bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification of Gene Expression Based Prognostic Markers in the Hematopoietic Stem Cells of Patients with Myelodysplastic Syndromes
Authors: Pellagatti Andrea , Benner Axel , Mills Ken I , Cazzola Mario , Giagounidis Aristoteles , Perry Janet , Malcovati Luca , Della Porta Matteo G , Jadersten Martin , Verma Amit , McDonald Emma-Jane , Killick Sally , Hellstrom-Lindberg Eva , Bullinger Lars , Wainscoat James S , Boultwood Jacqueline 
Published: October 2019

Abstract
Abstract 3857
The diagnosis of patients with myelodysplastic syndromes (MDS) is largely dependent on morphologic examination of bone marrow aspirates. Several criteria that form the basis of the classifications and scoring systems most commonly used in clinical practice are affected by operator-dependent variation. In order to identify more standardized molecular markers that would allow a more reliable prediction of prognosis, we have used gene expression profiling (GEP) data on CD34+ cells from MDS patients to determine the relationship between gene expression levels and prognosis in this disorder. GEP data on CD34+ cells from 125 MDS patients with a minimum 12-month follow-up since date of bone marrow sample collection were included in this study. Prediction for overall survival was performed using supervised principal components (“SuperPC”) and lasso penalized Cox proportional hazards regression applying the “Coxnet” algorithm. Supervised principal components analysis was performed on patients randomly split in a training set (n=84) and a test set (n=41), and 139 genes were identified the expression of which was significantly associated with MDS patient survival, including LEF1, CDH1, WT1 and MN1. In order to identify a smaller set of genes associated with patient survival, a second approach aiming at building sparse prediction models was used. A model was generated using the Coxnet algorithm and a predictor consisting of 20 genes was identified. Eight genes identified by the supervised principal components method were in common with the genes identified by the Coxnet model: ADHFE1, BTBD6, CPT1B, LEF1, FRMD6, GPR114, C7orf58 and LOC100286844. The Coxnet predictor outperformed other predictors including one which additionally used clinical information. To validate our findings, we evaluated the performance of our prognostic Coxnet gene signature in an independent gene expression profiling dataset on MDS bone marrow mononuclear cells (Mills et al, Gene Expression Omnibus series GSE15061). Our Coxnet gene signature based on CD34+ cells significantly identified a low-risk patient group in this independent GEP dataset based on unsorted bone marrow mononuclear cells, demonstrating that our signature is robust and may be applicable to bone marrow cells without the need to isolate CD34+ cells. These GEP-based signatures correlating with clinical outcome may significantly contribute to a refined risk classification of MDS.

Disclosures:
No relevant conflicts of interest to declare.
Tissue-Specific Transgene Expression in Induced Pluripotent Stem (iPS) Cell-Derived Megakaryocytes: Correction of Glanzmann Thrombasthenia (GT)
Authors: Sullivan Spencer K. , Mills Jason A. , Zhai Li , Paluru Prasuna , Vo Karen , Lambert Michele , Koukouritaki Sevasti B. , Fang Juan , Wilcox David A. , French Deborah L. , Poncz Mortimer , Gadue Paul 
Published: October 2019

