bluuebunny/crossref_metadata_2025 huggingface dataset:
Outcome of Refractory Anemia with Ringed Sideroblasts Associated with Marked Thrombocytosis (RARS-T) In a Large Cohort of Patients
Authors: Girodon Francois , Broseus Julien , Florensa Lourdes , Zipperer Esther , Schnittger Susanne , Malcovati Luca , Richebourg Steven , Lippert Eric , Cermak Jaroslav , Nangalia Jyoti , Mounier Morgane , Raya Jose Maria , Gattermann Norbert , Haferlach Torsten , Cazzola Mario , Garand Richard , Kaoutar Allou , Maynadie Marc , Besses Carlos , Germing Ulrich , Haferlach Claudia , Travaglino Erica , Hermouet Sylvie
Published: October 2019

Abstract 4113

Introduction:

Most of the data related to RARS-T, a rare disorder, involve small cohorts of patients. We aimed to analyze more patients also considering a variety of myelodysplastic or myeloproliferative disorders.

Objective:

To compare a large cohort of patients with RARS-T to refractory anemia with ringed sideroblasts (RARS), refractory anemia with ringed sideroblasts and multilineage dysplasia (RARS-MD) or essential thrombocythemia (ET) at the time of diagnosis and during disease evolution, in terms of survival and complications.

Materials:

Data of a European multi-center study was used including 199 cases of RARS-T 173 cases of RARS, 102 cases of RARS-MD and 431 cases of ET.

Results:

At baseline, compared to RARS and RARS-MD patients, RARS-T patients had similar hemoglobin concentration, but a higher white blood count. The JAK2V617F mutation was observed in 43%, 12% and 5% in RARS-T, RARS and RARS-MD patients, respectively. When separated in 2 groups (450,000<platelet count <600,000 and platelet count >600,000 × 109/l), RARS-T patients were comparable for sex, age, hemoglobin level and survival. However, patients with platelet count > 600,000 × 109/l had higher WBC (11 ×109/l versus 7.5 ×109/l, p<0.001). Similarly, no difference was noted in the survival in the JAK2 positive and negative RARS-T patients. The age and sex standardised overall survival of RARS-T patients was similar to RARS and RARS-MD patients, but lower than ET patients (p<0.001). This was despite a higher risk of transformation in acute leukemia, relative to RARS-T afflicted individuals, of 2.4 and 3.5 in RARS-MD and RARS patients, respectively.

Conclusion:

According to our results, the outcome in RARS-T more closely mimics myelodysplastic syndromes rather than myeloproliferative neoplasms. Our results agree with the WHO 2008 classification that considers RARS-T as a separate disorder.

Disclosures:

Schnittger: MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Gattermann:Novartis: Honoraria, Research Funding. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.
Prognostic impact of circulating Epstein-Barr virus (EBV) DNA concentration and EBV serology in 125 extranodal NK/T cell lymphoma, nasal type (ENKL) patients
Authors: Guo Chengcheng , He Huang , Guo Hongqiang , Xiao Jian , Zhang Yujing , Tian Ying , Cao Yabing , Fu Xiaohong , Zhai Linzhu , Lin Tongyu
Published: October 2019

Abstract 4148

Background

extranodal NK/T cell lymphoma, nasal type (ENKL) has worse efficacy and prognosis than B-NHL. Circulating EBV DNA concentration can reflect the efficacy and prognosis in some EBV related malignance (nasopharyngeal carcinoma). But there are few studies about the relation between EBV infection and ENKL. This prospective study is to confirm predictive value of circulating EBV DNA concentration and EBV serology in ENKL patients.

Methods

In the prospective study, serum samples from 125 previously untreated ENKL patients were collected from Jan 2002 to Dec 2006. We detect VCA-IgA and EA-IgA level by immunoenzyme methods and circulating EBV DNA concentration by real-time PCR assay. All patients were received long-term efficacy and survival assessment.

Results

The median follow-up time is 4.53 years. The positive rates of VCA ƒüIgA and EA ƒüIgA are 30.6% and 1.6% respectively, both of which could not predict the efficacy and survivals. The positive rate of circulating EBV DNA is 69.4%, with a median concentration of 13400 copies/ml. Patients with extranodal involvement, B syndrome, upper respiratory involvement, neutropenia or anemia or thrombocytopenia, liver dysfunction, and increasing of β2MG, have significantly higher EBV DNA positive rate(45.1% A54.4% A62.3% A53.5% A90.0% A59.3%, respectively). Patients in higher EBV DNA concentration group is easier to have bone and/or skin involvement (≤13400 copies/ml group: 45.8%vs. >13400 copies: 16.0%, p=0.024). The positive circulating EBV DNA group has a lower complete remission (CR) rate (38.8%vs.59.2%, p=0.026), higher relapse rate (52.6%VS.26.7%, p=0.046) than negative one. The 5-year DFS and 5-year OS decreased with the dose of circulating EBV DNA group (DFS: negative group74.3% vs. ≤13400 copies/ml group 55.0% vs. >13400 copies/ml group 28.6%, p=0.003; OS: negative group 55.8% vs. ≤13400 copies/ml group 48.4% vs. >13400 copies/ml group 29.2%, p=0.004).

Conclusions

The positive rate of circulating EBV DNA is much higher in ENKL. Circulating EBV DNA concentration, as measured by real-time PCR, is a useful tumor marker for diagnosis and prognostication with ENKL patients. Patients with higher dose of circulating EBV DNA level (>13400 copies/ml) may undergo more aggressive biological behavior.

