bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antithymocyte Globulin Treatment at the Time of Transplantation Impairs Donor Hematopoietic Stem Cell Engraftment
Authors: Hu Zheng , Jin Feng , He Jin , Jin Chunhui , Fan Wei , Shan Yanhong , Zhang Zefeng , Sun Liguang , Yang Yong-Guang 
Published: October 2019

Abstract
Antithymocyte globulin (ATG) is often included in the conditioning regimen to prevent graft-vs.-host disease in allogeneic hematopoietic stem cell (HSC) transplantation. However, because ATG contains antibodies targeting a wide range of antigens on human cells, its potential off-target effects remain a concern. Here, we explored this question in humanized mice that were made by transplantation of human fetal thymic grafts (under the renal capsule) and CD34+ human fetal liver cells (i.v.). We showed that ATG binds to almost all lineages of human hematopoietic cells including HSCs, and accordingly, it is capable of depleting almost all human hematopoietic cells. Interestingly, the efficacy of ATG was highly variable depending on the tissue of residence, with human cells in bone marrow significantly less susceptible than those in the blood and spleen. Recovery of multilineage human lymphohematopoietic reconstitution in humanized mice that received ATG 3 weeks after HSC transplantation indicates that ATG had a minimal effect on human HSCs that have settled in bone marrow niches. However, efficient human HSC depletion and engraftment failure were seen in mice receiving ATG immediately following transplantation. Our data indicate that the efficacy of ATG is tissue-dependent, and suggest a risk of impairing donor hematopoietic engraftment when ATG is used in preparative conditioning regimens in HSC transplantation.

Disclosures
No relevant conflicts of interest to declare.
Extramedullary Disease at Diagnosis of Acute Myeloid Leukemia Does Not Influence Outcome of Patients Undergoing Allogeneic Hematopoietic Cell Transplant in First Complete Remission
Authors: Michelis Fotios V. , Messner Hans A. , Alam Naheed , Gupta Vikas , Kim Dennis Dong Hwan , Kuruvilla John , Lambie Anna , Viswabandya Auro , Lipton Jeffrey H. 
Published: October 2019

Abstract
Occurrence of extramedullary (EM) disease at diagnosis of acute myeloid leukemia (AML) has been associated with increased risk of relapse and worse outcomes post-chemotherapy. There is minimal data in the literature concerning the association with outcomes following allogeneic hematopoietic cell transplantation (HCT). The purpose of this single-centre study was to retrospectively investigate the impact of EM disease at diagnosis on the outcome of 303 patients with AML in first complete remission (CR1) that underwent HCT during the time period 2000-2013.
Median age at HCT was 51 years (range 18-71), 151 (50%) patients were female. Myeloablative conditioning (MAC) was used in 202 (67%) patients, reduced-intensity (RIC) in 101 (33%) patients. Donors were related for 194 (64%) patients, unrelated for 109 (36%) patients. Grafts were peripheral blood stem cells (PBSC) in 253 (83%) patients and bone marrow in 50 (17%) patients. Median follow-up of patients alive was 63 months (range 12-168). Cytogenetics at diagnosis were available for 263 (87%) of patients, of which 16 (5%) were favorable, 185 (61%) were intermediate and 62 (20%) were unfavorable risk (MRC classification). Primary induction failure prior to achievement of CR was seen in 67 (22%) patients. In vivo T-cell depletion was performed in 71 (23%) patients. A total of 124 patients (41%) underwent HCT during the years 2000-2006 and 179 patients (59%) during the years 2007-2013. EM disease at diagnosis was seen in 39 patients (13%), of whom 11 patients had CSF disease, 7 patients had gingival infiltration and 5 patients had leukemia cutis.
Univariate analysis for overall survival (OS) demonstrated that EM disease at diagnosis had no influence (HR=0.96 for EM, 95%CI=0.60-1.51, p=0.85, Figure 1). Multivariable analysis for OS including the previously described variables verified this observation. EM disease did not influence cumulative incidence of relapse (CIR) on univariate analysis (HR=0.94 for EM, 95%CI=0.45-1.96, p=0.86, Figure 2), and this also was confirmed on multivariable analysis. Moreover, EM disease did not influence cumulative incidence of non-relapse mortality on both univariate (HR=0.94 for EM, 95%CI=0.53-1.66, p=0.83) and multivariable analysis.
In conclusion, EM disease at diagnosis of AML in patients achieving CR1, does not seem to influence outcomes post allogeneic HCT. This is significant in the consideration of allogeneic HCT for the treatment of this unfavorable subtype of AML. We are unable to comment on whether a similar percentage of patients with EM disease versus without EM disease, achieve CR1.
Figure 1. Figure 1. Figure 2. Figure 2.