Abstract
Abstract 387
Megakaryocyte-specific transgene expression in patient-derived iPS cells offers a new approach to study and potentially treat disorders that affect megakaryocytes and platelets. The feasibility of this method was demonstrated in GT, a disorder resulting from an absence of functional platelet integrin alphaIIb/beta3, leading to impaired platelet aggregation and clinically presenting with severe bleeding. While rare, GT can serve as a model of an inherited platelet disorder that would benefit from corrective cell therapy. For this study, iPS cells were generated from the peripheral blood of healthy controls and two patients with GT. Patient 1 is homozygous for a novel alphaIIb exon/intron 4 splice site mutation, leading to an alternatively spliced transcript and premature stop codon. Patient 2 is homozygous for a previously reported alphaIIb missense mutation in exon 8 (p.G273D), leading to impaired intracellular transport and surface expression of the heterodimer. Both patients express <5% alphaIIb/beta3 on the surface of their platelets, which was confirmed in IPS cell-derived megakaryocytes. To achieve megakaryocyte-specific expression, transgene constructs were created using the murine proximal GPIbalpha promoter driving either an eGFP reporter or wild type alphaIIb cDNA. These constructs were inserted into the AAVS1 safe harbor locus using zinc finger nuclease-mediated homologous recombination. When targeted to a single allele of the AAVS1 locus in human ES cells, the GPIbalpha promoter driving eGFP showed a high-level of expression in ES cell-derived megakaryocytes. Inserting the GPIbalpha promoter driving alphaIIb into a single allele of the AAVS1 locus in GT iPS cells restored ∼60% surface expression of integrin alphaIIb/beta3 when compared to control iPS cell-derived megakaryocytes. Transgenic alphaIIb mRNA levels were similar to endogenous alphaIIb mRNA levels in differentiated megakaryocytes. When stimulated with thrombin, corrected GT iPS cell-derived megakaryocytes demonstrated both PAC-1 antibody binding and fibrinogen binding. This study shows the GPIbalpha promoter construct targeted to the AAVS1 locus drives a high-level of expression in iPS cell-derived megakaryocytes, which offers a novel tool to study megakaryocyte and platelet biology in samples obtained from affected individuals. For GT, this study demonstrates a higher level of correction than seen with a lentiviral approach. To our knowledge, this is the first report of the generation and correction of iPS cell lines from patients with a disease affecting platelet function.

Disclosures:
No relevant conflicts of interest to declare.
IL4 and CD40L Prevent Apoptosis of Chronic Lymphocytic Leukemia Cells Via Intracellular pSTAT6 and NFkB Signaling and Not Via Receptor Kinetics
Authors: Mertens Daniel , Bhattacharya Nupur , Häbe Sarah , Döhner Hartmut , Stilgenbauer Stephan 
Published: October 2019

Abstract
Abstract 3893
Chronic lymphocytic leukemia (CLL) cells are highly dependent on microenvironmental input for their extended survival in vivo, but the underlying molecular mechanism is still unclear. Compared to non-malignant B-cells, CLL cells are more responsive to contact dependent complex stimuli like coculture on bone marrow derived stromal cell lines of both human (p<0.0001) and murine origin (p<0.01), but also to soluble factors (human conditioned medium p<0.0001, murine conditioned medium p<0.001, all student′s t-test). In order to understand the intrinsic difference of the anti-apoptotic phenotype of CLL cells, the signalling circuitry of the malignant cells was modelled. Compared to candidate ligands like SDF-1 (at concentrations between 10–1000ng/ml), BAFF (250–1000ng/ml), APRIL (250–1000ng/ml) and soluble anti-IgM (1–25μg/ml), the factors CD40L (10–2000ng/ml) and IL4 (0.1–10ng/ml) were the most efficient ligands in rescuing CLL cells from spontaneous death in vitro. The dose response of IL4 and CD40L displayed different saturation and cooperativity between CLL cells and non-malignant B-cells. Using IL4, saturation was reached both for CLL cells and B-cells at 0.2pM, but at 52% survival (+/− 8%) for CLL cells and 28% (+/−7%) for B-cells, and the estimated dissociation constant Kd was 0.01pM for both ligands. For CD40L, CLL cell survival reached saturation at 40nM, while no saturation was reached for B-cells. Intriguingly, B-cells showed cooperativity in their response to CD40L, with a cooperativity coefficient of 2.0 and a Kd of 70pM, while cooperativity for CD40L was lost in CLL cells (Kd of only 2.6pM). This pointed towards distinct differences in ligand-receptor interactions or in downstream signaling between CLL cells and non-malignant B-cells. However, high-throughput spatial analysis with a microscope-coupled cytometer did not show differences of receptor quantity or receptor distribution between malignant and non-malignant cells. In contrast, quantity and phosphorylation levels of downstream signalling nodes like STAT6 (measured by flow cytometry and validated by Western-blot) and the activity of NF-kB (p65 binding to DNA measured by oligonucleotide-coupled ELISA) were higher in CLL cells compared to B-cells from healthy donors. Therefore, the defect in IL4 and CD40L signalling that leads to an enhanced survival in CLL cells is likely caused by changes in the intracellular circuitry.

