bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Disease and Stage Risk Grouping System for Patients Undergoing Allogeneic Stem Cell Transplantation
Authors: Armand Philippe , Gibson Christopher J , Cutler Corey , Ho Vincent T , Koreth John , Alyea Edwin P. , Antin Joseph H. , Soiffer Robert J. , Kim Haesook T 
Published: October 2019

Abstract
Abstract 327

Background:
The outcome of patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT) varies significantly based on the patients' disease and stage at the time of HSCT. When analyzing outcomes of HSCT in heterogeneous patient populations, whether in retrospective or prospective studies, it is therefore necessary to stratify patients based on their disease/stage risk. At present, there is no robust method for doing so; the most commonly used breakdowns are based on older data that may not be applicable today, and do not incorporate cytogenetics for myeloid diseases, which are an important prognostic factor.

Methods:
We analyzed a cohort of 1539 patients transplanted between 2000 and 2009 at Dana-Farber/Brigham and Women's Hospital, and reviewed their disease type (including cytogenetics) and stage at HSCT. Based on proportional hazards modeling for overall survival (with a median follow-up of 35 months), we defined disease and stage risk groups, with independent analyses performed in the 812 patients who underwent myeloablative conditioning (MAC) and the 727 who underwent reduced intensity conditioning (RIC). We used the results to define overall disease/stage risk groups for both MAC and RIC HSCT.

Results:
Interestingly, the disease risk groups turned out to be identical for MAC and RIC; the stage risk groups were very similar, except for the assignment of CR>1 to low risk in MAC but high risk in RIC. The groups were as follows:

Low-risk disease:
AML with favorable cytogenetics, CLL, CML, Hodgkin lymphoma, and non-Hodgkin lymphoma (excluding extranodal T-cell lymphomas)

Intermediate-risk disease:
ALL, AML or MDS with intermediate cytogenetics, myeloproliferative neoplasms, and multiple myeloma

High-risk disease:
AML or MDS with adverse cytogenetics, extranodal T-cell lymphomas

Low-risk stage:
CR1, CR>1 (for MAC), PR1, untreated disease, CP CML

High-risk stage:
CR>1 (for RIC), PR>1, induction failure or active relapse, accelerated or blast phase CML
Those groups could be combined to form 4 overall groups with highly significantly different OS and PFS (Table and Figure).

Conclusion:
We propose a disease/stage risk grouping scheme for patients undergoing HSCT, applicable to both myeloablative and reduced intensity conditioning transplantation, which separates patients into 4 groups with significantly different OS and PFS. This scheme could be used for prognostic purposes, and to stratify patients in retrospective studies or in clinical trials. In the future, it may be further validated and refined through registry studies.

Disclosures:
No relevant conflicts of interest to declare.
Cyclin E Regulation by the Fbw7 Ubiquitin Ligase Pathway Is Required for Normal Mitophagy and Restraining Reactive Oxidative Species During Erythroid Cell Maturation In Vivo,
Authors: Xu Yanfei , Siu Ka Tat , Verma Amit , Minella Alexander C. 
Published: October 2019

Abstract
Abstract 3393
We previously described a knock-in mouse model that permits study of the physiologic consequences of cyclin E deregulation, by selective ablation of its regulation via the SCFFbw7 ubiquitin ligase. We found that erythroid progenitor cells in our cyclin ET74A T393A knock-in mice exhibit abnormally increased proliferation, increased apoptosis, impaired maturation, and dysplastic morphologies. Most prominent among the gene expression alterations we have identified in the cyclin E knock-in erythroid cells is induction of multiple p53 target genes, consistent with p53 pathway activation. In contrast to several recently described models of ribosomal protein gene mutations, in which p53 activation appears to induce dyserythropoiesis, we determined that p53 function actually maintains partially compensated erythroid cell maturation in vivo, in the context of impaired Fbw7-mediated cyclin E degradation. We next found that dysregulated cyclin E-CDK2 activity in cyclin ET74A T393A erythroid cells is associated with increased reactive oxidative species and increased mitochondrial mass and activity. These results coincide with findings of abnormal mitochondria retention in late-stage erythroid cells and significantly down-regulated expression of BNIP3L (NIX). BNIP3L encodes a critical regulator of erythroid cell mitophagy, and the transcriptional controls maintaining its expression in maturing erythroid cells likely account for why this lineage is acutely sensitive to deregulated cyclin E activity. Finally, we show evidence that reduced expression of BNIP3L may play a role in some cases of early-stage myelodysplastic syndromes.