Disclosures
Kim: Bristol-Myers Squibb: Consultancy, Research Funding; Novartis Pharmaceuticals: Consultancy, Research Funding.
Prevalence of Extramedullary Hematopoiesis, Vertebral, Hepatic and Splenic Hemangioma and Renal Cyst Among Thalassaemic Patients: A Retrospective Study from the Myocardial Iron in Thalassemia (MIOT) Network
Authors: Pepe Alessia , Meloni Antonella , Briatico Vangosa Alessandra , Terrazzino Fabrizia , Neri Maria Giovanna , Maddaloni Domenico , Roccamo Gaetano , Armari Sabrina , Maggio Aurelio , Salvatori Cristina , Positano Vincenzo , Ricchi Paolo 
Published: October 2019

Abstract

BACKGROUND: The prevalence and the clinical relevance of several extracardiac findings (EF) at Magnetic Resonance Imaging (MRI) have been recently estimated in cohorts of non thalassaemic patients.
AIM: In this study we sought to determine the prevalence of EF potentially related to anaemia and ipoxia in age- and sex- matched populations with thalassaemia major (TM) and Thalassaemia Intermedia (TI).
METHODS: We retrospectively considered 159 TM patients regularly transfused (73 F; 34±9.20 years) and 159 TI patients (73 F; 34±9.18 years) consecutively enrolled in the Myocardial Iron in Thalassemia (MIOT) Network to quantify cardiac and liver iron by T2* technique. Patients with TI were further subdivided in non transfusion dependent (NTD-TI) and transfusion dependent (TD-TI). All MRI images were used to assess the presence or absence of Extramedullary Hematopoiesis (EMH), kidney, splenic and liver cysts, and vertebral hemangiomas.
RESULTS: Overall, EF were detected in 33% and 26% of patients with TI and TM, respectively. Table 1 shows the comparison of MRI data between TM and TI patients. Both groups of patients had elevated but comparable prevalence of kidney, splenic and liver cysts and vertebral haemangiomas. TI patients were found to have significant higher EMH as compared to TM. The prevalence of total EF increased with advancing age and renal cysts were found in the 28.6% of the cohort aged 45-55 years. Patients with renal cysts had comparable serum creatinin level with respect to those without. Within the population of TI-TD it was observed the highest prevalence of patients with renal cysts, splenic cyst and vertebral haemangioma (26%, 3% and 3%, respectively).
Thalassemic patients had a was significant higher prevalence of renal cysts than the general population (19.2 vs 7.8%; P<0.0001).
CONCLUSIONS: EF are well-recognized features in patients undergoing MRI, being hepatic cysts or hemangiomas and renal cyst the most frequently observed. Our data on hemangiomas and renal cysts, particularly among patients with TI-TD, indicate a significant higher prevalence of EF compared to the general population. These data seem to suggest the role of the inappropriate activation of the Hypoxia-Inducible Factor (HIF) system linked to the chronic hypoxia as observed in the Chuvash polycythemia or in the the von Hippel-Lindau (VHL) syndrome. Furthermore, HIF in general population has been directly involved in the development and/or progression of clear cell renal cancer also described among thalassemic patients.
Table 1. Table 1.

Disclosures
Pepe: Chiesi: Speakers Bureau; ApoPharma Inc: Speakers Bureau; Novartis: Speakers Bureau.
Neutrophil Infiltration Is Partially Inhibited By EC-18 in the LPS-Induced Acute Lung Injury
Authors: Shin Su-Hyun , Lee Ha-Reum , Yoo Nina , Yoon Sun Young , Kim Myung-Hwan , Suh Cheolwon , Sohn Ki-Young , Kim Heung-Jae , Han Yong-Hae , Chong Saeho , Kim Jae Wha 
Published: October 2019

