bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling for Cure with Total Therapy (TT) Trials for Newly Diagnosed Multiple Myeloma (MM): Let the Math Speak.
Authors: Barlogie Bart , Shaughnessy John D , Anaissie Elias , van Rhee Frits , Alsayed Yazan , Waheed Sarah , Nair Bijay , Grazziutti Monica , Bolejack Vanessa , Crowley John 
Published: October 2019

Abstract
Abstract 744

Background:
Despite enormous progress over the past decade, the “cure” word has been avoided in the context of myeloma therapy. The observation of ∼90% sustained complete response (CR) with Total Therapy 3 (TT3) among the 85% with gene expression profiling (GEP)-defined low-risk disease prompted this investigation of modeling for cure in all Total Therapy (TT) trials.

Methods:
Kaplan-Meier plots of event-free survival (EFS) and complete response duration (CRD) were examined to determine whether cure fractions (CF) could be predicted from the presence of a plateau; in the case of CRD, estimating CF required the multiplication by the CR rate. Median follow-up times with TT1 (n=231), TT2 (n=668) and TT3 (n=303) were 15.7yr, 7.4yr and 4.2yr. CF estimates were examined overall and according to prognostically relevant baseline variables such as cytogenetic abnormalities (CA), available for all trials, and GEP, available to subsets of patients on TT2 and TT3. Relative survival ratios were computed by comparing patient survival with expected survival of a comparable group from the general population.

Results:
With TT1, significant CF estimates existed for EFS (6.4%) and CRD (6.0%). With TT2, significant CF estimates were noted for EFS with both control (9.9%) and thalidomide arms (23%). With TT3, CRD-derived CF for low risk patients was high at 55% (p<0.0001). Relative survival ratios revealed progressively earlier normalization of such ratios, apparent at 17yr in TT1, 10yr in TT2 and a remarkably short 5yr in TT3.

Conclusion:
Cure is a realistic goal of myeloma therapy whether or not CR was documented as evidenced through long-term follow-up in TT1. The observation of a high CF value of 55% in TT3 for low-risk myeloma with only 4.2yr of follow-up attests to the dramatically greater efficacy of this trial comprising both bortezomib and thalidomide. Therefore, cure should be an objective of contemporary trials for low-risk myeloma while intensive searches for more effective therapy are urged to improve outcomes for high-risk disease.

Disclosures:
van Rhee: Genzyme Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.
MCL1 Haploinsufficiency Protects Mice From MYC-Induced Acute Myeloid Leukemia.
Authors: Xiang Zhifu , Luo Hui , Payton Jacqueline E. , Wartman Lukas D , Ritchey Julie , DiPersio John F. , Ley Timothy J. , Opferman Joseph T , Tomasson Michael 
Published: October 2019

Abstract
Abstract 764
Anti-apoptotic Bcl2 family genes have been implicated in the pathogenesis of acute myelogenous leukemia (AML), but the functional significance and relative importance of individual proteins (i.e. BCL2, BCL-XL, MCL1) remains poorly understood. We examined the expression of BCL2, BCL-X and MCL1 in primary human hematopoietic subsets and in leukemic blasts from AML patients, and found MCL1 transcripts were consistently expressed at high levels in all samples tested (100%, n=111). Mcl1 protein was also consistently expressed at high levels in myeloid leukemic blasts in a murine Myc-induced AML model, and we used this model to test the hypothesis that Mcl1 facilitates AML development by allowing myeloid progenitor cells to evade oncogene-induced cell death. Activation of Myc for seven days in vivo substantially increased myeloid lineage cells while hematopoietic stem, progenitor and B-lineage cells were depleted. Haploinsufficiency for Mcl1 (Mcl1flox/null) abrogated the development of AML (median survival 56 days vs. not reached), and deletion of a single allele of Mcl1 from fully transformed AML cells significantly prolonged the survival of transplanted mice. In contrast, the rapid lethality of disease (median survival 25 days) was restored by co-expression of Bcl2 with Myc in Mcl1flox/null cells. Together, these data demonstrate a critical and dose-dependent role for Mcl1 in AML pathogenesis and suggest that Mcl1 may be an ideal therapeutic target in patients with de novo AML.

