bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessing Haemostatic Efficacy In VWF/FVIII Replacement Therapy Trials Utilizing Subjective Vs. Objective Criteria – a Way to Improve Comparability and Accuracy of Clinical Outcome.
Authors: Kessler Craig M. , Schwartz Bruce A. , Hegener Oliver , Walter Olaf , Knaub Sigurd 
Published: October 2019

Abstract
Abstract 1424

Objective:
The assessment of the clinical efficacy during the conduct of a clinical trial is critical to the potential acceptance of that product to be a viable therapeutic option. This is especially true in the conduct of clinical trials involving rare bleeding disorders such as VWD, where there is predictably small patient enrollment and limited use of a control group. A 4-point Likert hemostatic efficacy scale with mostly subjective general criteria (excellent, good, moderate, none) has been used previously in most clinical trials published to date in the VWD field.

Methods:
A validated and more objective set of criteria, intended to more specifically assess the therapeutic efficacy of VWF/FVIII replacement therapy was developed. These objective criteria include: quantization of transfusions of blood components; the need for salvage therapy utilizing alternative VWF/FVIII concentrates or other hemostatically active products; the requirement for significant dosing increases of replacement products; etc.
Patients in a VWD clinical trial with a new VWF/FVIII replacement product, wilateÒ (Octapharma AG, Lachen, Switzerland), were assessed for clinical hemostatic efficacy in the treatment of their acute bleeding episodes, using both the traditional 4 point Likert scale, as assessed by the treating physician, and the newly proposed set of objective success and failure criteria for bleeding episodes during treatment, as determined by evaluation of the actual clinical data generated for each individual patient.

Summary:
Results of the analysis using the new objective criteria when compared to the previous subjective efficacy assessment approach showed a comparable efficacy profile. This proposed objective hemostatic efficacy assessment examined specific clinical criteria that could be considered as indicative of a more accurate status of treatment.

Conclusions:
This objective approach avoids the potential pitfalls of observer bias and inconsistency, which form the basis of criticism of the previously used subjective assessment tools. Furthermore, this more objective type of assessment approach has been requested and accepted in recent registration trials by FDA in the US.

Disclosures:
Kessler: Grifols S.A.: Research Funding; Baxter-Immuno: Research Funding; NovoNordisk: Research Funding. Schwartz:Octapharma: Employment. Hegener:octapharma: Employment. Walter:Octapharma: Employment. Knaub:Octapharma: Employment.
Romiplostim (N-Plate) In Children with Chronic Refractory ITP.
Authors: Elalfy Mohsen Saleh , Abdelmaksoud Abeer Ahmed , Eltonbary Khadiga Yehia 
Published: October 2019

Abstract
Abstract 1443

Background:
Chronic immune thrombocytopenic purpura (ITP) is characterized by platelet deficiency due to platelet destruction and/or inadequate production. Romiplostim stimulates thrombopoietin receptor to increase platelet production in chronic ITP. This study aimed to evaluate the safety and short term efficacy of Romiplostim (N-Plate) in children with chronic refractory ITP.

Design and Methods:
Eighteen patients less than 16 years old suffering from refractory chronic ITP for more than a year who failed to maintain response on more than two therapeutic modalities (steroids, IVIG, Anti-D and/or immunosuppressive therapy) were enrolled. Written informed consent was taken from all parents and consent or ascent form from patients when applicable. Patients were randomized (2:1) to receive Romiplostim or placebo for 12 weeks, initiated at 1μg/kg/week escalated weekly to 5μg/kg/week; then tapered based on weekly platelet count and were followed up to week fifteen.