Abstract
Acute lung injury (ALI) is an acute respiratory failure and linked closely to neutrophil accumulation. It can lead to acute respiratory distress syndrome (ARDS). Mouse model of ALI was established by lipopolysaccharide (LPS) administration. LPS, an outer membrane of gram negative bacteria, is considered as immune stimulator via recognition as pathogen-associated molecular patterns (PAMP). ALI and neutrophil infiltration were readily induced by intranasal injection of LPS. In this study, we investigated whether EC-18 treatment attenuates LPS-induced ALI. EC-18 (1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol) is an immune modulator in the allergic asthma response through modulation of the balance between Th1 and Th2. To analyze the role of EC-18 in LPS-induced ALI mice, Balb/c mice were divided into three separate groups: control, LPS treated, and EC-18/LPS co-treated (n=5 per group). 25 mg/kg of LPS was administered by an intranasal route, and 250 mg/kg of EC-18 was orally administered. Mice were sacrificed after 15hrs, and various samples were collected. Bone marrow cells, whole blood cells, cells in lung and bronchoalveolar lavage fluid (BALF) were analyzed using complete blood count (CBC) assay. As results, the number of neutrophil in the bone marrow was decreased in the LPS treated group, and the circulating neutrophil, neutrophil in the lung and BALF were significantly increased in the LPS treated group. Neutrophils in the lung and BALF were dramatically decreased in the EC-18/LPS co-treated group. Also, Evans Blue staining of the lung indicated that capillary permeability was enhanced in the LPS injected mice, and this permeability was lessened in the EC-18/LPS co-treated group as much as that of control. These findings suggested that EC-18 could effectively block neutrophil transmigration into the lung and vesicular leakage. Consequently, EC-18 could be utilized as a potential therapeutic agent for acute and chronic inflammation related disease like ALI.

Disclosures
No relevant conflicts of interest to declare.
T Regulatory Cells Exhibit Surface Expression of FoxP3 Derived Peptides Presented within Class I MHC
Authors: Schultz Liora M. , Olsson Niclas , Khodadoust Michael , Narayan Rupa , Sagiv-Barfi Idit , Elias Joshua , Levy Ronald 
Published: October 2019

Abstract
Background:
FOXP3 is a transcription factor of central importance to the inhibitory function of CD4+, CD25+ FOXP3+ T regulatory cells (Tregs). Tregs function as critical inhibitory immunoregulatory cells and have been reported to be increased in tumor-bearing individuals, inhibiting optimal T effector mediated anti-tumor cytotoxicity. Treg depletion targeting CD25, a surface marker of Tregs as well as activated T cells, has been validated in pre-clinical models as a promising adjunctive therapeutic approach to improving T cell mediated therapy and is currently being explored in clinical trials. However, because CD25 expression is not limited to Tregs, CD25-directed therapies may also result in the undesired depletion of effector T cells. Although FOXP3 expression is more restricted to Tregs as compared to CD25, its intranuclear localization has made it challenging to target therapeutically. Vaccination of mice against FOXP3 using FOXP3 mRNA-transfected dendritic cells has been explored and can elicit FOXP3 specific CTL mediated cytotoxicity. This work implies that FOXP3 mRNA-transfected dendritic cells process FOXP3 and present FOXP3 derived peptides on the cell surface. Direct expression of FOXP3 derived peptides on the surface of Tregs has however, not been previously demonstrated.
Methods:
We utilized mass spectrometry to investigate if FOXP3 derived peptides presented within MHC class I complex are expressed on the surface of Tregs. CD4+, CD25+ T cells were isolated from healthy donors using magnetic bead selection to enrich for Tregs. Surface class I MHC was immunoprecipitated using a pan-MHC class I anti- HLA-A, HLA-B and HLA-C antibody and associated peptides were eluted from their MHC complex using acid elution. Peptide and fragment masses were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and the spectra of resulting epitopes were matched to known protein sequences by SEQUEST.
Results:
Four unique FOXP3 derived peptides were identified from the primary donor samples enriched for FOXP3+ cells as described. Predictive HLA binding algorithms demonstrate that the peptides identified are predicted binders to the specific HLA alleles of the original donors. No FOXP3 derived peptides were identified from the CD4+, CD25- T cell fraction analyzed to date.
Conclusions:
This work directly demonstrates for the first time to our knowledge that, although FOXP3 is an intra-nuclear transcription factor, FOXP3 derived peptides are presented within class I MHC on the surface of Tregs, representing a targetable Treg associated surface protein complex.

