bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prognostic Impact of Fc Gamma-Receptor Polymorphisms and Efficacy of Rituximab in Children and Adolescents with Mature Aggressive B-NHL
Authors: Burkhardt Birgit , Yavuz Deniz , Zimmerman Martin , Schieferstein Jutta , Kabickova Edita , Attarbaschi Andishe , Lisfeld Jasmin , Bonn Bettina R. , Reiter Alfred , Damm-Welk Christine 
Published: October 2019

Abstract
Abstract 1547
Recent studies in adult lymphoma patients indicated a correlation of polymorphisms of Fc gamma-receptors (FcγRs, encoded by the respective FCGR genes) and response to rituximab or outcome. FcγRIIIa is expressed on natural killer (NK) cells and macrophages representing the most important antibody-dependent cellular cytotoxicity (ADCC) effector cells. It is reported that the FcγRIIIa-158 valine (V) isotype has a higher affinity to human immunoglobulin G1 than the phenylalanine (F) isotype and that cells with FcγRIIIa-158V mediate ADCC more efficiently. Besides FCGR3A, a polymorphism of FCGR2A resulting in either histidine (H) or arginine (R) at amino acid position 131 was analyzed in clinical trials for its prognostic impact on rituximab response but the results remained inconclusive.
The trial B-NHL BFM Rituximab tested the efficacy of rituximab in pediatric patients (pts) with mature aggressive B-NHL. In this context the impact of FCGR-polymorphisms was analyzed in the current project.
Patients were registered and treated according to protocol B-NHL BFM Rituximab with a single dose rituximab (375 mg/m2 n= 88 and 700 mg/m2 n=40) at day one, rituximab response evaluation at day five, followed by standard chemotherapy. The FCGR3A-158V/F polymorphism and the FCGR2A-131H/R polymorphism were assessed.
Of a total of 128 pts, 105 were evaluable for rituximab response at day 5 with 47 responders and 58 non-responders (response rate 45%).
Rituximab response rate was 26% and therefore significantly lower in pts with FcγRIIa-131R/R isotype (n=23, 6 responders) compared to the response for FcγRIIa-131H isotype carriers (H/H n=34, 19 responders and H/R n= 45, 22 responders; response rate 52%). Concerning the FCGR3A polymorphism, the F/F genotype was highly significantly associated with favorable response rate of 70% (F/F n=33, 23 responders) compared to the response rate in FcγRIIIa-158V isotype carriers (V/V n=9, 2 responders and V/F n=63, 22 responders; response rate 33%). Response rate for FCGR3A-158F/F genotype was favorable for both, low-risk-R2 (14/21 responders) and higher-risk-R3/R4 (9/12 responders) pts.
In the current context of rituximab response evaluation after an upfront window, the FcγRIIIa-158 phenylalanine (F) isotype is associated with favorable response in pediatric pts with aggressive B-NHL, but not the high-affinity FcγRIIIa-158 valine isotype. These are conflicting results compared to published data for lymphoma trials in adults and the in vitro data on FcγRIIIa-158. This raises the question whether ADCC is a relevant mechanism of action in the current patient population or whether other factors might impact the interaction of NK cells, macrophages, neutrophils and lymphoma cells.

Disclosures:
No relevant conflicts of interest to declare.
Decreased Brain FDG Uptake in Patients with Diffuse Large B Cell Lymphoma (cold brain) Is Associated with High Risk Disease and Predicts Poor Response to R-CHOP Chemotherapy
Authors: Raghavendra Meghana 
Published: October 2019

Abstract 1593

Background:
Decreased 2-deoxy-2-(18F)fluoro-D-glucose (FDG) uptake by brain tissue, (henceforth “cold brain”) has been occasionally described in the literature in patients with bulky solid tumors. There is currently no data describing brain FDG uptake on positron emission tomography (PET) scan in patients with diffuse large B cell lymphoma (DLBCL) and its association with clinical characteristics as well as prognosis.

