bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rapid Turnaround ADAMTS13 Testing Is Likely to Improve Diagnosis of Thrombotic Thrombocytopenic Purpura and Avoid Unnecessary Plasma Exchange
Authors: McGinnis Eric , Martin Spencer D. , Smith Tyler W. 
Published: November 2020

Introduction: Thrombotic thrombocytopenic purpura (TTP) is a life-threatening thrombotic microangiopathy (TMA) resulting from severe ADAMTS13 deficiency, which is generally treated with therapeutic plasma exchange (PLEX). Although ADAMTS13 activity is often assayed to differentiate TTP from TMAs not requiring PLEX, technical and logistical constraints often limit rapid turnaround of results, with PLEX initiated based on clinical suspicion of TTP while awaiting ADAMTS13 activity results. We estimated the potential reduction in plasma product use if rapid turnaround ADAMTS13 activity testing were available in our centre.
Methods: We reviewed medical records for all Vancouver General Hospital patients with ADAMTS13 activity testing since assay implementation. Patients receiving PLEX but ultimately diagnosed with a disease not requiring PLEX were identified as "potentially avoidable PLEX" (paPLEX), and their plasma product exposures and related blood product costs were estimated. Laboratory results, ADAMTS13 activity, and PLASMIC scores (a validated clinical tool for TTP diagnosis) of this group were compared to those of newly diagnosed TTP patients (N=35).
Results: We identified 16 paPLEX patients, including TMAs secondary to malignant hypertension, infection, hemolytic uremic syndrome, illicit drug use, autoimmune renal disease, and malignancy (Table 1). These patients underwent 104 total PLEX cycles (3-12 per patient, median 6), involving 1,428 plasma units (28-199 per patient, median 71.5) and estimated product-associated costs of $187,759 CAD ($140,889 USD). Median platelet counts were significantly lower in TTP than the paPLEX group (7x109/L versus 38x109/L), as was serum creatinine (98µmol/L versus 224µmol/L). PLASMIC scores indicating low or intermediate likelihood of TTP were observed in 63% of patients receiving paPLEX and 17% of patients with TTP. All patients with TTP had ADAMTS13 activity &lt; 10%, while all patients receiving paPLEX had ADAMTS13 activity ≥ 30%.
Conclusions: Unnecessary PLEX carries significant patient blood product exposure risks and system costs that may be circumvented if TTP can be reliably distinguished from other TMAs at the time of initial presentation. In our cohort, ADAMTS13 activity results provided clear separation of these groups and improved upon TTP diagnosis by clinical judgement and PLASMIC scores. Rapid turnaround of ADAMTS13 activity testing results has the potential to reduce the unnecessary costs and blood product exposures resulting from PLEX administration to patients with non-TTP TMAs.
Figure 1

Disclosures
Smith: Alexion: Other: Participated in an advisory board without receiving financial compensation.
CD19/CD22 CAR-T Cell Cocktail Therapy Following Autologous Transplantation in Patients with Relapsed/Refractory B-Cell Lymphomas
Authors: Cao Yang , Xiao Yi , Wang Na , Wang Gaoxiang , Zhou Xiaoxi , Huang Liang , Chen Liting , Xiao Min , Zhang Tongcun , Zhang Yicheng , Zhou Jianfeng 
Published: November 2020