Disclosures:

No relevant conflicts of interest to declare.
Incidence and Risk Factors for Central Nervous System (CNS) Relapse In Patients with Diffuse Large B-Cell Lymphoma (DLBCL): Analysis with Competing Risk Regression (CRR) Model
Authors: Chihara Dai , Oki Yasuhiro , Matsuo Keitaro , Onoda Hiroshi , Taji Hirofumi , Yamamoto Kazuhito , Morishima Yasuo
Published: October 2019

Abstract 4154

Introduction:

CNS relapse is a challenging complication in patients with DLBCL. Identification of high risk population is therefore critical, in whom prophylactic intrathecal (IT) chemotherapy may play a significant role. To calculate the cumulative incidence of CNS relapse, Kaplan-Meyer method tends to overestimate the incidence because a censored individual by death is still assumed to have a chance to fail from CNS relapse. To overcome this methodological conflict, we evaluated the risk factors for CNS relapse in patients with DLBCL using CRR analysis.

Methods:

Medical records of patients with DLBCL newly diagnosed and treated with CHOP or R-CHOP at Aichi Cancer Center Hospital between 1995 and 2008 were reviewed. Patients were excluded if they had evidences of CNS involvement at initial diagnosis.

Results:

A total of 386 patients who met the criteria for the study were analyzed. The median age of patients was 62 (range 18–95). All patients received CHOP based systemic chemotherapy with (n=203) or without (n=183) rituximab. Prophylactic IT chemotherapy was provided to 6 patients with testicular involvement. At a median follow up duration of 52.9 months, 24 patients experienced CNS relapse. Nine patients presented with brain parenchymal mass, 12 patients presented with leptomeningeal disease, and 3 patients presented with both. The median time from initial diagnosis to CNS relapse was 20.5 months (range 5.3–91.8 months). Five-year cumulative incidence of CNS relapse was 6.7% (95%CI: 4.2–9.8). Five-year cumulative incidence of CNS relapse in patients treated with and without rituximab was 5.9% and 7.3%, respectively (p=0.42). Multivariate analysis for the risk factors of CNS relapse using CRR identified three independent risk factors for CNS relapse; bulky disease (SHR 3.34 [1.45-7.66], p=0.004), lymphocyte count<1.0 ×109/L (SHR 2.38 [1.05-5.39], p=0.017) and extranodal involvement (SHR 2.90 [1.01-8.33], p=0.047). Patients with all three risk factors represented 6% of all patients, in whom the 5-year cumulative incidence of CNS relapse was 26% (Figure 1). When the number of extranodal involvement was taken into account, patients with 3 or more sites of extranodal involvement had extremely high incidence of CNS relapse (28%), all occurring within 18 months after initial diagnosis. These patients may be good candidates for CNS evaluation at initial diagnosis even in the absence of neurological manifestation.

Conclusions:

We identified significant risk factors for CNS relapse in patients with DLBCL using CRR. Evaluation for CNS involvement and prophylactic IT chemotherapy should be considered in patients with high risk features.

Disclosures:

No relevant conflicts of interest to declare.
In Vivo Monitoring of Venous Thrombosis In Mice Using Ultrasonography
Authors: Aghourian Meghedi , Lemarie Catherine , Blostein Mark
Published: October 2019

Abstract 4214

Deep venous thrombosis is an important cause of morbidity and mortality in clinical medicine. There has been extensive research dedicated to the clinical aspects of venous thrombosis, especially with regards to its diagnosis and treatment. However, animal models studying this phenomenon are scarce and, in most cases, very crude, relying on sacrificing animals to excise the formed thrombi. Developing an in vivo murine model of venous thrombosis, detecting and monitoring thrombi non-invasively as is done in humans can be a powerful tool given our ability to genetically modify the murine genome. Therefore, we developed such a murine model using the Vevo770®, a microimaging ultrasound system previously developed to study the arterial circulation of mice. Two different thrombosis models were employed to generate clots in the inferior vena cava (IVC) of wild type C57Bl6 mice: 1) ligation of the IVC to generate venous stasis and 2) application of Ferric Chloride (FeCl3) to the outer layer of the IVC to injure the endothelium. Using both of these techniques, adequate thromboses were generated in the IVCs of mice as determined pathologically. Other mice were allowed to recover after surgery, and the development of venous thrombosis was assessed by ultrasonography using the Vevo 770®. In order to assess the precision of clot measurements using this novel technique, we then sacrificed the mice and excised the clots. In both models, the measurement of the clot pathologically correlates favorably (R2= 0, 9116 for the ligation model, and R2 = 0,905 for the FeCl3 model) with measurements done by ultrasonography (n=20 for the ligation model, and n=5 for the FeCl3 injury model). In the ligation model, a thrombus develops less than an hour after ligation of the IVC, and the size of the clot increases over time. For example, five hours after the ligation of the IVC, a clot develops and has a cross sectional area of 4,5 mm2. The clot size increases significantly (p=0.001) over time to 6.2 mm2 at 24 hours post ligation (n=20). Treatment of these mice with an anticoagulant (dalteparin at a dose of 200 u/kg) prior to the procedure prevented the development of IVC thrombosis as determined by ultrasonagraphy. These data suggest that the Vevo770® can be used as a reliable technique for the non-invasive assessment of venous thrombosis in mice. Developing a murine model for thrombosis using more accurate, and clinically more relevant techniques such as ultrasonography, is a step towards better understanding the pathophysiology of venous thromboembolism.

Figure 1. Clot length correlation using histology and ultrasonography, 24 hrs post ligation of the IVC in 20 mice. R2= 0,9116. Figure 1. Clot length correlation using histology and ultrasonography, 24 hrs post ligation of the IVC in 20 mice. R2= 0,9116.

