bluuebunny/crossref_metadata_2025_split huggingface dataset:
A New Murine Model of Immune Thrombocytopenia: Evidence of Both Antibody- and CD8+ T Cell-Mediated Platelet Destruction.
Authors: Chow Leola , Ni Heyu , Kim Michael , Speck Edwin R. , Aslam Rukhsana , Chen Pingguo , Freedman John , Semple John W. 
Published: October 2019

Abstract
Immune thrombocytopenic purpura (ITP) is an autoimmune-mediated bleeding disorder in which platelets are opsonized by autoantibodies and prematurely destroyed by Fc receptor (R)-mediated phagocytosis in the reticuloendothelial system (RES). Although the pathogenesis of the disorder has been considered to be primarily antibody mediated, recent reports have indicated that cell-mediated (e.g. CD8+ T cell) mechanisms can also lead to platelet destruction at least in those patients with ITP who have no detectible antibodies. To study these mechanisms, we developed a murine model of immune thrombocytopenia by transferring spleen cells (SC) from GPIIIa-knockout (KO) mice immunized against wild type (WT; GPIIIa-positive) platelets into syngeneic severe combined immunodeficient (SCID) mice. Results show that compared with naive SC, transfer of as few as 5x104 immune GPIIIa-KO SC caused significant thrombocytopenia and a bleeding diathesis and death in 60 percent of recipient SCID mice within 10 days post-transfer. Bleeding occurred primarily in the gut, lungs, subcutaneous tissues and brain. When the immune GPIIIa-KO SC were first depleted of CD4+T cells and transferred, thrombocytopenia or bleeding mortality occurred. In contrast, CD8+ T cell depletion of the GPIIIa-KO SC before transfer did not affect their ability to cause thombocytopenia nor bleeding. Interestingly, depletion of CD19+ B cells before transfer did not affect the ability of the SC to induce thrombocytopenia but prevented all bleeding. These results suggest that both antibody-mediated and CD8+ T cell-mediated platelet destruction occur in this animal model of immune thrombocytopenia, however, it appears that only antibody-mediated thrombocytopenia is associated with bleeding mortality. Because the immune thrombocytopenia is against a platelet-specific antigen e.g. GPIIIa (like in ITP), it will not only allow for the study of disease pathogenesis but may also be important for testing new immunospecific therapeutics to increase platelet counts in patients with ITP.
Mantle Cell Lymphoma Can Be Cured by Intensive Immunochemotherapy with In-Vivo Purged Stem-Cell Support; Final Report of the Nordic Lymphoma Group MCL2 Study.
Authors: Geisler Christian H. , Elonen Erkki , Kolstad Arne , Laurell Anna , Andersen Niels , Pedersen Lone B. , Boesen Anne Marie , Eriksson Mikael , Jerkeman Mats , Kimby Eva , Kuittinen Outi , Lauritzen Grethe F. , Nilsson-Ehle Herman , Nordström Marie , Ralfkiaer Elisabeth , Åkerman Måns , Ehinger Mats , Sundström Christer , Langholm Ruth , Delabie Jan , Karjalainen-Lindsberg Marja-Liisa , Brown Peter 
Published: October 2019

