bluuebunny/crossref_metadata_2025_split huggingface dataset:
Allogeneic Hematopoietic Stem Cell Transplantation Overcomes the Adverse Prognostic Impact of Minimal Residual Disease in Acute Myeloid Leukemia
Authors: Oran Betul , Singleton Timothy , Ramirez Pablo A. , Shanley Ryan , Brunstein Claudio , Ustun Celalettin , Warlick Erica D , Weisdorf Daniel J. 
Published: October 2019

Abstract
Abstract 2027

BACKGROUND:
The identification of minimal residual disease (MRD) can predict impending relapse in acute myeloid leukemia (AML) patients. Little data exists evaluating the prognostic impact of MRD, as determined by multiparametric flow cytometry (MFC), at the time of allogeneic (allo-HCT). Although disease outcomes may be worse for MRD positive (MRD+) patients, MRD is often associated with other adverse risk factors leaving it unclear whether MRD is an independent risk factor for relapse or a surrogate marker for underlying poor risk disease features.

METHODS:
We retrospectively analyzed 97 consecutive AML patients in complete morphological remission (CR) who underwent allo-HCT with a matched related donor (MRD, n=30, 31%), matched unrelated donor (MUD, n=4, 4%) or umbilical cord blood (UCB, n=63, 65%) at the University of Minnesota between January 2005 and June 2009. Presence of MRD at allo-HCT was determined by MFC. Analyses were done separately for myeloablative (MAC) and reduced intensity conditioning (RIC) patients, testing the impact of MRD along with conditioning intensity, age, donor type and disease status on allo-HCT outcomes.

RESULTS:
Of 97 patients, 41 (42%) had MAC; 57 (58%) had RIC. Sixty-six were in first CR (CR1) with the rest in CR2 or later remission (CR2+). MRD at allo-HCT was detected in 7 patients after MAC (17%) and 7 after RIC (12.5%); and this frequency was similar in patients in CR1 and CR2+ (13% vs. 16%, p=0.7). MRD+ and MRD- patients had similar median age (40 vs. 44 yrs), gender, donor source (MSD or MUD vs. UCB), CMV serostatus and diagnostic cytogenetic risk group. Six of 40 (15%) intermediate and 5 of 39 (13%) high risk cytogenetics patients had MRD+ (p=0.8). Only 3 of 53 patients with a cytogenetic abnormality at diagnosis had it detected prior allo-HCT and 1 of 3 had MRD.
The median follow-up of survivors was 25 months. Two-year probabilities for MAC and RIC patients were similar: Overall survival (OS), 48% and 47 % and leukemia free survival (LFS) 43% and 41% respectively. When disease outcomes were analyzed separately by MRD status (table), OS and LFS were markedly worse in MRD+ patients receiving RIC, but this difference was not statistically significant. In multivariate analysis, MRD+ was not an independent prognostic factor for OS and LFS. Although we identified no adverse prognostic factors for MAC patients, patient with RIC in CR2+ had worse OS and LFS vs. CR1 (HR 2.6, p=0.04 and HR 2.7, p=0.04 respectively).

CONCLUSION:
The negative prognostic impact of MRD was overcome by allo-HCT with MAC, but outcomes with MRD+ were suggestively inferior after RIC. However due to limited sample size, MRD in patients with RIC should be further investigated.

Disclosures:
Weisdorf: Genzyme: Consultancy, Research Funding.
A Randomized Trial of Dabigatran Versus Warfarin in the Treatment of Acute Venous Thromboembolism (RE-COVER II)
Authors: Schulman Sam , Kakkar Ajay K , Schellong Sebastian M , Goldhaber Samuel Z. , Henry Eriksson , Mismetti Patrick , Christiansen Anita Vedel , Schnee Janet , Kearon Clive 
Published: October 2019

Abstract
Abstract 205

Background:
Dabigatran has been compared with warfarin for treatment of acute venous thromboembolism in one previous trial (RE-COVER). Based on the low rate of the primary outcome as the RE-COVER study was running, we undertook this replica study to confirm the results of RE-COVER, and to allow for more rigorous sub-group analyses.

Methods:
In a randomized, double-blind, double-dummy trial of 2568 patients with acute VTE, treated with low molecular weight or unfractionated heparin for 5 to 11 days, we compared dabigatran, 150 mg twice daily, with warfarin, dose-adjusted to an International Normalized Ratio of 2.0 and 3.0, each given for 6 months. Primary outcome was recurrent symptomatic, objectively confirmed venous thromboembolism and deaths related to venous thromboembolism during 6 months. Safety endpoints included bleeding events, acute coronary syndrome, elevated liver function tests, and adverse events.

