bluuebunny/crossref_metadata_2025_split huggingface dataset:
Unrelated Cord Blood Transplantation for Severe Acquired Aplastic Anemia Using a Reduced-Intensity Conditioning: High Graft Rejection but Good Survival
Authors: Liu Huilan , Geng Liangquan , Wang Xingbing , Ding Kaiyang , Tang Baolin , Tong Juan , Yao Wen , Wang Zuyi , Sun Zimin 
Published: October 2019

Abstract
Abstract 2368
We report a single center experience in treating 16 consecutive patients (nine male and seven female) with severe aplastic anemia (AA) who received unrelated cord blood transplantation (UCBT) between 2006 and 2010. The main outcomes of interest were the tolerability and toxicity of UCBT, hematopoietic reconstitution and survival. The first two patients using a conditioning regimen consisting of cyclophosphamide (total dose 120°<<200 mg/kg), rabbit anti-thymocyte globulin (ATG, total dose 10°<<15 mg/kg) and methylprednisolone (total dose 1.5g). The other 14 cases received a reduced-intensity regimen composed of cyclophosphamide (total dose1200mg/©O), ATG (total dose 30 mg/kg) and fludarabine (total dose 120°<<180 mg/m2). Cyclosporine and mycophenolate mofetil were used as GVHD prophylaxis. The median age was 17 years (range 5–61 years) and the median weight was 48 kg (range 16–65 kg). Ten of sixteen were very SAA (VSAA). The median interval between diagnosis and UCBT was 30 days (range, 15–180). All except one did not received ATG-based immunosuppressive therapy before UCBT. Twelve patients received single UCB unit, four cases received double units. Donor/recipient HLA was at least four of six loci matching. The median nucleated cell dose infused was 4.27×107 cells/kg (range 2.34–13.41×107 cells/kg) and CD34+ cell dose infused was 2.02×105 cells/kg (range 0.71–4.35×105 cells/kg). Two patients were not evaluable for engraftment because of early death on day +21 and +22 due to severe infection and intracranial hemorrhages, respectively. Only one of the fourteen cases had engraftment with complete chimerism of single UCB unit from day 7, whose ANC© f 0.5 ×109/L and platelet© f20 ×109/L occurred on day 12 and day 31 post double UCBT, respectively. But she experienced secondary graft failure after three months post transplantation and attained survival by successful haplo-identical related transplantation. Thirteen patients experienced primary graft rejection, but all of them acquired autologous recovery. The 3-month and 6-month cumulative incidence of response was 61.5% and 85.7%, respectively. Currently, 14 patients are alive, having survived for 189 to 1712 days (median, 544 days) after their transplantations. The probability of overall survival at 4 years was 87.5%.Our data indicate that UCBT for new diagnosed SAA using no irradiation but fludarabine-based conditioning still seems to be inevitable to led to the high risk of rejection, but may facilitate autologous recovery and improve survival with low risk of transplant-related mortality.

Disclosures:
Sun: Fund of 11th Five-Year Science and Technology Key Project of Anhui Province (06013128B): Research Funding; Fund of Anhui Provincial “115” Industrial Innovation Program: Research Funding.
DEK/NUP214 Fusion Gene Predicts Good Outcome In Acute Myeloid Leukemia In Complete Remission After Allogeneic Hematopoietic Stem Cell Transplantation
Authors: Ishiyama Ken , Takami Akiyoshi , Nakao Shinji , Hidaka Michihiro , Maeda Tetsuo , Kawa Keisei , Nagamura Tokiko , Tabuchi Ken , Atsuta Yoshiko , Sakamaki Hisashi 
Published: October 2019

Abstract
Abstract 2386

Introduction
Acute myeloid leukemia (AML) with chromosomal translocation (6;9)(p23;q34) results in a chimeric fusion gene between DEK/NUP214 (formerly DEK/CAN), and is a rare disease, accounting for approximately 1% of cases. This entity is considered to be a good indication for allogeneic hematopoietic stem cell transplantation (allo-HSCT) due to its poor prognosis and non-responsiveness to chemotherapy. However, whether the prognosis of patients with exclusive DEK/NUP214 abnormality is improved by allo-HSCT has not been demonstrated. We conducted a retrospective study to examine the outcomes of allo-HSCT in AML patients with the DEK/NUP214 gene using the databases of the Japan Society for Hematopoietic Cell Transplantation (JSHCT) and the Japan Cord Blood Bank Network (JCBBN).

Methods
We identified de novo AML patients who underwent transplant between January 1996 and December 2007 with no prior treatment by allo-HSCT. Clinical features and outcomes of the patients with DEK/NUP214 abnormality and 3 different control groups (patients with chromosome 7 abnormalities, complex karyotype or normal karyotype) were compared.

