bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acquired Factor XIII Deficiency in the Inpatient Setting: Clinical Suspicion, Impact and Treatment: Retrospective Case Series
Authors: Chuliber Fernando , Schutz Natalia Paola , Otero Victoria , Barrera Luis , Altuna Diana , Fantl Dorotea Beatriz , Martinuzzo Marta 
Published: October 2019

Abstract
Introduction: Activated factor XIII (FXIII) stabilizes fibrin clots at the end of the coagulation cascade by bridging fibrin molecules. Disproportionate surgery related bleeding has been reported in association with FXIII deficiency, in patients with normal coagulopathies screening tests, and without a history of previous bleedings.
Methods: Retrospective case series. We performed immunological factor XIIIA (FXIIIA) studies in the inpatient setting of the Hospital Italiano de Buenos Aires, between January 2014 and March 2016. FXIIIA below 50% were considered deficient. Patients with suspicion of congenital Factor XIII deficiency or 2 years old or less were excluded. Descriptive statistics were used. Populations were compared with chi-square, Fisher and T test, or Mann Whitney tests with Stata13 software.
Results: FXIII was studied in 52 patients; 37 of these (26 females and 11 males) met inclusion and exclusion criteria. Median age was 43 years (range 9-81). Twenty two patients were studied because of disproportionate surgery related bleeding, 11 because of spontaneous bleeding; and 4 not specified. All patients presented normal coagulopathies screening tests, normal Von Willebrand factor and ristocetine cofactor activity and normal platelet function tests. Eleven patients (30%) had FXIIIA less than 50%. Statistically significant differences between groups were found for median drop in hematocrit points [3.5 (IQR 3-10) vs 1.5 (IQR 0-2, p=0.02)] and median number of red cell units transfused [4 (IQR 0-6) vs 0 (0-2), p=0.01]. Differences in rates of minor and major bleedings were not statistically significant. Only one patient of eleven presented FXIII deficiency associated spontaneous bleeding vs 8 out of 20 patients in the postsurgical setting. FXIII concentrate was used in two patients to treat persistent bleeding, resolving in less than 24 hours. Three patients died, none because of bleeding. Five of the 11 patients with FXIII deficiency returned to normal values when FXIII assay was repeated away from acute setting.
Discussion: FXIII acquired deficiency is associated with disproportionate bleeding in postsurgical setting in patients without apparent coagulation defects. FXIII deficiency could be underdiagnosed. Patients with FXIII deficiency in our series had more hematocrit drop and more transfusion requirements. We found no association with spontaneous bleeding. Alltough deficiency could be transient, treatment with FXIII concentrate could be useful to manage serious, persistent or life threatening bleedings.

Disclosures
No relevant conflicts of interest to declare.
Targeting FVIII-Specific B Cells Using BAR-Transduced Regulatory T Cells
Authors: Zhang Ai-Hong , Yoon Jeong Heon , Kim Yong Chan , Scott David W. 
Published: October 2019

Abstract
Up to a third of hemophilia A (HA) patients receiving therapeutic FVIII develop neutralizing antibodies termed "inhibitors". Once inhibitors develop, clinical management of HA patients becomes extremely difficult. Thus, a rational solution would be to establish FVIII-specific immune tolerance to FVIII in high risk patients. To address this issue in a mouse model of human HA, we elected to use an antigen-specific regulatory T cell (Treg) approach. Analogous to the chimeric antigen receptor (CAR) strategy successfully used in cancer immunotherapy, we have created a chimeric receptor comprising a protein antigen or its domain, linked with the transmembrane and signal transduction domains, CD28-CD3ζ. We termed this receptor "BAR" for B-cell-targeting antibody receptor. Human Tregs (CD4+CD25hiCD127low) were retrovirally transduced with a BAR containing FVIII C2 domain (C2-BAR) or FVIII A2 domain (A2-BAR) and expanded successfully in vitro. These cells stained positively with anti-C2 and anti-A2 monoclonal antibodies, respectively, and maintained Treg phenotypic markers in terms of co-expression of Foxp3 and Helios. Control human Tregs were transduced with a BAR containing chicken ovalbumin (OVA-BAR). To test the hypothesis that BAR-transduced Tregs could directly and effectively suppress the activity of specific B cells, a xenogeneic model was employed. On day 0, FVIII-/- HA mice were injected intravenously with 106 transduced human Tregs. The mice were then immunized subcutaneously on day 1 with FVIII in incomplete Freund's adjuvant, and anti-FVIII antibody development was followed. By two weeks after immunization, anti-FVIII antibodies could be detected in the control mice (n = 4). However, in the experimental group (n = 5) that received a mixture of equal number of C2-and A2-BAR Tregs, anti-FVIII antibody development was reproducibly completely blocked for at least 8 weeks. To examine the possible mechanism of BAR Treg suppression, purified B cells and T cells from "tolerized" (A2+C2-BAR) or "control" (OVA-BAR) recipients were mixed and tested for recall responses to FVIII in vitro. The results suggested that the FVIII-specific B cells were directly tolerized while the T-cell response remained intact. Taken together, we report here a successful approach utilizing FVIII-specific BAR-Tregs to directly target FVIII-specific B cells, an approach which could be adapted to address other adverse immune response as well. (Supported in part by a NIH grant HL127495)