Disclosures:

No relevant conflicts of interest to declare.
Epo Engages a Tnfr-13c Pathway to Advance for Primary Bone Marrow (Pro)Erythroblast Development
Authors: Singh Seema , Dev Arvind , Sathyanarayana Pradeep , McCrann Donald J , Emerson Christine , Pradeep Anamika , Wojchowski Don M.
Published: October 2019

Abstract 4238

In late stage erythroblasts, EPO can increase levels of Bclx, Bcl2 and/or Mcl1 anti-apoptotic factors. Proerythroblasts, however, are a key EPO target (and exhibit sharp dependence on EPO for growth, and survival). In these progenitors, however, Bclx, Bcl2 and Mcl1 are not prime EPO/EPOR targets. Via transcriptome-based analyses of EPO response circuits in developmentally staged primary bone marrow proerythroblasts (which we now analyze and present at a global level) an atypical TNF receptor, Tnfrsf13c proved to be among the top 1% of EPO/EPOR induced factors. Within lymphoid lineages, Tnfrsf13c is a known receptor for BAFF ligand; and BAFF is an essential mediator of B-cell survival and development. Possible effects of BAFF (a bone marrow stromal cell surface ligand) on primary erythroid cell formation therefore were assessed. Notably, limited BAFF exposure (15 hours) inhibited apoptosis; increased erythroid cell numbers; and enhanced the formation of late-stage Ter119pos erythroblasts. Specifically, cytoprotection by BAFF rivaled that afforded by EPO; cell numbers were enhanced 140% (in 15 hr); and frequencies of Ter119pos erythroblasts were enhanced to 200% of controls. In keeping with Tnfrsf13c's role as an EPOR target, each of the above effects further proved to depend upon proerythroblast exposure to EPO. With regards to Tnfrsf13c expression, analyses using primary erythroid progenitors with knocked-in minimal EPOR alleles indicated dependence for EPO- induction upon JAK2, STAT5 as well as EPOR C-terminal coupled pathways. Studies overall reveal a novel EPOR action route within primary proerythroblasts as a Tnfrsf13c/BAFF pathway (which engages non-canonical NF-kappaB molecular mechanisms).

Disclosures:

No relevant conflicts of interest to declare.
A Novel 3D Co-Culture System for Isolation and Amplification of Primary Liquid Cancer Cells
Authors: Caicedo-Carvajal Carlos , Liu Qing , Goy Andre , Pecora Andrew L , Mato Anthony R , Feldman Tatyana , Suh K. Stephen
Published: October 2019

Abstract 426

One of the important challenges in screening anti-cancer drugs is the lack of available “primary cultures systems” that is easy to use to screen new compounds or their combinations. The low yield of primary cancer cell cultures is mainly due to suboptimum environment in vitro and inefficient 2-dimensional cell culture conditions. To create an optimum in vitro environment, lymphoma cell lines were grown in 3-dimension model by using a scaffold and the stromal cells derived from neonatal foreskin was used as the feeder component. This 3-dimensional (3D) stromal co-culture generates an in-vitro model that may mimic the conditions/microenvironment of blood cancer cells interacting with stromal compartments. A specific 3D tissue culture scaffold 3D Insert-PS™ (300 μ m in fiber diameter and 400μ m in pore size) significantly enhances the cell proliferation and maintenance of liquid cancer cells in comparison to 2D stromal co-culture control. The combination of the neonatal stroma cells, a novel 3D scaffold, the constant gyration and a frequent nutrient stimulation allows the lymphoma cells to proliferate 10-fold faster than the cells grown in 2D under the same condition. Starting from the 2nd day of 3D cell culture, these lymphoma cells grew to form layers of aggregated clusters and caused disappearance of single cells morphology and phenotype that is typical of cells growing in suspension. The cell aggregates are continuously produced from the 3D scaffold, subsequently dislodge from the scaffold and then remain viable at the bottom of the dish below the scaffold. When the cell clusters are harvested and cultured in 3D condition, the contamination of fibroblasts is over 1,000 fold less than the cell clusters that are generated from 2D environment. In addition, the clusters of cancer cells generated from 3D co-culture using 3D scaffolds contained the fibroblasts contamination that is less than 0.00001% of the total cell count, suggesting that this novel 3D environment can be implicated for the isolation of primary lymphoma/cancer cells from patient's blood or tissue specimen. To investigate this feasibility, <1% lymphoma cells were premixed with 100 fold excess of neonatal stroma cells, and the mixture was grown using our 3D scaffolds. In 7 days, the 3D culture system was able to amplify lymphoma cells over 100 fold or over 10,000 % of the starting cell number. This preliminary data indicate that this 3D scaffold and co-culturing environment can be customized to amplify primary cancer cells from blood or tumor tissues and subsequently used for personalized drug screening procedures.

Disclosures: Goy:

Allos Therapeutics, Inc.: Consultancy, Honoraria.
Cardiac Iron Overload and Heart Function by CMR In Different Phenotypic Groups of Thalassemia Major Patients
Authors: Dell'Amico Maria Chiara , Meloni Antonella , Filosa Aldo , Rossi Giuseppe , Positano Vincenzo , Favilli Brunella , Marchi Daniele De , Grippo Teodosio , Trunfio Roberto , Maggio Aurelio , Lombardi Massimo , Pepe Alessia
Published: October 2019

Abstract 4264

Introduction.

β-thalassemia major is a genetic disorder characterized by the absence (β°) or reduced output (β+) of the β chains of haemoglobin. This disorder displays a great deal of phenotypic heterogeneity, not fully investigated in terms of cause-effect (Refaldi C et al, Blood Transf 2005; Thein SL, Haematologica 2005). The aim of our study was to detect if different phenotypes could be related to different levels of cardiac impairments, evaluated by cardiovascular magnetic resonance (CMR).

Methods.

