bluuebunny/crossref_metadata_2025_split huggingface dataset:
PSTPIP2 Limits Osteoclast Precursor Differentiation and Inflammation-Associated Bone Loss.
Authors: Chitu Violeta , Nacu Viorel , Charles Julia F , Ketchum Halley , Haskell Cristopher , Nandi Sayan , Stanley E. Richard 
Published: October 2019

Abstract
Abstract 1489
Chronic inflammatory conditions are frequently associated with bone loss. However, the common pathways linking these processes are still poorly defined. Here we show that PSTPIP2, an F-BAR domain containing protein, negatively controls inflammation and osteoclast formation. Mutations in Pstpip2 lead to autoinflammatory disease and secondary generalized osteopenia. Dentine disc implants are more rapidly and extensively resorbed in PSTPIP2-deficient mice than in wt controls due to increased osteoclast formation on the implant. Bone marrow and spleens of cmo mice contain increased numbers of multipotent c-Kit+ c-fmslo Mac-1lo myeloid precursors that give rise to more osteoclasts in vitro than cells from wt mice. All these phenotypes are corrected by administration of the CCR1 antagonist BX471. Our results identify PSTPIP2 as an essential limiting factor of myelopoiesis and osteoclast differentiation and MIP-1α as a mediator of inflammation-induced bone loss in PSTPIP-2 deficient mice.

Disclosures:
No relevant conflicts of interest to declare.
Neutrophil Proteinase (PR3) Regulates Neutrophil Transendothelial Cell Migration.
Authors: Kuckleburg Christopher , Tilkens Sarah , Santoso Sentot , Newman Peter J. 
Published: October 2019

Abstract
Abstract 1492
Neutrophil transmigration requires the localization of neutrophils to endothelial cell junctions where receptor-ligand interactions between these cells promotes leukocyte diapedesis. Neutrophils contain several different proteases which are thought to play a role in aiding in transendothelial cell migration, either by degrading extracellular matrix components or junctional proteins, or by inducing endothelial cell activation. Proteinase 3 (PR3) is a serine protease stored in azurophil granules that is released by activated neutrophils and can rebind to the neutrophil expressed cell surface protein NB1 (CD177). The neutrophil marker NB1 is expressed on a subset of neutrophils (∼50%) and has recently been demonstrated to be a heterophilic binding partner for PECAM-1, a protein highly expressed at endothelial cell junctions. Disrupting NB1-PECAM interactions has been reported to significantly inhibit neutrophil transmigration. Because of the critical role of NB1 in neutrophil transmigration we believe that the interactions between NB1 and PECAM-1 have the potential to localize PR3 to endothelial cell junctions where it may aid in leukocyte transmigration.
For this study we sought to test the hypothesis that NB1-PR3 interactions contribute to neutrophil transmigration. Human umbilical vein endothelial cells (HUVEC) were cultured on transwell membranes, treated with IL-1β, TNFα or fMLP and then incubated with NB1+ or NB1- PMN. Using flow cytometry we observed that transmigration alone resulted in a significant increase in PR3 expression on NB1+ but not NB1- neutrophils. Using a pan-serine protease inhibitor (AEBSF) total neutrophil transmigration was significantly inhibited. However, using a highly specific PR3 inhibitor (Elafin) we observed a selective inhibition in NB1+ but not NB1- neutrophil transmigration on IL-1β stimulated HUVEC. Similarly, antibodies against the NB1 recognition site on PECAM (Ig domain 6) inhibited neutrophil transmigration of NB1+ but not NB1- cells. Interestingly, in the presence of different stimuli (TNFα, fMLP), neutrophil transmigration was significantly less dependent on NB1-PECAM interactions and inhibition of PR3 activity did not inhibit transmigration. This is despite the fact that PR3 expression was highly up-regulated on NB1+ neutrophils incubated with either of these stimuli or following neutrophil transmigration.
In conclusion, the serine protease PR3 appears to play a significant role in the transmigration of NB1+ but not NB1- neutrophils. Likewise, the contribution of NB1 and PR3 in neutrophil transmigration is regulated in a stimulus-dependent mechanism which involves NB1 interactions with PECAM. These data therefore suggest that NB1 and PR3 may regulate recruitment of a neutrophil subset in response to specific inflammatory signals and this regulation may play a role in modulating the immune response.

