bluuebunny/crossref_metadata_2025 huggingface dataset:
Victims’ collective memory and transitional justice in post-conflict Colombia: The case of the March of Light
Authors: Tamayo Gomez Camilo
Published: October 2019

The construction of victims’ collective memory in post-conflict Colombia is crucial to understanding the violent past and its social consequences. This article argues that victims’ initiatives, such as the March of Light, are facilitating an active role of local communities in the configuration of their memory regimes after the war. Addressing a participative action research approach, this article’s significance rests in the idea that Colombian victims’ groups from Eastern Antioquia are establishing three particular types of collective memory developing the March of Light every week. It establishes that this effort is a powerful instrument to claim truth and reparation in Colombia, helping the ongoing process of transitional justice in the country. It demonstrates that the tension between official and non-official narratives of collective memory is an essential part of transitional justice scenarios in which the clash of values defines positions of power, visibility and recognition inside contexts of social transition.
Reprogrammed Adult Human Endothelium into Hematopoietic Stem Cells Yields Functional T Cells In Vivo
Authors: Barcia Durán José Gabriel , Lu Tyler M. , Lis Raphael , Rafii Shahin
Published: October 2019

During development, the hematopoietic stem cells that go on to populate the bone marrow and give rise to all blood cell lineages emerge from a specialized endothelial subpopulation. We have previously harnessed this vestigial identity to achieve the direct conversion of adult endothelial cells (ECs) into long-term engraftable hematopoietic stem and progenitor cells (rEC-HSPCs); however, to date, we had only detected and characterized functional T cells that result from the transplantation, engraftment, and differentiation of mouse rEC-HSPCs (Lis, R. et al., Conversion of adult endothelium to immunocompetent haematopoietic stem cells. Nature, 545:439-445. 2017).

We first reprogrammed adult human endothelium using lentiviral vectors encoding FOSB, GFI1, SPI1, and RUNX1 (FGRS) under constitutive promoters and an inductive vascular niche (Sandler V. et al., Reprogramming of human endothelium into hematopoietic cells requires vascular niche induction. Nature, 511:312-8. 2014). The resulting rEC-HSPCs maintained exogenous expression of the four transcription factors for over 20 weeks post-transplantation into immuno-compromised NSG mice. Constitutive expression of Spi1, however, has been shown to hinder lymphoid differentiation in vivo by blocking T lymphopoiesis (Anderson, M. et al. Constitutive expression of PU.1 in fetal hematopoietic progenitors blocks T cell development at the pro-T cell stage. Immunity 16:285-296. 2002). In addition, mice of the NSG strain cannot educate native B or T cells to maturity. Our system of constitutive exogenous FGRS expression was therefore unable to confer transplanted immuno-compromised mice the ability to generate an adaptive immune response.

Here, we obtained human rEC-HSPCs making use of (i) doxycycline-inducible vectors to temporarily overexpress FGRS and (ii) transgenic substrains of NSG mice (one carrying human stem cell factor, granulocyte/macrophage colony-stimulating factor, and interleukin 3; the other, human major histocompatibility complex class I as well as beta-2 microglobulin) for transplantation assays. We show that human rEC-HSPCs engraft primary- and secondary-transplanted mice for over a year at levels of up to 20% in the spleen or bone marrow. Engrafted cells differentiate into all blood lineages including phenotypically and functionally mature T cells in the absence of exogenous FGRS expression in vivo. Notably, the resulting T cells undergo TCR rearrangement and are able to clear viral particles one week post-LCMV infection. Functional and phenotypic analyses are presented in juxtaposition with experiments using cord blood-transplanted mice. These results demonstrate that our present direct conversion strategy generates bona fide human hematopoietic stem cells from adult endothelial cells.

Disclosures

Rafii: Angiocrine Bioscience: Equity Ownership.
Positive Stool Cultures Could Predict the Clinical Outcomes of Haploidentical Hematopoietic Stem Cell Transplantation
Authors: Hu Lijuan , Wang Qi , Zhang Xiaohui , Xu Lan-Ping , Wang Yu , Yan Chen-Hua , Chen Huan , Chen Yu-Hong , Liu Kaiyan , Wang Hui , Huang Xiaojun , Mo Xiao-Dong
Published: October 2019

We aimed to identify the impact of stool cultures on clinical outcomes among patients undergoing haploidentical hematopoietic stem cell transplantation (haplo-HSCT) (n=332). Positive stool cultures (PSC group) were observed in 61 patients (18.4%). Enterobacteriaceae in stool specimens was associated with a higher risk of bloodstream infection, and Candida in stool specimens was associated with a higher risk of platelet engraftment failure. The cumulative incidence of non-relapse mortality at 1 year after haplo-HSCT in the PSC group was higher than that of the patients who showed persistently negative stool cultures (NSC group; 22.2% vs. 12.7%, P=0.059). The probabilities of overall survival (71.4% vs. 83.8%, P=0.031) and disease-free survival (69.6% vs. 81.0%, P=0.048) at 1 year after haplo-HSCT were significantly lower for the PSC group than those of the NSC group, particularly for patients who had Candida in their stool specimens. In multivariate analysis, Candida in stool specimens significantly increased the risk of non-relapse mortality and was associated with poorer survival. Our results showed that PSC impacted the clinical outcomes after haplo-HSCT, particularly for those who had Candida in their stool specimens.

Disclosures

No relevant conflicts of interest to declare.
Multi-Omics of Aurora Inhibition Induced Polyploidy Reveals Mechanisms of Disease Relapse in MYC/BCL2-Addicted High Grade B-Cell Lymphoma
Authors: Islam Shariful , Paek Andrew , Hammer Michael , Rangarajan Savithri , Ruijtenbeek Robert , Cooke Laurence , Weterings Eric , Mahadevan Daruka
Published: October 2019

Key Points MYC mediated upregulation of TPX2, KPNA2 and RanGAP1 dysregulate the spindle assembly checkpoint in drug-induced polyploid cells. Drug-induced polyploid cells re-enter cell cycle via multipolar mitosis, fission or budding, a mechanism of disease relapse.