Results
Of 4517 AML cases meeting the above criteria, the number of patients with normal karyotype, chromosome 7 abnormalities, complex karyotype and DEK/NUP214 abnormality was 2227, 139, 416 and 64, respectively. The median age of each group was 41, 37, 41 and 34 years, respectively; patients with the DEC/NUP214 abnormality were significantly younger than those with the complex karyotype, and patients with normal chromosomes. Gender was not biased among the groups. Overall survival (OS) of the patients with DEC/NUP214 abnormality at 5 years was 49%, which was superior to the OS of the patients with normal karyotype, chromosome 7 abnormalities and complex karyotype (44%, 30% and 27%, respectively; P < 0.0001; Figure). This trend was significant in HSCT grafts with bone marrow and peripheral blood stem cells. In patients with DEK/NUP214 abnormality, none of the following factors improved survival; combination of gender between patient-donor, dose of total body irradiation prior to HSCT; and use of prophylactic immunosuppressants for graft-versus-host disease. However, the status at HSCT had a significant impact on outcome (5-year OS: 66% in patients in complete remission (CR) at HSCT vs. 31% in non-CR patients; P < 0.001). Analysis exclusively for the patients in CR at HSCT showed similar results as above.

Conclusion
Our results suggest that patients with the DEK/NUP214 abnormality are more likely to respond to allo-HSCT. Allo-HSCT should be particularly recommended for patients experiencing CR after prior remission-induction chemotherapy.

Disclosures:
No relevant conflicts of interest to declare.
4-1BB Ligand Mediates a “Vicious Cycle” of Immune Evasion Upon Reciprocal Interaction of Chronic Lymphocytic Leukemia and NK Cells
Authors: Buechele Corina , Baessler Tina , Schmiedel Benjamin J , Kanz Lothar , Salih Helmut R. 
Published: October 2019

Abstract
Abstract 2416
NK cells play an important role in tumor immunosurveillance. Their reactivity is governed by various immunoregulatory molecules, which influence both direct anti-tumor immunity and NK responses induced by therapeutic antibodies like Rituximab. Various members of the TNF/TNFR family modulate differentiation, proliferation, activation, and death of both tumor and immune effector cells including NK cells. Recently we reported that the TNFR family member 4-1BB/CD137 is expressed on human NK cells following activation. In contrast to the stimulatory role of its murine counterpart, we found that human 4-1BB impairs NK anti-tumor reactivity upon interaction with its ligand 4-1BBL expressed on blasts of a substantial proportion of acute myeloid leukemia patients (Blood 115: 3058-69; 2010). In addition, we found that expression of 4-1BBL is general feature of leukemic cells of chronic lymphocytic leukemia (CLL) patients causing impaired direct and Rituximab-induced NK cell reactivity (Blood 114: 279; 2009). Here we report that reverse signaling via 4-1BBL into CLL cells following interaction with 4-1BB, which is absent on NK cells of healthy donors, but expressed at substantial levels on NK cells of CLL patients, induced pronounced production of immunoregulatory cytokines like TNF, IL-6 and IL-8 by the CLL cells. Moreover, we found that sera of CLL patients contained elevated levels of these immunoregulatory cytokines as compared to healthy controls. When PBMC of healthy donors were exposed to supernatants of in vitro cultured CLL cells or sera from CLL patients, this resulted in pronounced 4-1BB expression on the NK cells. This effect could be prevented by addition of the TNF blocker Infliximab to patient sera. The 4-1BB expression induced by CLL sera resulted in impaired NK reactivity specifically against 4-1BBL-expressing targets as revealed by functional analyses with 4-1BBL transfectants and the respective mock-controls. Moreover, the induced 4-1BB expression also impaired NK cell reactivity against primary CLL cells constitutively expressing 4-1BBL, thus closing a cycle of immune evasion. Taken together, our data demonstrate that 4-1BBL enables CLL cells to evade NK anti-tumor reactivity, and disruption of the “vicious 4-1BB-4-1BBL cycle” in CLL - NK interaction e.g. by TNF- or 4-1BB-blockade may serve well to enhance NK reactivity in therapeutic strategies like antibody treatment or allogenic stem cell transplantation in CLL, which rely on sufficient NK cell function.