Disclosures
Levy: Bullet Biotechnology, Inc.: Consultancy.
Parstatin Mediates Platelet Activation That Is Unaffected By PAR Antagonism
Authors: Dunphy Paige Selvy , Kotha Jayaprakash , Dixon Mason L. A. , Jalenak Jay M. , Jennings Lisa K. 
Published: October 2019

Abstract
Thrombin cleaves PAR-1 at amino acids arg41-ser42 to yield the canonical tethered ligand as well as a soluble peptide, parstatin, which has been reported to have divergent physiological functions. In animal models, this peptide demonstrates anti-angiogenic, anti-inflammatory, and cardioprotective properties. In ex vivo studies, parstatin was also demonstrated to affect platelet aggregation and enhance GPIIb/IIIa-mediated adhesion, suggesting this cleaved peptide may participate in pathological thrombosis. With recent approval of a first-in-class PAR-1 antagonist as an antiplatelet agent, it is clinically imperative to fully appreciate the physiologic mechanisms through which thrombin-activation of PAR-1 contributes to platelet aggregation and thrombosis. As such, the effects of PAR antagonism in modulating parstatin-mediated platelet activation requires evaluation.
In this study, we characterized parstatin-mediated effects on platelets and investigated the potential involvement of platelet thrombin receptor (PAR-1, PAR-4)-associated signaling in this phenomenon. Light-transmission aggregometry was used to measure aggregation response in washed platelet preparations, and flow cytometry was used to assess expression of protein markers indicative of platelet activation. Consistent with previous reports, we demonstrated parstatin induces P-Selectin surface expression (degranulation), GPIIb/IIIa activation (PAC-1 binding), and aggregation independent of thrombin receptor cleavage (n=10, healthy donors). Interestingly, platelet shape change was not observed following parstatin treatment, even in the presence of PAR-1 activating peptide (PAR-1-AP, SFLLRN), suggesting parstatin-mediated activation does not signal through G12/13-dependent mechanisms, and may override canonical G12/13-associated PAR-1 signaling. Pretreatment with Gq-selective PAR-1 antagonist, ML161 (3 µM), or PAR-4-selective antagonist, ML354 (500 nM) did not inhibit parstatin-mediated platelet activation. These findings are consistent with previous reports suggesting this peptide may signal through a Gi-dependent mechanism. Platelet PAR receptors couple to Gαq and Gα12/13, but direct coupling to Gαi is controversial; therefore, parstatin-mediated activation may occur through a signaling cascade unrelated to canonical PAR-associated mechanisms.

Disclosures
No relevant conflicts of interest to declare.
Use of Clofarabine in Pediatric Multisystem Langerhans Cell Hystiocytosis
Authors: Pita Valentina , Betancourt Neiva , Ramirez Bertha , Bello Adriana C. 
Published: October 2019

Abstract
Langerhans cell hystiocytosis has been defined as an inflammatory and/or neoplasm of the hematopoietic system, mainly of myeloid precursors. There is recent evidence of mutations in the BRAFF V600 progenitor cells, which underline its neoplastic nature -myeloprolipherative condition.
The diagnosis of LCH relies on a positive biopsy identifying characteristic LCH cells by morphology and immunohystochemistry (CD1a and Langherin). Genetic tests have been added to the diagnostic armamentarium, with prognostic value.
Children younger than 2 years, and with risk organ involvement, have an unpredictable, often bad prognosis.
There is no current international consensus on LCH treatment, and guidelines are based on the best currently known treatment approaches.
Case #1:
4 year old girl with MS-LCH with hematologic, bone and lung involvement. She presented early at 18 months of age with pancytopenia, became transfusion dependant of red blood cells and occasional platelets. She was started on LCH-III after a lymph node biopsy showed extramedullary hemopoiesis and positive for LCH (Langherin, Cd1a). She received 12 weeks of initial therapy with vinblastine and prednisolone, with no improvement. Disease progressed with additional bilateral pleural effusion and fever. She was given Clofarabine 25mg/m2/d x5 during 2 courses, with improvement of counts and symptoms. A PET FDG scan was pending to assess disease status.
Case #2:
18 month old girl with systemic manifestations of MS-LCH since age 3 months, with fever, splenomegaly and anemia. Multiple cranial lesions were found, and skull biopsy at age 13 months was positive for LCH (langherin, Cd1a). BRAFF V600 mutation by PCR of biopsy was negative. cerebral MRI was normal. She was started on LCH-III (vinlastine plus steroids) during 6 weeks. Due to disease progression, worsening splenomegaly, anemia, fever, she was given clofarabine 25mg/m2/d x5. Fever disappeared post 1st course of treatment. Rest of manifestations were gone after 2nd cycle. Treatment was administered as inpatient, with no significant side effects.
Clofarabine is a second generation nucleoside analog with activity in refractory AML. It has been used with success as salvage therapy in LCH patients.
There is growing optimism with the use of nucleoside analogs as effective treatment of LCH, with dose-dependent effects on therapeutic efficacy, as well as toxicity.

