bluuebunny/crossref_metadata_2025_split huggingface dataset:
Early Management of Heparin-Induced Thrombocytopenia Using a Simple Scoring System
Authors: Messmore Harry L. , Fabbrini Nancy , Bird Mary L. , Choudhury Abdul M. , Cerejo Miguel , Prechel M. Margaret , Jeske Walter , Siddiqui Arshea , Thethi Indermohan , Wehrmacher William H. , Walenga Jeanine M. 
Published: October 2019

Abstract
Abstract 4679
Since stopping heparin therapy lessens the probability of severe complications of heparin-induced thrombocytopenia (HIT) such as arterial and venous thromboembolism, it is important to stop heparin as soon as the diagnosis is suspected. As HIT is a complex disorder and its diagnosis is difficult, the use of a clinical scoring system would facilitate clinical decision making. One of the foremost issues in these patients is whether to discontinue heparin (to avoid HIT complications) or not (to avoid thrombotic complications). This study was performed to develop a simple scoring system to aid in the early clinical management of suspected HIT patients with regard to decisions for continued heparin therapy. The system was designed to arrive at low (0) or possible (1) probability scores based on clinical criteria without knowledge of lab test results, except platelet counts, to avoid delays. As the safest clinical approach is to discontinue heparin, intermediate and high scores were combined. Historically, laboratory tests such as the heparin-induced platelet aggregation test (PA) and 14C-serotonin release assay (SRA) and nonfunctional tests such as the enzyme-linked-immunosorbent assay (ELISA) have been used for the diagnosis of HIT. These test results are frequently available only after 12 to 36 hours which, for some patients, is a risk due to continued heparin therapy while waiting for test results. One solution to this problem is to have a clinical scoring system to guide the clinician before test results are available. This study enrolled 100 critically ill VA hospitalized patients with a >=30% fall in platelet count. Assessment of platelet aggregation (PA), 14C-SRA and GTI ELISA was also performed. In this population 53% were scored 1 and of these 43% were positive by lab testing for HIT. Emphasizing the decision to discontinue heparin, the clinical signs of HIT were paramount for the immediate determination of a diagnosis of HIT. Specifically, this study demonstrated the value of a simple clinical score to aid in the clinical management decision making to continue or discontinue heparin in patients suspected of having HIT, without dependence on a positive HIT lab test. An algorithm is provided. This scoring system does not preclude reassessment of patients in terms of continuing heparin if subsequent laboratory tests and/or thrombosis become positive.

Disclosures:
No relevant conflicts of interest to declare.
Analysis of JAK2 V617F Mutation and Its Clinical Significance in Patients with Thrombocythemia and Other Myeloproliferative Neoplasms in Chinese
Authors: Xu Yue , Yin Changxin , He Han , Shu Lingling , Wu Fuqun , Meng Fanyi , Chong Beng , Yang Mo 
Published: October 2019

Abstract
Abstract 4687
JAK2 mutation is commonly found in Philadelphia-negative myeloproliferative neoplasms (MPNs). In Western countries, this mutation is found in approximately 96 percent of people with polycythemia vera, half of individuals with essential thrombocythemia or primary myelofibrosis. We used the method of amplification refractory mutation PCR (ARMS-PCR) to investigate MPN patients in China. We focused our study on patients with essential thrombocythemia (ET). ARMS-PCR was used to detect JAK2 V617F mutation in the bone barrow (BM) or peripheral blood of 37 MPN patients, which consisting of 7 ET, 5 polycythemia vera (PV), 5 chronic myeloid leukemia (CML), 5 chronic idiopathic myelofibrosis (CIMF), as well as 15 suspected MPNs. 17 cases of JAK2 V617F mutation (45.9%) were found in 37 patients, including 4 ET (57.1%), 4 PV (80.0%), 3 CIMF (60.0%), 6 suspected MPNs (40.0%). We did not find JAK2 V617F in the patients with CML. Our results indicated that the frequency of JAK2 V617F mutation in bcr/abl-negative MPNs in Chinese is similar to that in MPN patients in Western countries. At the same time, ARMS-PCR can distinguish the mutation is heterozygous or homozygous. Most patients were heterozygous for JAK2 but only a few were homozygous. In conclusion, our study showed that JAK2 V617F mutation frequency in Chinese MPN patients is similar to that in patients with this disorder in the West. It is the major molecular genetic abnormality in bcr-abl negative MPN and it can be used for diagnosis of MPN in China.