Abstract
Mantle cell lymphoma (MCL) is considered incurable, with a median survival of 4 years. Intensive immunochemotherapy and autologous stem-cell (ASC) support has appeared promising in small patient cohorts, but has not been tested in large, consecutive series. Here we report the final results of the 2nd Nordic MCL (MCL2) trial after a median of 3 years follow-up from study entry.
Methods: This unrandomized phase-II trial included 159 untreated patients younger than 66 years, 84% stage IV, 128 with classical, 31 with blastoid/pleomorphic cytology. Following 6 cycles of intensive induction immunochemotherapy with alternating cycles of rituximab (R) + maxi-CHOP and R+ high-dose AraC, responders received BEAM/BEAC with in-vivo purged (R) ASC support.
Results: 153 patients (96%) responded to induction therapy with CR in 55% and PR in 41%. The 5-year event-free (EFS) and overall survival (OAS) are 63% and 74% respectively on intention-to-treat, and the 144 (91%) responders who completed treatment had 72% 5-year response duration, with plateaus emerging in all three curves at these levels.
Figure Figure
There were 6 treatment-related deaths (3,8%). Of 77 patients with available primers, 90% had become PCR-negative two months posttransplant; those who remained PCR-negative more than 1 year posttransplant had a significantly longer clinical response duration than patients who did not (P<0.0001). Of 42 stem-cell products assessed 88% were PCR-negative as compared to only 12% in the MCL1 study (P<0.001). In a multivariate analysis including age, sex, international prognostic index (IPI), cytological variants and Ki-67 proliferation index, only IPI and Ki-67 were independent predictors of EFS and response duration respectively, and only IPI and cytological variant of OAS. Compared to the 41 patients of 1st Nordic MCL study who received 4 cycles of maxi-CHOP without rituximab before BEAM or BEAC + ASCT (1), the OAS, EFS and response duration were highly significantly increased.
Conclusion: The demonstration of long-term event-free survival in a large, consecutive prospective series now for the first time indicates that intensive immunochemotherapy including AraC and Rituximab with in-vivo purged stem-cell support may cure mantle cell lymphoma.
Cardiac Toxicity Associated with the Anti-VEGF Monoclonal Antibody Bevacizumab (Avastin) in Combination with CHOP (A-CHOP) Chemotherapy for Peripheral T Cell Lymphoma (PTCL): The ECOG 2404 Trial.
Authors: Advani Ranjana H , Hong Fangxin , Ganjoo Kristen N. , Manola Judith B. , Swinnen Lode J. , Habermann Thomas M , Horning Sandra J 
Published: October 2019

Abstract
Abstract 1671
Poster Board I-697

Background
Bevacizumab (Avastin), a humanized monoclonal antibody directed against vascular endothelial growth factor (VEGF-A), is approved in combination with chemotherapy in lung, colorectal, breast and brain cancers. VEGF-A expression is reported in all lymphoma subtypes, with strongest expression in PTCL. Given the relatively poor prognosis of PTCL with standard therapy, we combined bevacizumab (A) with CHOP in the ECOG 2404 phase II trial.

Methods
Untreated PTCL pts with a normal baseline cardiac ejection fraction received bevacizumab 15 mg/ kg IV and CHOP chemotherapy on day 1 for 6-8 cycles. Patients (pts) with CR/PR/SD received maintenance therapy with bevacizumab 15 mg/ kg IV q 3 weeks for 4 cycles. Due to the reported 3.7% incidence of cardiac toxicity associated with bevacizumab in metastatic breast cancer pt previously exposed to anthracyclines (Avastin package insert), cardiac function was monitored prospectively with ejection fraction (EF) determination at the completion of A-CHOP prior to the start of bevacizumab maintenance.

Results
Among 33 pts who came off study, toxicity data are available for all and coded using CTCAE Version 3.0. 22 received at least 4 cycles of A-CHOP (median treatment duration 3.6 months (< 1-10.6 months). One or more designated cardiac toxicities were recorded for 5 of these 22 pts. Congestive heart failure (CHF), defined as grade 2-4 left ventricular dysfunction was recorded in 4 pt (18%, 90% CI 5.2%-40.3%): grade 4 (n=1), grade 3 (n=3). In 3 pts clinical CHF occurred after A-CHOP x 6 and in one during bevacizumab maintenance after A-CHOP x 8. The median time to development of a cardiac adverse event was 5 months (3.5 – 8.8 months). One pt required a ventricular assist device in addition to medical management. In 3 of the 4 pts, ongoing medical management for CHF has been required. Other cardiac toxicities included ventricular arrhthymia (one grade 4, one grade 2), and one grade 2 cardiac troponin elevation. In addition, one patient experienced sudden death of uncertain cause. Three pts developed thromboses or embolic toxcities (two grade 4 and one grade 3).