Abstract

Double-hit (DH) or double-expresser (DE) diffuse large B-cell lymphomas (DLBCL) are high-grade B-cell lymphomas that are mostly incurable with standard chemo-immunotherapy due to treatment resistance. The generation of drug-induced aneuploid/polyploid (DIAP) cells is a common effect of anti-DLBCL therapies (e.g. vincristine, doxorubicin). DIAP cells are thought to be responsible for treatment resistance, as they are capable of re-entering the cell cycle during off-therapy periods. Previously (DOI: 10.1158/1535-7163.MCT-17-0089) we demonstrated that combination of alisertib plus ibrutinib plus rituximab can partially abrogate DIAP cells and induce cell death. Here, we provide evidence that DIAP cells can re-enter the cell cycle and escape apoptosis during anti-DLBCL treatment. We also discuss MYC/BCL2 mediated molecular mechanisms that underlie treatment resistance. We isolated aneuploid/polyploid populations (2n-similar, 4n and 8n) of DH/DE-DLBCL cells after treatment with the aurora kinase (AK) inhibitor alisertib. Time-lapse microscopy of single polyploid cells (8n) revealed that following drug removal, these cells divide and proliferate by reductive cell divisions, including multipolar mitosis, meiosis-like nuclear fission and budding. Genomic, proteomic, and kinomic profiling of DIAP cells demonstrated up-regulation DNA damage, DNA replication and immune evasion pathways. In addition, the immune-kinome, AKT/MTorc1/2, and ERK/MAPK pathway are over-represented in 8n cells. Further, MYC-mediates dysregulation of the spindle assembly checkpoints by over-expression of RanGAP1, TPX2 and KPNA2. Multiple mechanisms contribute to DIAP which are amenable to novel therapeutic intervention(s) in MYC/BCL2-addicted high-grade B-cell lymphomas.

Disclosures

No relevant conflicts of interest to declare.
Critical Role of Histone Demethylase Jmjd3 in T Cell Migration
Authors: Fu Chuntang , Li Qingtian , Zou Jia , Xing Changsheng , Yin Bingnan , Lin Meng , Chu Junjun , Yu Jiaming , Wang Rongfu
Published: October 2019

Jmjd3, a histone H3K27 demethylase, is known to play a critical role in macrophage and T cell differentiation, but its role in T cell migration and T cell memory maintenance remains largely unknown. In this study, we show that Jmjd3 deficiency resulted in multiple alterations in T cell migration. Jmjd3 deletion limits CD4+ T cells egress out of the thymus, leading to thymic T-cell accumulation and peripheral lymphoid organ T-cell reduction. Gene profiling analysis of wild-type and Jmjd3-deficient CD4+ T cells identified altered expression of Jmjd3 target genes that correlated with changes in H3K27 and/or H3K4 trimethylation in promoters and gene body regions. The expression of the Jmjd3 target gene Pdlim4 is also regulated by Klf2, which regulates T-cell migration. Thus, our findings identify a novel Jmjd3 target gene, Pdlim4, in CD4+ T cell migration and provide insight into the molecular mechanisms by which Jmjd3 regulates T-cell migration.

Disclosures

No relevant conflicts of interest to declare.
Epigenetic Modifier Mutations in the LL-100 Panel
Authors: Quentmeier Hilmar , Pommerenke Claudia , Drexler Hans G.
Published: October 2019

The NCI-60 human cell line panel, developed for use in drug development comprises sixty human cancer cell lines derived from nine different tissues. Only six cell lines of the NCI-60 were derived from blood cancers. Therefore, most forms and subtypes of leukemia and lymphoma are not represented in the NCI-60 panel. To respond to this apparent gap, we suggest the novel LL-100 panel, 100 leukemia and lymphoma cell lines representing the major leukemia/lymphoma entities, for basic research and drug development.

Whole exome sequencing and RNA sequencing were performed to identify mutations in 100 cell lines. Here we list the 100 cell lines, ordered by subtype and show mutations in epigenetic modifier genes.

We found cell lines with mutations in ASXL1, EZH2, IDH1, TET2 and in DNMT3A. Hitherto, cell line OCI-AML3 was the only human cell line described with a DNMT3A mutation. Twenty-two percent of patients with acute myeloid leukemia contain DNMT3A mutations and the median overall survival with DNMT3A mutations is shorter than without. Most DNMT3A mutations are heterozygous and alter amino acid R882, R882H being the most common DNMT3A mutation in AML. Exogenously mutant murine R878H (equivalent to human R882H) inhibits DNMT3A activity in a dominant negative manner. We describe here that the AML cell line SET-2 carries a heterozygous G to A transition at chr2_25234373 (hg38) which leads to the DNMT3A R882H amino acid substitution. Chip-based methylation analysis revealed that the described DNMT3A targets IRF8, KLF2, HOXA11 and HOXB2 are hypomethylated in cell lines OCI-AML3 (DNMT3A R882C) and in SET-2 (DNMT3A R882H). These data suggest that SET-2 is a novel model cell line for functional analysis of the DNMT3A R882 mutation and a first gain in knowledge through data mining the LL-100 panel.

Disclosures

No relevant conflicts of interest to declare.
Economics of Multiple Myeloma
Authors: Wong Rachel , Tay Jason
Published: October 2019

Background

Multiple myeloma (MM) accounts for about 10% of hematologic malignancies, and the 5-year survival rate of patients diagnosed with multiple myeloma has increased by 14% over the past two decades with median survivals between 29-62 months. Improvements in survival has been attributable to improved therapeutics, representing a significant expenditure within the healthcare system. We seek to quantify the cost for caring for patients with MM from a third-party perspective.