Disclosures:
No relevant conflicts of interest to declare.
Cytokine Profile of Patients with Invasive Apsergillosis- Preliminary Results.
Authors: Ceesay M. Mansour , Kordasti Shahram , Berry Lisa , Smith Melvyn , Wade Jim , Mufti Ghulam J. , Pagliuca Antonio 
Published: October 2019

Abstract
Abstract 1500
Invasive Aspergillosis (IA) is an important cause of morbidity and mortality in haemato-oncology patients undergoing haematopoietic stem cell transplantation (HSCT) or chemotherapy resulting in prolonged cytopenia. The host cytokine response to fungal infection in this immunocompromised state is a crucial component of susceptibility and response to IA. The aim of this study was to assess if a unique cytokine profile exist for patients who developed IA compared to those who didn't.
All adult haemato-oncology patients enrolled on the Aspergillosis study, a prospective cohort study of adult haemato-oncology patients undergoing HSCT or chemotherapy, have baseline and fortnightly follow up serum samples profiled for 30 inflammatory cytokines using multiplex bead immunoassays by Luminex 100™ instrument. The cytokines measured were: EGF, Eotaxin, FGF, G-CSF, GM-CSF, HGF, IFN-α, IFN-γ, IL-1RA, IL-1β, IL-2, IL-2R, IL-4, IL5, IL6, IL7, IL-8, IL-10, IL-12p40/p70, IL-13, IL-15, IL-17, IP-10 (CXCL10), MCP-1, MIG, MIP-1α, MIP-1β, Rantes, TNF-α and VEGF.
The first hundred patients enrolled with sufficient follow up data were included in this initial analysis. The median (range) age was 52.5 (19-73) years and M/F ratio was 58/42. The main diagnosis were AML/MDS (40), Myeloma (23), NHL (17) and aplastic anaemia (9) treated by allogeneic HSCT (43), autologous HSCT (32), chemotherapy (20), and immunosuppressive therapy (5). The diagnosis of invasive fungal infection was based on the revised 2008 EORTC/MSG criteria. The incidence of proven and probable infection was 17% and possible infection accounted for 12%. Eight patients were excluded from analysis because of lack of proper baseline sample prior to starting chemotherapy/transplant or had infective episodes that proved to be due to IA. Using a longitudinal logistic regression model (R2= 0.4355, p<0.001) and using each patient as a cluster from baseline to follow-up periods and adjusting for age, sex, underlying diagnosis and treatment received, the following were found to be statistically significantly different between those with proven/probable IA compared to those patients with no evidence of IA: lower IL-10 (P= 0.042), lower IL-12 (P=0.017), higher IL-6 (P=0.001), lower IL-15 (P= 0.026), and higher CXCL-10 (P=0.046). Age correlated significantly with IA (P= 0.014) but not gender (P=0.693).
This preliminary data suggests that there is a significant difference in the cytokine profile between patients with proven/probable IA compared to those with no evidence of fungal infection. Further analysis will be performed on the rest of the cohort to confirm this.

Disclosures:
No relevant conflicts of interest to declare.
The Evolution Between 2001 and 2010 In the Uk Costs of Resolving a Mild to Moderate Bleeding Episode with Pd-aPCC Versus rFVIIa In Haemophilia A Patients with inhibitors.
Authors: Sewpaul Paresh , Ashley Donna , Riley Paul 
Published: October 2019

Abstract
Abstract 1518

Introduction:
Haemophilia A is a rare inherited bleeding disorder characterised by spontaneous or trauma-related bleeding, most commonly into the joints, leading to pain, swelling and limited movement. Some 30–50% of patients with haemophilia A develop inhibitors to their standard treatment, comprised of FVIII concentrates. There are two bypassing agents used for the management of bleeding episodes in patients with haemophilia A with inhibitors in the UK: recombinant factor VII (rFVIIa, NovoSeven®) and plasma-derived activated prothrombin complex concentrate (pd-aPCC, Feiba®).

Objective:
A systematic review of the cost-effectiveness of pd-aPCC versus rFVIIa was published in 2003. Since the analysis, costs of bypassing agents in the UK have changed significantly (pd-aPCC +30% from ≤0.57/U to ≤0.74/U; rFVIIa -11% from ≤0.51/mcg to ≤0.46/mcg). The present study examines the evolution in costs of resolving a mild to moderate bleeding episode with treatment initiated outside hospital.