Conclusions
We observed four cases of clinical CHF early after cumulative doxorubicin doses of 300-400 mg/m2 in our study, The incidence of CHF among study patients who received 4 or more A-CHOP cycles is concerning and suggests that bevacizumab may potentiate the adverse cardiac effects of anthracyclines, resulting in clinically significant toxicity. Careful monitoring of cardiac function is warranted in ongoing trials combining bevacizumab and doxorubicin in lymphomas and solid tumors to assess long-term safety and better understand underlying mechanisms and risks.

Disclosures
No relevant conflicts of interest to declare.
CD40 Ligand Determines Whether Interleukin 21 Induces Differentiation of Human B Cells Into Plasma Cells or Into Granzyme B-Secreting Cytotoxic Cells.
Authors: Jahrsdoerfer Bernd , Hagn Magdalena , Sontheimer Kai , Schwesinger Elisabeth , Ebel Verena , Maier Julia , Beyer Thamara , Fabricius Dorit , Lunov Oleg , Tron Kyrylo , Syrovets Tatjana , Barth Thomas FE , Nienhaus G. Ulrich , Simmet Thomas 
Published: October 2019

Abstract
Abstract 2675
Poster Board II-651
Interleukin 21 (IL-21) is a novel and highly promising cytokine for the treatment of neoplastic and infectious diseases. Recently, IL-21 has been identified as inducer of plasma cell differentiation. Here we show that CD40 ligand is critically involved in this process and that, in its absence, human B cells differentiate into granzyme B (GzmB)-secreting cytotoxic cells rather than plasma cells. GzmB expression and secretion by human B cells was demonstrated by FACS analysis, ELISpot, ELISA, Sensizyme, Western immunoblotting, RT-PCR, and spinning disk confocal microscopy. GzmB secretion requires the presence of IL-21 and B cell receptor engagement, and depends on phosphorylation of JAK1/3 and STAT3. CD40 ligation effectively suppresses GzmB secretion by B cells, suggesting GrB-secreting B cells play a role in the early phase of inflammatory processes, before CD40 ligand-expressing T cells are present. Of note, ex-vivo re-stimulation of B cells from recently vaccinated individuals with inactivated viruses also induces GzmB expression. GzmB is enzymatically active and GzmB-secreting B cells induce apoptosis in various tumor cell lines, a process we were able to visualize by using spinning disk confocal microscopy. Our data reveal an as yet unrecognized role of IL-21-activated B cells, which involves GzmB secretion and cellular cytotoxicity. Our findings may have implications for the understanding of tumor immunosurveillance and early anti-viral immune responses, and may open novel approaches for the immunotherapy of neoplastic and viral diseases.

Disclosures:
No relevant conflicts of interest to declare.
Asymptomatic Familial Factor XI Deficiency.
Authors: Herrada Juan , Aloba Maria Chona , Adcock Dorothy M , Gupta Anuradha , Noble Luis S. , Landeros Mark M. 
Published: October 2019

Abstract
Abstract 4449

Background
Factor XI deficiency (known as Rosenthal syndrome or hemophilia C) is an autosomal disorder affecting both sexes which results in a bleeding disorder of variable severity. This condition is very uncommon among the non-Jewish population and consists mostly of sporadic cases, although an occasional familial cluster has been described (Bolton-Maggs et al. J Thromb Haemost 2004 Jun;2(6):918-24). We present two asymptomatic siblings with coagulation Factor XI deficiency.