Disclosures:
No relevant conflicts of interest to declare.
The Expression Pattern of Small Nucleolar and Small Cajal Body-Specific RNAs Characterizes Distinct Molecular Subtypes of Multiple Myeloma
Authors: Ronchetti Domenica , Todoerti Katia , Tuana Giacomo , Agnelli Luca , Mosca Laura , Lionetti Marta , Fabris Sonia , Colapietro Patrizia , Miozzo Monica , Ferrarini Manlio , Tassone Pierfrancesco , Neri Antonino 
Published: October 2019

Abstract
Abstract 3955
Small nucleolar RNAs (snoRNAs) and small Cajal body-specific RNAs (scaRNAs) are non-coding RNAs involved in the maturation of other RNA molecules and generally located in the introns of host genes. It is an emerging evidence that altered sno/scaRNAs expression may play a pathological role in cancer. Impaired sno/scaRNAs expression has recently been reported both in acute leukemia and smoldering myeloma that rapidly progressed to symptomatic disease. In addition, as regards multiple myeloma (MM), very recent data suggested an oncogenic role for SCARNA22 in those MM patients over-expressing SCARNA22/MMSET as a result of t(4;14) translocation. However, comprehensive information concerning the expression behavior of sno/scaRNAs in MM is still lacking.
This study elucidates the patterns of sno/scaRNAs expression in MM by profiling purified malignant plasma cells from 55 MMs, 8 secondary plasma cell leukemias (sPCL) and 4 normal controls using Human Gene 1.0 ST arrays.
Overall, a global sno/scaRNAs down-regulation was found in MMs and at more extent in sPCLs compared to normal plasma cells. Whereas SCARNA22 resulted the only sno/scaRNA characterizing the TC4 MM, TC2 group displayed a distinct sno/scaRNA signature overexpressing members of SNORD115 and SNORD116 families located in a region finely regulated by an imprinting center at 15q11 which, however, resulted overall hypomethylated in MMs independently of the SNORD115 and SNORD116 expression levels. In addition, impaired expression of sno/scaRNAs raised from the comparison between MM and sPCL, suggested a role in tumor progression. Furthermore, to uncover possible mechanisms at the basis of sno/scaRNAs deregulation, we investigated the correlation between sno/scaRNAs and the corresponding host-genes expression levels, outlining the coordinated expression of up to 50% of sno/scaRNAs/host-genes pairs. Finally, we investigated whether the sno/scaRNAs transcriptional pattern may be influenced by allelic imbalances involving their genomic location, as already demonstrated concerning mRNA expression, and revealed a dosage effect involving several chromosomal regions.
Our data extend the current view of sno/scaRNAs deregulation in cancer and add novel information into the bio-molecular complexity of plasma cell dyscrasias. Furthermore, our findings may contribute to develop functional approaches to examine the activity of deregulated sno/scaRNAs in MM, as well as to further enlighten their possible role as targets of novel therapeutic agents.