Methods:
A decision analytic model estimated the expected costs and outcomes of resolving a mild-moderate bleeding episode in patients with haemophilia A with inhibitors. The model compared three treatment regimens in patients with a mean weight 70kg. Each regimen comprised first-, second- and third-line treatment: (1) pd-aPCC-pd-aPCC-rFVIIa; (2) pd-aPCC-rFVIIa-rFVIIa; and (3) rFVIIa-rFVIIa-rFVIIa. Efficacy and dosing of pd-aPCC and rFVIIa were estimated from the published literature, with rFVIIa assumed to resolve 92% of mild-moderate bleeds when used as first and second line treatment and pd-aPCC resolving 79% and 88% of mild-moderate bleeds when used first and second line respectively. Patients whose bleeding episodes were not resolved with first-line treatment were admitted to hospital for second- and third-line treatment. Costs included in the economic model were bypassing agent costs and hospitalisation costs.

Results:
The different treatment regimens result in different total costs for the resolution of a single mild-moderate bleeding episode with up to three lines of treatment: (1) GBP 13,542 (EUR 15,180); (2) GBP 12,985 (EUR 14,556); and (3) GBP 8,569 (EUR 9,605). Since 2001, the costs of regimens 1 and 2 have increased by 26% and 18%, but regimen 3 has decreased by 11% in the UK.

Conclusion:
Divergence in the price of pd-aPCC and rFVIIa since 2001 has increased the cost-effectiveness of rFVIIa. The results reinforce the fact that effective first-line treatment with rFVIIa results in lower overall treatment costs due to a reduced need for further treatment and associated hospitalisation costs. Adopting rFVIIa as first-line treatment is cost-saving and more effective compared to reserving rFVIIa as a second- or third-line treatment option.

Disclosures:
Sewpaul: Novo Nordisk : Employment. Ashley:Novo Nordisk : Employment. Riley:Novo Nordisk Ltd: Employment.
A Cost-Utility and Budget Impact Analysis of Allogeneic Hematopoietic Stem Cell Transplantation for Severe Thalassemic Patients In Thailand.
Authors: Hongeng Suradej , Pakakasama Samart , Sirachainan Nongnuch , Chuansumrit Ampaiwan 
Published: October 2019

Abstract
Abstract 1536

Background:
Hematopoietic stem cell transplantation (HSCT) is the only curative treatment available to severe thalassemic patients. The treatment, however, is very costly, particularly in the context of low and middle income countries, and no studies have been carried out to explore its economic justifiability. This study aimed to estimate the cost-utility of HSCT compared with blood transfusions combined with iron chelating therapy (BT-ICT) for severe thalassemia in Thailand, and to investigate the affordability of HSCT using a budget impact analysis.

Methods:
A Markov model was used to estimate the relevant costs and health outcomes over the patients’ lifetimes taking a societal perspective as recommended by Thailand's health technology assessment guidelines. All future costs and outcomes were discounted at a rate of 3% per annum. Primary outcomes of interest were lifetime costs, quality adjusted life years (QALYs) gained, and the incremental cost-effectiveness ratio (ICER) in Thai baht (THB) per QALY gained.

Results:
Compared to BT-ICT, the incremental cost-effectiveness ratio increased with patient age from 80,700 to 183,000 THB per QALY gained for related HSCT and 209,000 to 953,000 THB per QALY gained for unrelated HSCT among patients aged 1 to 15 years (US$1= 34 THB). The governmental budget impact analysis showed that providing 200 related HSCT to patients aged 1 to 10 years, in accordance with the current infrastructure limitations, would initially require approximately 90 million additional THB per year.

Conclusions:
At a societal willingness to pay of 100,000 THB per QALY gained, related HSCT was likely to be a cost-effective and affordable treatment for young children with severe thalassemia in Thailand.

