bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spatial Transcriptomics Reveals DPP4 As Novel Marker of a More Proliferative Phenotype in Early AML Progression
Authors: Haase Christa , Gustafsson Karin , Mei Shenglin , Milosevic Jelena , Yeh Shu-Chi , Sykes David , Kharchenko Peter , Scadden David T. , Lin Charles 
Published: November 2021

Abstract
Acute myeloid leukemia (AML) is a hematologic malignancy with poor prognosis for which the standard-of-care chemotherapy treatment regimen has remained virtually unchanged over the past 40 years. We have employed "Image-Seq", a new technology that was developed in our laboratory, to study spatial variations in early leukemia progression in a mouse model of HoxA9-Meis1 AML. We visualized leukemia cells with differing proliferative phenotype using intravital microscopy, captured these cells under image guidance from individual bone marrow microenvironments and studied their differential expression by single-cell RNA sequencing. This analysis identified DPP4 as a key upregulated gene in AML cells from more proliferative bone marrow compartments and associated DPP4 expression with a cell cluster enriched in progenitor cell markers for HoxA9-Meis1 AML, including Flt3, Itgb7 and Ddx4. Strikingly, DPP4 is not expressed in vitro, and its expression in vivo (as quantitated by FACS analysis) correlated with disease progression and marked a more proliferative phenotype both at the 1-week and 2-week time-points during disease progression.

Disclosures
Sykes: Clear Creek Bio: Current equity holder in publicly-traded company; SAFI Biosolutions: Consultancy, Current equity holder in publicly-traded company; Keros Therapeutics: Consultancy. Scadden: Magenta Therapeutics: Current holder of individual stocks in a privately-held company, Membership on an entity's Board of Directors or advisory committees; VCanBio: Consultancy; LifeVaultBio: Current holder of individual stocks in a privately-held company, Membership on an entity's Board of Directors or advisory committees; Inzen Therapeutics: Membership on an entity's Board of Directors or advisory committees; Garuda Therapeutics: Current holder of individual stocks in a privately-held company, Membership on an entity's Board of Directors or advisory committees; FOG Pharma: Consultancy; Fate Therapeutics: Current holder of individual stocks in a privately-held company; Editas Medicines: Current holder of individual stocks in a privately-held company, Membership on an entity's Board of Directors or advisory committees; Dainippon Sumitomo Pharma: Other: sponsored research; Clear Creek Bio: Current holder of individual stocks in a privately-held company, Membership on an entity's Board of Directors or advisory committees; Agios Pharmaceuticals: Current holder of individual stocks in a privately-held company, Membership on an entity's Board of Directors or advisory committees.
Rural-Urban Disparities in Place of Death in Hematologic Malignancies in the US from 2003 to 2019
Authors: Hussaini Syed M. Qasim , Gupta Arjun 
Published: November 2021

Abstract
Background: more than 60,000 people die annually from hematologic malignancies in the united states (us). Patients with hematologic malignancies more frequently receive aggressive care toward the end-of-life and are more likely to die in a hospital compared to those with a solid tumor. Appropriate care of such patients is very dependent on an existing healthcare infrastructure. There are notable challenges to rural healthcare in the united states which contains less than 1/5th of all hospices in the us. In this study, we sought to investigate rural-urban disparities in place of death the us in individuals that died from hematologic malignancies.
Methods: we utilized the us centers for disease control and prevention wide-ranging online data for epidemiologic research database to analyze all deaths from hematologic malignancies in the us from 2003 to 2019. A population classification utilizing the 2013 us census was made using the national center for health statistics urban-rural classification scheme. These classifications included: large metropolitan area (1 million), small- or medium-sized metropolitan area (50 000-999 999), and rural area (&lt;50 000). We estimated deaths in a medical facility, hospice, home, or nursing care facility. We stratified the results by age, sex, and race/ethnicity. The annual percentage change (apc) in deaths was estimated. All data was publicly available and de-identified.
Findings: from 2003-2019, there were a total 1,088,589 deaths form hematologic malignancies in the united states, predominantly in large metropolitan areas (50.2%), followed by small or medium sized metropolitan areas (31.7%) and rural areas (18.2%). All regions noted decreases in medical facility and nursing facility related deaths, and increase in hospice and home deaths. While rural areas demonstrated the quickest uptake of hospice care (apc 61.5), they had the lowest overall presence of hospice care (8.3% of all rural deaths in 2019 vs. 14.9% for small or medium metropolitan vs. 12% for large metropolitan) and larger share of nursing facility related deaths (15.8% of all rural deaths in 2019 vs 12.3% for small or medium metropolitan vs 10.6% for large metropolitan).
Discussion: we demonstrate end-of-life disparities in hematologic malignancies based on where an individual resides in the us with rural areas having notably lower share of deaths in hospice facilities. Older infrastructure, inadequate access to care, and financial barriers add to the medical complexity of care for all patients, and especially hematologic patients with high needs and complex treatment planning. These have been aggravated by rural hospital closures in the previous 18 months. The us senate is currently debating a bipartisan infrastructure that may add billions in building rural healthcare infrastructure to state budgets. Our findings are timely in helping inform congressional policy.
Figure 1 Figure 1.

