSN: 2473-9529 , 2473-9537

URL: Article

DOI: 10.1182/bloodadvances.2021006727

Language: English

Publisher: American Society of Hematology

Publication Date: 2022

detail.hit.zdb_id: 2876449-3

In: Contact Dermatitis, Wiley, Vol. 68, No. 2 ( 2013-02), p. 111-115

Type of Medium: Online Resource

ISSN: 0105-1873

URL: Article

DOI: 10.1111/j.1600-0536.2012.02156.x

Language: English

Publisher: Wiley

Publication Date: 2013

detail.hit.zdb_id: 2027120-7

In: BIOspektrum, Springer Science and Business Media LLC, Vol. 21, No. 1 ( 2015-2), p. 58-61

Type of Medium: Online Resource

ISSN: 0947-0867 , 1868-6249

URL: Article

DOI: 10.1007/s12268-015-0540-8

Language: German

Publisher: Springer Science and Business Media LLC

Publication Date: 2015

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detail.hit.zdb_id: 2203536-9

SSG: 12

SSG: 15,3