Results:
The median age of the studied group was 8.5 years, median duration of thrombocytopenia was 3.5 years and the median baseline platelet count (PC) was 10.5 × 109/L. The median weekly dose of Romiplostim was 2μg/kg. Fifty percent of patients in both the Romiplostim and placebo arms had at least one AE with no serious AEs. Ten patients (83.3%) on Romiplostim achieved efficacy endpoint (platelet count of > 50 × 109/L for 2 consecutive weeks without rescue therapy at any point during the treatment period) and 6 patients (50%) maintained that response 3 weeks after treatment discontinuation in contrast to non in the placebo group. Four of the patients on Romiplostim reached the targeted range (>50 × 109/L) after the 2nd week and 11 patients reached the targeted range after the 5th week. None of our patients experienced thrombocytosis or rebound thrombocytopenia. The peak PC was reached in the Romiplostim arm by the 5th week of treatment at a dose of 5ug/kg with median PC of 73.50 ×109/L; compared to 18.50 ×109/L for the placebo group. Rescue medication was administered to 1/12 (8.3%) patient on Romiplostim due to accidental head trauma compared to 2/6 (33.3%) patients on placebo. Number of patients in the Romiplostim arm with grade 3 bleeding severity decreased from 33.3% (prior to study) to 0% (during the study and then after) and from 50% to 16.6% for grade 2.

Conclusion:
Romiplostim is well tolerated in children with refractory chronic ITP with no serious AEs. It was efficient in treating most of them with minimal bleeding during the study period while using lower doses of N-Plate compared to previous published data.

Abbreviations:
ITP; immune thrombocytopenia. PC; platelet count. AE; adverse event.

Disclosures:
No relevant conflicts of interest to declare.
Increased Number of B-Cells In the Red Pulp of the Spleen In ITP
Authors: Olsson Bob , Wadenvik Hans , Jernås Margareta , Ridell Börje 
Published: October 2019

Abstract
Abstract 1447

Background.
Platelets are targeted by autoantibodies and destroyed in the reticuloendothelial system, e.g. the spleen, in patients with chronic immune thrombocytopenia (ITP). However, other pathophysiologic mechanisms such as platelet destruction by cytotoxic T-cells and defective bone marrow production of platelets also contribute to the thrombocytopenia in ITP. Splenectomy normalizes the platelet count in around 70% of chronic ITP patients, however, precious little is known about the spleen micromorphology in this disease. We examined splenic pathology in patients with ITP, focusing on the intrasplenic distribution of lymphocyte subsets.

Patients and Methods.
The paraffin-embedded block containing representative material of the splenic tissue from 29 splenectomized chronic ITP patients (15 females and 14 males, mean age 45±21 (SD) years) and 11 controls, splenectomized because of traumatic splenic rupture (2 females and 9 males, mean age 48±19 (SD) years), was used to produce serial sections with a thickness of 5 μm. These sections were stained with conventional haematoxylin-eosin, and immunostained to identify CD3, CD4, CD8, CD20 and CD68 using the Dako Envision System in a Techmate Horizon Autostainer (Glostrup, Denmark). Using micromorphometry the lymphocyte subsets were enumerated in the red and white pulp of these spleens.

Results.
All ITP patients were preoperatively optimized, using corticosteroids and/or IVIg, and the immediate pre-splenectomy platelet count ranged 5–357 × 109/l.
Significantly more T-cells than B-cells were seen in the red pulp, both in ITP and control spleens (p<0.01). Conversely, more B-cells than T-cells were observed in the white pulp. There was no difference in the number of T-cells in the red and white pulp, between ITP patients and controls. However, the number of B-cells was increased in the red pulp of patients with ITP compared with the controls. Furthermore, numerous B-cells and CD8+ (cytotoxic) T-cells were located in the splenic cords, lining the sinusoids in the red pulp, a microenvironment where they readily can interact with the other blood cells, e.g. platelets.

Conclusion.
Chronic ITP is associated with an increased number of CD20+ B-cells in the red pulp of the spleen. The red pulp of the spleen also provides a microenvironment where close interaction between platelets, CD3+, CD4+, and CD8+ T-cells and B-cells can take place. Trafficking of regulatory and effector cells into this microenvironment might be a potential therapeutic target.