Case Report
In February 2004 a healthy 33 year-old non-Jewish white female without personal or family medical history presented with an elevated partial thromboplastin time (PTT) incidentally found during a routine pre-operative evaluation. Her prothrombin time (PT) was normal. Her PTT was 45 seconds (reference interval 23-37 seconds), and normalized with 1:1 mixing studies of patient and normal plasma. Preliminary laboratory evaluation included negative tests for the presence of a Lupus Anticoagulant, a normal serum albumin level, and a normal urinalysis. Additional laboratory testing of coagulation and included FXI and XII activities, measured by means of a one stage APTT-based clotting assay using APTT reagent (Automated APTT, Trinity Biotech, Bray Ireland), congenitally depleted deficient plasma (HRF, Inc, Raleigh NC) using the MDA II Trinity Biotech, Bray Ireland). FXI was 46% (reference range 60-150) and FXII was 42% (reference range 50-150). In March 2004, a repeated the laboratory evaluation showed a FXI of 41% and a FXII of 46%. In April 2006, FXI was 49%, and FXII was 40%. Is to be noted that the patient never had abnormal bleeding episodes despite abdominal and breast surgical procedures. In 2009, her only brother (aged 29 and otherwise healthy) underwent hematological evaluation that showed normal levels of PT, PTT, platelet count, fibrinogen, and factor XII (88% activity). His factor XI was 51% (decreased activity).

Conclusion
Although modern laboratory methods are able to identify unusual coagulation defects, their clinical significance requires additional investigation.

Disclosures:
No relevant conflicts of interest to declare.
Anthracycline Treatment of the Monocytic Leukemia Cell Line THP-1 Increases Phosphatidylserine Exposure and Tissue Factor Activity.
Authors: Boles Jeremiah , Glover Sam , Owens A. Phillip , Hollingsworth Rachel , Kasthuri Raj S. , Key Nigel S. , Mackman Nigel 
Published: October 2019

Abstract
Abstract 1136

Introduction:
Cancer associated thrombosis is a well-recognized phenomenon that results in considerable patient morbidity and mortality. While malignancy alone conveys an increased risk for thrombosis, treatment with cytotoxic chemotherapeutics further elevates this risk. However, the pathogenic mechanisms underlying this process remain poorly defined. We hypothesized that treatment of tumor cells with cytotoxic chemotherapeutic drugs leads to phosphatidylserine (PS) exposure on the cell surface, as well as increased cellular tissue factor (TF) activity and release of TF positive microparticles (MPs).

Aim:
The aim of this study was to determine the effect of anthracyclines on TF activity and MP release from the human monocytic leukemia cell line THP-1.

Materials and Methods:
THP-1 cells were treated with different concentrations of doxorubicin (0-10μg/ml) or daunorubicin (0-1μg/ml) for 0–24 hours. These concentrations are similar to those found in plasma of cancer patients. The intact cells were analyzed for TF activity using a two stage chromogenic assay. TF antigen was evaluated by ELISA and TF mRNA by realtime PCR. In addition, TF activity of MPs released into the culture supernatant was measured using a two stage chromogenic assay. PS exposure on cells and MPs were analyzed by flow cytometry and PS exposure on MP was also evaluated in an annexin V capture assay. Cell viability was assayed by a dye exclusion assay as well as by flow cytometry.

Results:
We found that doxorubicin and daunorubicin increased PS exposure on the cell surface. Treatment with anthracyclines increased both cellular TF and MP TF activity in a concentration-dependent manner that also resulted in concentration dependent increase in apoptosis. Furthermore, this increased TF dependent activity was abolished with the addition of annexin V or lactadherin supporting a role of PS exposure in this elevated activity.

Conclusion:
These results support our hypothesis that treatment of THP-1 cells with chemotherapeutic agents induces apoptosis and increases cellular TF activity. This increased activity appears primarily mediated by an increase in cell surface expression of PS. Additionally, the anthracyclines increase the release of TF positive MPs from the THP-1 cells. We propose that this increase in cellular TF activity in tumor cells and increased numbers of TF positive MPs may contribute to thrombosis in cancer patients treated with chemotherapeutic drugs.