Disclosures
No relevant conflicts of interest to declare.
Disparities in the Upfront Use of Hematopoietic Stem Cell Transplant Among Patients with Acute Myeloid Leukemia
Authors: Mehmood Tahir , Bartley Adam C , Hashmi Shahrukh K. , Go Ronald S. 
Published: October 2019

Abstract
Background:
The incidence for acute myelogenous leukemia (AML) is on the rise in the United States (US). Roughly 20,000 new AML patients are expected to occur in 2016 in the US (data from Surveillance Epidemiology and End Results Program). It is mainly a disease of older individuals with median age of 67 years. Unfortunately, most patients are not cured. Recent data suggest that early referral for hematopoietic stem cell transplant (HSCT) leads to more favorable outcomes, particularly those with non-good risk cytogenetics compared to alternate therapies. The objective of our study was to assess the use of upfront HSCT among AML patients with a focus on patients with non-good risk cytogenetics and determine disparity in its access based on sociodemographic and regional considerations.
Methods:
We analyzed data obtained from National Cancer Data Base (NCDB) Participant User Files for patients diagnosed with AML between 2004 and 2013 using the International Classification of Diseases for Oncology version 3 (ICD-O-3) codes 9840-9861, 9865-9874, 9891-9931. The data is collected prospectively by joint program of Commission on Cancer (CoC) and American Cancer Society. It covers nationwide oncology outcome from more than 1,500 CoC-accredited hospitals. Over 70% of all newly diagnosed cancer cases in the US are captured by NCDB. Since unique ICD-O-3 codes exist for the good-risk but not for intermediate- or poor-risk AML, we categorized the AML subtypes as good risk or non-good risk for analytic purposes. We considered patients with t(15;17), inv(16) and t(8;21) with corresponding ICD-O codes of 9871, 9896, and 9866, as good-risk patients. All others were considered non-good risk. Proportion of HSCT usage was estimated in various subgroups with 95% confidence intervals calculated using robust estimates of standard error.
Results:
We identified 80,087 patients who were diagnosed with AML between 2004 and 2013. Majority of these patients were Whites (85.9%), males (53.8%) and between the ages of 40 and 79 years (71.5%). The overall use of upfront HSCT increased consistently over time. This occurred predominantly among the non-good risk AML from a rate of 6.5% in 2004 to 12.5% in 2013 (Figure). Non-good risk patients who were Black, had Medicare insurance, with lower annual household income, and treated at facilities located in the East, South and Central parts of US ( AL, KY, MS, TN) had less access to HSCT (Table).
Conclusion:
The use of upfront HSCT in AML has almost doubled in the past decade, predominantly among those with non-good risk cytogenetics. Nevertheless, we found substantial disparity among sociodemographic and geographic subgroups. Future studies should try to understand and address how to bridge this gap.