Methods

We conducted a descriptive retrospective cohort costing study using administrative data from the Cancer Measurement Outcomes Research and Evaluations (C-MORE) at the Tom Baker Cancer Centre (TBCC). We identified incident cases of patients diagnosed with symptomatic multiple myeloma between 01 Jan 2002 and 31 Dec 2014. Demographic data were obtained together with their contact points with the healthcare system, including inpatient visits and lengths of stay, outpatient visits diagnostic and treatment visits, as well as medication usage. Using the Alberta Health Hospital Reciprocal Claim Guide and local pharmacy costs at TBCC, we assigned costs to health care utilization for incident cases of MM between our study period. Further, we stratified our data into 3 cohorts: 2002-2005, 2006-2010 and 2011-2014 to better appreciate secular trends.

Results

We identified 806 patients, but excluded 284 patients (35%) due to absence of data. The median duration of follow-up of the remaining cohort was 46 months (range 1-172). The median number of lines of therapy is 2 (range 1-8) with 32% overall enrolled in at least one clinical study. Table 1 details the cohort demographics with an overall survival (OS) of cohort of 55% (median survival of 81 months, 95% CI=68-94). The average cost of care per patient per year is $49,077, with $30,895, $46,333, $69,627 for Cohorts 1, 2 and 3 respectively. Chemotherapy (not including clinical trial medications) costs represents the largest cost-item.

Conclusions

Our study suggests that the survival of patients with MM diagnosed at the TBCC has improved consistent with the literature, but with an increasing cost of care. Despite incomplete administrative data from C-MORE, the current available data could help support health care Administrators better prioritize health care resources.

Table 1. Table 1.

Disclosures

No relevant conflicts of interest to declare.
Atypical Chronic Myeloid Leukemia
Authors: Ashangari Chandralekha , Tumula Praveen K.
Published: October 2019

Introduction: Atypical chronic myeloid leukemia (aCML), BCR-ABL1 negative is a rare myelodysplastic syndromes (MDS)/myeloproliferative neoplasm (MPN) for which no current standard of care exists. We present one of the rare presentations of aCML in an elderly patient.

Case: A 76 year old male presented to the Hematology clinic for consultation after discharge from local hospital for elevated WBC count. Past medical history was significant for COPD, acid reflux, peripheral arterial disease and hypertension. Physical exam was unremarkable. Initial labs were significant for leukocytosis of 30 k/cu mm, anemia with Hb 10 gm/dl, thrombocytosis 695,000 with neutrophilia of ANC 25,200. Peripheral blood was negative for JAK2 V617F and BCR-ABL. Peripheral blood flow cytometry showed granulocytic left shift with 1.5% myeloblasts. Bone marrow biopsy suggestive of hypercellular marrow (100%) with myeloid predominance, atypical megakaryocytes, increased ring sideroblasts (49% of NRBC), increased blasts (5%) and dysgranulopoeisis over all suggestive of Myelodyplastic Syndrome/Chronic Myeloproliferative Disorder (MDS/MPD). Cytogenetics were positive for U2AF1 positive, CSF3R T6181, CSF3R Q776 pathognomonicof atypical CML and negative for BCR-ABL, FLT3. He was considered transplant ineligible. He was started on Azacitadine and is currently receiving 2nd cycle therapy. He is also receiving darbepoeitin periodically to avoid frequent transfusions. He is currently transfusion independent.

Discussion: Increased WBC count (e.g., cutoffs of >40×109/L or 50×109/L), increased percentage of peripheral blood myeloid precursors, female sex, and older age are adverse prognostic factors for overall survival or leukemia-free survival in aCML. aCML cases lack in Philadelphia chromosome. Overall 50-65% of patients show cytogenetic abnormalities. The most frequent is +8 (25%). Other changes such as -7 and del(12p) have also been recurrently observed. Patients with aCML have an estimated median survival between 14 and 30 months. aCML tends to exhibit a more aggressive clinical course than other MDS/MPN subtypes.

Figure. Figure.

Disclosures

No relevant conflicts of interest to declare.
Safety of Autologous Stem Cell Transplantation in Patients with Known HTLV-1 Infection: A Case Series of 4 Patients
Authors: Gupta Vishal K , White Paul , Sanchorawala Vaishali , Quillen Karen , Sarosiek Shayna , Brauneis Dina , Sloan John Mark
Published: October 2019

Human T-cell lymphotrophic virus types 1 and 2 (HTLV-1/2) are delta retroviruses endemic to the Caribbean and Japan (Gessain et al., 2013). They are known to cause adult T-cell lymphoma-leukemia (ATLL) and tropical spastic paraparesis/HTLV-1 associated myelopathy (HAM) (Mahieux et al., 2003). Given the link between immunosuppressive states and development of lymphoproliferative disorders, there is hesitation on the behalf of clinicians to offer stem cell transplantation to patients who test positive for HTLV-1/2 antibody. We reviewed four cases of patients who underwent autologous stem cell transplantation (ASCT) at our institution after having tested positive for HTLV-1/2 antibody (Table 1). The median patient age at the time of ASCT was 58 years (range, 51-60). Two patients tested positive for HTLV-1 antibody and two tested positive for HTLV-2 antibody. Two patients underwent ASCT for treatment of multiple myeloma, one for diffuse large B-cell lymphoma (DLBCL), and one for light chain amyloidosis (AL). The myeloma patients received standard induction therapy with cyclophosphamide, bortezomib, and dexamethasone (CyBorD) or lenalidomide, bortezomib, and dexamethasone (RVD). The DLBCL patient received rituximab, ifosfamide, carboplatin, and etoposide (R-ICE), while the AL patient underwent ASCT without induction. Three patients underwent conditioning with high-dose melphalan (200 mg/m2; HDM) and the lymphoma patient received carmustine, cyclophosphamide, and etoposide (BCV). Median stem cell collection was 8.35 x 106 CD34+ cells per kg (range, 4.8 -30.7). The median follow-up for these patients from date of transplantation was 22.4 months (range, 7.3-38.6). Median time to neutrophil and platelet engraftment was 9.5 days (range, 8-10) and 10 days (range, 9-14) respectively. Among these four patients, none developed complications related to HTLV-1/2 infection during the follow-up period. Two patients had a post-transplant course complicated by febrile neutropenia, and one patient developed typhlitis. One patient died on day + 221 due to a recurrence of cholangiocarcinoma leading to liver failure, and the other three remained alive at the time of last follow-up. Our data provides support that testing positive for HTLV-1/2 does not preclude eligibility for ASCT.