Disclosures:
No relevant conflicts of interest to declare.
Multiple Apoptotic Defects In Hematopoietic Cellsfrom Mice Lacking Lipocalin 24p3.
Authors: Devireddy L.R. , Liu Zhuoming , Ciocea Alieta , Yang Amy , Wang Zhengqi , Bunting Kevin D. , Green Michael 
Published: October 2019

Abstract
Abstract 1560
The lipocalin mouse 24p3 has been implicated in diverse physiological processes including apoptosis, iron trafficking, development and innate immunity. Studies from our lab as well as others demonstrated the pro-apoptotic activity of 24p3 in a variety of cultured models. However, a general role for the lipocalin 24p3 in the homeostasis of the hematopoietic system has not been tested in vivo. To study the role of 24p3 in apoptosis, we derived 24p3 null mice on 129 SVE and C57BL/6 genetic backgrounds, which enabled us to test, for the first time, the in vivo role of 24p3 without any confounders. We find that homozygous 24p3-/- mice have apoptotic defects in several hematopoietic lineages, including neutrophils, cytokine-dependent mast cells, thymocytes and erythroid cells. The progressive accumulation of lymphoid, myeloid and erythroid cells in 24p3-/- mice demonstrate the importance of 24p3 in the regulation of homeostasis of hematopoietic cells in adults. Thymocytes isolated from 24p3 null mice displayed resistance to apoptosis-induced by Dexamethasone. In addition, Dexamethasone-induced apoptosis is also reduced in 24p3-/- mice. Collectively, these results indicate that 24p3 is an important target gene involved in GC-mediated apoptosis of lymphocytes and other hematopoietic cell types. Finally, our results also indicate that the genetic background of mice can modulate the effects of 24p3 deficiency. In summary, the results presented here, in conjunction with those of previous studies, reveal 24p3 as a regulator of the hematopoietic compartment with important roles in normal physiology and disease progression.

Disclosures:
No relevant conflicts of interest to declare.
IFNy Regulates the Balance Between Monocyte and Neutrophil Production During Immune Activation.
Authors: de Bruin Alexander M. , Touw Ivo , Nolte Martijn A. 
Published: October 2019

Abstract
Abstract 1562
Recruitment of the appropriate cells from the innate immune system to sites of infection is essential for the defense against pathogens. Depending on the type of invading pathogen, infection induces a rapid release from innate immune cells from the bone marrow, followed by an increased production of those myeloid cells that are most suitable to assist the ensuing immune response in the rapid eradication of the pathogen. However, it is thus far poorly understood what the cellular and molecular mechanism is that underlies this change in hematopoiesis.
Using a mouse model with increased numbers of IFNγ-producing T cells in the bone marrow, we have previously found that IFNg plays an important role in the production of myeloid cells and can directly inhibit the formation of eosinophils (De Bruin et al., Blood. 2010 Jun 29). Here we demonstrate that IFNg also skews the balance between monocyte and neutrophil production in the direction of the monocytes. Increased monocyte production was also observed in WT mice infected with LCMV, which was IFNg-dependent, as it was not observed in IFNg-deficient mice. Subsequently, we set out to investigate how IFNγ can modulate the balance between monocyte and neutrophil production. We found that IFNγ reduces the proliferation and differentiation of murine hematopoietic progenitors in vitro in response to G-CSF, while M-CSF responses were not inhibited, but even slightly increased. In addition, IFNγ reduces the capacity of GMPs to form granulocyte colonies in semi-solid cultures and increases their ability to form monocyte/macrophage colonies. On a molecular level, we demonstrate that IFNγ induces a strong upregulation of SOCS3 levels and thereby reduces the phosphorylation of STAT3 in response to G-CSF, thus explaining the reduction in granulocyte formation. The expression levels of M-CSF-R and G-CSF-R by GMPs were not affected by IFNγ, but we found that IFNγ does induce the expression of the monocyte-inducing transcription factors PU.1 and IRF8 in these cells. In conclusion, these data demonstrate that IFNγ can direct myelopoiesis in a lineage-specific manner, thereby modulating the production of the appropriate type of innate immune cells required to combat infection.