Method:
We retrospectively analyzed clinical data from 110 patients with histologically confirmed DLBCL diagnosed between November 1, 2004 and December 31, 2011. Initial staging PET scans prior to treatment were reviewed. Brain FDG uptake on PET scan was analyzed by an expert nuclear radiologist. Qualitative determination of cold versus normal brain activity was made relative to usual distribution and metabolism. Secondarily, a region of interest cursor was placed on the right basal ganglia for a quantitative standard uptake value (SUV) measurement. In cases where measurement of the right basal ganglia was not possible, the cerebellum was used. Patient characteristics were compared using Fisher's exact test. Survival analyses were performed using Kaplan-Meier curves and compared using log-rank test. Cox proportional regression model was used for multivariate analyses.

Results:
We included 110 patients in the study. Twenty patients (18%) had cold brain by initial PET scan. The cold brain subgroup had a median age of 72.5 years (range, 46 to 85) and 55.0% were males. Cold brain was associated with higher rates of stage III/IV disease (80.0% vs 52.2%; P = 0.026), International Prognostic Index (IPI) score of ≥3 (85.2% vs. 36.7%; P = 0.0001), and > 1 extranodal sites of involvement (50.0% vs. 26.7%; P = 0.059) compared to the non-cold brain subgroup.
Among patients who received rituximab/cyclophosphamide/doxorubicin/vincristine/prednisone chemotherapy (R-CHOP), those with cold brain had a lower complete response rate (44.0% vs. 86.0%; P = 0.030), shorter progression-free-survival (PFS) (4.5 months vs. 9.1 months; P = 0.06), but similar overall survival (OS) (47.9 months vs. 58.4 months; P = 0.26). After adjusting for IPI, patients with cold brain seemed to have a shorter PFS compared to those without cold brain, although this was not statistically significant (hazard ratio: 3.13; 95% CI: 8.20-1.22; P = 0.096).

Conclusion:
In our study, cold brain was a phenomenon frequently observed among patients with newly diagnosed DLBCL. It was associated with higher risk disease, lower complete response rate to R-CHOP chemotherapy, and potentially shorter PFS. Further studies in larger patient population are needed to determine its true prognostic significance.

Disclosures:
No relevant conflicts of interest to declare.
Primary Mediastinal B Cell Lymphoma Treated with CHOP-Like Chemotherapy with or without Rituximab: 5-Year Results of the Mabthera International Trial Group (MInT) Study
Authors: Witzens-Harig Mathias , Ho Anthony D , Kuhnt Evelyn , Trneny Marek , Rieger Michael , Österborg Anders , Pettengell Ruth , Stevens Robert , Gill Devinder S , Walewski Jan , Loeffler Markus , Pfreundschuh Michael 
Published: October 2019

Abstract
Abstract 1612

Purpose
The aim of this subgroup analysis of the MInT study was to evaluate the impact of chemotherapy and rituximab in primary mediastinal B cell lymphoma (PMBCL) in comparison to other diffuse large B-cell lymphoma (DLBCL). Extended follow-up was needed to establish long-term effects.

Patients and Methods
Eligible for the randomized open-label MInT study were patients aged 18–60 years with DLBCL who had 0–1 risk factors according to age-adjusted International Prognostic Index (aaIPI), stage II-IV disease, or stage I disease with bulk. Patients were randomly assigned to six cycles of CHOP-like regimens with or without rituximab. Consolidating radiotherapy was given to sites of primary bulky disease.

Results
Of 824 patients enrolled, 87 had PMBCL and 627 other types of DLBCL. Rituximab increased the rates of complete remission (unconfirmed) in both PMBCL (from 54% to 80%; p =.015) and DLBCL (from 72% to 87%; p<.001). In PMBCL rituximab virtually eliminated progressive disease (PD) (2.5% vs 24%; p =.006), whereas without rituximab PD was more frequent in PMBCL than in DLBCL (24% vs 10%; p =.023). With a median observation time of 62 months for PMBCL and 73 months for DLBCL, the 5-year event-free survival was improved by rituximab for PMBCL (79.1% vs 47.3%; p =.011) and for DLBCL (76.9% vs 59.7%; p <.001). Furthermore, 5-year progression-free survival was improved by rituximab for PMBCL (89.8% vs 60.1%; p=.006) and DLBCL (81.1% vs. 67.8%; p <.001). Overall survival benefit was similar for DLBCL (92.0% vs 80.9%; p <.001) and PMBCL (90.2% vs 78.3%; p =.234).