High-dose chemotherapy followed by autologous stem cell transplantation (HDT-ASCT) is the standard of care for relapsed or refractory(R/R) B-cell lymphoma. Eligibility for HDT-ASCT is based upon the presence of chemo-sensitive disease to salvage therapy. Patients with a positive PET scan prior to ASCT have a substantially inferior suvival. Furthermore, the outcomes of patients who have progressive disease after salvage treatment is extremely dismal. We hypothesized that, following HSCT, the immunosuppressive microenvironment would be diminished as a result of myeloablative conditioning and that administering CAR-T cell therapy during the hematopoietic reconstitution could eradicate posttransplant residual disease, leading to lower relapse rates after HSCT. Based on our previous work that a dual-targeting CAR T cell cocktail of sequential cell infusions targeting CD19 and CD22 may help overcome antigen escape relapse in B-cell malignancies, we therefore conducted an open-label, single-center, and single-arm pilot study of a treatment comprising the sequential infusion of CD22 and CD19 CAR-T cells following autologous hematopoietic stem cell transplantation (HSCT). We aimed to evaluate the safety and efficacy of the treatment in R/R B cell lymphoma patients with residual or progression disease after salvage treatment. Between November 14, 2016 and August 15, 2019, 42 patients underwent BEAM conditioned HDT-ASCT and followed by CAR 19 /22 T cells infusion. The overall response rate was 90.5% (95% CI, 77.4-97.3). At a median follow-up of 13.8 months, the median progression-free survival (PFS) and overall survival (OS) were not reached. The 12-month PFS rate was 85.7 % (95% CI, 70.9 to 93.3). Grade 3 cytokine release syndrome (CRS) occurred in only 2 (5%) patients. 21% patients experienced any grade of neurotoxicity, 5% was severe Grade 3. All CRS and neurotoxicity were reversible. Beyond its extremely high complete response rates, the durability of remission and low toxicity of the autologous HSCT plus CD19/CD22 CAR-T cell cocktail therapy examined in this study emphasize strong potential of such myeloablative conditioning and dual-targeting approaches for R/R B-cell lymphomas.

Disclosures
No relevant conflicts of interest to declare.
Iron Trafficking through Macrophages Regulates Signaling Pathways in Myeloma
Authors: Tan Xuelian , Ashby Timothy Cody , Zhu Yuqi , Li Can , Shen Xuxing , Brockman Qierra , Gai Dongzheng , Johnson Sarah K , Yong Donghoon , Schinke Carolina D. , Zangari Maurizio , van Rhee Frits , Shaughnessy John , Huang Dingming , Frech Ivana , Tricot Guido J. , Zhan Fenghuang 
Published: November 2020

Background
Iron is an essential element for cell growth, including cancer cells, and is present in the microenvironment. We have shown that multiple myeloma (MM) cells have abnormal iron metabolism and harbor increased intracellular iron. However, the mechanism by which MM cells retain iron has remained largely elusive.
Methods
Expression and clinical relevance of the transferrin receptor in MM samples were analyzed in publicly available microarray and RNA-sequencing databases. Macrophages were isolated from C57BL/6J mice and were induced to specific subtypes by cytokines or culturing with MM cells. The 5TGM1-KaLwRij MM mice were used to confirm whether MM cells induce macrophage polarization in vivo. Specific subtypes of macrophage and transferrin receptor expression in MM cells were assessed by flow cytometry. Expression of ferroportin (FPN1) and ferritin in MM cells and/or macrophages were analyzed by Western blots. Single-cell RNA-sequencing (scRNA-seq), RNA-seq, and gene expression profiles (GEPs) were employed to identify ferroportin-signaling pathways in both tumor cells and macrophages of primary human MM samples.
Results
MM cells induced polarization with a significant increase of CD38+CD206- M1 macrophages both in vitro and in vivo. We also confirmed that the tumor associated macrophages (TAMs) were increased in the 5TGM1-KaLwRij MM mice. MM cells upregulated ferroportin expression in macrophages to provide iron to MM cells in co-culture studies and in vivo models. The transferrin receptor antibody treatment prevented MM cells from taking up iron from macrophages. scRNA-seq identified a subset of FPN1+ TAMs in human bone marrow aspirates, which are assumed to provide iron to MM cells. Using RNA-seq and GEPs analyses in primary human samples, multiple signaling pathways were differentially modulated in FPN1+ versus FPN1- TAMs, including those related to inflammation and apoptosis
Conclusions
Increased expression of the transferrin receptor in MM cells strongly suggests that tumor cells take up iron from its environment. MM cells promote intracellular iron mobilization in macrophages, which provide iron to MM cells in a transferrin-dependent manner. Blockade of iron trafficking between MM cells and macrophages might be a promising approach to MM therapy.