Disclosures:
No relevant conflicts of interest to declare.
A Single Intramuscular Injection of AAV-8 Vector Expressing MDA7/IL-24 Efficiently Suppresses Tumor Growth Mediated by Multiple Anti-Cancer Mechanisms In Lymphoma Model Mice.
Authors: Wang Nanya , Fan Bai , Miyake Noriko , Miyake Koichi , Shimada Takashi 
Published: October 2019

Abstract
Abstract 1474
Melanoma differentiation-associated gene-7/interleukin-24 (MDA7/IL-24) selectively induces apoptosis in cancer cells without harming normal cells. It also exerts immunomodulatory and anti-angiogenic effects, as well as potent antitumor bystander effects, making it an ideal candidate for use in a new anticancer gene therapy. To examine the feasibility of adeno-associated virus (AAV) vectors expressing MDA7/IL-24 in systemic cancer gene therapy for lymphoma, we generated an AAV type 8 vector expressing MDA7/IL-24 (AAV-IL24). In vitro studies showed that medium conditioned by AAV-IL24-transduced C2C12 cells induces tumor cell-specific apoptosis against murine lymphoma cell line (A20 cell). To assess the in vivo effects of muscle targeted AAV-mediated systemic delivery of MDA7/IL-24 we established a lymphoma murine model in which the A20 cells expressing luciferase gene was inoculated into the caudal vein of BALB/C. Using this lymphoma murine model, we can detect the tumor growth and metastases by a real-time in vivo imaging analyze system (IVIS). After single injection of AAV-IL24 (1.5×1011 vg/body) into the right quadriceps muscle of the lymphoma model mice, tumor cell growth was monitored by IVIS. ELISA analysis showed high level of IL-24 was detected in plasma of treated mice (263±16 ng/ml). Suppression of tumor growth was observed in AAV-IL24 injected mice compared to control GFP expressing AAV injected mice (1.3×108vs.2.6×108 photon/sec; p<0.05). Survival effect was also detected in AAV-IL24 mice (66±6 vs. 47±5 days; p<0.03). In addition, TUNEL analyses showed significant induction of tumor cell-specific apoptosis within the tumors and suppression of angiogenesis was also detected in AAV-IL24 treated mice. Finally, immune modulating activity of induction of Th1 cytokines (IL-6, TNFα, IFNγ) secretion was observed after AAV-IL24 injection. These results clearly demonstrate that continuous systemic delivery of MDA7/IL-24 can serve as an effective treatment for lymphoma. Thus, AAV type 8 vector-mediated systemic deliverY of MDA7/IL-24 represents a potentially promising new approach to treat lymphoma.

Disclosures:
No relevant conflicts of interest to declare.
Targeting Histone Deacetylase 6 (HDAC6) as a Novel Approach to Overcome T-Cell Anergy.
Authors: Cheng Fengdong , Wang Hongwei , Woan Karrune , Rock-Klotz Jennifer , Wang Zi , Merino Oscar , Gill Ajay , Marante Danay , Vazquez Lianet , Seto Edward , Pinilla-Ibarz Javier , Sotomayor Eduardo M. , Villagra Alejandro 
Published: October 2019

Abstract
Abstract 1483
The anti-inflammatory molecules IL-10 and STAT3 are major hurdles in our efforts to harness effective anti-tumor immunity1. Previously, we have unveiled a role for histone deacetylase 11 (HDAC11) as a negative regulator of IL-10 gene transcriptional activity in antigen-presenting cells (APCs)2. In an effort to better characterize the epigenetic influences upon IL-10, we screened other HDACs and found that over-expression of HDAC6 in the macrophage cell line RAW264.7 was able to transcriptionally upregulate IL-10 in response to LPS. Next, using lentiviral vectors encoding shRNA for HDAC6, we generated stable knockdown clones of HDAC6 (HDAC6KD). In contrast to HDAC6 overexpression, HDAC6KD cells produced less IL-10 both at the mRNA and protein levels. Further analysis of HDAC6KD clones revealed elevated expression of the co-stimulatory molecule B7.2. Functionally, LPS-stimulated HDAC6KD cells were better able to activate anti-HA (hemagglutinin-influenza) transgenic CD4+ T cells to produce IL-2 and IFN-γ. More relevant to the tumor setting, anti-HA CD4+ anergic T cells isolated from animals bearing HA-expressing A20 B-cell lymphoma regained their ability to produce IL-2 and IFN-γ when cultured in vitro with HDAC6KD cells in the presence of cognate HA-antigen. These same T-cells remained anergic when cultured with control APCs displaying normal levels of HDAC6. Mechanistically, we have found that APCs lacking HDAC6 display a significant abrogation of STAT3 activation in response to LPS stimulation. Given the demonstration that HDACs, other than HDAC6, can regulate STAT3 activity3, we are actively investigating whether the effect we have observed is a result of direct HDAC6-STAT3 interaction or a diminished autocrine signaling through IL-10. Taken together, through abrogation of two well-known tolerogenic mechanisms in APCs, IL-10 and STAT3, HDAC6 inhibition represents an attractive therapeutic approach to overcome tumor-induced T-cell anergy and tip the balance towards effective anti-lymphoma immunity.
1. Cheng F., et al. Immunity 2003 Sep;19(3):425-36.
2. Villagra A., et al. Nat Immunol. 2009 Jan;10(1):92-100.
3. Yuan Z., et al. Science. 2005 Jan 14;307(5707):269-73.