Conclusion
Addition of rituximab to 6 cycles of CHOP-like chemotherapy improved long-term outcome for young patients with PMBCL and aaIPI 0–1 and eliminated differences in outcome between PMBCL and DLBCL.

Disclosures:
No relevant conflicts of interest to declare.
Transfusion Requirement, Spleen Size and Donor Type Are Strong Predictors of Outcome in Patients with Primary Myelofibrosis Undergoing an Allogeneic Stem Cell Transplant
Authors: Bacigalupo Andrea P , Dominietto Alida , Pozzi Sarah , Geroldi Simona , van Lint Maria Teresa , Raiola Anna Maria , Barosi Giovanni 
Published: October 2019

Abstract
Abstract 1725
Patients with myelofibrosis undergoing an allogeneic stem cell transplant (SCT), can be classified as low or high risk based on spleen size, transfusion history, and donor type (BMT 2010;45:458). In the present study we wished to validate this scoring system, based on a larger number of patients and longer follow up.
We have now analyzed 70 patients with myelofibrosis and a median age of 51, who underwent an allogeneic SCT in our Unit. The median follow up for surviving patients is 4.4 years (range 0.4–17 years). 33 patients had 0–1 unfavourable predictors (low risk) and 37 patients had 2 or more negative predictors (high risk).

Results.
The overall actuarial 10 year survival is 41%. In multivariate COX analysis independent unfavourable factors for survival were red blood cell (RBC) transfusions > 20 (RR 3,9; p=0,007), a spleen size >22 cm (RR 2,8; p=0.01) and an alternative donor (RR 3,4;p=0.001). Donor and patient age and gender, splenectomy and interval diagnosis transplant were not predictive.
The actuarial 10 year survival of patients with no risk factors (n=14), is 100%, with 1 risk factor (n=19) 47%, with 2 factors (n=27), 30%, and with 3 negative predictors (n=10) 0%.The actuarial 10 year survival of low risk (0–1 risk factors) and high risk patients (2–3 risk factors) is respectively 66% and 20%(p=0.0001): the difference is due both to a higher transplant related mortality for high risk patients (38% vs 9%, p=0.005) and a higher relapse related death (35% vs 21%; p=0.1). Peripheral blood CD34+ cell counts, pre-transplant, was a strong predictor of survival in univariate, but not in multivariate analysis.

Conclusions.
Patients with myelofibrosis undergoing an allogeneic SCT, can be classified as low or high risk based on spleen size, transfusion history, and donor type. This scoring system may be useful to identify patients who would most benefit of the transplant procedure.

Disclosures:
No relevant conflicts of interest to declare.
Germline MPLW515R Mutation in a Family with Isolated Thrombocytosis
Authors: Vilaine Mathias , Gourain Victor , Cleyrat Cédric , Feron Delphine , Girodon Francois , Morineau Nadine , Harutyunyan Ashot , Kralovics Robert , Hermouet Sylvie 
Published: October 2019

Abstract
Abstract 1764

Background:
Myeloproliferative neoplasms (MPNs) and related hereditary diseases form a group of chronic hematological diseases that represent a useful model of cancer development. Identification in 2005 of an activating somatic mutation (V617F) in the JAK2 gene in >50% MPN patients was of major importance in the understanding of these diseases. Later, somatic mutations of W515 in exon 10 of MPL were reported for 5–10% MPN patients with essential thrombocythemia (ET) and primary myelofibrosis (PMF), whereas certain germline mutations in the MPL and JAK2 genes (MPLS505N and JAK2V617I respectively) were associated with hereditary thrombocytosis. Here, we report the first cases of germline MPLW515 mutation (R515) in the context of familial, hereditary thrombocytosis.