Results:
Of 1279 patients randomized to dabigatran, 30 (2.4%) had recurrent VTE compared with 28 (2.2%) of 1289 patients randomized to warfarin; risk difference 0.2% (95% confidence interval [CI], −1.0 to 1.5); p<0.0001 for the pre-specified non-inferiority margin. The hazard ratio for dabigatran was 1.08 (95% CI, 0.64 to 1.80). Major bleeding occurred in 15 patients treated with dabigatran and 22 patients treated with warfarin (hazard ratio 0.69; 95% CI, 0.36 to 1.32) and any bleeding occurred in 200 versus 285 patients, respectively (hazard ratio 0.67, 95% CI, 0.56 to 0.81). The frequency of reported ACS events was less than 1% in the trial, with more cases in the dabigatran treatment group than those treated with warfarin. There were 25 deaths during each treatment, and serious adverse events were similar in the two groups. Analysis of outcomes based on demographic characteristics showed consistency of effects for both safety and efficacy. This included the analysis based on Asian race, which had been limited in RE-COVER. There were 537 Asian patients in RE-COVER II compared to only 65 in RE-COVER. The event rates of recurrent VTE and of any bleeding were similar in Asians and non-Asians.

Conclusion:
The study confirms that the efficacy of dabigatran is non-inferior to warfarin in the treatment of acute VTE and with a lower risk for bleeding. The safety of dabigatran is similar in the Asian population compared with non-Asians.

Disclosures:
Off Label Use: dabigatran for treatment of venous thromboembolism. Christiansen:Boehringer Ingelheim: Employment. Schnee:Boehringer Ingelheim: Employment.
Evaluating Trends in Diagnostic and Prognostic Testing for Multiple Myeloma
Authors: Fidler C. J. , Hussein Ahmed Kamel Abou , Gandhi Neel , Karur Vinit , Sharma Manish , Klumpp Thomas R , Kropf Patricia , Martin Mary Ellen , Emmons Robert V. , Mangan Kenneth F. 
Published: October 2019

Abstract
Abstract 2067

Introduction:
A battery of diagnostic and prognostic testing is recommended by both the NCCN and the International Myeloma Working Group (IMWG) at the time of diagnosis of myeloma. It has been our observation that many patients referred for Autologous Stem Cell Transplant (ASCT) to our center have not had a complete myeloma workup. In this report, we attempt to quantify the adherence to recommended guidelines for the workup of myeloma.

Methods:
We reviewed the records of all patients with a diagnosis of myeloma referred to our center for ASCT between 2006 and 2011. We looked for the following tests at the time of diagnosis: bone marrow biopsy, SPEP, 24hr urine for Bence-Jones proteinuria, serum β2 microglobulin, skeletal survey, serum free light chains, serum albumin and myeloma FISH panel. We used descriptive statistics to evaluate our results.

Results:
There were a total of 64 patients who underwent an ASCT in our center between 2006 and 2011. Of these 64 patients, 9 patients were excluded from this review due to incomplete records. At the time of initial diagnosis, the most commonly obtained tests included an albumin level (55/55, 100%), SPEP (54/55, 98%), bone marrow biopsy (52/55, 95%), skeletal survey (52/55, 95%), standard cytogenetics (47/55, 85%), and β2-microglobulin (46/55, 84%). The most commonly omitted studies included the myeloma FISH panel (26/55, 47%), 24-hour urine for Bence-Jones protein (30/55, 55%), and serum free light chains (37/55, 67%). Compliance with the use of serum free light chain assay improved over time, while the frequency of obtaining a myeloma FISH panel remains relatively low and the frequency of obtaining a 24-hour urine for Bence-Jones protein decreased (Tables 1 and 2).

Conclusions:
The most commonly omitted studies were the serum free light chains, 24hr urine and myeloma FISH panel. When assessed over time, compliance increased with the ordering of the SFLC assay, stable for the myeloma FISH panel but decreased for the 24hr urine for Bence-Jones protein. This trend reflects the perception that the serum free light chain assay is replacing the 24hr urine for Bence-Jones proteinuria. Referring community physicians need further education on the ordering of initial diagnostic and prognostic tests for multiple myeloma.