Disclosures

Sloan: Stemline Therapeutics: Consultancy.
The Appropriateness of Fresh Frozen Plasma (FFP) Administration in the Community Teaching Hospital
Authors: Shikdar Sufana , Ghionni Nicholas , Green Eric , Hommadov Kakageldi
Published: October 2019

Objective: Studies demonstrated that inappropriate usage of fresh frozen plasma (FFP) is associated with adverse reaction and poor health outcome in the hospitalized patients. Reducing inappropriate FFP administration in the inpatient settings can minimize potential for adverse events, and foster controllable cost expenditure. Guideline regarding indication of FFP transfusion is scarce. We aimed to assess the appropriateness of FFP transfusion in the setting of community teaching hospital.

Methods: A retrospective chart review of patients received FFP transfusion in two community teaching hospitals between 2016-2017 were included in our study. Frequency of appropriateness of FFP transfusion was reported. We also reported percent increase from previous years to compare the FFP usage from 2010-2011 to 2016-2017.

Results: Of 138 patients received FFP transfusion in 2016-2017, 62% (86 patients) received inappropriate transfusion. 18% of patients received FFP to correct high INR (>1.6) requiring emergency surgery. 53% of the patients received inappropriate transfusion for bleeding in 2016-2017 compared to 25% in 2010-2011. There was 10% rise of inappropriate or overuse of FFP transfusion in 2016-2017 than 2010-2011.

Conclusion: Inappropriate FFP transfusion is significantly associated with adverse health outcome and increased healthcare cost. This study justifies the need for continuous audit for appropriate use of FFP.

Disclosures

No relevant conflicts of interest to declare.
Single Institutional Experience with Nivolumab in Relapsed/Refractory Classic Hodgkin
Authors: Dada Reyad , Malas Al-Beirouti Bassim T. , Zabai Yazeed
Published: October 2019

Objectives : One of the newly discovered mechanisms to escape the immune response in classic Hodgkin lymphoma (cHL) is to induce immune tolerance through interaction of program cell death 1 (PD-1) on activated T cells and PD ligand-1 (PD-L1) on tumor cells. Tissue of patients with cHL was recently found to overexpress PD-L1. Nivolumab is a novel checkpoint inhibitor designed to block PD-1 and inhibits interaction between PD-1 and PD-L1. Unlike many available antibodies and chemotherapies, nivolumab itself is not cytotoxic but rather inhibits the tolerance of tumor cells through activation of the immune system.

Patients and methods: We report on ten patients with relapsed/refractory cHL who were treated between 05/2016 and 03/2018 with single agent nivolumab in a tertiary care hospital. Follow-up was performed after 4 cycles with positron emission tomography (PET). Patients' files were retrospectively analyzed.

Results:

Mean age was 26.2 year (range 15-40). Prior to nivolumab 3/10 and 5/10 patients failed ASCT and brentuximab vedotin respectively. Mean follow-up time was 12.3 months (range 5-32). Average of prior lines was 6.3. After 4 cycles of nivolumab response rate was 80% with complete metabolic (CR) and partial remission rates of 70% and 10% respectively. In one case PET showed stable disease and another patient experienced progressive disease. Three deaths occurred after 5, 9 and 32 months of nivolumab's initiation.

One patients experienced pneumonitis grade 2 which was manageable by oral steroids. Another patient had an asymptomatic TSH elevation. Two patients had grade 2 neutropenia. No serious adverse events (grade ≥3) were observed. All patients experienced a remarkable improvement of quality of life. On treatment start, two patients had performance status ECOG 3 and 4 which were attributed to refractory Hodgkin lymphoma. They recovered dramatically each to ECOG 2 within 7 days and 10 days after nivolumab start respectively.

Conclusion: The CR rate seen in our cohort supports the high sensitivity of relapsed/refractory cHL to checkpoint inhibition seen in Checkmate 205. Nivolumab induces impressive clinical and radiological responses with excellent tolerance. The drug enriches our treatments armamentarium in treating cHL. Further controlled studies are needed to determine the effectiveness on a large patients' cohort and its role in earlier lines.