Methods:
A father and daughter presented with isolated thrombocytosis. Their JAK2, THPO and MPL genes were analyzed by direct sequencing on genomic DNA extracted from whole blood, CD3+ lymphocytes, buccal swabs and hair follicles. Whole blood DNA was also analyzed on Affymetrix 6.0 SNP arrays. Impact of MPLW515R mutation on thrombopoietin (Tpo) signalling was determined by comparison with wild-type and mutated (W515K/L/A) MPL in the Ba/F3-EpoR and K562 cell lines using transient transfection.

Results:
A 36 year old woman presented with chronic isolated thrombocytosis (628–780.109 Plts/L), known for >10 years. There was a familial history of isolated thrombocytosis for the father (74 years old; 646.109 Plts/L) and the father's mother (deceased). The JAK2V617F mutation was not detected in these patients; all other blood tests and bone marrow examination were normal. The two patients presented no evidence of MPN, no splenomegaly, no hepatomegaly, no cause of secondary thrombocytosis and no history of thrombosis. The daughter has two pregnancies without complication. A germline T1588C (W515R) mutation in exon 10 of MPL was found in all tested tissues; no other mutation was found in the JAK2, MPL and THPO genes. Affymetrix 6.0 SNP array analysis revealed no genomic abnormality except for a chromosome Y deletion for the father. Transient transfection in Ba/F3-EpoR and K562 cell lines showed that R515 was activating compared to wild type Mpl, as assessed by the constitutive and Tpo-induced tyrosine phosphorylation of Stat5, Stat3 and Akt. However, R515 was less activating than the K/L/A515 mutants.

Conclusion:
We report the first germline MPLW515R mutation, found associated with isolated hereditary thrombocytosis. W515R increases Mpl activity but to a lesser extent than the somatic MPLW515K/L/A mutations observed in the context of MPNs. Thus the presence of a clearly activating JAK2 or MPL mutation is not sufficient for MPN development. Further investigation of this family might reveal why MPLW515R does not lead to MPN.

Disclosures:
No relevant conflicts of interest to declare.
The Metabolic Signature of CLL: Enhanced Glucose Metabolism in A Subset of High-Risk CLL Patients
Authors: Liu Tingyu , Weinberg J. Brice , Davis Evan D. , Volkheimer Alicia D. , Rathmell Jeffrey 
Published: October 2019

Abstract
Abstract 1785

Background:
Chronic lymphocytic leukemia (CLL), the most common hematopoietic malignancies in adults, remains incurable, and new approaches to treatment are needed. Previous research has defined certain molecular characteristics of CLL (e.g., cytogenetic abnormalities, dysregulated signaling pathways, and alterations of apoptotic proteins) that improve our understanding of this disease and provide prognostic information. In addition to these molecular signatures, it is now clear from multiple settings that changes in cellular metabolism can impact the survival and promote the growth and proliferation of malignant cells. Unlike many cancers, however, CLL cells can have a very low rate of proliferation. Because targeting cancer metabolism may attack a fundamental feature of cancer biology, we sought to characterize the metabolic program of CLL in hopes of establishing new prognostic markers and identifying novel treatment targets. We evaluated the glycolytic and lipid metabolism profiles of B-CLL cells from low- and high-risk CLL patients.

Methods:
We collected blood from CLL patients seen at the Duke Center for CLL and enrolled in IRB-approved protocols at the Duke University and Durham VA Medical Centers. CLL lymphocytes were isolated using negative selection yielding greater than 95% purity of CLL lymphocytes. Standard prognostic testing was done as we have described before. Glut1 expression was detected by immunoblot. Glycolytic rate and lipid oxidation rate was measured by using 3H-labled glucose or palmitic acid respectively as described in the literature. Cell viability was measured by propidium iodide exclusion assay.