We performed a retrospective review of the CMR results and of clinical data about 328 TM patients (age 29 ± 9 years, 52% females) enrolled in the Myocardial Iron Overload in Thalassemia (MIOT) project (Meloni A et al, Int J Med Inform). In the MIOT network all CMR and thalassemia centers are linked by a web-based network, configured to collect patients' anamnestic, clinical, and diagnostic data. Myocardial iron overload was assessed by using a multislice multiecho T2* approach (Pepe A et al, Eur J Haem 2006). Three short axis views (basal, medium, and apical) of the left ventricle (LV) were acquired and analyzed using a custom-written, previous validated software (HIPPO MIOT®). The myocardium was automatically segmented into a 16-segments standardized LV model and the T2* value on each segment was calculated as well as the global T2* value. Cine sequences were obtained to quantify biventricular morphological and functional parameters.

Results.

Three groups of patients were identified: heterozygous (N=172), homozygous β+ (N=58), homozygous β° (N=98). No significant differences for sex and age were found among the groups. The homozygous β+ group showed higher global heart T2* values than the heterozygous and homozygous β° group (32 ± 11 ms vs 26 ± 13 ms vs 23 ± 13 ms, P=0.001) (see figure). The homozygous β+ group showed lower left LV mass index than the heterozygous group (54 ± 10 g/m2 vs 60 ± 14 g/m2, P=0.045). The homozygous β+ group showed higher LV ejection fraction (EF) values than the heterozygous group (64 ± 5 % vs 60 ± 7 %, P<0.0001) and higher right ventricular EF values than the heterozygous and homozygous β° group (64 ± 5 % vs 59 ± 8 % vs 60 ± 7 %, P<0.0001).

Conclusions.

The homozygous β+ TM patients showed less myocardial iron overload and a concordant better global systolic heart function and cardiac remodelling. These data support the knowledge of the different phenotypes in the clinical and instrumental management of the TM patients suggesting stricter monitoring by CMR in homozygous β° TM patients.

Disclosures:

No relevant conflicts of interest to declare.
NK Cell Proliferation and Cytolytic Function Are Compromised In the Hypoxic Tumor Microenvironment
Authors: Ang Sonny , Silva Maria Lima Da , Dawson Margaret , Figliola Matthew , Maiti Sourindra , Huls Helen , Shpall Elizabeth J. , Champlin Richard , Lee Dean A. , Silla Lucia , Cooper Laurence J.N.
Published: October 2019

Abstract 4291

Natural Killer (NK) cells have important and potent innate immunoregulatory and immune surveillance functions against tumor. The paradoxical coexistence of tumors and anti-tumor immune cells (“Hellstrom Paradox”) may in part be explained by the pathophysiology of the “hostile” tumor microenvironment which suppress immune-cell function, such as hypoxia, low pH, low tissue glucose, and the presence of immunosuppressive cytokines and metabolites. However, the effect of the malignant environment on the ability of NK cells to infiltrate tumor and exhibit effector function is largely unknown. Therefore, we investigated the ability of NK cells to operate under conditions of hypoxia. Importantly, NK cells showed a 1,000-fold reduction in proliferative capacity when grown under chronic hypoxia (4 weeks of 1% O2). In addition, there was a corresponding decrease in cytotoxicity as revealed by chromium release assay. This was in contrast to autologous T cells which could numerically expand under corresponding growth conditions. Expression profiling uncovers profound upregulation of hypoxia-inducible genes such as EGLN1(9.9x), EGLN3(52x), LDHA(11.5x), SLC2A1(30.5x), PDK1(16.8x), VEGFA(286x) and BNIP3(138x) in hypoxic NK cells. Protein expression confirmed these changes, as NK cells under normoxic culture produced 520 nmoles/million cells of ATP, while those under hypoxic culture managed only 100 nmoles/million cells. This is consistent with a bioenergetic switch from oxidative phosphorylation to glycosis resulting from PDK1 upregulation. NK cells in hypoxia produced 61 pg/mL of VEGF compared to 1480 pg/mL for NK cells in normoxia (20% O2), as determined by ELISA. The inability of NK cells to propagate under conditions of hypoxia may be due to a drop in mitochondrial content we observed when cells were exposed to chronic hypoxia, a potential mitophagic effects of BNIP3 upregulation. In addition to the poor proliferative capacity of NK cells under hypoxia, we also noted the loss of CD56 expression on hypoxic NK cells which is associated with loss of cytotoxicity. Sequence analysis reveals that miR-210 can bind to the 3′UTR of CD56 mRNA, targeting it for degradation. Therefore, we investigated whether miR-210 levels are upregulated in hypoxic NK cells and found that increased presence correlated with loss of CD56 expression. This leads to the conclusion that NK-cell immunotherapy may be improved by downregulating miR-210 levels. Indeed, our findings help shape strategies for obtaining robust and sustained NK-cell effector function for adoptive immunotherapy in the hypoxic tumor microenvironment.

Disclosures:

No relevant conflicts of interest to declare.
Infantile Hemangioma: A Tumor Involving Hemogenic Endothelium with Erythropoetic Potential
Authors: Itinteang Tinte , Vishvanath Anasuya , Brasch Helen D , Day Darren J , Tan Swee T
Published: October 2019

Abstract 4305

Background

Infantile hemangioma (IH) is a tumor of the microvasculature predominantly composed of proliferating endothelial cells, but also contains progenitor cells of mesenchymal and hematopoietic lineages. We have previously shown that IH has a primitive mesodermal origin. Here we investigated expression of hematopoietic associated proteins (Tal-1, GATA-2, CD133 & CD34) as well as the erythropoietin receptor (EPOR) and the embryonically-associated hemoglobin zeta chain (HBZ) by both the cells of the endothelium and the cells emanating from proliferating IH explants. Additionally we investigated if the cells emanating from the explants generate erythrocytes in vitro.

Purpose

To investigate the expression of hematopoietic associated proteins and the primitive erythropoietic capacity of proliferating IH.