Disclosures:
No relevant conflicts of interest to declare.
PKA Mediated Phosphorylation of TAL1 Regulates Its Interaction with LSD1 During Hematopoiesis.
Authors: Li Ying , Deng Changwang , Hu Xin , Fu Xueqi , Qiu Yi , Huang Suming 
Published: October 2019

Abstract
Abstract 2599
TAL1 is a member of the basic helix-loop-helix (bHLH) family of transcription factors and is required for the development of all hematopoietic cell lineages. TAL1 is a phosphorylated protein and its activities are mediated by the corepressors and coactivators that associate with TAL1. However, the functional link between phosphorylation and the recruitment of co-regulators by TAL1 is currently unknown. We showed that TAL1 dynamically interacts with LSD1 complex containing both histone H3K4 demethylase and deacetylase activities during hematopoiesis (Proc. Natl. Acad. Sci. USA 106: 10141–10146). To further understand the molecular mechanism that regulates the TAL1 and LSD1 interaction during hematopoiesis, we determined whether TAL1 directly interacts with LSD1 and characterized the domains required for this interaction. TAL1 directly interacts with LSD1, and the interacting domain encompasses amino acids 142–185 proximal to the bHLH domain, which contains a serine 172 residue that becomes phosphorylated by Protein kinase A (PKA) during the transcriptional activation of TAL1. The PKA inhibitor, H89, stimulated TAL1 interaction with LSD1 in hematopoietic cells, while Forskolin, an activator of PKA, completely abolished TAL-LSD1 interaction. We further mutated serine 172 of TAL1 to Alanine (Ala) or to Aspartic acid (Asp) to mimic unphosphorylated or phosphorylated TAL1, respectively. While the TAL1Ser172Ala mutant remains interacted with LSD1, TAL1Ser172Asp specifically loses its interaction with LSD1 indicating that serine 172 phosphorylation of TAL1 by PKA destabilizes the TAL1 and LSD1 interaction. Our previous results indicate that LSD1 inhibits TAL1 mediated erythroid differentiation. To further test whether the activity of TAL1 is mediated through an interaction with LSD1, we expressed the TAL1 mutant that deleted the LSD1 interacting domain in erythroid progenitor cells and showed that the deletion of the LSD1 interacting domain of TAL1 leads to a promotion of erythroid differentiation and H3K4 hypermethylation of the P4.2 promoter. In contrast, the expression of the TAL1Ser172Ala mutant and TAL1-LSD1 chimerical fusion enhanced cellular proliferation and colony formation ability of the hematopoietic progenitor cells while these constructs inhibited erythroid differentiation. Thus, our data revealed that histone lysine demethylase LSD1 may negatively regulate TAL1-mediated transcription and erythroid differentiation. The results suggest that the dynamic regulation of TAL1-associated LSD1/HDAC1 complex may determine the onset of erythroid differentiation programs.

Disclosures:
No relevant conflicts of interest to declare.
Evaluation of Exercise Capacity In Children with SCD by Six Minute Walk Test
Authors: Minniti Caterina , Alam Shoaib , Kato Gregory J. , Nouraie Mehdi , Sable Craig , Ensing Gregory , Campbell Andrew , Rana Sohail , Darbari Deepika , Gladwin Mark , Castro Oswaldo , Gordeuk Victor R. 
Published: October 2019

Abstract
Abstract 2664

Background:
The six-minute walk (6MW) test is used in pediatrics in clinical practice and research to determine cardiopulmonary functional status. A change in 6MW may be affected by factors not strictly related to cardiopulmonary function, which may be different in different patient populations. In children and adolescents, age and height has been found to be a strong predictor of 6MW distance. We set out to study the effects of hematological and echocardiographic variables on 6MW distance in children with sickle cell disease (SCD) and its changes over time.

Methods:
We reviewed prospectively collected hematological, 6MW distance, and echocardiographic data from four hundred children with SCD (including 311 Hb SS or β0) and 69 controls (including 21 Hb AS) enrolled in PUSH (Pulmonary Hypertension and the Hypoxic Response in SCD). Subjects were evaluated at baseline and after 18–24 months, as per protocol. An un-encouraged 6MW was performed in children 5 years or older by trained personnel as per the guidelines of the American Thoracic Society. Subjects were studied at steady state, at least three weeks after any acute exacerbation of SCD. We used ANOVA for univariate analysis and stepwise linear regression for multivariate analysis.

Results:
Median (interquartile range) 6MW in severe SCD genotype (SS and S-β0) was 444 (399-508) and in controls was 495 meters (435-539) (P = 0.0002), while it was 461 meters (408-518) in milder SCD genotypes (P=0.2 for comparison with severe genotypes) (Table 1). In multivariate analysis, Hb, WBC and history of frequent pain episodes were significantly associated to distance of 6MW.
Follow up 6MW obtained in 174 SCD subjects revealed a decline of 10% or more in distance in 22% of subjects with severe genotypes and 33% of other genotypes. The decline was more frequent in the subset of SS subjects with TRV>2.59 (40% vs 19%).