Results:
CLL cells exhibited higher expression of the major glucose transporter Glut1 compared to naïve B cells purified from healthy donors (n=20 for CLL and n=3 for normal). CLL cells from a subset of high-risk patients (unmutated IGVH; total n=6) had higher glycolytic rate compared to those from low-risk (mutated IGVH; total n=11) patients. In contrast, no significant change in lipid oxidation was observed between high-risk (IGVH unmutated; n=2) to low-risk (IGVH mutated; n=4) patients. CLL cells were also sensitive to glycolysis inhibitor 2-deoxyglucose (2-DOG), with 2-DOG (5uM) mediating cytotoxicity in vitro.

Conclusion:
We establish for the first time that purified, malignant CLL cells overexpress the glucose transporter Glut1, and that the glycolysis inhibitor 2-DOG is cytotoxic for CLL cells in vitro. In addition, our results demonstrate that cells from high-risk CLL patients have enhanced glucose metabolism relative to leukemia cells from low-risk patients. Therefore, glucose metabolism in these malignant B cells may represent a novel prognostic marker and a novel therapeutic target in this incurable disease.

Disclosures:
No relevant conflicts of interest to declare.
Heparanase Expression Correlates with Bone Destruction in the Patients with Multiple Myeloma
Authors: Wei Shi , Innis-Shelton Racquel , Nan Li , Ruan Jian , Sollie Rebecca S , Reddy Vishnu V B , Yang Yang 
Published: October 2019

Abstract
Abstract 1813
Multiple myeloma is an incurable malignancy, and excessive bone destruction is a major cause of morbidity in myeloma patients. However, the biologic mechanisms involved in the pathogenesis of myeloma-induced bone disease are poorly understood. Heparanase, an enzyme that cleaves the heparan sulfate chains of proteoglycans, is upregulated in a variety of human tumors, including myeloma. In the present study, bone marrow biopsies from 40 myeloma patients were stained with antibodies raised against heparanase, RANKL (an osteoclastogenic cytokine), OPG (a decoy receptor for RANKL), TRAP (a marker of osteoclastogenesis) and osteocalcin (a marker of osteoblastogenesis). The radiologic studies for bone lesions of these patients were also recorded. We analyzed the correlations between heparanase expression in bone marrow myeloma cells with (1) the numbers of TRAP positive osteoclasts, (2) RANKL and OPG expression in myeloma cells and osteoblastic cells, (3) the numbers of osteocalcin positive osteoblasts in bone marrow, and (4) the presence/absence of lytic bone lesions. We found a positive correlation between heparanase expression and RANKL expression as well as the numbers of TRAP positive osteoclasts in myeloma and bone marrow cells, but no correlation was found between the expressions of heparanase and OPG in bone marrow cells (myeloma cells do not express OPG). In contrast, heparanase expression was negatively correlated with the numbers of osteocalcin positive osteoblasts. Taken together, these data suggest that heparanase expression by myeloma cells promotes osteoclastogenesis and at same time inhibits osteoblastogenesis. Clinical data show that 92% of patients with high level of heparanase had one or more lytic bone lesions, while only 63% of patients with median∼ low levels of heparanase had bone lesions (p<0.0001). In summary, enhanced heparanase expression in myeloma cells promotes bone resorption and inhibits bone formation; these events contribute to the uncontrolled bone destruction that is characteristic of myeloma. These data provide novel insight into the mechanisms driving myeloma bone disease and suggest that heparanase inhibitors are valid therapeutic targets for the treatment of multiple myeloma.

Disclosures:
No relevant conflicts of interest to declare.
The RNA Editase ADAR1 Promotes Malignant Progenitor Reprogramming in Chronic Myeloid Leukemia.
Authors: Jiang Qingfei , Crews-Robertson Leslie , Barrett Christian L , Chun Hyn-June , Court-Recart Angela C. , Goff Daniel J , Minden Mark D. , Sadarangani Anil , Rusert Jessica , Dao Kim-Hien , Morris Sheldon R , Goldstein Lawrence S. B. , Marra Marco A. , Frazer Kelly A , Jamieson Catriona 
Published: October 2019