Methods

Proliferating IH biopsies from 5 patients were (i) processed for IHC staining for Tal-1, GATA-2, CD133, CD34, HBZ and EPOR; (ii) used to determine the relative expression of Tal-1, GATA-2, CD133, CD34, HBZ & EPOR transcripts by qRT-PCR; (ii) cultured as explants using our in vitro model and differentiated the cells down the erythropoietic lineage.

Results

IHC showed that the cells that line the endothelium forming the capillaries of proliferating IH expressed Tal-1, GATA-2, CD133, CD34, HBZ and EPOR. qRT-PCR confirmed the IHC data as abundant expression mRNA transcripts for the same proteins was detected in both the tissue and the cells emanating from the cultured explants. Following 5 months in culture morphological biconcave cells were visible, and were confirmed to be erythrocytes by immunoreactivity to the erythrocyte-specific cell surface marker glycophorin A.

Conclusion

The mRNA and protein expression of hematopoietic associated proteins in proliferating IH supports our previous studies showing this tumor expressing markers of primitive mesoderm and confirms a hemogenic endothelium phenotype. The expression of the primitive erythropoiesis-associated proteins HBZ and EPOR by proliferating IH and its functional ability of proliferating IH explants to form erythrocytes in vitro confirms the erythropoietic potential. Proliferating IH thus represents an extra-medullary site of tumor-associated erythropoiesis.

Disclosures:

No relevant conflicts of interest to declare.
EFFECTS of Zoledronic ACID On eNOS Exppression and Vascular Contractility IN Rat Aorta
Authors: Avcu Ferit , Soner Burak Cem , Yildiz Oguzhan , Ozturk Kamile , Elci Pinar , Sarper Meral , Ural Ali Ugur
Published: October 2019

Abstract 4318

Zoledronic acid (ZOL) is a potent nitrogen-containing bisphosphonate used in the treatment of skeletal metabolic disorders and bone metastatic diseases. It has been shown that the nitrogenous bisphosphonates inhibits enzymes of mevalonate pathway. Similar with statin derivatives, ZOL affects the biological activity of geranyl-geranylated proteins in mevalonate pathway, as shown for the small GTPase RhoA. Although, beneficial effects of statin derivatives on vascular tissue have been reported, there is no study on effects and of ZOL on endothelial functions in vascular tissue and mechanisms of its action. It is important to elucidate the mechanism regulating NO production for endothelial cells to develop new therapeutic strategies for the treatment of impaired endothelial function associated with the vascular diseases. The aim of this study is to demonstrate the molecular mechanism of ZOL in the regulation of endothelial responses and eNOS expression in rat aorta. For his aim, potassium chloride and phenyleprine induced vasoconstriction was evaluated in endothelium intact and denuded isolated rat aorta preparations (n=6) after incubation with ZOL 100 μM and the results were compared with those without ZOL incubation. In addition, to evaluate endothelium dependent or independent effects of ZOL, vasodilator effects of acetylcholine and sodium nitroprussid were tested in the presence and absence of ZOL. To evaluate the influence of protein geranylation in effect of ZOL, contractile effect of phenylephrine vasocontractions was tested after incubation with ZOL in the presence of geranylgeranyl pyrophosphate and farnesyl pyrophosphate, important enzymes of mevolonate pathway. In addition, eNOS mRNA expressions were evaluated with RT-PCR in intact rat aorta or after incubation with ZOL. According to our results, incubation with ZOL decreased potassium chloride and phenylephrine-induced contractions significantly. This decrease was reversed NO-syntase inhibitor Nı,-nitro-L-arginine methyl esther (L-NAME) 0.1mM. Additionally, incubation with ZOL, increased endothelium-dependent acethycholine-induced relaxations and this effect of ZOL was inhibited by L-NAME. In rat aorta preparations incubated with ZOL, eNOS mRNA expression was increased significantly (1.52 fold) compared with control group. According to these results, we herein provide the first experimental evidence for the physiological role of ZOL in the regulation of eNOS expression and the contractility in the vascular tissues. This effect of ZOL is probably via its influence on RhoA. Since the restoration of NO bioactivity is a major target of present pharmacological and non-pharmacological treatments in cardiovascular medicine, further laboratory and clinical studies to explore the effect of ZOL on vascular endothelium may be helpful to demonstrate the possible benefits.

Disclosures:

No relevant conflicts of interest to declare.
Childhood B-Precursor-ALL Presenting as Hepatitis - A Diagnostic and Therapeutic Challenge
Authors: Schneider Henriette , Adam Ruediger , Marx Alexander , Duerken Matthias
Published: October 2019

Abstract 4331

Liver involvement in childhood acute lymphoblastic leukemia (ALL) at presentation is common with hepatomegaly but severe impairment or hepatitis is rare with only 9 reported cases. The need to start anti-leukemic treatment despite the potential hazard of severe liver failure poses a clinical dilemma. We report a 6 year old girl who presented with jaundice, fever, vomiting and diarrhoea, cytopenia, hyperbilirubinemia of 5.7 mg/dl (direct 5.2), ASAT of 3389, ALAT of 2747 U/L, increased INR to 1.33, but normal ammonia. An acute common-ALL was diagnosed and serology, PCR-studies and cultures were negative for viruses causing hepatitis. Liver biopsy revealed diffuse hepatic blast infiltration, piecemeal necrosis and hepatocellular cholestasis without signs of infectious hepatitis. We treated the patient according to the ALL-BFM-2000-protocol without dose reductions and on day 8, hyperbilirubinemia had completely normalized and liver enzymes had significantly decreased. Further therapy was uneventful and the patient is alive and well 12 month after diagnosis, without any signs of hepatic dysfunction. Reviewing the literature on children with ALL presenting with hepatitis revealed 9 patients with a mean age of 8.8 years (range 4 to 15), female to male ratio of 2.0 and precursor B-cell immunophenotype in 8/9 patients. Patients had a mean bilirubin of 8.7 mg/dl (range 2 – 16.5), 3 had highly elevated transaminases above 2000 U/L, and two of them died initially. Another patient with moderately increased liver enzymes but hepatic encephalopathy needed transient hemofiltration, but survived. In none of the reported cases a viral organism has been identified and abnormal liver function normalized during chemotherapy in most of the patients. This indicates, that leukemia rather than infection was responsible for hepatitis. In conclusion, severe hepatitis in children with ALL is rare, seems to affect the older girl, and highly elevated liver enzymes are associated with early death. After infective organisms have been excluded, instant start of an effective induction therapy is required, even despite severe hepatitis, most probably caused by blast infiltration.