Disclosures:
No relevant conflicts of interest to declare.
Relationship of Soluble Adhesion Receptors to Red Cell Apoptosis In SCD.
Authors: Mutucumarana Charmaine P. , Chandler Catherine , Telen Marilyn J. , Delahunty Martha 
Published: October 2019

Abstract
Abstract 1654
The interaction of sickle red cells (SS RBCs) with endothelium can cause endothelial injury, leading to increased expression of soluble endothelial cell adhesion molecules and plasma markers of endothelial activation and dysfunction. Among such plasma markers, sVCAM-1 levels are increased in SCD and rise further during vaso-occlusive crisis (Duits et al. 1993), and several groups have shown that sVCAM-1 levels are positively related to LDH levels, a marker of hemolysis. Perfusion of endothelial cells with SS RBCs has been shown to increase the expression of the cellular adhesion molecules ICAM-1 and VCAM-1 by endothelial cells (Shiu et al. 2000). Furthermore, sVCAM-1, sICAM-1, and sE-selectin have been independently associated with risk of mortality (Kato et al. 2005). We were interested in determining whether identifiable characteristics of SS RBCs themselves might be associated with the degree to which soluble adhesion molecules are expressed in SCD patient plasma. Therefore, we measured sVCAM-1, sICAM-1, sCD40 ligand (sCD40L) and sP-selectin in SCD patient plasma by ELISA (n=46) and looked at the relationship of these biomarkers of disease activity to SS RBC characteristics. We specifically examined phosphatidylserine exposure (as measured by annexin V binding analyzed by flow cytometry) and the degree of SS RBC adhesion to laminin and endothelial cells, measured in vitro in a graduated height flow chamber. We found that the degree of red cell damage measured by annexin V binding correlated with the level of soluble adhesion receptors sVCAM-1 (p=0.036) and sICAM-1 (p=0.026). However, annexin V binding did not correlate with sCD40L or sP-selectin expression in plasma, and neither annexin V binding nor levels of soluble adhesion molecules correlated with SS RBC adhesion to laminin or endothelial cells in vitro. In addition, the concentrations of sVCAM-1 and sICAM-1 in plasma were strongly correlated with each other (p<0.0001), suggesting that both of these adhesion molecules may be released from activated endothelial cells in SCD patients as a result of the same mechanism involving contact with phosphatidylserine-exposing SS RBCs. These data support the hypothesis that phosphatidylserine exposure on SS RBCs is a critical factor in SS RBC interaction with the endothelium (Setty et al., 2002), including the release of soluble cellular adhesion markers that indicate endothelial activation and/or injury.

Disclosures:
Telen: GlycoMimetics, Inc.: Consultancy.
12-Month Follow-up for Patients with Sickle Cell Disease in an Ongoing 3-Year, Prospective, Non-Interventional Registry Trial
Authors: Heeney Matthew M. , Mueller Brigitta U. , Baltz Brad , Adams-Graves Patricia , Yang Elizabeth , Paley Carole , Esposito Jason , Vichinsky Elliott P. 
Published: October 2019

Abstract
Abstract 1010

Introduction:
Sickle cell disease (SCD) is a clinically heterogeneous disease. Patients (pts) may present with severe symptoms in childhood, resulting in early morbidity and mortality, or may be asymptomatic until adulthood. Therapeutic goals include the prevention and treatment of complications across the spectrum of disease. We describe baseline and 12-mo assessments and therapies for pts in an ongoing registry documenting treatment patterns, natural history, and outcomes.

Methods:
Pts ≥2 years old with HbSS, HbS/β-thalassemia, or HbSC were enrolled from 57 US centers and assessed every 6 mos for up to 3 years. Differences between pediatric (age <18) and adult (age ≥18) pts at 12 mos follow-up are reported. (ClinicalTrials.gov identifier, NCT01220115.)

Results:
In all, 498 pts completed the baseline visit. Most pts had HbSS disease (age <18, 76.3%; age ≥18, 70.2%). Adult pts had worse performance status, and more frequent avascular necrosis, gallbladder disease, leg ulcers, and pulmonary hypertension at baseline (Table 1). They also had more transfusions, higher serum ferritin, more chelation exposure, more hospitalizations for pain, and potentially more strokes (Table 2). Pediatric pts had higher frequencies of asthma, abnormal transcranial Doppler (TCD) readings, dactylitis, splenic sequestration, acute chest syndrome, infections, hospitalizations at baseline, and more prevalent hydroxyurea use on study. Absenteeism from school (age <18, 1 to 10 d missed prior to study, 50.8%; 1 to 10 d missed on study, 65.8%) and work (age ≥18, 1 to 10 d missed prior to study, 44.4%; 1 to 10 d missed on study, 45.1%) was frequent.