Disclosures
van Rhee: EUSA: Consultancy; CDCN: Consultancy; Karyopharm: Consultancy; Adaptive Biotech: Consultancy; Takeda: Consultancy.
The Role of Alpha 2 Macroglobulin in Chronic Activation of the Complement System in Patients with Chronic Lymphocytic Leukemia
Authors: Naseraldeen Naseba , Michelis Regina , Barhoum Masad , Chezar Judith , Tadmor Tamar , Aviv Ariel , Shvidel Lev , Litmanovich Adi , Yuklea Mona , Shehadeh Mona , Shaoul Ety , Braester Andrei 
Published: November 2020

The immunotherapy treatments offered for Chronic lymphocytic leukemia (CLL) activate various cellular and biochemical mechanisms, including the complement system. Recently it was shown that the classical complement pathway (CP) in CLL patients is persistently activated at a low level through (Michelis et al. PlosOne, 2019), and that the mechanism of chronic CP activation involves the formation of IgG-hexamers (Michelis et al. PlosOne, 2020). According to recent studies, formation of ordered IgG-hexamers occurs on cell surfaces via specific interactions between Fc regions of the IgG monomers, which occur only after antigen binding. The study investigated the formation of IgG-hexamers in CLL patients and normal controls (NC), their ability to activate complement, their incidence as cell-free and cell-bound forms and the identity of the antigen causing their formation.
Sera from 30 patients and NC were used for separation of IgG-hexamers. The obtained IgG-hexamers were measure and used for assessment of CP activity. For evaluation of the presence of IgG-hexamers on blood cells, whole blood samples were stained and assessed by flow cytometry.
Serum levels of IgG-hexamers were higher in patients compared to NC. Also, they activated the complement system to a higher extent in patients than in NC. Alpha 2 macroglobulin (A2M) was recognized as the antigen causing the hexamerization of IgG, and was found to be part of the hexamer structure by mass spectrometry, Western blot and flow cytometry analysis. The presence of A2M-IgG-hexamers on B-cells suggests that it may be formed on B cells surface and then be detached to become cell-free. Alternatively, it may form in the plasma and then attach to the surface of the cells. The exact course of A2M-IgG-hexamers formation in CLL should be further studied. The results in this study may be useful for improvement of current immunotherapy regimens.

Disclosures
Tadmor: Neopharm: Consultancy, Speakers Bureau; AbbVie: Consultancy, Speakers Bureau; Janssen: Consultancy, Speakers Bureau; Takeda: Consultancy, Speakers Bureau; Sanofi: Consultancy, Speakers Bureau; Medison: Consultancy, Speakers Bureau; 6. Novartis Israel Ltd., a company wholly owned by Novartis Pharma AG: Consultancy, Speakers Bureau. Aviv:Abbvie: Honoraria.
IDH Mutations Identify a Subgroup of NPM1 Patients with a More Favorable Prognosis. a Retrospective Multicenter Study of the Filo Group
Authors: Garciaz Sylvain , Hospital Marie Anne , Saillard Colombe , Hicheri Yosr , D'Incan Evelyne , Rey Jerome , Lacombe Catherine , Pigneux Arnaud , Béné Marie-Christine , Recher Christian , Mozziconacci Marie-Joelle , Vey Norbert 
Published: November 2020

IDH mutations are strongly enriched in cytogenetically normal AML harboring NPM1 mutation (CN-NPM1mut-AML). The impact of these mutations on response to treatment is still a matter of debate. In the ELN 2017 classification, NPM1mut/FLT3-ITD allelic ratio &gt;0.5 (FLT3-high) are considered intermediate-risk AML, whereas NPM1mut/ FLT3-ITD neg or &lt;0.5 (FLT3-low) are low-risk. We aimed to evaluate the impact of IDH mutation in CN-NPM1mut-AML patients (pts) treated intensively. For this purpose, we retrospectively analyzed 177 CN-NPM1-AML pts from the Paoli-Calmettes Institute and from the French Innovative leukemia organization (FILO) databases who had received conventional intensive chemotherapy according to the FILO protocols (anthracycline-cytarabine based regimen for induction and High-intermediate dose cytarabine (HIDAC) for consolidation. Forty-seven (26%) AML pts had an IDH mutation -18 IDH1-R132 (10%), 27 IDH2-R140 (15%) and 2 IDH2-R172 (1%) - while 130 AML pts were IDHwt. Pts characteristics are presented in the Table.The complete response rate after one or two courses of chemotherapy (CR1) was 100% and 90% (p-value=.03) in the IDHmut and IDHwt groups, respectively. For pts in CR1, NPM1 molecular residual disease after the first consolidation (MRD2) was negative (&gt;4 Log reduction) in 86% vs 53% of pts (p-value=.04). Nine (19%) and 24 (18%) pts received an allogeneic transplantation in CR1. The median time between CR1 and relapse was 11 months and 8 months, in IDHmut and IDHwt pts, respectively (p-value=.008). Day-100 non-relapse mortality was 8% and 12% respectively (p-value=ns). Median follow-up is 45 months (range, 2.4-115). Median EFS and OS are 21 months vs 12 months (p-value=.01) and 112 vs 23 months (p-value=.02), in the IDHmut vs IDHwt groups respectively (Figure). No survival differences were observed between IDH1mut and IDH2mut AML patients. Multivariate analyses with age&gt;65, FLT3-high and IDHmut as covariates showed that IDHmut was independently associated with a higher EFS (HR=1.7, ranges 1.1-2.6) and OS (HR=1.7, ranges 1.1-2.7). Our results suggest that IDHmut is associated with a better response and a good disease control with high-dose chemotherapy. Nevertheless, some relapses still occur justifying the use of an IDH inhibitor combined with first-line chemotherapy or in a post-remission maintenance setting.
Figure