Disclosures:
No relevant conflicts of interest to declare.
Role of hSET1 Complex in Epigenetic Controls of HoxB4 Expression and Development of Hematopoietic Stem Cells
Authors: Deng Changwang , Li Ying , Liang Shermi , Salz Tal , Qiu Yi , Roeder Robert , Zhao Keji , Bungert Jorg , Huang Suming 
Published: October 2019

Abstract
Abstract 212
Hox genes play an important role in embryonic development and are sequentially activated in a temporal and spatial fashion. Among them, HoxB4 regulates the self-renewal ability of adult and embryonic hematopoietic stem cells. It was shown that USF proteins positively regulate the transcription of HoxB4 gene. However, the epigenetic mechanism specifically controlling HoxB4 transcription during HSC formation remains unknown. In this report, we found that USF1 interacts with histone H3K4 methylatransferase SET1 complex, but not MLL proteins. The interaction is mediated by SET1/MLL core component, ASH2L. Both USF1 and hSET1 are colocalized at the HoxB4 promoter in hematopoietic progenitors, which is accompanied by H3K4 trimethylation and transcriptional activation. siRNA-mediated knockdown of both SET1 and HCF1 specifically impaired H3K4 trimetylation and the HoxB4 promoter-driven reporter gene activity. Overexpression of AUSF1, a dominant negative mutant of USF1 in which the basic DNA recognition domain is deleted and thereby, inhibits endogenous USF DNA binding activity, leads to dramatically decrease in HoxB4 transcription, disruption of embryonic body formation and inhibition of hematopoietic stem cell population in mouse ES (mES) cells and the AUSF1 transgenic mice. The suppression of USF activity drastically reduces SET1 recruitment, H3K4 trimethylation, and pol II binding at the HoxB4 promoter. Furthermore, knock-down of SET1, an enzymatic subunit of the SET1 complex, also resulted in reduction of HoxB4 transcription and impairment of hematopoietic differentiation capacity of mES cells that are accompanied by reducing the HoxB4 promoter H3K4 methylation and recruitment of RNA PolII machinery. Thus, our data reveal that recruitment of hSET1 complex and its H3K4 methyltransferase activity by USF1 is essential for HoxB4 transcription and expansion of hematopoietic stem cells.

Disclosures:
No relevant conflicts of interest to declare.
NK Cells in Hodgkin Lymphoma Are Impaired but Can Be Activated
Authors: Kessler Joerg , Reiners Katrin S. , Sauer Maike , Engert Andreas , von Strandmann Elke Pogge 
Published: October 2019

Abstract
Abstract 2182

Introduction:
NK cells represent the key component of the innate immune system to recognize and eliminate cancer cells. Defects in NK cell function including impaired cytotoxicity/cytokine secretion, aberrant receptor expression profile, NK cell number and NK cell anergy are reported in non Hodgkin lymphoma and correlate with a bad prognosis. So far, nothing is known about the phenotype of peripheral NK cells and serum levels of ligands for NK cell receptors in Hodgkin Lymphoma (HL) patients. Here, cytotoxicity, expression pattern of activating NK cell receptors and the serum levels of several ligands for the key cytotoxic receptors NKG2D and NKp30 are determined.

Methods:
The cytotoxicity of NK cells isolated from HL patients was analysed by europium release assay using the HL cell line L428 as target cells. The serum level of the NKp30-ligand BAT3 and ligands for NKG2D (MICA, MICB and ULBP1,2,3) was estimated in sera of 117 HL patients and 40 healthy donors by ELISA. The expression pattern of NKp30, NKp44, NKp46, CD16 and the activation markers CD25, CD69 and CD71 was determined by 4-colour FACS analysis of peripheral blood lymphocytes.

Results:
The cytotoxicity assays reveal a significantly reduced killing efficacy of NK cells from HL patients against the Hodgkin cell line L428 in comparison to NK cells from healthy donors. Correlating with the impaired NK cell function, we observed that the serum level for BAT3 and MICA was significantly elevated in HL patients, whereas other ligands (MICB and ULBP1,2,3) remained unchanged. NKG2D showed a significantly decreased expression on NK cells of HL patients. No significant difference was observed for all other receptors and activation markers tested.

Conclusion:
Our results suggest that soluble BAT3 and MICA, ligands for NKp30 and NKG2D, contribute to the NK cell inhibition in HL patients. Since soluble ligands for NK cell receptors are known to inhibit NK cell-cytotoxicity, the release of these ligands might represent an immune escape mechanism of HL tumors to avoid detection and killing by the innate immune system. To overcome NK cell inhibition in HL patients we design, express and purify bispecific proteins (immunoligands) that target NKG2D and a HL-specific tumorantigen. Work to activate HL-derived NK cells with immunoligands ex vivo will be discussed.