Disclosures

No relevant conflicts of interest to declare.
A New Cellular Immunotherapy for the Treatment of Multiple Myeloma without Development of Graft-Versus-Host Disease
Authors: Firer Michael A , Yado Sofi , Galia Luboshits , Or Reuven
Published: October 2019

Multiple myeloma (MM) is a malignant plasma cell disorder that accounts for approximately 10% of all hematological cancers. Despite recent advances, long-term survival is rare after autologous bone marrow transplantation (auto-BMT) and/or treatment with recently introduced anti-myeloma agents and disease recurs in virtually all patients. Allogeneic bone marrow transplantation (allo-BMT) is an effective treatment that can provide partial or complete remission in patients with MM. The therapeutic potential of allo-BMT is attributed to the "graft-versus-myeloma" (GvM) effect that aims to destroy residual tumor cells that survived an induction protocol of chemotherapy/radiotherapy and to maintain immune surveillance to prevent relapse. However, allo-BMT remains a controversial treatment, since the donor T cells that mediate the GvM effect are also the source of the cells that react to other tissue alloantigens and induce graft versus-host disease (GvHD), a major cause of morbidity and mortality in allo-BMT recipients. Nonetheless, allo-BMT remains the only potentially curable treatment for MM. Recently TCR Vβ CDR3-size spectratype analyses in an animal model of MM identified T cells subfamilies involved in the anti-host and anti-tumor reactivity. We have now carried this work further and tested the potential of integrating auto-BMT with a donor lymphocyte infusion (DLI) composed only of anti-MM reactive Vβ 2, 3 and 8.3 T cell subfamilies. The results demonstrate that these T cell subsets are indeed involved in the generation of a potent GvM response in MM bearing mice and is associated with enhanced survival. Importantly, the GvM response was not accompanied by the development of GvHD. Nonetheless, the GvM response was not sufficient to completely inhibit relapse. We then pre-stimulated donor T cells with MM cells in vitro in the presence of co-stimulatory factors and found that our selective DLI protocol induced a vigorous and long-lasting GvM which translated into long-term survival, again in the complete absence of GvHD. Interestingly, quite similar results were obtained by treating MM-bearing mice with repeat doses of naïve donor Vβ 2, 3 and 8.3 T cell subfamilies. The treated mice showed significantly lower serum paraprotein levels and myeloma infiltration in bone marrow and spleen. Taken together, the results suggest that a transplantation protocol involving only tumor cell-reactive donor T cell subfamilies might be devised for MM patients that results in a potent GvM with enhanced survival but without symptoms of GvHD.

Disclosures

No relevant conflicts of interest to declare.
The Experience of Postpartum Bleeding in Women with Inherited Bleeding Disorders
Authors: Vandermeulen Heather , Petrucci Jessica , Floros Georgina , Dainty Katie , Sholzberg Michelle
Published: October 2019

Introduction and Objective: Women with inherited bleeding disorders have a maternal mortality rate nearly ten times higher than women without bleeding disorders. To date, the postpartum bleeding these women experience has not been well studied. Postpartum hemorrhage (PPH) affects 6% of all deliveries and is the leading cause of maternal death worldwide (19.7%). The incidence of PPH in women with inherited bleeding disorders is greater than unaffected women however estimates of relative risk are highly variable. In this high-risk population, we set out to explore the experience with, understanding of and attitudes regarding postpartum bleeding.

Materials and Methods: This qualitative study involved focused interviews of women with inherited bleeding disorders about postpartum bleeding. Women followed at a multidisciplinary clinic for women with inherited bleeding disorders who have experienced childbirth within the last 5 years were included in the study. The interview style was semi-structured and questions were designed in collaboration with a qualitative methodologist. Interviews continued until the point of saturation of themes. All interviews were transcribed and then analyzed using qualitative descriptive analysis.

Results: We interviewed ten women with inherited bleeding disorders. Saturation of themes occurred after six interviews. Themes that emerged include normalization of excessive bleeding, difficulty distinguishing normal from abnormal postpartum bleeding and empowerment of women by having a clear delivery care plan. Although these women felt generally prepared for immediate postpartum bleeding, there was less awareness regarding delayed postpartum hemorrhage.

Conclusion: To our knowledge this is the first study to assess the experience of postpartum bleeding in women with inherited bleeding disorders. Our analysis shows that these women become desensitized to heavy vaginal bleeding. As a result, excessive postpartum bleeding was not recognized by many of the women we interviewed. We also highlight the importance of a multidisciplinary delivery care plan for these women. We have identified key areas for targeted intervention for these patients and their healthcare providers.

Disclosures

Sholzberg: Octapharma: Research Funding; CSL Behring: Research Funding; Amgen: Research Funding; Shire: Research Funding.
Kinetics of Iron Depletion in Hereditary Hemochromatosis
Authors: Sanz Cristina , Garcia-Carulla Anna , Pereira Arturo
Published: October 2019

Introduction: Hereditary hemochromatosis (HH) is a genetic disorder that results in an increased accumulation of dietary iron. The only effective treatment is iron depletion by phlebotomy or erytrocytapheresis (EA). The kinetics of iron depletion in response to these treatments has been little studied and its temporal profile and the influence of patient's factors are not fully known.

Objective: To describe the kinetics of iron depletion in patients with HH on phlebotomy or EA.

Material and methods: Patients in depletive treatment with phlebotomy (once per week) or EA (one every two weeks) were selected for this study if they had no associated inflammatory disorder, at least 3 ferritin determinations were available during treatment, and more than 70% of the established therapeutic schedule was fulfilled. The average reduction of serum ferritin was measured in ng/ml per ml of red blood cells (RBC) removed per Kg of patient's body weight, and was analyzed as natural logarithms (ln). Categorical variables were expressed as proportions and continuous variables, as median and interquartile range (IQR).

Results: Median age of the 34 included patients was 51 (44-58) years and 32 (94%) were men. Initial and final ferritin values were 1035 (IQR: 777-1564) ng/ml and 83 (IQR: 50-123) ng/ml, respectively. Transaminase levels were high (ALT> 50 U/L) in 9 patients, and 2 of them had been diagnosed with liver cirrhosis secondary to HH. With regard to genotype, 27 patients were C282Y homozygous, 4 were compound heterozygous (C282Y/H63D), 1 had a TFR2 mutation, and no mutation was found in 2. The average reduction of serum ferritin was 1.04 (IQR: 1.03-1.05) ng/mL per mL of removed RBCs/Kg of patient's body weight. Figure 1 shows the mathematical expression that best described the kinetics of serum ferritin.