Disclosures:
DiPersio: Genzyme: Honoraria.
Annexin II Interactions with the Annexin II Receptor Enhance Multiple Myeloma Cell Adhesion and Growth In the Bone Marrow Microenvironment
Authors: D'Souza Sonia , Kurihara Noriyoshi , Shiozawa Yusuke , Taichman Russell , Galson Deborah , Roodman David 
Published: October 2019

Abstract
Abstract 130
Multiple myeloma (MM) is an incurable B-cell malignancy that develops in the bone marrow. The marrow microenvironment plays a critical role in supporting homing, lodging, and growth of MM cells by activating signaling pathways in both MM and bone marrow stromal cells (BMSC). Recently, we identified that annexin II (AXII) is involved in prostate cancer cell lodgment to the bone marrow as well as mobilization of prostate cancer cells to the peripheral blood. AXII expressed on stromal cells supports prostate cancer cell lodgment via the annexin II receptor (AXIIR) on prostate cancer cells. We hypothesized that MM cells use a similar mechanism to lodge and grow in the bone marrow. We demonstrated using bio-AXII, that MM cell lines and primary MM cells from 8 MM patients express the AXIIR protein. In addition, MM cells adhered significantly better to BMSC from wild-type mice than from AXII−/− mice. Knockdown of AXIIR by siRNA in MM.1S and ANBL.6 MM cells resulted in decreased AXII binding and decreased adherence of MM cells to KM101 stromal cells and BMSC from wild-type mice. Furthermore, the adhesion of MM.1SsiCon and MM.1SsiAXIIR cells to AXII−/− BMSC was similar indicating that AXII produced by MM cells does not act in an autocrine manner on attachment. Therefore, our studies indicate the importance of the interaction of AXII on BMSC with AXIIR on MM cells in adhesion. Our studies also revealed a role for AXIIR signaling on MM cell growth. We found that soluble AXII was released by osteoclasts into their conditioned media and stimulated the growth of MM cells via ERK1/2 and AKT phosphorylation in MM cells. AXII stimulation of MM cell growth was blocked by AXII antibody or by blocking ERK1/2 and AKT phosphorylation. In contrast, endogenous AXII produced by MM.1S cells did not stimulate MM.1S cell growth suggesting that autocrine AXII/AXIIR signaling in MM.1S cells does not contribute to MM.1S cell growth. Taken together, these results suggest that AXII/AXIIR axis in the myeloma microenvironment plays an important role in MM cell adhesion and growth through production of AXII by BMSC and osteoclasts.

Disclosures:
No relevant conflicts of interest to declare.
Discovery of a New Signaling Complex Based on Spinophilin That Regulates Platelet Activation In Vitro and In Vivo
Authors: Ma Peisong , Cierniewska Aleksandra , Signarvic Rachel , Sinnamon Andrew , Cieslak Marcin , Stalker Timothy J. , Brass Lawrence F. 
Published: October 2019

Abstract
Abstract 161
Platelets play an essential role in hemostasis, but excessive platelet responses to vascular injury or disease can be catastrophic. We have recently reported that members of the RGS protein family can modulate platelet responses to injury by limiting the duration of G protein-dependent signaling initiated by platelet agonists. Here we show that platelets contain a previously-unrecognized regulatory complex comprised of the 130 kDa scaffold protein, spinophilin (SPL) with at least two RGS proteins (RGS10 and RGS18) and the protein tyrosine phosphatase, SHP-1. In resting platelets, this complex is phosphorylated on spinophilin residues Y398 and Y483. Mutating both tyrosines to phenylalanine inhibits the binding of SHP-1 to spinophilin. Platelet activation by thrombin or thromboxane A2, but not ADP or collagen, stimulates a transient increase in spinophilin-associated SHP-1 tyrosine phosphatase activity and causes dephosphorylation and decay of the SPL/RGS/SHP-1 complex. Conversely, blocking SHP-1 phosphatase activity in platelets or omitting SHP-1 in transfected CHO cells inhibits dephosphorylation of spinophilin and prevents dissociation of the SPL/RGS/SHP-1 complex. While we have shown previously that inhibiting interactions between G proteins and RGS proteins produces a gain of function in platelets, knocking out spinophilin in mice inhibits platelet aggregation. This aggregation defect does not occur with all agonists, but is selective for those that are able to trigger decay and dephosphorylation of the SPL/RGS/SHP-1 complex. In addition to inhibiting platelet aggregation in vitro, the spinophilin knockout delays carotid artery occlusion in vivo following application of FeCl3 and reduces platelet accumulation following laser injury in cremaster muscle arterioles. Underlying these effects of the knockout is a decrease in Rap1 activation, an event that supports integrin activation, and attenuation of the cAMP increase otherwise caused by endothelial PGI2. Collectively, these observations show for the first time that a regulatory complex based on spinophilin helps to regulate platelet responses to injury and suggest that it does this by sequestering RGS proteins in resting platelets and releasing them after activation begins. Dissociation of the SPL/RGS complex is regulated by an agonist-induced increase in the activity of SHP-1 associated with spinophilin.