Disclosures:
No relevant conflicts of interest to declare.
Lenalidomide and Dexamethasone in the Treatment of AL Amyloidosis: Final Results of A Phase II Trial
Authors: Nair Divya , Sanchorawala Vaishali , Shelton Anthony C , Fennessey Salli A , Finn Kathleen T , Skinner Martha , Zeldis Jerome B. , Seldin David C 
Published: October 2019

Abstract
Abstract 4084
AL amyloidosis is a plasma cell dyscrasia in which clonal immunoglobulin light chains misfold, forming fibrils that are deposited in tissues and vital organs. Immunomodulatory drugs including thalidomide, lenalidomide (LEN), and pomalidomide have activity in AL amyloidosis. We conducted a prospective phase II trial of LEN with dexamethasone (DEX) in the treatment of AL amyloidosis (ClinicalTrials.gov: NCT00091260), enrolling 82 patients from 2004–2011. We now report the final results of this trial. The majority of the patients were treated with LEN at a starting dose of 15 mg/d for 21 days out of a 28 day cycle, and received DEX at 20 or 40 mg weekly, depending upon age, congestive heart failure, and/or peripheral edema, and aspirin prophylaxis for venous thromboembolism (VTE) was used for most. Of the 82 patients, the median age was 62 (range, 40–84) and 63% were men. 95% of the patients had prior therapy for AL, often including high dose melphalan and autologous stem cell transplantation. The median number of cycles delivered was 11 (range, 1–69). Of the 68 evaluable patients, 16% achieved a complete hematologic response, 44% achieved a partial hematologic response, 9% achieved a minor hematologic response, and 29% had no response to treatment. The median time to best hematologic response was 6 months. Sixty-three patients had quantifiable organ involvement prior to treatment with LEN/DEX, and 44% of those patients had measurable organ response. Reasons for discontinuation of study drug were side effects (29%), non-response (39%) and complete response or completion of trial (15%). The most common side effects during treatment were fatigue (88%), anemia (67%), muscle cramps (66%), dizziness/lightheadedness (60%), respiratory tract infections (55%), increased creatinine (56%) and skin rash (48%). In conclusion, LEN administration achieved a 60% hematologic response rate (CR+PR) even in heavily pre-treated AL patients, when used at a starting dose of 15 mg/d with weekly dose-modified DEX, VTE prophylaxis, and appropriate management of side effects.

Disclosures:
Off Label Use: Lenalidomide for AL amyloidosis. Sanchorawala:Millennium: Research Funding. Zeldis:Celgene: Employment. Seldin:Celgene: Research Funding.
Mycophenolate Mofetil Vs. Methotrexate for the Prophylaxis of Graft-Versus-Host-Disease - Systematic Review and Meta-Analysis of All Comparative Trials
Authors: Ram Ron , Yeshurun Moshe , Vidal Liat , Shpilberg Ofer , Gafter-Gvili Anat 
Published: October 2019

Abstract
Abstract 4169

Background:
Mycophenolate mofetil (MMF) has emerged as a potential substitute to methotrexate in patients given calcineurin inhibitors for the prophylaxis of GVHD prior to allogeneic hematopoietic cell transplantation. However, a comprehensive literature evaluation of MMF vs. methotrexate is lacking.

Objectives:
This study aims to compare the efficacy and safety of MMF vs. methotrexate as part of the GVHD prophylaxis regimen in patients given allografts.

Methods:
Systematic review and meta-analysis of all comparative trials of patients given allografts and administered GVHD prophylaxis with a regimen containing MMF or methotrexate. Electronic search was conducted until June 2012. Primary outcome was acute GVHD. Secondary outcomes were all-cause mortality, relapse rate, non-relapse mortality, chronic GVHD, rate of mucositis, and the time to neutrophil and platelet engraftment. For dichotomous data, relative risks (RR) with 95% confidence intervals (CIs) were estimated and pooled. For continuous variables we calculated weighted mean difference (WMD).