The rate of serum ferritin reduction, as measured by this mathematical expression, was independent of the initial ferritin level, the total reduction of ferritin, the presence of high transaminase levels or cirrhosis, as well as the patient's age and body mass index. In contrast, the rate of ferritin reduction varied with the genotype; it was significantly lower in patients homozygous for the C282Y mutation than in patients with other genotypes (median: 1.03, IQR: 1.02-1.05 vs. 1.07, IQR: 1.06-1.11 ng/mL per mL of removed RBCs/Kg; p < 0.001; figure 2).

Conclusions: In patients with HH and good adhesion to the therapeutic schedule, the reduction of serum ferritin is predictable as a function of the volume of removed RBCs and the patient's weight. Patients homozygous for the C282Y mutation have a slower kinetics of iron depletion.

Disclosures

No relevant conflicts of interest to declare.
MYC Functions As a Master Switch for Natural Killer Cell-Mediated Immune Surveillance of Lymphoid Malignancies
Authors: Swaminathan Srividya , Heftdal Line Dam , Liefwalker Daniel F , Dhanasekaran Renumathy , Deutzmann Anja , Horton Crista , Mosley Adriane , Liebersbach Mariola , Maecker Holden T. , Felsher Dean
Published: October 2019

Background: The MYC oncogene drives T and B cell lymphoid malignancies, including Burkitt's lymphoma (BL) and Acute Lymphoblastic Leukemia (ALL). Such lymphomas are said to be "oncogene-addicted" to MYC. In order to develop targeted therapies for MYC-driven cancers, it is vital to understand how MYC regulates both cell autonomous and non-cell-autonomous processes, including host immunity.

Approach: We have used a particularly tractable approach for studying the role of oncogenic MYC on the host immune system during lymphomagenesis through a tetracycline (tet)-system regulated transgenic mouse model of MYC-driven T cell lymphoma (SRα-tTA/Tet-O-MYC mice; Felsher and Bishop, Molecular Cell, 1999). By delineating the global immunological changes during primary MYC-driven T cell lymphomagenesis in SRα-tTA/Tet-O-MYC mice using mass cytometry (CyTOF) and CIBERSORT, we identified anti-tumor immune subsets that can be developed as therapies to treat MYC-driven lymphomas.

Results: Amongst the immune subsets evaluated, our results demonstrated a specific systemic suppression of natural killer (NK) cell-mediated surveillance in SRα-tTA/Tet-O-MYC mice bearing overt MYC-driven T cell lymphomas. Inactivation of lymphoma-intrinsic MYC restores NK cell-mediated immune surveillance, suggesting that the regulation of NK cell-mediated surveillance may be integral to MYC-induced lymphomagenesis. We observed that lymphoma-specific MYC transcriptionally represses STAT1/2 and secretion of Type I Interferons (IFNs) required for normal NK cell homeostasis and NK cell-mediated immune surveillance in the tumor microenvironment. Concordantly, treating T cell lymphoma-bearing SRα-tTA/Tet-O-MYC mice with Type I IFN improves survival by rescuing NK cell production, and in part overriding MYC-mediated suppression of NK surveillance. We showed that human lymphomas with both high levels of MYC and low levels of STAT1/2 have lower NK surveillance, and are associated with poor prognosis. Finally, we established the therapeutic implications of our findings by showing that adoptive transfer of NK cells significantly delays lymphoma initiation, and recurrence after MYC inactivation; suggesting that NK cell-based therapy may be effective against MYC-driven lymphomas.

Conclusion: Subversion of NK cell surveillance is integral to MYC-induced lymphomagenesis. Our studies provide a rationale for further developing the NK subset as a cell-based immunotherapy to effectively treat MYC-driven lymphomas in the future.

Disclosures

No relevant conflicts of interest to declare.
Promising Effect of PDL1 Inhibitors in PCNSL
Authors: Hamed Rasha , Alshemmari Salem , Hamadah Abdulaziz , ElHagrasy Rehab S , Shaisha Mohamed Elbialy , Seif Marwa
Published: October 2019

PCNSL or secondary CNSL both are associated with poor prognosis & inferior survival, and some cases are refractory to currently available lines of treatment. PDL1 inhibitors started to emerge in the literature as a new line of treatment in this disease entity. The programmed death ligand PD-L1 negatively regulate immune response & promote escape of tumor cells from immune surveillance, PD1 is expressed on T lymphocytes, including tumor infiltrating lymphocytes (TILs), while PDL1 expression is found on antigen presenting cells & on tumor cells in various cancer types, including some lymphomas. Binding of PDL1 to PD1 inhibits the proliferation of activated T lymphocytes & thus the anti-tumor adaptive immune response. In this case we evaluated the effect of PDL1 inhibitor Nivolumab in PCNSL refractory to 1st line (high dose MTX/AraC-Rituximab). Efficacy was evaluated using MRI which showed complete remission following 4 bi-weekly cycles, maintained complete remission on repeated evaluation after 10th & 14th cycles. The patient was shifted to monthly doses. The patient tolerated the treatment well apart of mild elevation of trans-aminases. Time to treatment failure was not reached till time of submission of this abstract (8 months). PDL1 Inhibitors showed effective clinical and radiological response in PCNSL. Further studies are needed to assess this point and follow up to assess the time to treatment failure. The remaining un-answered question is: How to consolidate the achieved response?

Figure. Figure.

Disclosures

No relevant conflicts of interest to declare.
Parallel Evaluation of Three Global Hemostatic Assays in Response to Factor VIII Inhibitors
Authors: Chen Ping , Jani Jayesh , Zheng Gang , Kickler Thomas S.
Published: October 2019

Background Current laboratory tests measuring factor and factor inhibitor levels are limited in their ability to fully evaluate the hemostasis status of hemophilia patients. There are global assays including thromboelastogragh (TEG), Innovance ETP, and thrombinoscope measuring thrombin generation potential, which have potentials to provide more objective and clinically relevant markers to guide clinical management. However, performance characteristics of these global assays are not well-studied, and no parallel comparisons of three global assays have been made.