Disclosures
No relevant conflicts of interest to declare.
Testing for Heparin Induced Thrombocytopenia in Hospitalized Patients: In Line with Evidence?
Authors: Grewal Udhayvir Singh , Gaddam Shiva Jashwanth , Thotamgari Sahith Reddy , Brown Tyiesha , Beedupalli Kavitha , Mills Glenn M. 
Published: November 2021

Abstract
Background: Heparin-induced thrombocytopenia (HIT) is an immune complication of heparin therapy caused by antibodies to complexes of platelet factor 4 (PF4) and heparin. Both clinical probability and laboratory testing are needed for establishing a diagnosis of HIT. The 4Ts clinical scoring system, due to a very high negative predictive value when low, offers a robust means to exclude a diagnosis of HIT. However, these strategies are under-employed in clinical practice and limited evidence indicates a high prevalence of over-testing for HIT.
Methods: This retrospective analysis was conducted to identify patients who underwent heparin/PF4 antibody testing over a period of 12 months. The testing was performed using an ELISA-based IgG anti-heparin/PF4 antibody assay and an optical density (OD) of 0.4 was used as a cut-off for a positive value. Electronic medical records were reviewed for 4T score documentation, anti-PF4 results, SRA testing and 4T scores were retrospectively calculated for all the patients. SAS v9.4 (Cary, NC) was used for statistical analysis.
Results: A total of 105 patients who underwent anti-PF4 antibody testing were included for analysis. Majority of the patients in our cohort were admitted in an intensive care unit setting (75/105,71.4%). On chart review, only 17 patients (16.2%) were noted to have documentation of 4T score. Based on the retrospectively calculated 4T scores, 60 patients (57.1%) had low pre-test probability, 41 (39%) had intermediate pre-test probability and 4 (3.8%) patients were noted to have high pre-test probability. Anti-PF4/heparin antibodies were positive in 9 patients, of which 5 (55.5%) patients did not undergo concomitant SRA testing. Out of 9, 4 (44.4%) had weakly positive (0.4-1.0 OD units), 2 (21.1%) had strongly positive (1.0-2.0 OD units) and 2 (21.1%) patients had very strongly positive (&gt;2 OD units) anti-PF4 antibody titers. Out of 105 patients, SRA was tested in 11 patients (10.5%) and was noted to be positive in 1 (0.95%). Overall, 2 patients were diagnosed and treated for HIT, out of which the diagnosis was not confirmed with SRA in 1 patient (due to high pre-test probability and very strong anti-PF4 titers). In the remaining patients, sepsis (48, 46.6%) and drug-induced thrombocytopenia (29, 28.2%) emerged as the most common possible causes of thrombocytopenia.
Conclusion: Among hospitalized patients, over-testing for HIT is common. Practices to promote 4T score documentation and evidence-based anti-PF4 testing may help prevent unnecessary costs associated with serological testing and costly alternate anticoagulants. To improve overall outcomes, clinicians should also attempt to identify and treat other more likely causes of thrombocytopenia, especially in patients with low pre-test probability for HIT.

Disclosures
No relevant conflicts of interest to declare.
CD200 Expression on Multiple Myeloma Cells Induces Attenuation of T Cell-Mediated Cytotoxicity Via DOK2
Authors: Shah Pooja , Stuehmer Thorsten , Bruennert Daniela , Munawar Umair , Leich Ellen , Kraus Sabrina , Hudecek Michael , Chatterjee Manik , Schlosser Andreas , Bargou Ralf C , Einsele Hermann , Berberich-Siebelt Friederike , Steinbrunn Torsten 
Published: November 2021