Disclosures:

No relevant conflicts of interest to declare.
Outcome of Adults with Acute Lymphoblastic Leukemia Treated with a Pediatric-Inspired Therapy: A Single Institution Experience
Authors: Ruiz-Delgado Guillermo J. , Macias-Gallardo Julio , Lutz-Presno Julia , Montes-Montiel Maryel , Ruiz-Arg\)elles Guillermo J.
Published: October 2019

Abstract 4337

The results of treatment of adults with ALL remain unsatisfactory. Pediatric-inspired treatments seem to be related with better outcomes. Eighty adult ALL patients were prospectively treated in a single institution in a 16-year period with a schedule based on the St. Jude's TOTAL XI pediatric protocol employing vincristine, prednisone, asparaginase, daunorubicin, etoposide, cytarabine, methotrexate, mercaptopurine and triple intratecal therapy. Median age was 31 years (range 18 – 86); 92% were B-cell malignancies and 14% were Ph1 (+). Ten patients did not complete the first course of chemotherapy and 4 exited early. 44 of 66 patents (67%) achieved a complete remission; relapses presented in 57%. The median probability of overall survival (OS) was 28 months, whereas the 144-month OS was 27%. The median probability of leukemia-free survival (LFS) was 28 months, and the 144-month LFS 35%. Ph1 (+) patients did worse than Ph1-negative and T-cell leukemias did better than B-cell ones. Concerning toxicity, eight patients had toxic deaths (12%), two developed acute pancreatitis and one secondary diabetes. This pediatric-inspired therapy rendered better results than those obtained in similar socioeconomic circumstances using adult-oriented treatments; tolerance was acceptable and costs were low since it employs affordable drugs and can be delivered as outpatients.

Disclosures:

No relevant conflicts of interest to declare.
Results of the Treatment for Relapsed Acute Lymphoblastic Leukemia (ALL) in Childhood
Authors: Guitter Myriam Ruth , Alfaro Elizabeth M , Rossi Jorge , Gallego Marta , Alonso Cristina , Felice Maria S
Published: October 2019

Abstract 4339

INTRODUCTION:

Relapses occur in 25–30% of childhood ALL. We evaluated the outcome of this group of patients (pts) according to the duration of the 1st CR, immunophenotype and site of relapse in our Institution.

PATIENTS AND METHODS:

From Sept’94 to Aug’09, 245 ALL relapses were diagnosed: 73 cases were not evaluable due to: different treatments received (n: 36), palliative care (n: 26) and insufficient data (n: 11); 172 pts were evaluable (54 F/118 M), with a mean age at the moment of the relapse of 9.8 (range 1.8–20.8) years. Induction therapy combined a pre-phase with 10 days of prednisone and 1 block of high doses of chemotherapy, followed by 5 blocks of similar intensity, CNS or testicular (preventive/therapeutic) radiotherapy, and weekly rotational maintenance, until completing two years from the moment of diagnosis. High-risk relapsed pts who had an available identical donor received HSCT.

RESULTS:

Immunophenotype was B-cell precursor (Bcp) in 89% of the pts and T-cell in 11 %. The duration of the 1st CR was <18 mo in 41 (24%), 18–36 mo in 79 (46%), >36 mo in 52 (30%) pts. The sites of relapse were bone marrow (BM) in 106 pts (61%), combined bone marrow (cBM) in 27 pts (17%) and isolated extramedullar in 39 pts (22%). The response to induction was: CR 134 pts (78%), death during induction 20 pts (12%) and partial/null response 18 pts (10%). Among the 134 pts who achieved CR, 69 (52%) presented a second relapse at 18,8 (r 0.7–88.8) mo from the 2nd CR, 10 (7%) died in CR and 1 developed a 2nd neoplasm. With a mean follow-up of 49 (r 2–155) mo, 54 pts remain in CR, 37 of them out of therapy. Of the 26 pts who received HSCT, 12 relapsed and 3 died in CR. The EFSp (SE) for the total group of pts was 25 (3)% and LFS probability (SE) 33 (4)%; for Bcp relapses it was 28%, and for T relapses 6% (P=0.0025); for BM+cBM cases it was 21%, and 40% for extramedullar (P=0.0061). However, testicular relapses achieved EFSp of 80%, and 12% for the remaining extramedullar cases (P=0.0004). The EFSp for relapses at <18mo of 1st CR was 5%, between 18–36 mo 25% and >36 m 41% (P=0.0001).

CONCLUSIONS:

The immunophenotype, the duration of the 1st CR and site of relapse significantly influenced the EFSp. Isolated testicular relapses achieved the best EFSp. HSCT is an eligible option for a small group of pts. New therapeutic approaches must be developed to improve outcome of most of relapsed ALL patients.

Disclosures:

No relevant conflicts of interest to declare.
Predictive Factors for Achieving Complete Remission In 69 Mexican Patients with Adult Acute Lymphoblastic Leukemia Treated with Hyper-CVAD
Authors: Chávez-Güitrón Eduardo , Rocha Fernando Perez
Published: October 2019

Abstract 4340

Background.