Disclosures:
No relevant conflicts of interest to declare.
Circulating Mesenchymal Stromal Cells As a New Prospective Cancer Marker,
Authors: Kolonin Mikhail , Zhang Yan , Simmons Paul J. , Bellows Charles 
Published: October 2019

Abstract
Abstract 3404
Mobilization of progenitor cells is implicated in pathology and can be indicative of disease progression. Recently, we reported the influence of body mass index (BMI) on level of circulating progenitor cells (Bellows et al., Obesity 2011). Comparative analysis of peripheral blood mononuclear cells (PBMC) from 12 non-obese (BMI < 30) and 14 obese (BMI > 30) disease-free donors by flow cytometry revealed that obesity is associated with a 10-fold increased frequency of circulating mesenchymal stromal progenitor cells (MSC), which circulate at a very low level in healthy lean individuals. We showed that obesity is also associated with a 5-fold increased frequency of circulating progenitor cells (CPC), a population consisting of hematopoietic and endothelial precursors, while the frequencies of mature endothelial cells (EC) and CD34-bright leukocytes (CD34b LC) are unaffected by BMI. Here, we followed up on the assessment of circulating MSC as a potential surrogate pathology marker by analyzing the frequency of circulating CD34-positive progenitor and endothelial cells in a cohort of colorectal cancer patients. PBMC were collected from 45 obese and lean cancer patients and compared to control cancer-free donors. Flow cytometric enumeration of cells was performed based on established immunophenotypes: CD34brightCD31dimCD45dim (CPC), CD34dimCD31brightCD45- (EC), CD34brightCD31-CD45- (MSC) and CD34brightCD45bright CD34b (LC). Groups were compared using multivariate regression analysis. After adjusting for co-founders such as age and BMI, the mean frequencies of MSC and CD34bLC, but not of CPC and EC, were found to be significantly higher in the circulation of CRC patients compared to cancer-free donors. Interestingly, the frequency of circulating MSC, but not of the other cell populations, was also found to be significantly higher in the circulation of obese CRC patients compared to lean CRC patients and obese cancer-free controls. We conclude that markedly increased frequency of MSC in the peripheral blood may represent a new diagnostic CRC marker. BMI-dependent changes in circulating MSC, potentially mobilized from adipose tissue may reveal their trafficking to tumors, which could be one of the mechanistic links between obesity and cancer progression. Validation of MSC as a new surrogate marker of cancer could provide a tool for determining prognosis, predicting response to therapy, and detecting relapse following treatment.

Disclosures:
No relevant conflicts of interest to declare.
High Frequency of Large Gene Deletions Detected by Multiplex Ligation-Dependent Probe Amplification in Diamond Blackfan Anemia,
Authors: Quarello Paola , Garelli Emanuela , Carando Adriana , Pappi Patrizia , Brusco Alfredo , Dianzani Irma , Ramenghi Ugo 
Published: October 2019

Abstract
Abstract 3428

Background:
Diamond-Blackfan anemia (DBA,#MIM105650) is a rare congenital pure red cell aplasia characterized by normochromic macrocytic anemia, reticulocytopenia, and normocellular bone marrow with a selective deficiency of erythroid precursors.
Although mutations of eleven ribosomal protein (RP) genes have been detected in more than 50% of DBA patients the remaining patients appear to have intact ribosomal protein genes using stadard sequencing methods (Boria et al. Hum Mut 2010).
We previously described the detection of three large RPS19 deletions using the MLPA (Multiplex Ligation-dependent Probe Amplification) technique (Quarello et al. Haematologica 2008). As MLPA is an efficient and rapid technique that detects gene dosage alterations, we thus decided to apply this approach also to other RP genes.

Aim:
To search for unidentified RP large deletions we applied the MLPA technique in Italian DBA patients who have been found mutation-negative by sequencing.

Methods:
Italian DBA patients without RP genes mutations (73/156, 47%) were included in this study. The analysis was performed using a homemade MLPA kit following the recommendations provided by MRC Holland (Amsterdam, The Netherlands, www.mlpa.com). The probes were designed to detect deletions of six RP genes (RPS17, RPS19, RPS26, RPL5, RPL11, RPL35A). Deletions of probe recognition sequences were apparent by a 35–50% reduced relative peak area of the amplification product of that probe.