Abstract
Introduction
The CD200/CD200 receptor (CD200R) axis is known to exert immunoregulatory effects in myeloid-derived cells and constitutes a putative immune checkpoint in hematological malignancies, in which CD200 expression is associated with poor prognosis. In multiple myeloma (MM), CD200 is expressed in the majority of patient-derived primary cells. However, its functional importance as well as the related downstream mechanism upon CD200 ligand binding to its CD200R on T cells are not well understood. In this study, we analyze the functional role of CD200 as a potential immune checkpoint in MM and decipher the mechanism of CD200-mediated immune escape.
Methods
Primary MM cells and MM cell lines were analyzed for CD200 surface expression by flow cytometry. To overexpress CD200 on non-expressing MM cell lines we used a Sleeping Beauty transposon vector system. CD200+/- MM cell lines L363, U266 and MM.1s were co-cultured with CD3/CD28-activated healthy donor T cells. T cell-mediated cytotoxicity in these co-cultures was assessed with flow cytometry and/or luciferase assay. Moreover, to analyze the effects of CD200R activation on downstream signaling pathways, activated T cells were treated with recombinant human CD200 (rhCD200) and/or anti-CD200 blocking antibody and subsequently, Western blotting was performed.
Results
Of n=120 primary MM samples (n=120) analyzed, CD200 protein expression could be detected in ca. 75 % of the cases. In contrast, all n=9 MM cell lines tested neither displayed surface nor cytoplasmic CD200 expression. Therefore, using a Sleeping Beauty transposon vector system we stably expressed CD200 on MM cell lines for further analyses. In the presence of CD200-expressing MM cells up to 50% decrease in CD3+ T cell-mediated cytotoxicity against MM cells was observed in flow cytometry and luciferase assay. Proliferation rates of MM cell lines remained unchanged regardless of the level of CD200 overexpression as determined by Alamar blue assays. In myeloid-derived cells, CD200R directly interacts with docking protein-2 (DOK2). In activated T cells, we observed DOK2 phosphorylation upon CD200 binding when treated with rhCD200 in a time- and concentration-dependent manner. Applying an anti-CD200 blocking antibody, this effect could be reversed, thus revealing a possible mechanism for the observed attenuation of T cell function.
Conclusion
Our study shows that anti-MM cytotoxicity from primary healthy donor CD3+ T cells is attenuated by CD200 expression on MM cells. We also demonstrate that this inhibitory mechanism in CD3+ T cells is mediated via DOK2, providing a potential target for immunotherapeutic approaches in MM.

Disclosures
Einsele: Janssen, Celgene/BMS, Amgen, GSK, Sanofi: Consultancy, Honoraria, Research Funding.
Carfilzomib-Lenalidomide-Dexamethasone in the Management of Lenalidomide-Refractory Multiple Myeloma
Authors: Cerchione Claudio , Nappi Davide , Pareto Anna Emanuele , Pane Fabrizio , Catalano Lucio , Martinelli Giovanni 
Published: November 2021

Abstract
Carfilzomib is an epoxyketone proteasome inhibitor of second generation, proved to be effective and safe in relapsed and refractory Multiple Myeloma (rrMM), in combination with dexamethasone or lenalidomide and dexamethasone.
In this retrospective observational trial, it has been evaluated efficacy and safety of carfilzomib, in combination with lenalidomide-dexamethasone (KRD) as salvage regimen in patients with rrMM, refractory to lenalidomide, where lenalidomide-based regimens have no proven efficacy.
41 patients (23 M/18 F), with rrMM, median age at diagnosis 63.7 years (r. 43-82), median age at start of treatment 67 years (r. 48-84) previously treated with several lines of treatments (median 3, r. 2-11), underwent to KRD regimen (ASPIRE trial schedule) for a median treatment cycles of 8 (r 2-18). ISS was equally distributed, and all patients had previously been treated with bortezomib and IMIDs, and were refractory to this agents. 61% (19/31) of them had undergone at least to a single ASCT.
According to IMWG criteria, after a median follow-up of 9 months (r. 2-18), ORR was 68,2% (28/41: 9 CR, 12 VGPR, 7 PR) with 5 progressive diseases (PD) and 8 patients in stable disease (SD): this can be considered as an impressive result in this subset of rrMM patients, refractory to lenalidomide. In particular, for 11 patients, KRD was, after having achieved at least a PR, a bridge to second/third autologous SCT. Median time to response was 1.3 months (r.1-4), median OS from diagnosis was 62 months (r. 9-170), median OS from start of Carfilzomib was 11 months (r. 2-18). Carfilzomib was well tolerated, with grade 2 anemia in 39%(16/41) of patients, successfully managed by ESAs, without necessity of blood transfusions; 29% (12/41) grade 3-4 neutropenia (pegfilgrastim in primary prophylaxis was given, no ospedalization was required, no septic shocks were observed); 34% (14/41) grade 2, 21% (9/41) grade 3 and 12% (5/41) grade 4 thrombocytopenia, without hemorrhagic events and transfusion-dependency. Moreover, it was observed pneumonia in 39% (16/41) of patients, treated by common antibiotic drugs and always solved. A cardiac monitoring was performed for all patients: hypertension (grade 2-3) in 34% (14/41) of patients; fatigue in 39% (16/31) of patients.
Carfilzomib-Lenalidomide-Dexamethasone has shown significant efficacy in a particularly severe setting of patients, relapsed and refractory to all available therapeutic resources, also lenalidomide, and it could be considered as a bridge to a second autologous or allogenic SCT.