Disclosures:
No relevant conflicts of interest to declare.
Naive CD4+ T Cells Exert Superior Alloreactive Capacity Than Central Memory CD4+ T Cells in Fully HLA-Matched Setting
Authors: Choufi Bachra , Cherel Mathilde , Thiant Stephanie , Despicht Damien , Dessaint jean-Paul , Labalette Myriam , Yakoub-Agha Ibrahim 
Published: October 2019

Abstract
Abstract 4702

Background:
Allogeneic stem cell transplantation provides donor-derived mature T cells which are involved in post-transplant immune reactions including engraftment, graft-versus-host disease (GVHD) and graft-versus-leukemia (GVL) activity, and thus play a major role in determining clinical outcome. In a prior clinical study, we showed that receiving a high percentage of CD4+CCR7+ T cells that includes naive and central memory (CM) subsets, was correlated with increased incidence and severity of acute GVHD. In a recent update of our results on 126 patients, we confirmed our previous results with a particular impact of CD4+ naive subset on acute GVHD development. The aim of the present study was to investigate in vitro the alloreactive response of CD4+CCR7+CD45RA+ naïve T cells and CD4+CCR7+CD45RAneg central memory T cells in HLA-A, -B, -C, -DRB1 and -DQB1 allele matched setting (so called 10/10 match)

Materials and methods:
The alloreactivity was investigated by mixed lymphocyte dendritic cell reaction using five HLA-identical healthy male and female sibling pairs to include at least a H-Y mismatch. Stimulators were mature dendritic cells (derived from monocytes of the male sibling) co-cultured with each one of the three highly purified CD4+ T cell subsets (naive, central memory and effector memory) from the female sibling. Alloreactive response was assessed by 3H thymidine incorporation at day 5, and functionally at day 4, 6 and 10 by IFN-gamma ELISpot and measurement of Th1/Th2/Th17 cytokines in co-culture supernatants.

Results:
Four out of five sibling pairs developed an alloreactive response to mHAs. Maximal proliferation was supported by the CCR7+CD45RA+ naive CD4+ T cells with proliferation indices from 1.75 to 3.85. This proliferation was accompanied by a functional differentiation: only naive CD4+ T cells were able to produce significant amounts of IL-6, TNF-alpha and IFN-gamma at day 6 and day 10 (120 to 174 IFN-gamma spots at day 10).

Conclusion:
This study demonstrates the superior capacity of naive CD4+ T cells to mount a primary alloreactive response as compared to central memory T cells. Their proliferative response associated with a pro-inflammatory differentiation makes naive CD4+ T cells potential acute GVHD inducers. These in vitro results confirm what we have observed in clinical studies and may also lend support to approaches of selective T cell depletion for GVHD prevention.

Disclosures:
No relevant conflicts of interest to declare.
Effectiveness of Subcutaneous Low-Dose Alemtuzumab and Rituximab Combination Therapy for Steroid-Resistant Chronic Graft-Versus-Host Disease
Authors: Gutiérrez-Aguirre Cesar H , Flores-Jiménez Juan A. , Cantú-Rodríguez Olga , Cuervo-Sierra Jorge , Ceballos-López Adrián A. , Martínez-Hernández Ramón A , Gómez-Almaguer David 
Published: October 2019

Abstract
Abstract 4703

Background:
Chronic graft-versus-host disease (cGVHD) is a common late complication of allogeneic hematopoietic stem cell transplantation. Corticosteroids are the standard initial treatment for cGVHD. A second-line treatment is not well defined. We prospectively evaluated the effectiveness and safety of low doses of alemtuzumab and low doses of rituximab as treatment steroid-refractory cGVHD.

Materials and Methods:
Ten men and 5 women with cGVHD refractory to steroids and CSA were included. All patients received subcutaneous Alemtuzumab 10 mg/day/3 days and intravenous Rituximab 100 mg on days +1, +7, +14 and +21.

Results:
The median age was 41 years. The main organ involved were oral mucosa (86.7%), eyes (66.7%), liver (60%), skin (53%), lungs (13.3%) and intestinal tract (6.7%). The overall response was 100% at 30-day evaluation; 10 patients (67%) had partial remission (PR), and 5 patients (33%) had complete remission (CR). At 90-day evaluation, 7 (50%) patients had PR, 4 (28%) had CR; three (21%) relapsed and 1 patient not reached evaluation. Currently, 5 patients have reached the 365-day follow-up evaluation, 2 (40%) had PR, 2 had CR and 1 showed progression. The adverse effects were mainly infectious and one patient died from pneumonia.