Disclosures
No relevant conflicts of interest to declare.
Mitochondrial Calcium Entry Is Essential in Agonist-Induced Procoagulant Platelet Formation
Authors: Kholmukhamedov Andaleb , Janecke Rae , Choo Hyojung , Jobe Shawn M 
Published: October 2019

Abstract
Procoagulant platelets are a subpopulation of activated platelets with high-level phosphatidylserine (PSer) externalization. When initiated by co-stimulation with thrombin (THR) and a GPVI agonist, such as convulxin (CVX) or collagen, both extracellular calcium entry and mitochondrial permeability transition pore (mPTP) formation are required to mediate the transition to the procoagulant platelet phenotype. The intracellular mechanisms coordinating these processes remain unclear. Here we investigated the role of the mitochondrial calcium uniporter in the regulation of procoagulant platelet formation.
The flux of calcium from the cytosol to the mitochondrial matrix is limited by the ion-impermeable inner mitochondrial membrane. Initially, a pharmacologic approach was utilized to investigate the importance of mitochondrial calcium entry and elevation. Washed human or murine platelets were stimulated with THR and/or CVX in physiologic buffer with 2 mM CaCl2. Mitochondrial transmembrane potential was evaluated using 0.5 μM tetramethylrhodamine methylester (TMRM). Limitation of mitochondrial calcium entry either through alteration of pre-stimulatory mitochondrial membrane potential (i.e. inhibition of F0F1 ATP-ase, mitochondrial uncoupling etc.) or using the ruthenium red analog (Ru360) abrogated both mPTP and procoagulant platelet formation consistent with the hypothesis that elevated calcium levels within the mitochondrial matrix drives these processes.
The molecular pathway mediating this rapid mechanism of calcium entry was investigated using mitochondrial calcium uniporter (MCU) null platelets. MCU is a transmembrane ion channel that allows the passage of Ca2+ from the cytosol into the mitochondrial matrix. Neither platelet aggregatory ability nor granule release was altered in response to single or dual-agonist stimulation. In contrast, procoagulant platelet formation in MCU null platelets was significantly decreased coincident with decreased mPTP formation as measured by loss of mitochondrial transmembrane potential. Whereas the number of annexin V positive platelets decreased from 60% in WT to 32% in MCU null (p<0.05, n=4). Thus, these results identify a key role of mitochondrial calcium uptake channel in the regulation of strong agonist-initiated procoagulant platelet formation and suggest a novel pharmacologic target that could be used the treatment of procoagulant-platelet related pathologies.

Disclosures
No relevant conflicts of interest to declare.
Over-Expression of RPS3 Promotes Acute Lymphoblastic Leukemia Growth and Progress By Down-Regulating COX-2 through NF-κb Pathway
Authors: Hua Wang , Yue Lu , Dingbo Shi 
Published: October 2019

Abstract
The Ribosome protein S3 (RPS3) is a component of 40S ribosomal subunit, which is important in ribosomal maturation.In addition, RPS3 plays a central role in the regulation of cell cycle,proliferation,migration,DNA repair,and apoptosis.Recent study has also been reported that RPS3 is secreted as a homodimer in cancer cells. The increased level of secreted RPS3 was detected in more malignant cells.These findings suggest that the RPS3 protein is an indicator of malignant tumors.Therefore, we studied the roles and the functions mechanisms of RPS3 in leukemia in order to understand whether RPS3could be a key target for leukemia therapy.
qRT-PCR and western blot analysis were carried out in a small cohort of acute lymphoblastic leukemia patients(ALL) and multiple leukemia cell lines to evaluate RPS3 mRNA and protein expression levels.To assess its biological functions relevance, its expression was down modulated by transient RNA interference in ALL cell lines.Our results show that RPS3 mRNA and protein expression is higher in both ALL patients and the ALL cell lines when compared to the healthy donors peripheral blood mononuclear cell or myeloid leukemia cell lines. Correspondence with this, the ALL patients with higher expression of RPS3 had shorter overall survival than those with lower expression of RPS3 (25.1% vs. 63.4%, P<0.001, for 5 year-OS).Furthermore,blocking RPS3 activity in four ALL cell lines, by either knockdown or treatment with the RPS3 inhibitor, causes significant decrease in their cell proliferation.This decrease in cell proliferation was coupled with both an induction of the G1/S cell cycle arrest and with an increase of apoptosis induced in the leukemia population. In vivo,we also found that knockdown of RPS3 significantly inhibited tumor growth in a ALL xenograft mouse model. Finally, mechanism studies showed that RPS3 knockdown in ALL cells triggered suppression of COX-2 expression and its down-stream targets PGE2 release,inhibited COX-2 promoter activity by decreased P50 /P65 Binding to cox2 promotor.
In conclusion,our results suggest that overexpression of RPS3 promotes acute lymphoblastic leukemia growth and progress by up-regulating COX-2 through NF-κB pathway. and that targeting RPS3could be an attractive strategy for ALL therapy.

