bluuebunny/crossref_metadata_2025_split huggingface dataset:
CD39 As a Master Regulator of Pulmonary Thrombosis in Sickle Cell Disease
Authors: Brzoska Tomasz , Tutuncuoglu Egemen , Tofovic Stevan P. , Jackson Edwin K. , Gladwin Mark T , Sundd Prithu 
Published: November 2019

Acute systemic painful vaso-occlusive crisis (VOC) often serves as an antecedent to acute chest syndrome (ACS), which is a type of acute lung injury and the leading cause of mortality among sickle cell disease (SCD) patients. Thrombocytopenia secondary to pulmonary thrombosis is major risk factor for ACS, however, only 20% of ACS patients are diagnosed with pulmonary thrombosis as an underlying cause of ACS. Although clinical evidence supports the presence of prothrombotic state in subset of SCD patients, the molecular, cellular and genetic mechanisms that selectively render subset of SCD patients at either higher or lower risk of developing pulmonary thrombosis remains elusive. Adenosine diphosphate (ADP) released from lysed erythrocytes can activate platelets by stimulating their purinergic P2Y1 and P2Y12 receptors, however, P2Y12 receptor antagonists have not shown any benefit in clinical trials, justifying the need for better understanding of purinergic signaling in SCD.
Here, we use intravital lung microscopy in transgenic humanized SCD mice to show that intravenous administration of ADP triggered pulmonary thrombosis in control mice but failed to trigger pulmonary thrombosis in SCD mice. In contrast, collagen evoked pulmonary thrombosis identically in both control and SCD mice. Identical to intravital findings, IV ADP administration also evoked transient thrombocytopenia in control but not SCD mice, while, IV collagen led to comparable drop in platelet count in both SCD and control mice. ADP is metabolized by the ecto-nucleoside-tri-phosphate-diphosphohydrolase-1 (E-NTPDase1) CD39. IV administration of fluorescent analogue of ADP, N⁶- ethenoadenosine- 5'- O- diphosphate (ε-ADP) followed by invivo microdialysis and HPLC analysis revealed impaired ε-ADP degradation in SCD mice, suggestive of decreased CD39 activity.
Our current findings suggest that loss of CD39 activity in SCD possibly prevents ADP-mediated pulmonary thrombosis. Currently, experiments are underway to identify pathways contributing to loss of CD39 activity in SCD, how that affects purinergic signaling and whether selective activation vs deactivation of this pathway is responsible for risk of pulmonary thrombosis in only 20% of ACS patients.

Disclosures
Gladwin: Globin Solutions, Inc: Patents & Royalties: Provisional patents for the use of recombinant neuroglobin and heme-based molecules as antidotes for CO poisoning; United Therapeutics: Patents & Royalties: Co-inventor on an NIH government patent for the use of nitrite salts in cardiovascular diseases ; Bayer Pharmaceuticals: Other: Co-investigator.
Characterization of Leukemic Stem Cells Heterogeneity in Chronic Myeloid Leukemia
Authors: Warfvinge Rebecca , Sommarin Mikael , Dhapola Parashar , Pfisterer Ulrich , Geironson Ulfsson Linda , Safi Fatemeh , Krishna Thakur Ram , Richter Johan , Karlsson Göran 
Published: November 2019

In chronic myeloid leukemia (CML), a rare subset of leukemic stem cells (LSC) persists in patients responding to conventional tyrosine kinase inhibitor (TKI) therapy. The failure to eradicate these LSCs results in indefinite therapy dependence and a risk of leukemic relapse. However, the conventional LSC compartment (Lin-CD34+CD38-) is highly heterogeneous where only a subpopulation is believed to be functional, TKI-insensitive LSCs.
Previously, using single-cell gene expression analysis we characterized the heterogeneity within the LSC population (Lin-CD34+CD38-) in CML patients using a selected panel of 96 primers. Interestingly, by comparing LSC heterogeneity at diagnosis with the heterogeneity following 3 months of TKI therapy we uncovered a therapy-insensitive, quiescent subpopulation, which could be isolated at high-purity using a combination of the surface markers: Lin-CD34+CD38-CD45RA-cKIT-CD26+ (Warfvinge, Geironson, Sommarin et al., 2017).
Here, we expand the single-cell analysis of CML LSC populations to include combined immunophenotype-/RNA sequencing analysis (CITE-seq). CITE-seq allows for unbiased, further in-depth transcriptome analysis as wells as immunophenotypic characterization by pre-staining cells with a panel of DNA-barcoded antibodies prior to sequencing. DNA-barcoded antibodies convert the protein expression into readable sequences through unique oligo-conjugates as identifiers.
Using CITE-seq with a panel of 44 distinct surface markers designed to immunophenotypically differentiate between stem/progenitors cells and leukemic clones we simultaneously characterize the molecular and immunophenotypic heterogeneity within Lin-CD34+/Lin-CD34+CD38- CML stem/progenitor compartment at diagnosis. Additionally by comparing the LSCs transcriptome from patients with different therapeutic outcome after 12 months of therapy we describe how differences in heterogeneity and the presence of immunophenotypic therapy-insensitive LSCs at diagnosis (Lin-CD34+CD38-CD45RA-cKIT-CD26+) contribute to therapy response.