Acute adult lymphocytic leukemia (ALL) is an infrequent oncologic entity whose rates of global response and cure remain unsatisfactory, when compared to results obtained in treatment of other neoplastic disorders, and of ALL itself in pediatric population, where cure rates approach 90%. Most current induction protocols achieve remission rates of 70 to 90% worldwide, but 5-year disease free survival remains unchanged. MD Anderson Cancer Center (MDACC) published their results with HyperCVAD more than a decade ago, reporting rates of complete remission of 92%, and 5-year disease free survival of 38%. We have used HyperCVAD at our center since 1999, but have not reported the baseline patient characteristics and outcomes.

Methods.

We conducted a retrospective analysis on 69 patients treated with HyperCVAD from 2005 to 2009, evaluating traits at baseline and response to treatment, using descriptive statistics. Survival analysis (overall survival and disease free survival) were described using the Kaplan-Meier method. Baseline traits and their association to response were measured using Chi-square test. Comparison between the original cohort described by MDACC and ours was also analyzed by this test.

Results.

Sixty nine patients with a median follow up of 12 months (range 1–144) were evaluated. Complete remission rates were 77%; induction mortality 4.3%; the estimate of overall survival and disease free survival at 60 months was less than 10% in both cases. The pretreatment variables associated to an increased probability of achieving remission were age <30, baseline hemoglobin >10g/dL and pre B phenotype (p<0.001). Leukocyte count and baseline DHL did not predict ability to achieve remission as shown in the original MDACC study. A 15% difference in complete remission response rate between the original series and ours was found to be statistically significant (p<0.0001).

Discussion.

HyperCVAD as applied to Mexican patients has an efficacy similar to other remission induction protocols, as reported elsewhere, but is inferior to the original results published by MDACC. Survival analysis requires a longer median follow-up for valid conclusions to be drawn.

Disclosures:

Perez Rocha: genzyme: Employment, Honoraria.
Efficacy and Effectiveness of Azacitidine In Elderly Patients with Acute Myeloid Leukemia and Blasts Counts below 30%: Experience of the Spanish Registry
Authors: García Regina , Arnar Monserrat , Luño Elisa , Bargay Joan , Romero Ma Mar , Besalduch Juan , Amutio Elena , Garrido Raquel , Carnicero Fernando , Smd Grupo Andaluz de
Published: October 2019

Abstract 4354

Introduction:

The incidence of acute myeloid leukemia (AML) increases exponentially with age. Elderly patients normally have a previous hematologic condition like myelodysplastic syndrom (MDS), cytogenetic abnormalities that correlate with resistance to conventional chemotherapy schemes and a shorter duration of response. Not only responses are worse, also the hospitalization duration is longer, and the mortality associated to the treatment is higher (30%). Therefore, treating these patients with standard chemotherapy schemes is associated, in many cases, to a low probability of obtaining satisfactory results. Introducing less toxic and/or more efficient agents can change the course of the illness for this sub-group of patients. Azacitidine (AZA) is a hypomethylating drug recently approved in Europe for the treatment of AML with 20 – 30% blasts.

Materials and methods:

We present clinical data analysis of a longitudinal, multicenter and retrospective Spanish patients’ registry of patients with de novo and relapse AML. Data on the course of the disease and managment of patients with de novo and relapse AML with low blasts count (20-30%) treated with AZA under compasionate use were analized.

Result:

Twentyfive patients (male/female 13/12) with a median age of 67 years with AML were included in the registry. Ten patients (40%) had refractory/relapsed AML and had received previous treatment with intensive chemotherapy. Cytogenetic alterations were reported in 10 patients (4 monosomy-7). An average of 7 cycles of AZA were administered to the patients (range 1–25). The most frequently used dose was 75 mg (82%), of which 28% received a scheme of 5 days, 24% received a scheme of 5+2 and 48% of 7 days. The global responses were of 56% with 20% of complete responses. The most frequent toxicity described was hematologic.

Conclusion:

Our data corroborates, with a similar rate of responses, what Journal of Clinial Oncology published about the sub analysis of the AZA-001. 5-Azacitidine is an efficient and safe drug in patients with AML. Good response rates and a toxicity and mortality related to the acceptable treatment in this sub-group of patients.

Disclosures:

García: Celgene: Research Funding. Bargay:Celgene: Research Funding.
The Apoptosis of Acute Myeloid Leukemia Cell Line (SHI-1 cells) Induced by Bortezomib In Vitro
Authors: Yang Mingzhen , Zhang Xiaoyu , Huang Zhenqi , Li Qingsheng , Wang Lin , Liu Qinhua
Published: October 2019

Abstract 4382

Background:

The proteasome plays a critical role in the regulation of many cellular processes, including the cell cycle and tumor growth. The proteasome inhibitor Bortezomib has been used in multiple myeloma and other lymphoid malignancies because of its antitumor activity. Here we investigated the induction of apoptosis by proteasome inhibitor Bortezomib in human acute myeloid leukemia (AML) cell lines SHI-1 cells and try to explore the mechanism of anti-leukemia.

Method:

We incubated SHI-1 leukemic cells with different concentration of bortezomib. cell proliferation was detected with MTT, apoptosis was measured by FCM, the protein expression of PI3K and p-Akt were determined by Western blot.

Result:

0.5ug/ml bortezomib suppressed SHI-1 cells proliferation and induced SHI-1 cells apoptosis after incubated 24hr, 100ug/ml bortezomib suppressed 61.7% SHI-1 cells proliferation. Apoptosis increased obviously with the increasing bortezomib concentration and the culture time, about 39.77% SHI-1 cells were apoptosis when bortezomib concentration was 100ug/ml, the leukemia cell apoptosis was significant at 150ng/ml bortezomib, the protein expression of PI3K, and p-Akt gradually declined with bortezomib concentration increasing, The protein expression of PI3K and p-Akt in SHI-1 cells decreased 50.6% and 71.6% respectively at 100ug/ml bortezomib for 48hr.when 150ng/ml bortezomib incubated with leukemia cells for 24 hours, The protein expression of PI3K and p-Akt were lowest.