Conclusion:
This combination therapy appears to be an efficacious and safe as treatment for steroid-refractory cGVHD.

Disclosures:
No relevant conflicts of interest to declare.
Gene Therapy of Human Blnk Deficiency in NOD/SCID/Gc Ko Murine Model
Authors: Lagresle-Peyrou Chantal , Milili Michèle , Rouiller Julien , Picard Capucine , Cavazzana-Calvo Marina , Schiff Claudine , Andre-Schmutz Isabelle 
Published: October 2019

Abstract
Abstract 4717
Blnk deficiency is an autosomal recessive immune disorder characterized by the absence of B cells in periphery and the absence of any seric immunoglobulins due to an early blocage at the pro-B cell stage in the bone marrow. The very rare patients affected by blnk deficiency develop severe infections. In the murine model of the disease, a similar blocage in B cell development is described as well as susceptibility to infections and to pre-B lymphomas.
A homozygote stop mutation in blnk gene was identified in a 8-yr old boy. Bone marrow cells analysis revealed that CD34+CD10+CD24-CD19- lymphoid progenitors were present as well as CD34+CD10+CD24+CD19- early B cells and CD34+CD19+ pro B cells. However, no surface IgM or seric Ig were detected in this patient.
To demonstrate the implication of Blnk in the B-cell differentiation process, we transduced CD34+ sorted bone marrow cells from this patient with a lentiviral construct containing human wild type Blnk cDNA. The transduced cells were intravenously injected into irradiated NOD/SCID/IL2rg knock-out mice. Twelve weeks after transplantation, recipients were analysed. Human engraftment was detected in bone marrow and spleen. Among bone marrow human CD45+ cells, more than 80% were CD19+ and 6 to 8% express surface IgM. In the spleen, between 14 and 30% of CD19+ cells were detected. Eight to 42% of CD19+ cells expressed surface IgM.
This is the first demonstration that Blnk is absolutely required for the differentiation of pro-B cells toward mature B cells.

Disclosures:
No relevant conflicts of interest to declare.
Manumycin Induces Apoptosis of Leukemic Stem Cells Through Down-Regulation of Bcl2
Authors: She Miaorong , Li Jinggao , Chen Xilin , Du Xin , Lin Wei , Lu Zesheng , He Yanjie , Guo Kunyuan 
Published: October 2019

Abstract
Abstract 4738
Acute myeloid leukemia (AML) is a serious and often lethal hematopoietic malignant disease arising from stem cells. LSCs play the central role in the relapse and refractory of AML and highlight the critical need for the new therapeutic strategies to directly target the LSC population for ultimately curing leukemia. Unfortunately, very few agents have been shown to directly target the LSC population. The present studies demonstrate that manumycin, a farnesyltransferase inhibitor, resulted in viability decrease in a dose-dependent and soft agar clonogenic formation inhibition in LSCs isolated from KG1a cell line. Furthermore, manumycin induces LSC apoptosis in a dose-dependent. The molecular mechanism of manumycin mediated apoptosis is associated with down regulation of Bcl2 and Bcl-xL. In conclusion, manumycin triggers apoptosis in LSC and represents a potentially important new class of drugs for LSC-targeted therapy.

Disclosures:
No relevant conflicts of interest to declare.
Application of Clinical Microsystems Improves the Speed of the Initial Pain Relief in Sickle Cell Disease (SCD) Patients Admitted with Acute Vaso-Occlusive Crisis (VOC)
Authors: Aghalar Jahan , Barnett Barbara , Cohen Rubin , Tan Venessa , Marcus David , Ouchi Kei , Cascetta Krystal , Fulman Magda , Jaffrey Fatima , Roy Rajasree 
Published: October 2019

Abstract
Abstract 4740

Background-
The management of acute vaso-occlusive crisis continues to be a challenge in patients with sickle cell anemia. Long Island Jewish Medical Center is a 500 adult bed, tertiary care facility, with more than 500 reported admissions for acute vaso-occlusive crisis in 2009. Suboptimal pain management in the Emergency Department (ED) frequently resulted in unrelieved pain, recurrent admissions, prolonged hospitalization, and increased patient dissatisfaction.