Results:
Our search yielded 11 trials, 3 were randomized control trials (RCTs) and 8 were either one arm intervention trials compared to historical controls or retrospective studies. There was no difference in the overall incidence of acute GVHD (RR 1.06; 95% CI 0.93–1.21, 11 trials) with similar results in a sensitivity analysis including only RCTs. Conversely, incidence of grade 3–4 acute GVHD was higher in patients given MMF (RR 1.61; 95% CI 1.18–2.20, 6 trials, Figure). However, this association was no longer statistically significant when only patients given allografts from matched siblings or those given myloablative conditioning were analyzed (RR 1.56; 95% CI 0.95–2.55, 5 trials and RR 1.40; 95% CI 0.82–2.39, 4 trials). All cause mortality, non relapse mortality, relapse rate and the incidence of chronic GVHD were comparable between the two groups. Incidence of mucositis was significantly lower in patients given MMF (RR 0.35; 95% CI 0.25–0.49, 8 trials) and the time to neutrophil and platelet engraftment was shorter in the MMF arm (WMD (−4.05); 95% CI (−6.17) – (−1.3), 6 trials and WMD (−3.74); 95% CI (−6.3) – (−1.18), 4 trials, respectively).

Conclusions:
MMF, compared to methotrexate, given as GVHD prophylaxis is associated with reduced transplantation associated toxicities, however with increased severity of acute GVHD. Further RCTs to identify the subgroups of patients who will benefit the most from MMF are warranted.

Disclosures:
No relevant conflicts of interest to declare.
Minor Histocompatibility Antigen Mismatch and Incidence of Graft Versus Host Disease, Event-Free, and Overall Survival in Patients Undergoing Unrelated Donor Allogeneic Hematopoietic Cell Transplantation
Authors: Shaffer Brian C , Tremblay Christine , Peaceman Daniel , Hsu Jennifer , Steinberg Seth M. , Uribe Marcela , Adams Sharon , Flegel Willy A. , Pavletic Steven Z. 
Published: October 2019

Abstract
Abstract 4201
Graft versus Host Disease (GvHD) is a potentially devastating complication of allogeneic hematopoietic cell transplantation (HCT) initiated in part due to donor-recipient disparities in immunoreactive proteins, or minor histocompatibility antigens (mHAgs). There are no established prognostic tools to predict which patients will get acute or chronic GvHD. Analysis of mHAg mismatch is a potential predictive tool for GvHD; however, previous studies attempting to establish a relationship between mHAg mismatch and GvHD have been largely equivocal. Here we tested the hypothesis that analysis of an expanded set of mHAgs for mismatch in the GvH direction can be predictive of acute or chronic GvHD by NIH criteria. We additionally analyzed event-free (EFS) and overall survival (OS) in the mHAg matched and mismatched subgroups. Recipient/donor pairs from 45 HLA-A, -B, -C, and DRB1 matched unrelated donor transplants from 2007–2011 were retrospectively typed for 19 mHAgs using an SSP-PCR typing kit (Minor Histocompatibility Antigen Typing Kit; Life Technologies, Carlsbad, CA). Genomic DNA was obtained from peripheral blood mononuclear cells. EFS and OS were estimated using the Kaplan-Meier method. The relationship between mismatch and acute or chronic GvHD was described using Fischer's Exact Test. Cumulative incidence of treatment related mortality (TRM) was calculated using the Gooley Method. Two patients expired of early TRM and were excluded from the GvHD analyses. The rate of acute GvHD grades II-IV was 6 of 14 in those without a mHAg mismatch and 21 of 29 in those with a mismatch (43% versus 72%, P = 0.062). The rate of chronic GvHD was 8 of 14 in those without a mismatch and 10 of 29 in those with a mismatch (53% versus 34%, P = 0.140). The presence of a mismatch did not significantly impact EFS (P = 0.42) or OS (P = 0.26). The cumulative incidence of TRM at 24 months post transplantation was greater in patients with a mismatch (36% versus 13%). Two year OS was superior in patients who were conditioned with alemtuzumab (N = 24) and had a lower degree of mismatch (0–1 mismatch = 72% versus 2+ mismatches = 38%, P = 0.038). This study suggests the possibility of a relationship between mHAg mismatch and acute GvHD and TRM. Further study using this expanded mHAg analysis on a larger cohort of individuals would more adequately define the potential benefit of mHAg mismatch analysis in the context of unrelated donor HCT.