Disclosures:
Engert: Affimed Therapeutics AG: Honoraria, Research Funding.
The Neuronal Protein GAP-43 Associates with Microtubules and Lipid Rafts in Platelets and Megakaryocytes and Is Involved in Platelet Genesis
Authors: Begonja Antonija Jurak , Nguyen Lilly , Italiano Joseph E. , Falet Herve , Meiri Karina F. , Hartwig John H. 
Published: October 2019

Abstract
Abstract 2201
GAP-43 (neuromodulin) is a membrane-associated protein involved in neurite outgrowth, pathfinding and branching during development where it regulates neurotransmitter release and endocytosis, and plays a role in cytoskeletal signal transduction at the nerve ending. We have found GAP-43 to be expressed in platelets and megakaryocytes (MK) as evidenced by immunoblot and flow cytometry analysis. Immunofluorescence shows that GAP-43 localizes intracellularly as discrete punctuate structures mostly near the marginal microtubule (MT) coil of platelets and along the MT bundles in MKs and proplatelets. In contrast to neuronal cells where GAP-43 is associated with their detergent insoluble F-actin cytoskeleton, it is mostly soluble in platelets unless the platelets are first treated with taxol, a drug that stabilizes MTs. MT disruption with nocodazole or by chilling decreases the amount of GAP-43 in the detergent-insoluble cytoskeleton and disturbs its localization in proplatelets. GAP-43 colocalizes in platelets and MKs with the glycosylphosphatidylinositol-linked lipid raft marker Thy-1 and Cherry-PH PLC-delta1 (pleckstrin homology domain of phospholipase C-delta1) that stains membrane rafts. Since GAP-43 overexpression in MKs diminishes proplatelet formation, it appears to play a negative role in thrombopoiesis. Together, the data shows that GAP-43 is associated with MT and lipid rafts and suggests a role in signaling reactions between these two components to modulate proplatelet elaboration.

Disclosures:
No relevant conflicts of interest to declare.
Activated Protein C Controls p66shc: A Novel Defense Mechanism in Diabetic Nephropathy
Authors: Bock Fabian M , Shahzad Khurrum , Madhusudhan Thati , Wang Hongjie , Nawroth Peter P , Isermann Berend H. 
Published: October 2019

Abstract
Abstract 2204

Introduction:
Previously it has been shown that activated protein C (APC) protects against diabetic nephropathy (DN). APC's cytoprotective effect in DN may be related to its in vitro ability to downregulate reactive oxygen species (ROS) and maintain mitochondrial membrane potential in glucose stressed cells. Cellular targets, through which APC, an extracellular serine protease, regulates mitochondrial function, are unknown. Since mice lacking the ROS-inducing mitochondrial protein p66shc are protected from DN we hypothesized that APC's cytoprotective effect may be mechanistically linked to p66shc.

Material & methods:
Immortalized mouse podocytes and murine endothelial cells were stressed in vitro with glucose (30 mM). In mice persistent hyperglycaemia was induced by streptozotocin injections. Markers of DN were analysed in wild-type mice, mice expressing a thrombomodulin (TM) mutant lacking cofactor activity towards protein C activation (TMPro/Pro), mice expressing high levels of APC (hPChigh), and p66−/− x TMPro/Pro double mutant mice. Immunoblotting, RT-PCR, cellular subfractionation, immunohistochemistry and immunofluorescensce were employed for analyses.

Results:
8-OH-Desoxyguanosine, a marker for ROS, is induced in diabetic mice. Nitrotyrosine, a marker for ROS-dependent damage, localizes mainly to podocytes. This is paralleled by p66shc-upregulation in glomerular podocytes. These effects are aggravated in diabetic TMPro/Pro, ameliorated in aPChigh, and reversed in p66shc x TMPro/Pro mice. In vitro APC counteracts glucose dependent upregulation of p66shc and inhibits mitochondrial translocation of p66shc in mouse podocytes, but not in endothelial cells in vitro.

Conclusion:
This study identifies a novel mechanism through which APC mediates cytoprotection. In glucose stressed podocytes, but not endothelial cells, APC prevents mitochondrial translocation of the ROS-inducing redox-protein p66shc, which is required for protection against DN in vivo.

Disclosures:
No relevant conflicts of interest to declare.
HLADRB3*0101 Combined with DRB4*0101 Are Potential Predictor of Neonatal Alloimmune Thrombocytopenia (NAIT) Development
Authors: Salomon Ophira , Loewenthal Ron , Kalt Rivka , Rosenberg Nurit , Dardik Rima , Yahalom Vered , Avishai Ofelia , Frenkel Orit , Gazit Ephraim , Lipitz Shlomon 
Published: October 2019