Methods-
An interdisciplinary team which included a patient with SCD was assembled to meet weekly to address the above issues. The team was educated in Clinical Microsystem methods as described by Nelson et.al (1) over 6 months. Preliminary data was collected to assess performance with respect to pain management in adult SCD patients presenting to the ED through pain diaries. The admission process was analyzed and significant delays were noted from time of presentation to the time that sufficient sustained analgesia was achieved. The PDSA (Plan Do Study Act) cycle method to test and study change was utilized. The specific aim was to achieve a sustained 2 point reduction in subjective pain score within 2 hours of inpatient admission. Four interventions were simultaneously tested. First, given the high frequency of admission from our ED for this patient population, we tested proactive bed designation initiated when the patient presented to the ED. Second, we educated the housestaff on providing appropriately dosed narcotic administration upon admission after pharmacy verification of previous patient specific dose requirements. Third, we arranged expedited transfer to the medical floors for these patients. Lastly, we arranged for storage of PCA pumps on the medical unit designated for SCD patients, facilitating immediate initiation of pain medication via this modality. Timing of analgesic response was assessed based on patient interviews and the above mentioned diaries.

Results-
During the pre-intervention stage it took an average of 55 hours and 20 minutes to achieve a sustained reduction in pain by two points. Post intervention, the team achieved a sustained 2 point reduction in subjective pain score by an average of 9 hours and 58 minutes (see figure).

Conclusion-
The Clinical Microsystems Methodology is an effective means of engaging an interdisciplinary team in improving the initial analgesic response to treatment in sickle cell patients admitted with acute vaso-occlusive crisis.

Disclosures:
No relevant conflicts of interest to declare.
Efficacy of Short Oral Leucovorin Rescue (SOLR) In Managing Recurrent Pralatrexate (Folotyn) Induced Mucositis (RPIM) Despite Dose Reduction
Authors: Haddad Philip A 
Published: October 2019

Abstract
Abstract 4745
Mucositis is a frequent complication experienced by patients receiving weekly Pralatrexate, an antifolate agent, which often leads to significant morbidity, decreased quality of life, and early discontinuation of this active therapy in aggressive and almost universally fatal Peripheral T-cell Lymphomas (PTCL). Despite its frequency, there is no standard medical management currently except omitting doses followed by one step dose reduction and subsequent discontinuation, many times despite notable responses. Since Leucovorin is approved as antidote for Pralatrexate overdose, we reviewed our clinical experience with its reactive (not pre-emptive) use in our PTCL patients with Grade 2+ RPIM that have already gone through dose omissions and dose reductions and had no other alternative but to discontinue therapy. SOLR consisted of 25 mg po Q6h for 5 days the week of RPIM to be stopped at least 48hours prior to the planned subsequent weekly dose. We reviewed our experience with such approach which amounted to 17 such interventions. All 17 SOLR regardless of grade lead to resolution of subjective symptoms by the 7th day with time to initial subjective improvement at around the 4th day from SOLR initiation. Sixteen SOLR interventions had complete resolution of RPIM on exam on the 7th day and one had almost complete resolution. As such, all cases were ready to resume weekly recommended dosing per standard PTCL regimen. None of SOLR patients discontinued Pralatrexate for RPIM. None of SOLR patients lost their response attained prior to the intervention. In fact, the patient with transformed Mycosis Fungoides continued to show notable further skin response. When compared to the PROPEL Trial which used dose omission and delay to address mucositis, SOLR further shortened the time to resolution by 3–5 days (7 days vs. median of 10 days for Grade 2 and 12 days for Grade 3- Allos unpublished data).
Although further controlled studies are recommended, our clinical observation suggests that reactive SOLR intervention in RPIM offers rapid and effective symptom management by aiding faster mucosal healing and further decreases drug holidays and discontinuation of therapy without any discernable compromise in efficacy.

Disclosures:
Haddad: Allos: Consultancy, Honoraria, Research Funding, Speakers Bureau. Off Label Use: Use of Leucovorin in treating Pralatrexate induced Mucositis.
Participation for Innovation: Survey of Motivation for Clinical Studies Evaluating New Treatments for Hemophilia
Authors: Henrard Severine , Speybroeck Niko , Lambert Catherine M , Hermans Cedric R. 
Published: October 2019