Disclosures
Off Label Use: Clofarabine. Second generation nucleoside analog.
Lymphocyte Activation Gene 3-a Novel Therapeutic Target in Chronic Lymphocytic Leukemia
Authors: Shapiro Mika , Katz Ben-Zion , Perry Chava , Sun Clare , Dezorella Nili , Kay Sigi , Avivi Irit , Wiestner Adrian , Yair Herishanu 
Published: October 2019

Abstract
A novel therapeutic approach in cancer attempting to stimulate host anti-tumor immunity involves blocking of immune checkpoints. Lymphocyte-activation gene 3 (LAG3) is an immune checkpoint receptor expressed on activated/exhausted T-cells. When engaged by MHC Class II (MHCII) molecules, LAG3 negatively regulates T-cell function thereby contributing to tumor escape. Intriguingly, a soluble LAG3 variant was reported to activate both immune and malignant MHCII-presenting cells. In this study, we examined the role of LAG3 in the pathogenesis of CLL and show that CLL cells express and secrete LAG3. High levels of surface and soluble LAG3 were associated with the unmutated immunoglobulin variable heavy chain CLL and a more aggressive disease. It was evident that recombinant soluble LAG3-Ig fusion protein activated CLL cells, induced increased levels of Bcl-2 and Mcl-1 and protected the cells from spontaneous apoptosis, utilizing a mechanism mediated through MHCII engagement. Our data suggest that autocrine secretion of soluble LAG3 from CLL cells and its subsequent interaction with MHCII on their surface, promotes CLL cell activation and anti-apoptotic effects. Moreover, CLL cells may impose immune exhaustion on their microenvironment by expressing MHCII, thus affecting the surrounding, LAG3-presenting immune cells. Hence, blocking LAG3-MHCII interactions is a potential therapeutic target in CLL.

Disclosures
Avivi: Tel Aviv Sourasky Medical center: Consultancy, Other: consultancy to :BMS Roche. Wiestner:Pharmacyclics: Research Funding; Acerta Pharma: Research Funding.
Inhibition of Casein Kinase 2 Impairs Wnt Signaling and Cell Survival in Chronic Lymphocytic Leukemia
Authors: Wu Christina , Lao Fitzgerald S , Nan Emily , Li Hongying , Choi Michael Y. , Messer Karen , Carson Dennis A. 
Published: October 2019

Abstract
The oncogenic Wnt pathway is aberrantly activated in most CLL clones, and hence is an attractive target for therapy. The casein kinase 2 (CK2) enzyme is an established positive regulator of Wnt signaling. The inhibitor Silmitasertib, also known as CX-4945, is a nanomolar inhibitor of CK2. It has been reported that CK2 is overexpressed in CLL. Here we have investigated the effects of CX-4945 on WNT signaling in primary CLL cells.
We confirmed that CX-4945 displayed in vitro cytotoxic activity toward CLL cells at very low µM concentration, as previously reported by others. However, at least 2-3 fold higher concentration of CX-4945 was required to achieve a similar toxicity against normal PBMC. Previously, our laboratory has successfully utilized a short-term CLL "parking" model in immunodeficient RAG/gamma chain knock out (RG-KO) mice to evaluate the in vivo efficacy and potential toxicity of anti-CLL agents. CX-4945 at dosages of 0.3-10 mg/kg was administered by oral gavage daily for 6 days to mice injected i.p. with 10 million CLL cells. These dosages of drug were well tolerated, and potently inhibited CLL persistence in the xenotransplanted mice.
In a reporter gene assay, CX-4945 dose-dependently inhibited Wnt target gene expression. Furthermore, inhibition of dishevelled-2 (Dvl-2) protein expression was observed in primary CLL patient samples treated with 3-10 µM CX-4945 for 4-16 hours. Similar reduction in p-GSK3b(S9) protein was also observed. Quantitative RT-PCR also confirmed down regulation of b-catenin gene expression in primary CLL patient samples treated with 10 µM CX-4945 for 4h. Further molecular analyses of predictive or correlative biomarkers is ongoing using Nanostring PanCancer multipathway gene analysis. In a preliminary study, we found that CX-4945 perturbed the expression of multiple genes implicated in CLL development and survival.
In summary, the CK2 inhibitor CX-4945 inhibited Wnt signaling and CLL survival, and displayed oral activity in mice. CK2 inhibitors are thus potential therapeutic agents for CLL.

Disclosures
No relevant conflicts of interest to declare.