Abstract
Abstract 2221
Neonatal alloimmune thrombocytopenia (NAIT) is a life-threatening bleeding disorder in the fetus/ neonate caused by maternal alloantibodies directed against fetal platelet antigens inherited from the father. Of the 21 allonatigens described up to date http://www.ebi.ac.uk/ipd/hpa/table2.html, the human platelet antigen (HPA) −1 defined as a leucine /proline polymorphism at residue 33 in b3 integrin is the immune-dominant antigen leading to severe NAIT. Immunization to HPA-1a occurs only in 10% of HPA-1bb pregnant women, 90% of them carrying histocompatibility leukocyte antigen (HLA) DRB3*0101. The aims of the present study were: 1. to prospectively study whether in addition to HLA DR B3*0101 there other potential HLA DR antigens involved in the immune process. 2. To analyse whether the response to IVIgG treatment correlates with maternal HLA DR genotype 3. to determine whether, anti HLA antibodies in addition to HPA1a antibodies, resulted in a more severe thrombocytopenia. We enrolled 21 pregnant women who had previously given birth to newborns with NAIT due to HPA1 incompatibility and had antibodies directed to their spouses HPA1 phenotype (leucine or proline polymorphism ) at the Sheba Medical Center from May 2001 to January 2011. The control group consisted of 21 women who delivered at term newborns with thrombocytopenia and a diagnosis of NAIT was ruled out. Twelve women of 21 (57%) in the study group carried both HLADRB3*0101 and DRB4*0101phenotype. But in none of the women in the control group such combination was detected. Interestingly is the observation that of 20 women who gave birth once more following IVIgG treatment, four did not respond to IVIgG and 3 (75%) of them harbor both DRB3*0101 and DRB4*0101. When lymphocytotoxic cross match analysis was performed in eighteen couples of the study group seven (39%) of them had positive lymphocytotoxic cross match. However the presence of both HLA and HPA1 antibodies against their partner phenotype did not affect platelets' counts in the newborn. Taken together we postulate that the presence of both HLADRB3*0101 and HLADRB4*0101 in the mother increases the risk of NAIT development when HPA1 incompatibility between the couples is found and can serve as a diagnostic tool. The presence of HLA antibodies against the spouse did not alter response to IgG treatment.

Disclosures:
No relevant conflicts of interest to declare.
Ticlopidine-, Clopidogrel-, and Prasugrel-Associated Thrombotic Thrombocytopenic Purpura: A Twenty Year Review
Authors: Qureshi Zaina Parvez , Armstrong John , Bennett Charles 
Published: October 2019

Abstract
Abstract 2226

Objective:
Thrombotic thrombocytopenic purpura (TTP) is a rare syndrome, with our group having identified the thienopyridines ticlopidine and clopidogrel as the most common drugs associated with TTP in Food and Drug Administration (FDA) databases. We review clinical, epidemiologic, laboratory, and drug safety findings for thienopyridine-associated TTP, including the first reported cases with prasugrel, a thienopyridine approved in 2009.

Methods:
Data sources included FDA's Adverse Event Reports database, pharmaceutical manufacturers, package inserts, physician surveys, phase III reports, insurance databases, and an epidemiologic study (1989–2011). Causality was assessed with the World Health Organization scale.

Results:
Since 2002, FDA received reports of 10 ticlopidine-, 140 clopidogrel-, and nine prasugrel-associated TTP cases, including four, 11, and 9 cases respectively, in the first year of marketing of each agent. Surveys of hematologists by our group identified 32 ticlopidine- and ten clopidogrel-associated TTP cases. Thienopyridines were administered for > two weeks for 90% of 93 ticlopidine-associated cases, 26% of 35 cases clopidogrel-associated cases, and none of nine prasugrel-associated cases. In the Phase III setting, one of 2,932 ticlopidine-, none of 27,961 clopidogrel-, and none of 1,769 prasugrel-treated patients developed TTP. Insurance databases identified three clopidogrel-associated TTP case among 15.3 million individuals. Ticlopidine- (n=30) versus clopidogrel-associated TTP patients (n=8) presented with severe ADAMTS13-deficiency (80% versus 0%) and neutralizing auto-antibodies to ADAMTS13 (100% versus 0%) and had higher survival rates following therapeutic plasma exchange (87% versus 50%) (p<0.05). Greater than 95% of ticlopidine-associated TTP cases were assessed as having a probable causal relationship versus none of the clopidogrel- or prasugrel-associated TTP cases. TTP is described in a Black Box warning for ticlopidine (1998, incidence of 1 in 2,000) and as a warning for clopidogrel (2000; 12 per million) and prasugrel (2010; no incidence reported)

Conclusion:
TTP is associated with all thienopyridines, although causal relationships remain under active investigations.

Disclosures:
Armstrong: LeadHorse Technologies Inc.: Employment.