Disclosures:
No relevant conflicts of interest to declare.
Incidence and Geographic Distribution of Adult Acute Lymphoblastic Leukemia in the State of Georgia
Authors: El Rassi Fuad , Arellano Martha , Heffner Leonard T , Waller Edmund K. , Winton Elliott F. , Ward Kevin , Khoury H. Jean 
Published: October 2019

Abstract
Abstract 4309
We investigated an apparent increase in acute lymphoblastic leukemia (ALL) referral from north Georgia to Emory University Hospital, a tertiary care center located in Atlanta, Georgia. Cases reported between 1999 and 2008 to the Georgia Comprehensive Cancer Registry (GCCR) and the national Surveillance Epidemiology and End Results (SEER) cancer registry were analyzed. Age-adjusted incidence rates were calculated for all counties and public health regions within the state of Georgia and compared to national rates calculated using SEER 17 data for those ages 20 and above. Cases of adult acute myeloid leukemia (AML) served as control for health referral patterns, completeness of data collection and healthcare availability. The associations between geographic residence and acute leukemia were analyzed using Poisson regression analysis, and additional models were created to control for the effects of race and ethnicity. The age-adjusted incidence rate of adult ALL (0.8/100,000) and AML (4.6/100,000) for the state of Georgia were comparable to the national rates (0.9/100,000 and 5.2/100,000 respectively). Overall, the rate of ALL observed in parts of the North Georgia region (1.1 (95% CI 0.8, 1.5) were similar when compared to the rest of the state; and not affected after adjusting for race. We conclude that the higher number of cases of ALL cases referred from North Georgia is likely related to a physician-related referral pattern rather than an increased incidence.
Age-adjusted incidence rate of ALL by state and public health region and rate ratios comparing the rate of ALL within each region to the pooled rates demonstrated in all other Georgia public health regions.
Region of Georgia (GA) Rate SE Lower CI Upper CI Count Pop GA: Clayton (Jonesboro) 1.1 0.3 0.6 1.8 17 1,715,865 GA: DeKalb 0.8 0.1 0.5 1.1 37 5,111,685 GA: Fulton 0.6 0.1 0.4 0.8 37 6,565,834 GA: Northwest (Rome) 0.9 0.1 0.6 1.2 35 3,962,399 GA: North Georgia (Dalton) 0.9 0.2 0.6 1.4 23 2,632,276 GA: North (Gainesville) 1.1 0.2 0.8 1.5 41 3,723,276 GA: Cobb-Douglas 0.8 0.1 0.5 1.1 38 5,357,377 GA: Gwinnett 0.7 0.1 0.5 1 38 5,712,772 GA: LaGrange 0.8 0.1 0.5 1.1 37 4,818,090 GA: South Central (Dublin) 0.3 0.2 0.1 0.9 4 1,009,356 GA: North Central (Macon) 0.7 0.1 0.4 1 24 3,476,472 GA: East Central (Augusta) 0.7 0.2 0.4 1.1 20 3,017,677 GA: West Central (Columbus) 0.6 0.2 0.3 1 14 2,492,172 GA: South (Valdosta) 0.3 0.1 0.1 0.8 5 1,638,741 GA: Southwest (Albany) 0.9 0.2 0.5 1.3 22 2,500,405 GA: Coastal (Savannah) 0.8 0.2 0.6 1.2 29 3,568,163 GA: Northeast (Athens) 0.9 0.2 0.6 1.3 26 2,903,745 GA: All Georgia 0.8 0 0.7 0.8 463 62,540,286
Rates are per 100,000 and age-adjusted to the 2000 US Std Population (19 age groups - Census P25–1130) standard; Confidence intervals (Tiwari mod) are 95% for rates.

Disclosures:
Waller: Outsuka: Research Funding.