Disclosures
No relevant conflicts of interest to declare.
the NADPH Oxidase Catalytic Subunit Nox2 Displays Differential Roles in Arterial Vs. Venous Thrombosis
Authors: Sonkar Vijay , Jensen Melissa J , Lentz Steven R. , Dayal Sanjana 
Published: October 2019

Abstract
NADPH oxidase is a major superoxide generating enzyme in vascular tissues. Deficiency of the Nox2 (gp91phox) catalytic subunit of NADPH oxidase is a genetic cause of X-linked chronic granulomatous disease. These patients are prone to infection due to loss of oxidant production by neutrophils, and recent evidence suggests they also have a defect in platelet adhesion to collagen. However, the role of Nox2 in thrombosis is controversial, with one study demonstrating no effect of murine Nox2 deficiency on platelet activation and another study implicating Nox2 in platelet aggregation as well as thrombosis in small vessels. Given that Nox2 may be important for both platelet activation as well as release of neutrophil extracellular traps (NETs, a mediator of venous thrombosis), we hypothesized that genetic deficiency in murine Nox2 leads to decreased susceptibility to experimental thrombosis in both arterial and venous systems. We studied male Nox2 deficient (Cybb-/y) mice and wild type (Cybb +/y) littermates at 10-14 weeks of age. There were no differences in platelet count (921.9±33.6 x103/µl vs. 978±85.2 x103/µl), hematocrit (36.5±0.6% vs. 38.7±0.8% ) or white blood cell count (5.5±0.3 x103/µl vs. 6.1±0.6 x103/µl) between Cybb+/y and Cybb-/y mice. We next, examined platelet activation in response to thrombin (0.05 and 0.2 U/ml) or collagen (80 and 320 ng/ml) using flow cytometry. We observed similar levels of integrin α2bβ3 activation, fibrinogen binding, and intra-platelet levels of H2O2 in platelets from Cybb+/y and Cybb-/y mice after activation with either agonist, which suggests no alteration in platelet inside-out signaling due to loss of Nox2. No significant difference in susceptibility to carotid artery thrombosis in a photochemical injury model was observed between Cybb+/y and Cybb-/- mice (time to stable occlusion 21.97±4.7 vs 27.6±4.2, P>0.4). In contrast, Cybb-/y mice demonstrated significant decreases in the weight and length of venous thrombi in the inferior vena cava after 48 hours of stenosis (P<0.05). Our findings suggest that Nox2 is not a major mediator of platelet activation or arterial thrombosis but contributes to the development of venous thrombi. Future studies are warranted to examine the role of NETs and the prothrombotic effects of Nox2 in association with other cardiovascular risk factors.

Disclosures
Lentz: Novo Nordisk: Consultancy, Research Funding; Celgene: Equity Ownership; Opko: Membership on an entity's Board of Directors or advisory committees.
Platelet-Induced T Cell Activation in Patients with Myocardial Infarction; The Role of miR155
Authors: Solomou Elena E. , Kalyvioti Elena , Verigou Evgenia , Katsanaki Katerina , Gogos Charalambos , Hahalis George , Alexopoulos Dimitrios 
Published: October 2019