Disclosures:
No relevant conflicts of interest to declare.
Exhaled Carbon Monoxide as a Marker of Hemolysis In Transgenic Mouse Models of Sickle Cell Anemia.
Authors: Belcher John D , Nguyen Julia , Furne Julie , Vineyard Julie , Beckman Joan Denise , Marker Paul H , Hebbel Robert P , Levitt Michael D , Vercellotti Gregory M 
Published: October 2019

Abstract
Abstract 1642

Sickle cell disease is characterized by recurring episodes of hemolysis and painful vasoocclusion, which leads to ischemia-reperfusion injury and organ damage. Recently, the roles of heme-induced oxidative stress, nitric oxide consumption, endothelial cell activation, and inflammation in sickle cell disease have been recognized, in part because of the development of transgenic murine models of this condition. These mouse models provide insights into the pathophysiology of human sickle cell disease and the development of new therapeutic approaches. However, hemolytic rates and disease severity vary considerably between mouse models. Ferrous (Fe2+) hemoglobin (Hb) is easily oxidized in circulation to ferric (Fe3+) Hb, which readily releases free heme. Free heme is degraded by heme oxygenase which produces carbon monoxide (CO) as a byproduct. Endogenous CO production has been used as a measure of in vivo hemolysis in humans and mice, but there have been no reports of endogenous CO production in sickle mouse models. VCO was measured in sickle mouse models using a previously described rebreathing technique t (Levitt et al. J Lab Clin Med 113:241-247). Expired CO levels were highest in Hb-S knock-in Townes-SS sickle mice, almost 7-fold higher than normal control Townes-AA mice (p<0.05). Expired CO also was significantly (p<0.05) higher in HbS-BERK mice compared to normal control HbA-BERK. Injection of phenylhydrazine or hemin into normal C57BL/6 mice also raised expired CO levels 24 hours after injection (p<0.05). Expired CO levels were not significantly higher than controls in the New York, S+S-Antilles, het-BERK and Townes-AS models. These data confirm that hemolytic rates differ markedly between models. Additional data will be presented on the effects of inhaled CO on expired CO and the hemolytic rate in the Townes-SS model.

Disclosures:
Belcher: Sangart: Consultancy, Research Funding. Vercellotti:Sangart: Consultancy, Research Funding.
Novel Influenza A (2009/H1N1) Infection In Patients with Hematological Malignancies During the 2009 Pandemic Outbreak: Early Antiviral Treatment Improves Survival
Authors: Vigil Karen Joan , Adachi Javier A , Jiang Ying , Popat Uday , Mahani Mohsen Ghadimi , Granwehr Bruno P , Gaeta Susan , Malik Imrana , Champlin Richard , Raad Isaam I , Chemaly Roy F 
Published: October 2019

Abstract
Abstract 1731

Novel influenza A (2009/H1N1) is a new influenza virus of swine origin. The epidemiology, morbidity, and mortality are different from those of seasonal influenza viruses, with this new strain affecting younger patients. We describe the risk factors and outcome associated with 2009/H1N1 Influenza A (herein H1N1) infection in patients with hematological malignancies.
Among the first 69 cases of H1N1 infections in cancer patients occurring between April 17 to October 21, 2009, 54 (78%) had hematological malignancies (leukemia or lymphoma) and 22 (41%) had undergone hematopoietic stem cell transplantation. H1N1 strain was the only influenza A virus reported in Texas during the study period.
Most of the patients with H1N1 and hematological malignancy were old (50% were 50 years of age or older), moderately to severely immunosuppressed (67%) and obese (39%), High rates of hospitalization (48%), pneumonia (24%), and death (11%) were encountered in our patients. The majority of patients who developed pneumonia due to H1N1 were on immunosuppressive therapy at the time of diagnosis (11 (85%) of 13 cases with pneumonia vs. 20 (49%) of 41 with upper respiratory infection [URI], p=0.02). Delay in initiation of oseltamivir from onset of symptoms was the only significant predictor of progression to pneumonia (7 days in patients with pneumonia vs. 1 day in patients with URI, p=0.002) and of mortality (9 days in patients who died vs. 1 day in those who survived, p=0.003). The development of H1N1 pneumonia was significantly associated with higher mortality (p<0.001). Starting antiviral therapy within 72 hours of onset of symptoms was significantly associated with better survival (p=0.05, Figure 1) and with a trend towards less progression to pneumonia (p=0.07).
Novel influenza A (2009/H1N1) infection affected older, obese, and moderately to severely immunosuppressed patients with hematologic malignancies. Early initiation of antiviral therapy may impact outcome with less progression to pneumonia and may improve survival in this immunosuppressed patient population.
———— Patients who received antiviral therapy ≤ 72 hours after onset of symptoms
——–—- Patients who received antiviral therapy >72 hours after onset of symptoms
○ ○ ○ ○ ○ ○ Censored observations