Disclosures
No relevant conflicts of interest to declare.
Adenylate Kinase 2 Is a Selective Dependency in NSD2-High Multiple Myeloma
Authors: Sobh Amin , Kaestner Charlotte , Li Jianping , Riva Alberto , Bennett Richard Lynn , Licht Jonathan D. 
Published: November 2020

Background: Multiple myeloma (MM)-associated t (4;14) chromosomal translocation leads to overexpression of NSD2, the histone H3 lysine 36 specific methyltransferase. t(4;14) MM patients have a high risk of relapse and NSD2 overexpression drives an oncogenic epigenetic and transcriptional program promoting clonogenicity, proliferation, altered adhesion and chemoresistance in MM cells. The lack of a specific and potent NSD2 inhibitors mandates finding alternative strategies for treating NSD2-high MM.
Aim: This study aims to test the hypothesis that NSD2 overexpression in MM cells generates cellular vulnerabilities that can be therapeutically exploited for treatment of t (4;14) MM.
Methods: We conducted a genome wide CRISPR-based loss-of-function genetic screen using the human Brunello library in isogenic NSD2-high (NTKO) and NSD2-low (TKO) KMS-11 derived MM cells to define genes whose loss is selectively detrimental to cells with NSD2 overexpression. The cellular dependency of each identified candidate was then investigated across hundreds of human cell lines using the Cancer Dependency Map portal (www.Depmap.org). Candidate genes were validated using CRISPR-Cas9 gene knockout and shRNA knockdown of individual target genes followed by in vitro competitive growth assays and cell viability assays.
Results: Our study revealed multiple candidate genes with increased dependency in NSD2-high cells including the adenine nucleotide regulator Adenylate Kinase 2 (AK2). AK2 catalyzes the reversible conversion of ADP to AMP and ATP and can thus modulates energy balance within the cell. Dependency map analysis showed that AK2 is not a commonly essential gene. The top enriched lineages with AK2 dependency included MM with notable representation of t(4;14)-positive MM cell lines. The increased dependency of NTKO and other t (4;14) MM cells on AK2 was confirmed by in vitro competition assays. Disruption of AK2 in TKO cells had a minimal effect on cellular fitness but the dependency on AK2 was restored upon engineered overexpression of NSD2 in these cells. In addition, NSD2-high cells displayed higher sensitivity to the proteasome inhibitor bortezomib than NSD2-low cells suggesting elevated levels of endoplasmic reticulum (ER) stress in cells overexpressing NSD2. Elevated ER stress necessitates increased levels of ATP to refold proteins and could underlie the increased dependency of NSD2-high cells on AK2. Notably, suppression of AK2 increased bortezomib sensitivity in t (4;14) MM cell lines.
Conclusions: Our findings indicate that NSD2 high t(4;14) MM may have a vulnerability due to increased proteostatic stress. Accordingly, AK2 inhibition could be used in combination with proteasome inhibitors to treat MM patients with t (4;14) translocations by inducing the accumulation of lethal levels of unfolded proteins.