Material and Methods With plasmas of 20 healthy individuals the normal variation of thrombin generation potential was determined for all three global assays. With five commercially available and three clinical plasma samples with different levels of factor VIII inhibitors, serial dilutions were made, and thrombin generation potentials were measured with the global assays.

Results The means and standard deviations for thrombin generation potential of healthy individuals are 761.27±70.30 mm/min, 2126.43±441.62 nM/min, and 411.04±48.87 mA, by TEG, throminoscope and Innovance ETP respectively. Thrombinoscope shows a dose-dependent response to different levels of factor VIII inhibitors from the same patients, while Innovance ETP shows virtually no response to factor 8 inhibitors regardless of inhibitor levels. TEG appears more sensitive to factor VIII inhibitors than thrombinoscope, as a moderate level of factor VIII often abolishes thrombin generation by TEG (see Figure 1 for an example). Importantly, it was shown that the same levels of factor VIII inhibitor from different patients result in different level of inhibition for thrombin generation potential by thrombinoscope (Figure 2), which potentially explains the phenotypic heterogeneity of patients with same levels of factor VIII inhibition.

Conclusion Global assays like thrombinoscope, but not Innovance ETP, offer an objective measurement of hemostasis in hemophilia patients with factor VIII inhibitors, which may lead to individualized hemophilia patient management. Future studies are warranted to validate the global assays clinically.

Disclosures

No relevant conflicts of interest to declare.
Regulating Transcriptional Co-Activator PGC-1α for the Treatment of Sickle Cell Disease
Authors: Habara Alawi , LE Cuong , Murphy George J , Chui David H.K. , Steinberg Martin H. , Cui Shuaiying
Published: October 2019

Sickle cell disease (SCD) is the most common inherited human hematologic disease, which causes hemolytic anemia, pain, disability, progressive multi-organ damage and early mortality. Clinical studies have shown that increased synthesis of fetal hemoglobin (HbF) in sickled erythroid cells leads to diminished severity of many clinical features of SCD. Therefore, therapeutic agents that can increase HbF production will be of benefit to SCD patients. Hydroxyurea (HU) is the FDA-approved therapeutic for treatment of SCD, but not all patients respond favorably or adequately. Therefore, other methods of targeting HbF are highly desired, particularly those that act by different mechanisms that might be used in combination with HU or alone (for those who do not tolerate HU).

We recently identified PPARγ co-activator (PGC-1α) as a new protein involved in the regulation of the fetal globin genes. Forced overexpression of PGC-1α in vitro by adenovirus infection in bone marrow cells from SCD mice resulted in significantly increased human γ- and murine εy- and βh1-globin genes. Furthermore, up-regulation of PGC-1α by a small molecular agonist (Compound Z) in human umbilical cord blood-derived erythroid progenitor (HUDEP-1) cells markedly increases γ-globin gene expression and HbF synthesis. The highest response was achieved when HUDEP-1 cells were treated with 5µM Compound Z for 2 days, which results in 66.6% HbF+ cells compared to vehicle control (29.5% HbF+ cells). The effect of Compound Z in inducing HbF was further validated in erythroblasts derived from cultures of normal adults' CD34+ cells as well as in iPSC-derived sickle erythroblasts (SS24 cells). These data suggest that modulating PGC-1α activity may be effectively applied to the treatment of SCD since enhanced HbF synthesis would alleviate pathophysiological effects of SCD.

Disclosures

No relevant conflicts of interest to declare.
Preclinical Evaluation for the Gene Therapy of Patients with Leukocyte Adhesion Deficiency Type I
Authors: Almarza Elena , Mesa-Núñez Cristina , Damián Carlos , Fernández-García María , Díez-Cabezas Begoña , Schwartz Jonathan D , Bueren Juan A
Published: October 2019

Leukocyte Adhesion Deficiency Type I (LAD-I) is a severe primary immunodeficiency characterized by recurrent and life-threatening bacterial infections. It is caused by mutations in the ITGB2 gene, encoding the integrin β2 common subunit (CD18). These mutations lead to defective or absent expression of β2 integrins on leukocyte surfaces, rendering leukocytes unable to extravasate to infection sites. Severe LAD-I is characterized by less than 2% of normal CD18 neutrophil expression and is fatal during the initial 2 years of life in 60-75% of patients in the absence of allogeneic hematopoietic transplant. As it is the case with other monogenic immunodeficiencies, LAD-I is a disorder that could be corrected by ex vivo gene therapy. To this aim we have developed a lentiviral vector (LV) that has recently obtained the Orphan Drug designation (EU/3/16/1753 and DRU-2016-5430). In this LV the expression of hCD18 is driven by a chimeric promoter with a higher activity in myeloid cells. Comprehensive safety and efficacy preclinical LV-mediated gene therapy studies have been conducted in LAD-I mouse models harboring either hypomorphic or knock-out mutations in the ITGB2 gene. Our studies demonstrate stable engraftment of gene corrected LAD-I mouse hematopoietic stem cells in LAD-I recipients and indicate a phenotypic correction of peripheral blood neutrophils. A complete preclinical safety evaluation of the vector was also carried out demonstrating the absence of hematotoxic and genotoxic effects in treated animals. Further studies have been conducted with GMP-produced LVs in human CD34+ cells aimed at optimization of cell transduction. The use of transduction enhancers (TEs) significantly improved the efficacy of genetic correction of human CD34+ cells transduced with LVs at low MOIs. Additionally, transplants into immunodeficient mice showed no changes in the repopulating ability of CD34+ cells when these cells were transduced in the presence of TEs. As occurred in in vitro cultures, significant increases in the transduction of repopulating cells were also associated with the use of TEs, indicating that optimized TE combinations will enable practical and cost-effective transduction of human HSCs in gene therapy protocols. Taken together, these results demonstrate the efficacy and safety of a gene therapy approach directed towards the therapy of LAD-I patients.