Conclusions:
This study showed differences in baseline characteristics and treatment patterns between adult and pediatric pts with SCD. Ongoing follow-up will provide further information on disease patterns, treatment practices, and outcomes, thus increasing our understanding of appropriate SCD management.

Disclosures:
Heeney: Novartis: Consultancy, Research Funding; Eli Lilly: Research Funding. Off Label Use: Hydroxurea is indicated to reduce the frequency of painful crises and to reduce the need for blood transfusions in adult patients with sickle cell anemia. It is not approved for use in children. Mueller:Novartis: Research Funding. Adams-Graves:Novartis: Consultancy, Speakers Bureau. Paley:Novartis: Employment. Esposito:Novartis: Employment. Vichinsky:Novartis: Consultancy, Research Funding; ApoPharma: Consultancy, Research Funding; ARUP Research Laboratory: Research Funding.
Novel 2-Phenyl-1-Pyridin-2yl-Ethanone (PpY) Based Iron Chelators Increase Expression of IkBα and Heme Oxygenase-1 and Inhibit HIV-1
Authors: Kumari Namita , Xu Min , Kovlaskyy Dmytro , Dhawan Subhash , Nekhai Sergei 
Published: October 2019

Abstract
Abstract 1052
HIV-1 transcription is activated by HIV-1 Tat protein, which recruits CDK9/cyclin T1 and other host transcriptional co-activators to the HIV-1 promoter. Tat itself is phosphorylated by cell cycle kinase 2 (CDK2) and inhibition of CDK2 by small interfering RNA or iron chelators inhibits HIV-1 transcription. HIV-1 transcription is also activated by NF-kB that binds to HIV-1 LTR independent to Tat but can also be recruited Tat-dependently by CDK9/cyclin T1. Recently, induction of heme oxygenase-1 (HO-1) by hemin was shown to inhibit HIV-1 in vitro and in vivo. Here, we analyzed the effect of novel phenyl-1-pyridin-2yl-ethanone (PPY) based iron chelators, PPYeT and PPYaT, on HIV-1. Both chelators efficiently inhibited one round of HIV-1 replication in T cells at low nanomolar IC50s without exhibiting cytotoxicity at 24 hrs incubation. The iron chelators efficiently bound intracellular labile iron as it was determined in calcein binding assays. Because we previously showed that iron chelators inhibited the activity of CDK9, we analyzed expression of several cellular genes dependent on CDK9. Unexpectedly, chelators were found to induce the expression of IkBα, an inhibitor of NF-kB (Fig1). Treatment with the iron chelators retained NF-kB in cytoplasm of the treated cells suggesting reduction in NF-kB in nucleus (Fig2). The chelators were also shown to induce HO-1 expression in cultured monocytes, likely to do a decrease of intracellular iron pool. This effect of iron chelators mimicked the effect of hemin treatment which also induced HO-1 and inhibited HIV-1 infection in our experimental conditions. Low nanomolar IC50s for the PPY-based iron chelators and lack of toxicity suggest their potential usefulness as future anti-retroviral therapeutics. Further studies are needed to investigate additional targets for iron chelators in HIV-1 life cycle that may include reverse transcription and capsid assembly. Therefore iron chelators need to be carefully assessed not only to understand the mechanism but also as a therapeutic strategy.

Acknowledgments.
This work was supported NIH Research Grants SC1GM082325, R25 HL003679, 2G12RR003048, 8G12MD007597, K25GM097501 and 1P30HL107253.

Disclosures:
No relevant conflicts of interest to declare.