Disclosures
No relevant conflicts of interest to declare.
Incidence and Outcomes of Heparin-Induced Thrombocytopenia Associated with a Heparin Shortage at a Large Academic Medical Center
Authors: Seto Stephanie L. , Barra Megan E. , Roberts Russel J. , Rosovsky Rachel P. 
Published: November 2020

Heparin-induced thrombocytopenia (HIT) is a life-threatening complication associated with significant morbidity and mortality in hospitalized patients. The 2019 African swine fever outbreak in China resulted in a critical national shortage of porcine-derived heparin products in the United States. As a result, our institution implemented a multitude of mitigation strategies to reduce heparin utilization by &gt;80% and optimize safe and effective alternative therapies. The aim of this study was to determine whether this change in clinical practice impacted the incidence of HIT and associated outcomes.
A single-center, retrospective cohort study was performed on patients admitted to Massachusetts General Hospital who were ≥ 18 years of age and had a positive platelet factor 4 (PF4) drawn between February 2019 and January 2020. Patient demographics, comorbidities, baseline labs, serotonin release assay results, timing and magnitude of platelet count fall, and characteristics of heparinoid and non-heparinoid anticoagulant use were collected from the medical record. Thrombotic and hemorrhagic outcomes were characterized.
Seventy-five patients were included in the final analysis, of which 56 (75%) were critically-ill. Baseline characteristics were similar between groups including median age 66.8 years, 49% male, 80% Caucasian. Forty-four (59%) patients underwent surgery, 23 (31%) required continuous renal replacement therapy, and 13 (17%) underwent extracorporeal membrane oxygenation. Incidence of HIT with any exposure to heparinoid product was 0.3% and 0.15% (p=0.002) in the pre-shortage and shortage periods, respectively. In those who received therapeutic dose unfractionated heparin, incidence of HIT was 1.26% and 1.05% (p=0.63) in the pre-shortage and shortage groups, respectively. Thrombotic complications were observed in 19 (41%) patients in the pre-shortage group and 11 (38%) in the post-shortage group (p=0.77). Bleeding events were observed in 8 (17%) and 5 (17%) (p=0.99).
We observed a lower incidence of HIT resulting from our institution's efforts to conserve unfractionated heparin supply and utilize alternative anticoagulants during a critical national drug shortage. There were no significant differences in associated thrombotic and bleeding events.

Disclosures
Rosovsky: Bristol-Myers Squibb, Dova, Janssen, Portola: Consultancy; Bristol-Myers Squibb, Janssen: Research Funding.
Recombinant Human Thrombopoietin in the Treatment of Chemotherapy-Induced Thrombocytopenia in Acute Myeloid Leukemia
Authors: Can Can , Ding Lu , Tan Yuxin , Wu Balu , Zhang Dongdong , Chen Yanling , Luo Ziyi , Liu Xiaoyan , Liu Li , Shen Hui , Zhou Fuling 
Published: November 2020

Objective: To investigate the efficacy and safety of recombinant human thrombopoietin(rhTPO) in the treatment of thrombocytopenia after chemotherapy for acute myeloid leukemia in vivo and in vitro.
Methods: A retrospective collection of 95 patients with acute myeloid leukemia who suffered thrombocytopenia after chemotherapy in Zhongnan hospital from July 2014 to April 2019 were collected. The patients were divided into two groups according to different medications, one group was treated with reorganized human thrombopoietin, the other one with recombinant IL-11, the platelet counts between two groups was analyzed and the platelet recovery under different ages, medical conditions and other factors were analyzed; mice patient derived xenograft model of acute myeloid leukemia with thrombocytopenia after chemotherapy was established to verify the efficacy and the mechanism of rhTPO.
Results: Since the platelet counts began to recover, the platelet increase in rhTPO group was significantly greater than that in IL-11 group, the platelet count is significantly higher than IL-11 group at Day42 (P&lt;0.05). Age and whether it is chemotherapy-naive patient has no significant effect on the function of rhTPO in restoring platelet counts. It is verified that rhTPO can increase platelet counts, but has no significant effect on leukocytes, erythrocytes. The injection of rhTPO leads to more synthesis of TPO in liver by activating the JAK2-STAT3 pathway.
Conclusion: Our work has paved the way for further study on the clinical application of rhTPO in managing thrombocytopenia for AML after chemotherapy.

Disclosures
No relevant conflicts of interest to declare.