Disclosures
Martinelli: Jazz Pharmaceuticals: Consultancy; Stemline Therapeutics: Consultancy; Astellas: Consultancy, Speakers Bureau; Celgene /BMS: Consultancy, Speakers Bureau; Abbvie: Consultancy; Daichii Sankyo: Consultancy; Roche: Consultancy; Pfizer: Consultancy, Speakers Bureau; Incyte: Consultancy.
Spontaneous Calvarial Infarction with Epidural Hematoma and Subgaleal Hemorrhage in a Teenager with Sickle Cell SS Disease and Glucose-6-Phosphate Dehydrogenase Deficiency
Authors: Nestor Jennifer , Sanders Danielle , Mysore Sukrita , Ahmed Rafat , Milano Aubri , Ostrowicki Renata , Nwankwor Odiraa , Presenza Thomas , Scattergood Emily 
Published: November 2021

Abstract
Introduction:
Sequelae of sickle cell disease (SCD) are often the result of vaso-occlusion (VOC) related to the dysmorphic shape of sickled red blood cells (RBC). Bone infarction occurs commonly in patients with sickle cell, most notably in long bones and axial skeleton. Infarct occurs much less frequently in the bones of the skull. Calvarial bone infarct results in MRI findings of T2 hyperintensity in areas of bone marrow edema with associated swelling or hemorrhage. Symptomatic headaches in children with SCD are more likely to be due to severe underlying cerebral pathologies than in those children without SCD. When evaluating a child with SCD presenting with headache, it is important to consider calvarial infarct.
Case Description:
A 15 year old male with a history of sickle cell disease (type SS) and G6PD deficiency presented with chief complaints of headache and swelling over the left parietal region of the skull for two days with associated left sided visual disturbance. He denied head trauma or seizure-like activity. Upon presentation he was febrile with tachycardia and a normal neurological exam. CT scan of his head was significant for a left subgaleal hemorrhage and bilateral epidural midline and left parietal fluid collections consistent with bone marrow infarcts and associated subacute epidural hematomas, without evidence of brain parenchymal injury or sinus venous thrombosis. A follow up MRI obtained during hospitalization indicated that the left subgaleal hematoma remained stable with breakdown of subgaleal blood products. The patient was treated primarily with supportive care including hydration, packed red blood cell transfusions and pain management. He did not require neurosurgical intervention. His hospital course was complicated by VOC, sickle cell hepatopathy and acute chest syndrome.
Discussion:
Rarely, cranial VOC has resulted in epidural hematoma. In this case, calvarial infarct with unilateral headache, acute vision loss and acute cranial swelling resulted in subgaleal hemorrhage. This clinically significant finding results from bleeding between the periosteum and scalp galea aponeurosis, which may lead to hypovolemic shock. Calvarial infarcts should be considered on the differential in sickle cell disease patients presenting with a headache as prompt diagnosis can improve morbidity outcomes.

Disclosures
No relevant conflicts of interest to declare.
p53 Is a Crucial Regulator of Hemogenic Endothelial Cell Differentiation from Human Induced Pluripotent Stem Cells
Authors: Kanaujiya Jitendra K. , Lingenheld Elizabeth G. , Skarnes William C. , Oguro Hideyuki 
Published: November 2021