CONCLUSION:
Six minute walk distance is significantly shorter in children with SCD, even as young as 5 years of age, when compared to age and race appropriate controls, indicating early compromise of exercise capacity. SS and S-β-0 genotype subjects have more impairment of exercise capacity compared to milder genotypes. Predictors of 6MW distance are similar in SCD and non SCD subjects, which validates the use of this test in this patient population.
Longitudinal changes in subjects with SCD are similar, with declines in about a quarter of the subjects. Patients with SS who have an elevated TRV have the highest rate of decline in 6MW.
These results validate the use of 6MW as a tool for assessing exercise capacity in children with SCD.

Disclosures:
No relevant conflicts of interest to declare.
Unrelated Umbilical Cord Blood Transplantation for Hematological Malignancies Using Fludarabine/BUCY2 Conditioning Regimen
Authors: Sun Zimin , Liu Huilan , Geng Liangquan , Wang Xingbing , Ding Kaiyang , Wu Yun , Zhou Chenyang , Tong Juan , Song Kaidi , Liu Hongjun , Li Chun , Wang Zuyi 
Published: October 2019

Abstract
Abstract 4572
Cord blood transplantation (CBT) is largely used to treat patients affected by hematological malignant disorders. Myeloablative TBI-based conditioning appears to provide reliable engraftment after CBT for malignancies. However, the toxicity of TBI limits their widespread use. So far, a standard non-TBI based regimen has not been firmly established. In order to overcome graft failure, we investigated a strategy using Fludarabine (FLU)/BUCY2 regimen in CBT for patients with hematologic malignancies. Seventeen patients(children 16, adult 1) with hematologic malignancies who underwent single-unit CBT used a conditioning regimen comprising FLU 120 ‡r/‡u, intravenous busulfan (BU) 12.8‡r/kg and cyclophosphamide (CY)120 mg/kg (FLU/BUCY2). All patients were given a combination of cyclosporine A and mycophenolate mofetil for graft-versus-host disease (GVHD) prophylaxis. Seventeen patients with acute leukemia (n=13), chronic myelogenous leukemia (n=4) were treated, thirteen of whom were high risk diseases and two were advanced-stage at CBT. Seventeen patients with a median age of 8 years (range,2.5–46 years) and a median weight of 32 kg (range, 12–55 kg)received the median number of nucleated cells and CD34+cells infused were 5.70× 107/kg (range: 3.15–9.60×107/kg) and 3.84× 105/kg (range:1.27–5.24 ×105/kg), respectively. The cumulative incidence of primary donor engraftment was 94% (16 patients); one patient had secondary graft failure. Median time to neutrophil≥0.5×109/L was 17 days (range 12–30) and platelet engraftment (≥20×109/L) was 35 days (range 14–56). Preengraftment syndrome (PES) developed in 71% of the patients at a median of 7days (range: 5–13).9 cases developed acute GVHD (56%), more than grade II in three cases. Two of fourteen patients who survived more than 100 days developed chronic GVHD. 12 cases are alive at a median follow-up of 7 months (range 3~ 11).The probability of overall survival at 100 days and 1 year are 88.2% and 67.9%, respectively. Two cases had extramedullary relapsed. Five cases died of severe GVHD (n=3), pulmonary toxicity (n=1) and secondary graft failure (n=1). Preliminary evidence of the small study suggests successful engraftment and decreasing relapse rate following FLU/BUCY2 regimen for CBT in patients with hematologic malignancies. But it had a tendency towards increasing the incidence of GVHD-related morbidity and mortality. Whether this regimen offers a survival benefit for patients with poor-risk leukemia has to be tested in larger prospective trials.

Disclosures:
No relevant conflicts of interest to declare.
CD9 Alters Migration and Morphology of CD9-Positive B Acute Lymphoblastic Leukemia Cells
Authors: Vallée Audrey , Dondi Elisabetta , Bonneau Jacinthe , Leroy Christine , Rio Anne-Gaelle , Troadec Marie-Bérengère , Varin-Blank Nadine , Galibert Marie-Dominique , Gandemer Virginie 
Published: October 2019