Disclosures

Almarza: Rocket Pharmaceuticals: Equity Ownership, Patents & Royalties, Research Funding. Schwartz:Rocket Pharmaceuticals: Employment, Equity Ownership. Bueren:Rocket Pharmaceuticals: Consultancy, Equity Ownership, Patents & Royalties, Research Funding.
Erythroferrone Inhibits the Induction of Hepcidin By BMP6
Authors: Arezes Joao , Foy Niall , McHugh Kirsty , Sawant Anagha , Benard Susan , Quinkert Doris , Terraube Virginie , Brinth Alette , Tam May , LaVallie Edward , Taylor Stephen , Armitage Andrew E , Pasricha Sant-Rayn , Cunningham Orla , Lambert Matthew , Draper Simon J , Jasuja Reema , Drakesmith Alexander
Published: October 2019

Decreased hepcidin mobilizes iron, which facilitates erythropoiesis, but excess iron is pathogenic in beta-thalassemia and other iron-loading anaemias. Erythropoietin (EPO) enhances erythroferrone (ERFE) synthesis by erythroblasts, and ERFE suppresses hepatic hepcidin production, through an unknown mechanism. The BMP/SMAD pathway in the liver is critical for control of hepcidin, and we show that EPO suppressed hepcidin and other BMP target genes in vivo in a partially ERFE-dependent manner. Furthermore, recombinant ERFE suppressed the hepatic BMP/SMAD pathway independently of changes in serum and liver iron, and in vitro, ERFE decreased SMAD 1/5/8 phosphorylation and inhibited expression of BMP target genes in hepatoma cells. ERFE specifically abrogated the induction of hepcidin by BMP5, BMP6 and BMP7, but had no or very little effect on hepcidin induction by BMP2, 4, 9 or Activin B. A neutralising anti-ERFE antibody prevented the ability of ERFE to inhibit hepcidin induction by BMP5, 6 and 7. Cell-free Homogeneous Time Resolved Fluorescence assays showed that BMP5, BMP6 and BMP7 competed with anti-ERFE for binding to ERFE. Biacore analysis showed that ERFE binds to BMP6 with a higher affinity compared to its binding to BMP2, BMP4 or Activin B, and does not bind to GDF15. We propose that ERFE suppresses hepcidin by inhibiting hepatic BMP/SMAD signaling via preferentially binding and impairing the function of an evolutionarily closely related BMP sub-group consisting of BMP5, BMP6 and BMP7. These findings indicate that ERFE can act as a natural ligand trap generated by stimulated erythropoiesis in order to regulate availability of iron.

Disclosures

Arezes: Pfizer: Research Funding. Foy:Pfizer: Employment. McHugh:Pfizer: Research Funding. Sawant:Pfizer: Employment. Benard:Pfizer: Employment. Quinkert:Pfizer: Research Funding. Terraube:Pfizer: Employment. Brinth:Pfizer: Employment. Tam:Pfizer: Employment. LaVallie:Pfizer: Employment. Cunningham:Pfizer: Employment. Lambert:Pfizer: Employment. Draper:Pfizer: Research Funding. Jasuja:Pfizer: Employment. Drakesmith:La Jolla Pharmaceutical Company: Research Funding; Pfizer: Research Funding; Alnylam: Consultancy; Kymab: Membership on an entity's Board of Directors or advisory committees.
Cost Consideration of Second Line Therapy for Relapsed Diffuse Large Lymphoma in the Community Setting
Authors: Landau Danny , Wilds Brandon , Mouslly Sammy
Published: October 2019

Cost consideration of second line therapy for relapsed diffuse large lymphoma in the community setting

Introduction

Despite treatment with curative intent chemotherapy, many patient with diffuse large B cell lymphoma (DLBCL) will relapse. Post relapse, the majority of patients will remain sensitive to cytotoxic chemotherapy. Commonly used regiments in this situation include Rituximab plus a combination of other agents such asifosfamide, carboplatin, etoposide (R-ICE)etoposide, methylprednisolone, cytarabine, cisplatin (R-ESHAP)dexamethasone, high-dose cytarabine, cisplatin (R-DHAP)gemcitabine, oxaliplatin (R-Gem/Ox)lenalidomide (R squared)bendamustine (R-Bendamustine

As few clinical trials exist that compare these different regimens head to head, the decision is often left to the treating physician. We opted to look at cost as a consideration.

Methods:

For the regimens listed above, we calculated drug costs using the average wholesale price. For regimens that require inpatient hospital stays, we used historical data for cost of average hospital stay from Beckers Hospital review. A body surface area of 1.75 was used for each regimen. We determined the cost for four cycles of the different regimens. Growth factor support was included as many of these regimens require this. As our focus was on our own community institution, and is it isn't yet widely available, CAR-T was not included.

Results:

In table

Conclusions:

While a number of decisions will factor into the use of one of these regimens, cost is an important factor. Based on the above information, there is a wide range of cost. This can be one factor in deciding which combination to use. Few clinical trials have compared these regimens in a head to head fashion. One trial that did compared R-ICE to R-DHAP and essentially showed only minor outcome differences between them. In such situations, cost as well as inpatient vs outpatient hospital stays, patient preference, physician comfort with the different regimens will all play a role in determining which regimen to use.

Table. Table.

Disclosures

Landau: celgene: Honoraria; novartis: Honoraria.