Abstract
Specific aim: We have previously shown that platelets from patients with myocardial infarction (with ST elevation-STEMI) can activate T cells in vitro. In this study we wanted to expand our initial observation and explore the mechanism of this T cell activation.
Methods: After written informed consent was obtained, peripheral blood mononuclear cells (PBMCs) were isolated from heparinized venous blood obtained from 30 patients with STEMI (28 men and 2 women) at the time of hospital admission at diagnosis, before receiving any treatment, as well as 5 days and 30 days later. We also analyzed 15 healthy subjects (12 men and 3 women), and 7 patients with unstable angina who served as the disease control group. PBMCs were analyzed by flow cytometry with the following markers and their isotypic controls: CD4, CD25, CD127, FOXP3, and CD69. We also isolated platelet rich plasma or plasma alone from the patients and the healthy subjects, and used in mixed cultures with PBMCs. miR 155 levels were examined with real-time PCR.
Results: Initially, we incubated T cells with platelets from patients with STEMI and examined T cell activation by CD69 expression. These T cells showed increased expression of CD69 compared to T cells treated with platelets from healthy subjects (p<0.05). No T cell activation was observed following incubation with plasma alone from patients or healthy controls.
Next, the percentages of CD4+CD25+hi CD127low FOXP3+ (regulatory T cells, Tregs) were examined in all study subjects. Patients at presentation showed comparable Treg levels with the controls (healthy subjects and disease control group). Five days later, patients with STEMI displayed increased levels of Tregs compared with the controls (p<0.05) (Fig.2). To explore the mechanism of Treg up-regulation the miR155 levels through real time PCR were evaluated. Patients with STEMI showed comparable levels of miR155 at presentation, but five days later showed decreased miR155 levels compared to controls (p<0.001) (Fig. 1); we observed an inverse correlation between miR155 levels and Treg numbers in patients with STEMI. At re-evaluation, one month later, patients with STEMI displayed Treg numbers comparable to the initial presentation levels
Conclusion: Herein, we show that platelets from patients with STEMI can activate T cells in vitro. This platelet activation in patients with STEMI, results in an increase in Tregs through down-regulation of miR155, that return to normal levels a month later. This Treg increase reflects possibly an effort to suppress immune system activation secondary to platelet activation, shortly after the infarct.
Figure 1 Figure 1. Figure 2 Figure 2.

Disclosures
No relevant conflicts of interest to declare.
"Etiology of Non-Cirrhotic Portal Vein Thrombosis in Adults: Experience of 12 Years in a Chilean University Hospital"
Authors: Gonzalez Jaime A , Conte Guillermo F , Marin Arnaldo A 
Published: October 2019

Abstract
Introduction: Portal Vein Thrombosis (PVT) is a rare disease primarily caused by a thrombotic obstruction in the origin of portal vein in extrahepatic portion. PVT is a frequent complication in advanced chronic liver disease (CLD), but the etiology and complications of non-CLD PVT (nPVT) are not well understood. The etiology of nPVT is heterogeneous and involves both local and systemic prothrombotic factors such as abdominal inflammatory processes, inherited and acquired thrombophilia, and JAK 2 positive mieloproliferative neoplasm (MPN).
Methods: The aim of this study was to evaluate etiological and prognostic factors in nPVT patients in chilean population. All patients referred to University of Chile Clinical Hospital between January 2002 and January 2012 with nPTV diagnosis were included in this study, with no previous history of solid or hematologic malignancy or CLD. We studied demographic characteristics, risk factors and in-hospital mortality rate. Statistical tests were two-tailed with the level of significance set at p<0.05, and we use analysis multivariate. The presence of the JAK2 mutation was determined by polymerase chain reaction in patients from whom DNA was available. It was decided that CLD was not possible through clinical history, abdominal ultrasound and liver enzymes. Screening for Thrombophilia was made with C and S protein, prothrombin gene mutation, V Leyden factor mutation, hyperhomocysteinemia, AT-III deficit and screening for anti-phospholipid syndrome.
Results: 265.089 adult patients were hospitalized at Clinical Hospital, University of Chile between 2002 and 2012, and 119 had nPVT diagnoses (0.04%). Median age at the diagnosis was 56.8± 2.43 years, with 52.1% of female sex. 15.9% died at the hospital. Thrombophilia was diagnosed in 33 patients (27.73%), newly diagnosed solid tumors in 16 patients (13.44%) and JAK 2 positive MPN in 4 patients. In analysis multivariate, patients with nPVT and Thrombophilia diagnosis was significantly associated to previous deep venous thrombosis diagnosis (OR 7.78, p=0.0007), female sex (OR 3.06, p=0.01) and age below 50 years (OR 1.82, p=0.03)
Conclusions: nPTV is a rare disorder, and its development is associated to the presence of inflammatory intra-abdominal process, newly diagnosed solid tumors, MPN and Thrombophilia. The previous deep venous thrombosis diagnosis, female sex and age below 50 years are associated to thrombophilia diagnosis.

Disclosures
No relevant conflicts of interest to declare.