Abstract
De novo generation of hematopoietic stem cells (HSCs) from human induced pluripotent stem cells (hiPSCs) could provide a virtually unlimited supply of autologous HSCs for clinical transplantation, and offer various approaches that enable gene therapy, drug discovery, disease modeling, and in vitro modeling of human hematopoietic development. However, the derivation of long-term self-renewing HSCs from hiPSCs in culture remains elusive. The tumor suppressor protein p53 plays important roles in normal and malignant hematopoiesis, and Trp53-deficient mice exhibit increased number of HSCs. Although activation of p53 is known to promote differentiation of hPSCs and hPSCs recurrently acquire TP53 dominant negative mutations, its role in hematopoietic differentiation of hiPSCs has not been explored.
To differentiate hiPSCs into hematopoietic stem and progenitor cells (HSPCs), we used embryoid body (EB) formation method to first differentiate hiPSCs into hemogenic endothelial (HE) cells that express the CD34 highCD144 +CD73 -CD184 -CD43 -CD235a - cell-surface markers. HE cells were then transferred onto a Matrigel-coated plate to undergo endothelial-to-hematopoietic transition (EHT) to generate HSPCs that express the CD34 midCD45 mid cell-surface markers. Developed HSPCs were functionally evaluated by colony forming assay.
We observed that the expression of CDKN1A, a p53 target gene, was upregulated in hiPSC-derived EBs and HSPCs over the course of differentiation. To investigate the role of p53 in the generation of HSPCs from hiPSCs, we genetically deleted TP53 in hiPSCs followed by hematopoietic differentiation. While TP53 deletion increased the growth of EBs, it resulted in severe impairment of differentiation into HE cells and overall production of HSPCs that can form colonies. During HE differentiation from hiPSCs, TP53-deficient EBs showed significant reduction of endothelial-lineage gene expression, such as ETV2, CDH5, and PECAM1, as well as expression of RUNX1, a master transcription factor required for HE specification. These results indicate the indispensable role of p53 in HE differentiation from hiPSCs.
We then examined the effect of p53 activation on HE differentiation from hiPSCs by pharmacological activation of p53 in hiPSC-derived cells. Transient activation of p53 by Nutlin-3, a small molecule that inhibits the p53-HDM2 interaction and protects p53 from proteasomal degradation, only during HE differentiation but not during EHT significantly promoted HSPC generation as compared to the vehicle treated control.
Our findings shed light on the importance of selecting hiPSC lines that retain normal p53 activity for HE differentiation, and provide an approach to promote hematopoietic differentiation of hiPSCs by transiently activating p53 during HE differentiation.

Disclosures
Kanaujiya: Synthego: Other: Scientific Advisory; eGenesis: Other: Scientific Advisory.
Fotemustine-Containing Regimens Versus Regimens Based on High-Dose Methotrexate in Newly Diagnosed PCNSL
Authors: Wu Jingjing , Zhang Mingzhi , Wang Wenhua 
Published: November 2021

Abstract
Objective: This study was conducted to compare the effectiveness and safety of fotemustine-containing regimens and high-dose methotrexate-based regimens in newly diagnosed primary central nervous system lymphoma(PCNSL). Methods: From April 2012 to April 2020, 88 patients with PCNSL who received fotemustine-containing regimens and regimens based on high-dose methotrexate were retrospectively assessed in this study.47 patients were treated with fotemustine-containing regimens, of which 25 patients were treated with R-FPD (Rituximab , formustine, pemetrexed, dexamethasone) regimen, and the other 22 patients were treated with FVD (formustine, vincristine,dexamethasone) regimen. 41 patients were treated with high-dose methotrexate-based regimens, of which 26 patients were treated with MA(Methotrexate ,Cytarabine ) regimen, of which 8 patients were treated with R-MT(Rituximab ,methotrexate ,temozolomide)regimen,of which 5 patients were treated with R-MA(Rituximab ,methotrexate ,Cytarabine) regimen, and the other 2 patients were treated with RM(Rituximab ,methotrexate) combined Zebutinib regimen. Results: In the fotemustine-containing regimen groups (n=47), 18 cases were complete response(CR), 19 cases were partial response(PR), 6 cases were
stable disease (SD), 4 cases were disease progression (PD), objective response rate(ORR )was 79%, and diease contral rate(DCR) was 91%.10 cases were CR in the high-dose methotrexate groups (n=41) , 17 cases of PR, 7 cases of SD, 7 cases of PD, ORR was 66%, DCR was 83%.there was no significant difference in ORR (79%vs66%, P=0.176)and DCR(91%vs83% , P=0.226) between the two groups.No significant difference was observed in the 2-year PFS rate (19.4%vs10%, P=0.149) and 3-year OS rate (24%vs15%, P=0.200) between the two groups. The main adverse reactions in the high-dose methotrexate groups were myelosuppression and mucositis. In the fotemustine-containing regimen groups, myelosuppression was the main adverse reaction. The incidence of leukopenia of grade 3 and above in the high-dose methotrexate groups and fotemustine groups was 54% and 23%, respectively. The high-dose methotrexate groups had more severe leukopenia (P= 0.001). The incidence of mucositis in the high-dose methotrexate groups (68%) was significantly higher than that in the fotemustine group (26%). Conclusion: The fotemustine-containing regimens for the treatment of newly diagnosed PCNSL has the similar efficacy to the high-dose methotrexate group, with fewer adverse reactions, better safety and tolerability, and may be a feasible regimen.

Disclosures
No relevant conflicts of interest to declare.