Conclusion:

Bortezomib could inhibit SHI-1 cells proliferation and induce leukemia cells apoptosis, and could down-regulate the expression of PI3K and p-Akt significantly, this might be the one of mechanisms that bortezomib induce SHI-1 cells apoptosis, we presume that bortezomib inhibit proliferation of acute myelogenous leukemia cells through effect of PI3K/Akt signaling pathways.

Disclosures:

No relevant conflicts of interest to declare.
Increased Use of Direct Thrombin Inhibitor Argatroban In Hospitalized Patients
Authors: Jain Amit , Smit Kristen , Manchanda Naveen
Published: October 2019

Abstract 4398

Heparin Associated Thrombocytopenia (HAT) is associated with profound thrombo-embolic complications and Heparin substitutes are widely used as prophylactic and sometimes as therapeutic anticoagulants. Argatroban is one of several Direct Thrombin Inhibitors (DTI) used in these patients. We observed over the past several years that there was increasing use of Argatroban in hospitalized patients without a suspicion or diagnosis of HAT. In order to determine the extent and indications for use of Argatroban at our university hospital we analyzed medical records of all patients who had received this drug over a three-year period.

Of the 60 individual patients who received Argatroban over a one year period, most of them received this drug once during their hospitalization and few received it multiple times over several hospitalizations. Seven of these patients (11.6%) received this drug for non-HAT related diagnoses. The following indications were provided for use of this agent:

1. Recurrent VTE on therapeutic Enoxaparin/Fondaparinux in patients with cancer: 3

2. Recurrent VTE on therapeutic Enoxaparin/Fondaparinux: 1

3. Anti-thrombin deficiency: 2

4. Heparin allergy: 1

Outcomes:

1. Cancer associated DVT: One survived, one died of progressive thrombosis; one lost to follow-up

2. Recurrent VTE on Enoxaparin/Fondaparinux: currently off Argatroban

3. Patients with AT deficiency and Heparin allergy are off anticoagulants.

Argatroban, a DTI, is a drug with a narrow therapeutic index and is licensed for use in patients known or suspected to have HAT. Recently, it has found increasing use as an anticoagulant considered to have increased efficacy as compared to Enoxaparin and Fondaparinux. While accepted as an alternate to UFH in several instances, it is considered less effective in situation involving Cardiopulmonary bypass. However, whether it is a better agent to treat patients with or without cancer who have recurrent or progressive VTE and have failed conventional anticoagulants needs to be investigated further.

Disclosures:

No relevant conflicts of interest to declare.
A New Procoagulant Mechanism Mediated by Fucoidans
Authors: Dockal Michael , Panholzer Erwin , Hartmann Rudolf , Ehrlich Hartmut J. , Scheiflinger Friedrich
Published: October 2019

Abstract 4420

Fucoidans are heterogeneous, polyanionic molecules with procoagulant activities in a wide concentration range. They have been described as non-anticoagulant sulfated polysaccharides (NASP) and shown to improve clotting in FVIII- and FIX-deficient plasma. In vitro characterization has suggested that fucoidans exert their procoagulant activity by inhibiting tissue factor pathway inhibitor (Liu et al. Thromb Haemost 2006; 95:68) and by accelerating thrombin-dependent FVa formation (Mutch et al. J Thromb Haemost 2007; 5 Suppl2). In our study we describe a new, previously unrecognized mechanism by which fucoidans act as procoagulant agents. The procoagulant activity of several fucoidans was characterized by calibrated automated thrombography in tissue factor (TF)-dependent experiments and by using coagulation factor-deficient plasmas. Spiking experiments with purified coagulation factors or inhibitory antibodies verified the mechanism.

Stimulation of thrombin generation (TG) by fucoidans requires anionic lipid surfaces like synthetic phospholipid vesicles which contain phosphatidylserine and is TF-dependent (0-20pM). However, stimulatory activity was most pronounced in the absence of TF. Control experiments with corn trypsin inhibitor or FXII-deficient plasma excluded any involvement of the contact system. Plasmas from patients with congenital coagulation factor deficiencies were screened for TG to identify the target coagulation factor by which fucoidans exert their procoagulant activities. In the absence of TF, plasmas deficient in coagulation factors from the common pathway do not support fucoidan-mediated thrombin generation, whereas FVII-deficient plasma does. FXI was identified as the most upstream factor of the intrinsic pathway which is required for fucoidan-stimulated thrombin generation, suggesting it to be the target for the procoagulant activities of fucoidan. Spiking 30nM FXI to FXI-deficient plasma restored fucoidan-mediated TG and addition of polyclonal FXI inhibitory antibodies to normal plasma abrogated TG. Fucoidan-dependent TG did not improve when FXIa (60pM) was added to FXI-deficient plasma, suggesting activation of FXI by fucoidan. The relevance of this mechanism in hemophilia A plasma was studied by addition of low levels of FVIII (0.2-10%) resulting in a FVIII concentration-dependent increase in fucoidan-mediated TG. These results highlight the requirement of a functional intrinsic pathway for this new mechanism of fucoidans. Our findings present FXI activation at low TF concentrations as a possible mechanism for fucoidan.

Disclosures:

Dockal: Baxter Innovations GmbH: Employment. Panholzer:Baxter Innovations GmbH: Employment. Hartmann:Baxter Innovations GmbH: Employment. Ehrlich:Baxter Innovations GmbH: Employment. Scheiflinger:Baxter Innovations GmbH: Employment.