Abstract
Abstract 4623
CD9 is a member of the tetraspanin family and has been involved in various pathways. The expression of CD9 has been correlated to the risk of metastases or a poor clinical outcome in various types of cancer.
We have previously shown that TEL/AML1-positive acute lymphoblastic leukemia (ALL) is characterized by deregulation of 14 genes, including CD9 gene.
Here, we investigated the role of CD9 in cell motility in the context of TEL/AML1-positive ALL.
Leukemic blasts isolated from bone marrow of patients and B lineage ALL cell lines that expressed or not CD9 (REH CD9+, Raji CD9- and Raji transfected with CD9) were used for the following assays. For adhesion assay, plates were coated with 1mg/ml superfibronectin. Cells were allowed to attach for 1h30 with or without blocking CD9-antibody (Ab). Adherent cells were quantified using MTS. For migration assay, cells were seeded in the upper chamber on 5mm transwell microporous polycarbonate membranes, treated with different blocking Abs or drugs (CD9-Ab, IgG control, AMD3100) while 100 ng/ml CXCL12 (B-ALL specific chemokine CXCR4 ligand) was added to the medium of the lower chamber. After 5 hours, the migrated cells were recovered from the lower chamber, numbered and analysed by FACS.
We showed that the expression of CD9 decreased the ability of lymphoblasts to attach to fibronectin both in cell lines and in patients cells. This effect was reversed by CD9 blocking antibody. Conversely, migration induced by CXCL12 was reduced by anti-CD9 antibody. We also demonstrated an alteration in cell morphology in CD9-positive cells compared to their CD9-negative control cells. We thus provide novel evidence that CD9 is a key player of the CXCR4-mediated migration pathway by promoting actin rearrangement in response to CXCL12. As CXCR4/CXCL12 axis is central for supporting normal and pathological hematopoiesis, our data could highlight the impact of CD9 expression on the abilities of blasts to disseminate and may explain the specific outcome of TEL/AML1 B-ALL, especially in the perspective of late relapses.
This work was supported by la Ligue Régionale contre le cancer (Ille et Vilaine) et la Fondation pour la Recherche Médicale.

Disclosures:
No relevant conflicts of interest to declare.
Cerebral Aneurysm Bleeding Due to Disseminated Fusarium Infection in a Patient with Acute Monocytic Leukemia
Authors: Qian Shenxian , Gao Da-quan , Jun-feng Tan 
Published: October 2019

Abstract
Abstract 4736
Fusarium is a saprophytic organism that is found widely distributed in soil, subterranean and aerial plants, plant debris and other organic substrates. The organism can cause local tissue infections in immunocompetent patients such as onychomycosis, bone and joint infections, or sinusitis. Since the first case of disseminated Fusarium was described, the incidence of disseminated disease has increased significantly, particularly affecting those immunocompromised with hematological malignancies. We report here a disseminated Fusarium infection with skin manifestations and cerebral aneurysm bleeding in a patient of acute monocytic leukemia. A 49 year old female with acute monocytic leukemia (M5) underwent three courses of therapy with FlAG(cytarabine puls Fludarabine) in second relapse. At the time of hospital admission, she was receiving G-CSF for severe granulocytopenia post-intensification with FLAG, and had also received broad-spectrum antibiotics and fluconazole prophylaxis during previous episodes of febrile neutropenia. Despite treatment with liposomal amphotericin B for five days, She presented persistent fevers, he developed, nonpruritic erythematous Skin Eruption or bleb on her right shin, right shoulder (Figure 1), scalp and foot. The lesions developed central necrosis after four days. The Exudatin in erythematous skin bleb on foot culture was positive for Fusarium solani(Figure 2), which was also confirmed on two different skin lesional drainage culture. Although the patient was treated with liposomal amphotericin B, the clinical symptoms worsened. After liposomal amphotericin B was replaced with voriconazole (VRCZ), Recovery was observed after voriconazole introduction and resolution of neutropenia. Thrombocyte count increased up to 50×109. she suddenly lost consciousness duing lunch. Brain CT scan revealed the hemorrhage in brain. Magnetic Resonance Imaging(MRI) and CTA revealed rupture of brain aneurysm(Figure 3 A,B). Cerebral aneurysm caused by infections differ from congenital brain aneurysm, which often occur the junctions where these arteries come together and form weak spots. The clinical presentation, diagnosis, prognosis and therapeutic options of fusariosis in immunocompromised patients are briefly discussed.Figure 1:Skin EruptionFigure 1:. Skin EruptionFigure 2:The Exudatin in erythematous skin bleb culture was positive for Fusarium solaniFigure 2:. The Exudatin in erythematous skin bleb culture was positive for Fusarium solaniFigure 3:Magnetic Resonance Imaging(MRI) and CTA revealed rupture of brain aneurysm(Figure 3 A,B).Figure 3:. Magnetic Resonance Imaging(MRI) and CTA revealed rupture of brain aneurysm(Figure 3 A,B).

Disclosures:
No relevant conflicts of interest to declare.