Results:
The results of the MLPA assay revealed that 13 out of the 73 probands (18%) had a multi-exonic deletion in one of the six DBA genes analyzed. We identified four deletions of the RPS17 gene, three of the RPS26 gene, three of the RPL35A, two of the RPL11 gene and one of the RPL5 gene. No additional RPS19 deletions were found. DBA patients with deletions showed a severe phenotype with a very high percentage of transfusion dependence (85%). Somatic malformations were observed only in two patients.

Conclusion:
We detected a high percentage of deletions of known DBA genes in a cohort of patients in whom no mutations were found by RP sequencing.
Mutation screening of the RP genes with a combination of sequencing and MLPA reached an overall detection rate of 61.5% (96/156). In our cohort, large genomic deletions represent up to 18% of all mutations detected.
In conclusion, we stress the high percentage of identified RP genes deletions in DBA patients. We also highlight that a gene-dosage technique, such as MLPA, should complement sequencing in a clinical environment since only a combined approach of this kind permits the comprehensive detection of all mutations in the DBA RP genes.

Disclosures:
No relevant conflicts of interest to declare.
Successive Development of T-Cell Acute Lymphoblastic Leukemia, Non-Langerhans-Cell Histiocytose and Histiocytic Sarcoma with a Common Origin: Evidence for Common Oncogenetic Transformation Before Full Lineage Commitment,
Authors: te Loo D. Maroeska W.M. , Waanders Esmé , Groenen Patricia JTA , Simons Annet , van Dongen Jacques J.M. , Hoogerbrugge Peter M. , Hebeda Konnie M 
Published: October 2019

Abstract
Abstract 3470
Hematopoiesis is traditionally seen as the unidirectional maturation of stem cells into lineage committed cells. Recent data are suggestive for some degree of lineage flexibility in both normal as malignant cells. We here present a boy that presented with T-cell acute lymphoblastic leukemia (T-ALL). During T-ALL treatment, the patient developed in short time a non-Langerhans-cell histiocytose in the ileum, and subsequently a disseminated form of histiocytic sarcoma (a.o. also in the liver). Interestingly, the same clonal T cell receptor (TCR) gene rearrangements were found in all three malignancies (TCRB-VJ, TCRG-VJ and TCRB-DJ) indicating they were related. There were no immunoglobulin rearrangements. To understand the evolution from T-ALL to non-Langerhans-cell histiocytose and to histiocytic sarcoma, an extensive genetic analysis was performed. Using a SNP6.0 array platform we analyzed DNA isolated from T-ALL cells, a bone marrow sample obtained during complete remission from theT-ALL, a biopsy from the ileum tumor, the liver tumor, and DNA isolated from skin fibroblasts.
The three tumor samples were not fully concordant in the SNP analysis, with lesions acquired but also absent from subsequent samples. All three tumor samples showed identical TCR gene rearrangements as well as a loss of the CDKN2A/B region, the only gene-containing copy number aberration (CNA) present in the T-ALL. The T-ALL sample showed a homozygous loss of the CDKN2A/B region, whereas both the ileum and liver samples showed a heterozygous loss. In addition, the three tumor samples shared two 1Mb regions of loss of heterozygosity (LOH) on chromosomes 6p and 11p, containing DDB2, MADD and RUNX2, amongst others. A gain on chromosome 19q containing 12 genes was shared between the ileum and liver sample only. In addition, the ileum tumor showed 14 non-shared CNAs of which 11 losses, 2 homozygous losses, and 1 gain, affecting 11 genes including ZFAT, PTPRK and beta-catenin (CTNNB1). The liver tumor acquired gains of a large part of chromosome 5, the p-arm of chromosome 11 and the q-arm of chromosome 22 reminiscent of a chromothrypsis event. The PAX5 gene indicated in the progression of an ALL to histiocytic sarcoma was not affected in either of the samples. These results indicate that the three tumors are related but did not evolve from each other in a linear manner. Apparently, the common oncogenetic transformation occurred at an early differentiation stage with lineage plasticity, i.e. with some lineage specification but without full lineage commitment.