Abstract
Abstract 2772
While advanced malignancies in Chronic Myeoloid Leukemia (CML) are diverse in phenotype, they often exhibit stem cell properties including enhanced survival, quiescence and self-renewal potential. The molecular etiology of human progenitor reprogramming into self-renewing leukemia stem cells (LSC) has remained elusive. While DNA sequencing has uncovered spliceosome gene mutations that promote alternative splicing and portend leukemic transformation, isoform diversity may also be generated by aberrant RNA editing mediated by adenosine deaminase acting on dsRNA (ADAR) family, which have been shown to promote an embryonic transcriptional program and regulate fetal and adult hematopoietic stem cell (HSC) self-renewal as well as stem cell responses to inflammation. In this study, whole transcriptome sequencing of normal, chronic phase (CP) and functionally validated blast crisis (BC) chronic myeloid leukemia (CML) progenitors revealed increased inflammatory pathway gene expression in concert with BCR-ABL amplification, enhanced expression of interferon-responsive ADAR1 and a propensity for increased A-to-I RNA editing during CML progression. Mechanistic studies demonstrated that lentivirally enforced ADAR1 p150 expression induced expression of the myeloid-skewing transcription factor PU.1 and skewed cell fate towards granulocyte-macrophage progenitors - the initiating LSC population in BC CML. Moreover, lentiviral ADAR1 knockdown reduced BC LSC self-renewal capacity in RAG2−/−gc−/− mice. These data shed new light on the role of ADAR1-directed RNA editing in myeloid progenitor reprogramming and self-renewal potential of malignant progenitors that drive disease progression and therapeutic resistance in CML, and provide a compelling rationale for developing ADAR1-based LSC detection and eradication strategies.

Disclosures:
No relevant conflicts of interest to declare.
Controlling Long-Range Genomic Interactions to Reprogram the β-Globin Locus
Authors: Deng Wulan , Rupon Jeremy W , Wang Hongxin , Reik Andreas , Gregory Philip D. , Blobel Gerd A 
Published: October 2019

Abstract
Abstract 280
Distal enhancers physically contact target promoters to confer high level transcription. At the mammalian β-globin loci long-range chromosomal interactions between a distal enhancer, called the locus control region (LCR), and the globin genes are developmentally dynamic such that the LCR contacts the embryonic, fetal and adult globin genes in a stage-appropriate fashion. LCR-globin gene interactions require the nuclear factor Ldb1. Recently, we employed artificial zinc finger (ZF) proteins to target Ldb1 to the endogenous β-globin locus to force an LCR-promoter interaction. This led to substantial activation of β-globin transcription and suggested that forced chromatin looping could be employed as a powerful tool to manipulate gene expression in vivo (Deng et al., Cell 2012). Reactivation of the fetal globin genes in adult erythroid cells has been a long-standing goal in the treatment of patients with sickle cell anemia. Therefore, building on our findings, we investigated whether the developmentally silenced embryonic globin gene βh1 can be re-activated in adult murine erythroblasts by re-directing the LCR away from the adult type globin gene and towards its embryonic counterpart. To this end, Ldb1 was fused to artificial ZF proteins (ZF-Ldb1) designed to bind to the βh1 promoter. ZF-Ldb1 was introduced into definitive erythroid cells in which only the adult but not the embryonic β-like globin gene is expressed. In vivo binding of the ZF-Ldb1 to its intended target was verified by chromatin immunoprecipitation assay. Strikingly, expression of ZF-Ldb1 re-activated βh1 transcription up to approximately ∼15% of total cellular β-globin production. This suggests that forced tethering of a looping factor to a select promoter can be employed to override a pre-existing developmental long-range chromatin interaction to reprogram a developmentally controlled gene locus. We are now in the process of testing whether our approach might be suitable to reactivate the silent fetal globin genes in adult human erythroid cells. These studies are underway and the results will be discussed at the meeting.

Disclosures:
Reik: Sangamo BioSciences, Inc.: Employment. Gregory:Sangamo BioSciences, Inc.: Employment.