Abstract
Abstract 4778
Over the last 50 years, clinical research into new treatments has helped to transform the care of individuals with hemophilia. Life expectancy for severe hemophiliacs has indeed increased from 11 years in the 1960s to more than 60 years today and many patients with hemophilia are now able to lead an active and fulfilled life. All this has been possible largely through the commitment of people with hemophilia to active participation in clinical research. While much has been achieved, much remains to be accomplished such as the development and validation of longer acting clotting factor concentrates, new bypassing agents and the validation of treatment strategies aiming at preventing or reducing the risk of inhibitor development. Although many clinical trials are currently ongoing around the world, most of them are facing difficulties in recruiting candidate patients, mainly in developed countries. In this context, there is a major need to improve the patients' awareness of the importance of clinical research in hemophilia and highlight the opportunities of an active participation in clinical trials. A survey was launched to evaluate the motivation of patients with hemophilia for clinical studies and identify factors which might influence their willingness to participate. A specific questionnaire was sent to 189 patients with hemophilia (127 adults and 62 children) regularly attending the hemophilia treatment Center of the Cliniques Universitaires Saint-Luc, Brussels, Belgium. Different aspects such as socio-demographic status, familial situation, current hemophilia treatment, knowledge about principles and perceived benefits and risks of clinical studies, positive and negative factors for motivation were extensively addressed. Preliminary results show that most patients have a limited knowledge about the general principles of clinical research. Patients on prophylaxis show a higher motivation to participate than patients treated on demand. Patients are mainly concerned by possible side effects of new treatments. The time lost from school or work refrains many motivated patients from an active participation. Moreover, very few patients are ready to take part in phase 1 trial fearing unknown reactions or side-effects. This survey, which will soon be extended to several hemophilia centers in Europe, highlights the importance to raise awareness and provide better knowledge about the modalities, the risks and benefits of clinical research.

Disclosures:
No relevant conflicts of interest to declare.
Hypoxia Alters the Main Characteristics of the Hematopoietic Stem and Progenitor Cell Microenvironment in Vitro
Authors: Wobus Manja , Duohui Jing , Poitz David M , Müller Katrin , Ordemann Rainer , Ehninger Gerhard , Bornhäuser Martin 
Published: October 2019

Abstract
Abstract 4803

Background:
Hematopoietic stem and progenitor cells (HSPC) are located in a specialized microenvironment, called the stem cell niche, where their stem cell phenotype and differentiation are tightly regulated via interactions with the supporting mesenchymal stromal cells (MSC). These niches have been shown to be localized in regions with a lower oxygen tension which may also impact on the functional properties of MSC. For a better understanding to what extent hypoxia contributes to the establishment of an undifferentiated niche microenvironment that prevents inopportune differentiation of HSPC, we investigated MSC/HSPC co-cultures as well as MSC single cultures under low oxygen conditions.

Design and Methods:
Distribution, functional and phenotypical characteristics of CD34+ HSPC in hypoxic co-cultures (0.5% O2) were analyzed by flow cytometry. The effect of co-culture medium on the HSPC migration potential was tested in a transwell assay. The secretion of vascular endothelial growth factor A (VEGF-A), stromal-derived factor 1 (SDF-1), IL-6 and IL-8 by MSC was determined using ELISA whereas the expression of cell surface molecules was detected by flow cytometry. Moreover, the MSC proliferation as well as adipogenic and osteogenic differentiation was compared between hypoxic and normoxic culture conditions.

Results:
In the hypoxic co-culture, the adhesion of HSPC to the MSC layer was inhibited, whereas HSPC transmigration beneath the MSC layer was favoured. Increased VEGF-A secretion by MSC under hypoxic conditions, which enhanced the permeability of the MSC monolayer, was responsible for this effect. Furthermore, VEGF expression in hypoxic MSC was induced via hypoxia-inducible factor (HIF) signalling. Whereas IL-6 and IL-8 secretion were increased, SDF-1 expression by MSC was down-regulated under hypoxic conditions in a HIF-independent manner. The MSC immunophenotype which is characterized by expression of CD73, CD90, CD105, and CD166 was not significantly changed by hypoxia. Interestingly, a significant decrease of CD146 mRNA and protein expression levels was observed. The MSC proliferation was not significantly affected by lower oxygen tension. Culture of MSC in adipogenic induction medium for 14 days under hypoxia resulted in a reduced appearance of adipocyte-like cells containing lipid droplets and almost 50 % lower mRNA levels of fatty acid binding protein 2. The ALP activity as readout for osteogenic differentiation was decreased between 10% and 60% in hypoxic MSC.

Conclusions:
Low oxygen tension reduces the in vitro differentiation capacity and alters the cytokine secretion profile of primary human MSC. These functional changes may favour the homing and maintenance of quiescent HSC simulating the physiologically hypoxic niche conditions in vitro.

Disclosures:
No relevant conflicts of interest to declare.