Disclosures:
No relevant conflicts of interest to declare.
Long Term Followup of Bystander Vaccine Therapy in Mantle Cell Lymphoma (MCL),
Authors: Shah Bijal D. , Tao Jianguo , Sokol Lubomir , Chervenick Paul A. , Tomblyn Marcie , Pinilla-Ibarz Javier , Moscinski Lynn , Antonia Scott , Sotomayor Eduardo M. , Dessureault Sophie 
Published: October 2019

Abstract
Abstract 3720

Background:
A Phase I study revealed that vaccination of cancer patients with irradiated autologous tumor cells and GM.CD40L bystander cells (engineered to secrete GM-CSF and express CD40L) is safe, recruits/activates dendritic cells, and elicits tumor-specific T cell responses. We report the long term followup using this vaccine strategy in patients with MCL, an aggressive and incurable B-cell malignancy.

Methods:
After lymph node resection for autologous tumor harvest, 4–6 cycles of chemotherapy, and restaging (CT, endoscopy, bone marrow biopsy), patients with usable vaccine who achieved a PR or CR lasting 1 month were vaccinated x4 at 28-day intervals with IL-2 (0.5 × 106 U SC BID × 14 d/cycle). Patients were monitored for toxicity, tumor response, tumor-specific immune responses, and EFS/OS.

Results:
43 were enrolled, including 21 with relapsed MCL, 20 with int/high MIPI, and 6 with blastoid MCL. Twenty never received vaccine: 2 withdrew consent, 1 progressed rapidly prior to lymph node harvest, 7 had insufficient or contaminated specimens, and 10 progressed/died during chemotherapy. The unvaccinated were older (68.4y vs 62.8y; p=.026) but otherwise did not differ significantly by stage, LDH, MIPI, de novo status, or number of prior treatments.
Among 23 treated, 10 had relapsed disease, 10 had an int/high MIPI, and 2 had blastoid MCL. Pre-vaccination response following chemotherapy included 7 CR, 15 PR, and one SD. At 6 months after vaccination, 2 pts in PR had resolution of MRD within the bone marrow, 10 progressed (including 3 who progressed after only 1–2 vaccines), and 11 had no change. Two are still in CR at 49 & 50 months. Median EFS and OS are calculated from receipt of first vaccine. Median EFS is 9 mo, however, this high risk cohort continues to show a prolonged median OS, which has not yet been reached (median follow-up 43 mo, range 4–79 mo). An increase in interferon gamma secretion as measured by ELISPOT assays was observed in 15 of the 23 patients (65%). Additionally, this was accompanied by an increase in EFS among those with a positive response.

Conclusions:
These phase 2 data are analogous to what we have seen among 4 patients with relapsed MCL treated on our phase 1 trial (EFS 6.5 mo, OS 82 mo), and support the need for further studies using GM.CD40L bystander vaccination. Similar discrepancies in EFS and OS have also been observed with other approved immunotherapeutics, ipilumumab & sipleucel-T (Hodi et al. 2010, Kantoff et al. 2010).

Disclosures:
No relevant conflicts of interest to declare.
Angiogenic Factors eNOS and VEGF Have Increased Expression in Granulocytes of JAK2V617F Homozygous Forms of Polycythemia Vera,
Authors: Cokic Vladan P , Markovic Dragana , Mitrovic Olivera , Vignjevic Sanja , Djikic Dragoslava , Beleslin-Cokic Bojana B , Perunicic Maja , Ilic Bojana , Jovcic Gordana , Gotic Mirjana , Noguchi Constance Tom , Schechter Alan N 
Published: October 2019