Disclosures:
No relevant conflicts of interest to declare.
Mastl Kinase Gene Disruption Causes Embryonic Lethality.
Authors: Johnson Helen Jan , Davizon Pavel D , Lopez Jose A. , Gilligan Diana M. 
Published: October 2019

Abstract
Abstract 1567
Microtubule-associated serine/threonine like kinase (MASTL kinase) was originally identified by genetic linkage as the probable mutant gene responsible for the platelet phenotype in a family with autosomal-dominant thrombocytopenia. MASTL kinase is the mammalian ortholog of Drosophila Greatwall kinase, which is required for cell cycle regulation. Affected members of the thrombocytopenic family carried a mutant MASTL kinase allele with a single nucleotide change that converted a glutamic acid codon to one specifying aspartic acid at amino acid 167 of the protein; no unaffected members of the family carried the mutant allele. Affected family members had a 60% reduction in the numbers of circulating platelets and megakaryocytes that were less mature and less polyploid than normal megakaryocytes. We have sought to determine how MASTL kinase affects platelet production and circulation by generating a strain of mice deficient in MASTL kinase. For this, we obtained embryonic stem (ES) cells containing a gene trap mutation within the murine Mastl gene from the Mutant Mouse Regional Resource Center of the National Center for Research Resources (MMRRC, University of California, San Diego). The mutation was generated by an insertional disruption, and the resulting mutant allele carries a beta–galactosidase/neomycin fusion expression cassette within the fourth intron of the Mastl kinase gene. Chimeric animals were bred and their offspring were genotyped by Southern blotting, confirming germ-line transmission. F1 heterozygote offspring were produced and appear developmentally normal and healthy, with platelet counts indistinguishable from those of their wild-type littermates. We have yet to observe a single weaned animal that is homozygous for the mutant allele in the F1 mice, indicating that MASTL kinase deficiency results in embryonic lethality. We observed decidual swellings at 13.5 days post coitus (dpc), which contained no traces of either embryos or yolk sac membranes. While this has made it impossible to genotype these malformed embryos, it does indicate that the embryos are viable to 3.5–5.5 dpc and are able to implant within the uterine horn. This unexpected phenotype demonstrates a significant and previously unknown role for Mastl kinase in embryonic development. We hypothesize that Mastl kinase may be involved in regulating cell differentiation during embryogenesis. In terms of role of MASTL kinase in familial thrombocytopenia, the mutant animals have allowed us to conclude that the thrombocytopenic syndrome is very unlikely to be the result of haploinsufficiency of MASTL kinase because heterozygous animals have normal platelet counts. Because of the dominant nature of the syndrome, this suggests that the mechanism involves either gain-of-function of the mutant allele or a dominant-negative inhibition of MASTL function specific to the megakaryocyte, two possibilities we are examining.

Disclosures:
No relevant conflicts of interest to declare.
Heat Shock Protein 47: A New Platelet Collagen Receptor
Authors: Kaiser William J , Sage Tanya , Sasikumar Parvathy , Kemp Frederick , Pugh Nicholas , Dobson Laura , Holbrook Lisa , Gibbins Jonathan M. 
Published: October 2019

Abstract
Abstract 158
We recently reported that Heat shock protein 47 (Hsp47), a well established collagen binding protein, was present on the surface of human platelets. In the current study we demonstrate that anti-Hsp47 antibodies and a small molecule inhibitor of Hsp47 selectively prevent aggregation of platelets induced with collagen fibrils. Inhibition of Hsp47 was also found to reduce the size of thrombi produced upon perfusion of blood under arterial flow conditions over collagen in vitro. Inclusion of Integrilin, to prevent platelet-platelet interactions via fibrinogen, indicated that the reduced size of thrombi was due to fewer direct platelet-collagen interactions. Collagen-induced tyrosine phosphorylation of Syk, an early marker of signalling from the collagen receptor GPVI was unaffected by the Hsp47 inhibitor, suggesting that any contribution to platelet function by Hsp47 may be independent of GPVI-proximal signalling. Surface plasmon resonance analysis of recombinant his-tagged human Hsp47 revealed its ability to interact directly with collagen fibrils, an interaction that was disrupted by the small molecule inhibitor of Hsp47.
Mouse platelets were also found to contain Hsp47, and aggregation induced with collagen was reduced by inhibitors of Hsp47. Infusion of Hsp47 inhibitor into mice increased tail bleeding times and volumes of blood lost, even in the absence of anticoagulant. This effect was likely due to inhibition of platelet function, since the thrombi formed in cremaster muscle arterioles using an intravital laser-injury model of thrombosis were smaller following administration of the Hsp47 inhibitor.
Together these data indicate Hsp47 to function on the platelet surface as a collagen receptor that potentially represents a new target for antithrombotic therapy.

Disclosures:
No relevant conflicts of interest to declare.