Disclosures:
No relevant conflicts of interest to declare.
Failure of Plasmacytoid Dendritic Cells to Drive Functional Regulatory T Cell Differentiation In Human Disease
Authors: Hart Derek NJ , Ju Xinsheng , Ding Yitian , Azlan Maryam , Clark Georgina 
Published: October 2019

Abstract
Abstract 1746
Dendritic cells (DC) initiate and direct immune responses. Plasmacytoid DC (pDC) produce type I interferon (IFN) in response to viral and/or bacterial challenge and have been implicated in the pathogenesis of a number of chronic inflammatory disesases. pDC also induce the generation of regulatory T cells (Treg) from naïve CD4+ T cells. Treg control the balance of T cell responses and maintain immune homeostasis so the primary contribution of pDC to Treg induction in disease states is an important question. Psoriasis is a common chronic inflammatory skin disease associated with over expression of type I IFN–inducible genes in patients and this response apparently overwhelms any pDC regulatory contribution. The numbers of peripheral blood Treg cells and pDC are decreased in psoriatic patients but why pDC fail to generate a significant counterbalancing Treg response in psoriasis is unknown.
We compared purified blood pDC from normal donors with those from psoriasis donors, who were well and either untreated or only on topical therapy at the time of donation, for their ability to induce Treg. Freshly purified pDC from both normal and psoriasis donors lacked CD80 and CD83, but expressed similar amounts of HLA-DR and CD86. pDC from healthy psoriasis donors, when stimulated with TLR9 ligands, secreted high amounts of IL-6, expressed little surface inducible costimulator-ligand (ICOS-L, CD275) and exhibited low indoleamine 2, 3–dioxygenase (IDO) enzymatic activity compared to normal controls. To assess the capacity of pDC from psoriasis patients to induce the differentiation of naïve CD4+ T cells, we performed sequential co-culture experiments. In these, TLR-9 stimulated pDC from psoriasis patients failed to induce the differentiation of naïve CD4+ T cells into IL-10 secreting, functional regulatory T cells. In addition, the CD4+CD25+ T cells resulting from co-culture with psoriasis pDC were less effective in suppressing an allogeneic MLR. In contrast, the pDC from psoriasis patients, unlike those from normal donors, induced T cells capable of secreting IL-22. Further investigation as to why psoriatic pDC failed to induce Treg showed that the differentiated CD4+CD25+ (CD127-) T cells from these co-cultures expressed dramatically less Foxp3 following priming with psoriatic pDC. Exogenous kynurenine, to replace IDO restored the ability of psoriatic pDC to induce Treg.
In conclusion, our data demonstrate that aberrant pDC produce dysfunctional Treg development in psoriasis and highlights the contributions of IL-6/IDO/CD275/IL-22 to the disease pathogenesis. This insight is now driving studies in other disease states, notably graft versus host disease, where our focus is on manipulating DC for therapeutic benefit.

Disclosures:
No relevant conflicts of interest to declare.
The Effect of Vitamin D Supplementation On Calcium Excretion in Thalassemia
Authors: Balachandar Sadana , Randolph Rachel , Kleinert Dorothy A. , Sheth Sujit , Giardina Patricia , Vogiatzi Maria G 
Published: October 2019

Abstract
Abstract 1029

Purpose of study:
Transfusion dependent thalassemia (TM) patients are routinely supplemented with vitamin D due to their increased risk of developing osteoporosis. Recent studies from North America have found that these patients have high rates of vitamin D “deficiency” and “insufficiency,” despite supplementation. The amount of vitamin D supplementation required to raise serum 25 hydroxy-vitamin D (25-OHD) to optimal levels is not known in these patients. Recent studies have linked 25-OHD levels to hypercalciuria and nephrolithiasis in patients with TM. The purpose of this study is to determine the effect of various doses of vitamin D supplementation on vitamin D stores and calcium excretion in TM patients.