Abstract
Abstract 3847
The microvessel density of bone marrow is increased in myeloproliferative neoplasms (MPN) parallel with vascular endothelial growth factor (VEGF). VEGF-mediated angiogenesis requires nitric oxide (NO) production from activated endothelial NO synthase (eNOS). NO as well as hypoxia stimulate the VEGF gene expression and angiogenesis by enhancing hypoxia inducible factor (HIF)-1 activity. We studied 126 newly diagnosed patients with BCR-ABL− MPN: 64 polycythemia vera (PV), 36 essential thrombocythemia (ET), 26 primary myelofibrosis (PMF) and 12 healthy individuals. We performed a combined analysis of hematopoietic CD34+ progenitor cells and granulocytes in peripheral blood of these individuals. The eNOS protein level is more than three-fold elevated in granulocytes of JAK2V617F homozygous PV patients. The essential inducer of angiogenesis VEGF-A has also about three-fold elevation at the protein level in granulocytes of PV patients, with major increases in JAK2V617F homozygous forms. Immunohistochemical analysis reveal that the percentage of VEGF-A-positive cells is increased in bone marrow of PV (5.58±0.7%) compared to normal controls (2.78±0.7%) and VEGF-A mRNA levels are increased in hematopoietic progenitor cells of PV origin. Transcription factor HIF-1α gene expression is decreased in hematopoietic progenitor cells and increased in granulocytes of PV patients. Negative regulator of HIF-1α activity, a transcription factor HIF-3α, has decreased expression in hematopoietic progenitor cells and not changed in granulocytes. In contrast to PV patients, PMF and ET disorders with a minor JAK2 mutation burden demonstrate reduced eNOS and VEGF protein levels and decreased HIF-1a gene expression in peripheral blood granulocytes, although the increase in percentage of VEGF-A-positive cells in bone marrow observed in PV patients is also evident. The present results expand the significance of JAK2V617F mutation in induction of angiogenic factors eNOS and VEGF in granulocytes of PV patients with enhanced HIF-1α presence. Moreover, the stromal and hematopoietic cells also show increased VEGF protein expression in bone marrow of PV patients. Therefore, we find that variations in angiogenic factors expression among MPN patients appear to be related to JAK2V617F mutation allele burden.

Disclosures:
No relevant conflicts of interest to declare.
CD38 Regulates Homing and Engraftment of CLL Cells,
Authors: Vaisitti Tiziana , Serra Sara , Audrito Valentina , Pepper Chris , Rossi Davide , D'Arena Giovanni , Laurenti Luca , Zucchetto Antonella , Gattei Valter , Gaidano Gianluca , Malavasi Fabio , Deaglio Silvia 
Published: October 2019

Abstract
Abstract 3873
Chronic lymphocytic leukemia (CLL) is considered the result of a dynamic balance between proliferating cells in lymphoid organs and circulating cells resisting apoptosis. Re-circulation of leukemic cells from blood to growth-permissive niches represents an essential step in the maintenance and progression of the disease. This equilibrium is finely tuned by a set of surface molecules expressed by CLL cells and modulated in response to environmental conditions.
We previously reported that CD38, an enzyme and a receptor, functionally cooperates with the CXCL12/CXCR4 axis, enhancing the ability of CLL cells to home to bone marrow and lymph nodes. In addition, the use of anti-CD38 mAbs can enhance or impair the chemotactic behavior of the neoplastic cells. New evidence also indicates that CD38 synergizes with the CD49d integrin, increasing adhesion of CLL cells to VCAM-1 or the CS-1 fibronectin fragment, two known ligands of CD49d. To complete the picture, CD38 expression denotes a CLL subset with increased activity of the matrix metalloproteinases MMP-9. Ligation of CD38 with specific antibodies increases MMP-9 secretion and the invasive properties of CLL cells, using in vitro assays. The effects on chemotaxis, adhesion and invasion are obtained through modulation of a ERK1/2-dependent pathway.
To further confirm the involvement of CD38 in CLL homing to specific niches, in vivo experiments have been set using NOD/SCID/γ chain−/− (NSG) mice. The CLL-like cell line Mec-1, constitutively CD38−/CD49d+, was adopted as a model and compared to transfectants stably expressing wild-type (wt) CD38, as well a mutant lacking enzyme activities. Results after i.v. injections of tumor cells indicate that de novo expression of CD38 by Mec-1 cells increases growth kinetics in vivo with a higher proliferation rate and metastatic potential, as compared to the Mec-1 mock-trasfected cells. Both these features are lost when the animals are injected with the enzyme-deficient variant of CD38, suggesting that the enzymatic activity is critical for in vivo growth and re-circulation of Mec-1 cells. Microarray data confirm that the genetic signature of the CD38-enzyme mutant overlaps with the wild-type cell line, clearly distinct from cells transfected with CD38. The latter cell line shows up-modulation of several genes involved in chemotaxis and adhesion.
All together, these results support the notion that CD38 is part of a complex network of molecules and signals, that regulate homing of CLL cells to growth-permissive niches, suggesting a relationship between the expression of CD38, the ability to migrate and invade and the poor clinical outcome of the CD38+ subset of patients.

Disclosures:
No relevant conflicts of interest to declare.