Disclosures:
No relevant conflicts of interest to declare.
A Systematic Review of Diagnostic Features and Treatment Outcomes In Hemophagocytic Syndromes In the Adult Population
Authors: Gob Alan , Lazo-Langner Alejandro 
Published: October 2019

Abstract
Abstract 1497

Background:
The hemophagocytic syndrome (HPS) is a rare but serious condition with a poor prognosis. The syndrome is characterized by hypercytokinemia, macrophage proliferation, and systemic inflammation. In children, the disorder is most commonly a primary dysregulation of the immune system, however, in adults hemophagocytic syndrome is generally a secondary process that is associated most frequently with viral infections, solid or hematologic malignancies (especially lymphoma), and systemic inflammatory conditions. Diagnostic criteria have been extrapolated from experience in children, and prognostic factors have not been well described. It has not been established whether the adult form of HPS is identical to the secondary form in children, or a distinct clinical entity. Additionally, management focuses on controlling the underlying cause, but it is unclear whether further benefit is derived from immunosuppression; optimal management strategies remain unclear.

Objectives:
To document the clinical, biochemical, and histopathological features associated with HPS in adults. To describe treatments used and document clinical outcomes.

Methods:
We performed a systematic review of all case reports or case series of hemophagocytic syndrome between January 1990 and July 2009. We searched Medline (Ovid), Embase (Ovid), Imbiomed, Artemisa, and Lilacs for cases and case series of hemophagocytic syndrome in adults. We included in our analysis those studies that a) clearly described patient demographics, b) described the underlying diagnosis, c) provided sufficient information on diagnostic criteria, d) met the HLH Study Group diagnostic criteria, e) provided sufficient information on therapeutic approaches, and f) provided follow up and/or survival data. For each included case, we extracted demographic, biochemical, clinical, and therapeutic data. Statistical analysis was done using χ2 or unpaired Student's t tests. Potential predictors of mortality were explored using logistic regression.

Results:
A total of 85 cases met our selection criteria. Characteristics are summarized in the table. Among the 44/85 (51.7%) patients that died, mean survival time was 30 days (Figure). Only age, ALP, and –marginally- underlying etiology were significantly different between groups. Other than age, none of the variables in the multivariate analysis were found to correlate significantly with survival.

Conclusion:
Hemophagocytic syndrome in adults carries a high mortality rate. Age may be a predictor of survival. Prospective collaborative studies on HPS in adults are needed to further define the diagnostic characteristics, prognosis and treatment outcomes.
Figure. Kaplan-Meier plot of survival in adult patient with HPS.

Disclosures:
No relevant conflicts of interest to declare.
Race, Access to Care, and Outcome After Autologous Hematopoietic Stem Cell Transplantation for Multiple Myeloma.
Authors: Alexander Erin T , Stuart Robert K , Costa Luciano J 
Published: October 2019

Abstract
Abstract 1509

Background:
Autologous hematopoietic stem cell transplantation (AHSCT) is an essential modality in the management of younger, newly diagnosed multiple myeloma (MM) patients. Some reports have indicated inferior survival for African-American (AA) patients following diagnosis of MM, when compared to Caucasian (Ca) patients. We hypothesized that previously claimed racial differences in outcome may reflect disparity in access to care and might be negated by timely, standard, and uniform treatment.

Methods:
We reviewed a mature database of MM patients undergoing AHSCT at a single institution to describe and compare overall survival from diagnosis and from transplantation in AA and Ca patients. Additionally, we described time from diagnosis to transplantation in both cohorts as an additional surrogate of access to care.