Description of project:
Prospective, single-blind, placebo-controlled study of TM patients followed in the transfusion center at Weill Cornell/New York Presbyterian Hospital. Patients with 25-OHD concentrations between 15–29 ng/mL were eligible for this 3-month study. Subjects were assigned in a block type of enrollment to the “high dose” equivalent of 2,000 IU of vitamin D per day versus placebo.

Results:
14 subjects were enrolled, with 8 assigned to the “high dose” group and 6 assigned to the placebo group. The “high dose” group consisted of 6 females, aged 15.2–45.5 years with an average baseline 25-OHD level of 22.4 ng/mL (15–26). The “placebo” group consisted of 4 females, aged 22.5–45.7 years with an average baseline 25-OHD level of 19.8 ng/mL (16–24). After the 3 month study period, hypercalciuria developed more frequently in those treated in the “high dose” group. In the placebo group, hypercalciuria was noted in 1/6 (16.7%) spot urine calcium/creatinine tests and 0/3 (0%) 24 hour urine calcium estimations. In the “high dose” group, the corresponding number of patients based on the same methods of testing were 5/8 (62.5%) and 2/5 (40%). No episodes of hypocalcemia, hypercalcemia or nephrolithiasis occurred in either group.

Conclusion:
Our findings suggest that “high dose” vitamin D supplementation results in higher rates of hypercalciuria in TM patients. Further studies are necessary to determine the optimal dose of vitamin D supplementation to minimize the risk of osteoporosis while preventing nephrolithiasis in TM patients.

Disclosures:
No relevant conflicts of interest to declare.
NK Cell Subsets Isolated From Human Thymus Differ From Peripheral Blood NK Cells in Their Cytotoxic and Cytokine Secreting Capability
Authors: Krieg Stephanie , Koehler Wolfgang , Heidkamp Gordon , Schneider Julia , Ganss Franziska , Purbojo Ariawan , Mackensen Andreas , Cesnjevar Robert , Dudziak Diana , Ullrich Evelyn 
Published: October 2019

Abstract
Abstract 1053
Until recently, studies on human NK cells have been mainly focused on NK cells from peripheral blood. Little is known about the functional role of human NK cell subpopulations in different lymphoid organs. We therefore aimed to characterize the phenotypical and functional profile of human NK cell subsets from different organs with a special focus on early forms of thymic NK cells in comparison to mature peripheral blood NK cells from adults and children.
Human NK cells can be classified according to the expression of CD56 and CD16 into immunoregulatory, cytokine producing CD56highCD16dim and mature cytotoxic CD56dimCD16high NK cells. It is widely accepted that NK cell development takes place in secondary lymphoid tissues leading to the maturation from CD56highCD16dim into CD56dimCD16high NK cells. Additionally, it has been reported that thymic CD34+ cells can differentiate into NK cells under treatment with IL-2 in vitro.
Here we report for the first time on a different composition of human NK cell subpopulations in the thymus compared to peripheral blood. NK cells isolated from the thymus did not only express lower levels of CD56 but also showed a different ratio of CD16high/CD16dim NK cells compared to peripheral blood NK cells. Extensive phenotypical analysis revealed significant alterations in expression patterns of killer-cell immunoglobulin-like receptors, natural cytotoxicity receptors and other maturation or differentiation markers on thymic NK cells. Functional analyses showed that the whole NK cell population from thymus as well as from peripheral blood of young children produced only low amounts of IFN-γ compared to adult peripheral blood NK cells.
Furthermore, functional assays of sorted NK cell subsets revealed important differences of CD16high and CD16dim thymic NK cells. Upon stimulation with IL-2 +/− K562 tumor cells, thymic CD16 high NK cells gain cytokine producing capacity, while CD16dim develop a tumor killing capacity comparable to naive peripheral blood NK cells.
In summary, this comparative study of NK cell subsets provides important information on the development and function of NK cells that may be of great value for the optimization of cellular immune therapy.

Disclosures:
No relevant conflicts of interest to declare.