Results:
Between August 1996 and July 2010, 128 patients underwent a first AHSCT for MM at the institution. Fifty-three patients (41%) were AA and 75 (59%) were Ca. Median age at the time of diagnosis was 54.7 years for AA and 58.3 for Ca. Sixty-six (52%) of patients were female. One hundred twenty-six (98%) patients received conditioning chemotherapy with Melphalan 200 mg/m2. Median interval from diagnosis to transplant was 10 months (IQR 7.1–15.9) for AA and 9.2 months (IQR 6.7–15.6) for Ca (p=0.23). Median overall survival for the entire group was 63 months (95% C.I. 51–76) from time of diagnosis and 51.8 months (95% C.I. 39–63) from AHSCT. There was no difference in overall survival from time of AHSCT between AA and Ca, respectively 62.6 (95% C.I. 30.9–94.4) and 51.8 months (95% C.I. 33.5–70.3, Log-rank test P=0.76). Similarly, no significant difference was seen in overall survival from time of diagnosis between AA and Ca, respectively 70.4 (95% C.I. 29.6–111.3) and 59.3 months (95% C.I. 46.8–71.8), as displayed in the Figure (Log-rank test P=0.36).

Conclusion:
These findings suggest that previously reported differences in outcome between AA and CA patients with MM are related to disparities in access to healthcare and not intrinsic biological differences.

Disclosures:
No relevant conflicts of interest to declare.
Essential Function of PDGF-B Signaling In the Placental Microenvironment In Protecting Hematopoietic Progenitors From Erythroid Differentiation.
Authors: Chhabra Akanksha , Lechner Andrew J , Acharya Asha , Ueno Masaya , Van Handel Ben , Tallquist Michelle , Mikkola Hanna 
Published: October 2019

Abstract
Abstract 1559
The goals of hematopoiesis during embryogenesis are two-fold, to rapidly produce red blood cells to support the survival and development of the embryo, and to establish a pool of undifferentiated hematopoietic stem cells (HSC) for postnatal life. These goals are achieved by segregation of fetal hematopoiesis in multiple waves that are executed in distinct anatomical sites and microenvironmental niches. However, the microenvironmental cues that promote “stemness” vs. differentiation remain poorly understood. The placenta is a recently discovered hematopoietic organ that supports HSC generation and expansion without promoting their differentiation. The placental HSC pool is thought to reside in the placental labyrinth, which is comprised of an intricate vascular network surrounded by trophoblasts. So far, it has been unknown how a disruption of the integrity of the placental vascular labyrinth affects fetal hematopoiesis. The structure of the placental labyrinth is compromised in embryos that lack components of PDGF-B signaling. PDGF-B-/- and PDGF-Rβ-/- (receptor for PDGF-B) embryos display dilation of fetal blood vessels and reduction of trophoblast cells in the placental labyrinth. Our studies revealed that loss of PDGF-B signaling alters the unique placental hematopoietic microenvironment, resulting in active erythropoiesis in the placenta. The unexpected erythropoiesis in the placenta exhibited the same hallmarks of normal definitive erythropoiesis observed in the fetal liver as confirmed by flow cytometry for erythroid markers, morphological analysis and association of erythroblasts with macrophages. Interestingly, deletion of PDGF-Rβ in hematopoietic cells by using a Tie2-Cre strain did not induce the differentiation of placental hematopoietic progenitors into erythroid cells, implying that the ectopic definitive erythropoiesis results from the lack of PDGF-B signaling in the placental microenvironment rather than in the hematopoietic cells themselves. Our studies revealed that the erythroid differentiation in placentas of PDGF-B-/- embryos was induced by marked upregulation of Epo in placental trophoblasts. Strikingly, lentiviral overexpression of Epo specifically in the placental trophoblasts was sufficient to convert the placenta into an ectopic erythropoietic organ. These data reveal a critical function of PDGF-B signaling in protecting the integrity of the placental microenvironment that is required for preventing hematopoietic progenitors from differentiation during their residence in the placenta. Furthermore, these studies highlight the placenta as a versatile hematopoietic organ that supports HSC development during normal pregnancy but can be recruited as a site for definitive erythropoiesis during pathological conditions.

Disclosures:
No relevant conflicts of interest to declare.