Disclosures
Richter: Novartis: Consultancy; Pfizer: Consultancy, Research Funding.
Impact of Histologic Type on Survival in Primary Parotid Lymphomas
Authors: Al-Juhaishi Taha , Khurana Arushi , Shafer Danielle , Yazbeck Victor 
Published: November 2019

Introduction:
Primary extranodal lymphomas of the salivary glands constitute 12% of head and neck lymphomas, and less than 5% of salivary gland neoplasms. Parotid gland is the most commonly involved structure. Mucosa-associated lymphoid tissue (MALT) lymphoma is considered the most common histology in parotid lymphomas and carry a favorable prognosis. In this study, we sought to explore the impact of histologic subtype on survival.
Methods:
The Surveillance, Epidemiology and End Results (SEER) database was used to identify patients (≥18 years) diagnosed with primary parotid lymphomas between 1975 and 2016. B-cell, T-cell, and Hodgkin's lymphomas were included. Treatment effect (surgery, radiation, chemotherapy) was analyzed when available. Only stage I lymphomas by Ann-Arbor staging system were included to ensure parotid gland as the primary site. Overall survival was estimated using the Kaplan-Meier method, and compared using Log-Rank test. Cox proportional hazards models were used for adjusted survival analyses.
Results:
A total of 1482 patients were included in the analysis. Median age was 66 years (18-102), and the majority were female (n=904, 61%) and Caucasian (n=1074, 72.5%). MALT was the most common histology (N=681, 46%), followed by follicular lymphoma (FL; N=407, 27.5%), and diffuse large B-cell lymphoma (DLBCL; N=310, 21%). Small lymphocytic lymphoma was the least common histology (CLL/SLL; N=3, 0.8%). A total of 1084 patients (73%) had surgery, 433 (29%) had systemic therapies and 691 (47%) had radiation. Median overall survival was 13 years [12-14.5; 95% CI]. Survival was different by histological type (Figure 1, P<0.001). Compared with MALT, DLBCL was associated with higher mortality (HR 2.05 [1.60-2.63], P <0.001), while FL was not significantly different (HR 1.11 [0.89-1.40], P=0.32); independent of other variables. In a multivariate model; surgery (HR 0.81 [0.66-0.99], P=0.042) and radiation (HR 0.67 [0.56-0.82], P <0.001), but not systemic therapies (HR 0.93 [0.76-1.15], P=0.55) were associated with lower mortality (Figures 2-4). Adjusted mortality decreased by a relative 3% annually (HR 0.97 [0.95-0.99], P=0.03).
Conclusion:
Primary parotid lymphomas are rare extranodal lymphomas affecting mostly elderly Caucasian women. Using a large population database, MALT was still the most common histology and carried a favorable prognosis with a median overall survival of greater than 10 years despite the high median age at diagnosis. DLBCL histology did significantly worse which highlights the need for potentially more aggressive interventions to improve outcomes. Surgery and radiation were associated with improved outcomes.

Disclosures
Yazbeck: Gilead Sciences: Research Funding; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees.
Caudal Type Homeobox 2 Is Required for Leukemogenesis but Not for Normal Hematopoieisis
Authors: Jones Morgan A , Zhao Meiling , Liu Lu , Feng Ying , Ross Adam , Fearon Eric R , Li Qing 
Published: November 2019

Caudal Type Homeobox 2 (CDX2) is a caudal-related homeobox family transcription factor known to be developmental regulator involved in murine axial elongation and anteroposterior vertebral patterning and cell fate determination in the intestine. In adults, CDX2 expression is restricted to the small intestine and the colon. Interestingly, CDX2 is overexpressed in ~90% of human acute myeloid leukemias and the majority of acute lymphoblastic leukemias. Hence, aberrant expression of CDX2 may play a contributing role in leukemogenesis. The role of CDX2 in normal hematopoietic development is unknown. To assess the role of CDX2 in normal hematopoiesis we characterized hematopoietic development in Cdx2 fl/fl Mx1-Cre+ mice after poly (I:C)-mediated gene deletion compared to wildtype littermates. Under steady state conditions, no significant defects were identified in long-term hematopoietic stem cells (LT-HSCs), multipotent progenitors, myeloid progenitors, or mature cell lineages. To test if long-term hematopoietic stem cells were functionally impaired following Cdx2 deletion, competitive transplantation assays were performed. We found that CDX2 was not required for long-term hematopoietic reconstitution in the competitive transplant setting. Together, these data establish that CDX2 is not required for adult steady state hematopoiesis or LT-HSC function. We then asked whether or not CDX2 was essential for leukemogenesis. To interrogate this, Cdx2 fl/fl Mx1-Cre+, Cdx2 fl/+ Mx1-Cre+, and wildtype littermates were treated with poly (I:C) to facilitate gene deletion or for control purposes. Bone marrow cells from the mice were then transformed using well-established HOXA9/MEIS1 or MLL-AF10 leukemogenesis models. In both systems, Cdx2-deficiency prevented leukemia development, whereas wildtype controls succumbed to leukemia within 200 days. Cdx2 heterozygous knockout animals had a delayed onset of leukemia compared to wildtype animals. Taken together, these data indicate that CDX2 is not required for steady state adult hematopoiesis or LT-HSC function, but is necessary for the development of leukemia. Our findings suggest CDX2 has potential as a novel therapeutic target that could be exploited in the majority of AML and ALL patients across a broad mutational spectrum. The nomination of CDX2 as a key target for the majority of leukemias is significant, as current targeted treatment strategies are limited to only particular patient subsets.

Disclosures
No relevant conflicts of interest to declare.
Recurrent JAK3 Mutations in Post-Transplant Lymphoproliferative Disorder
Authors: Butzmann Alexandra , Jangam Diwash , Kumar Jyoti , Sridhar Kaushik , Pinsky Benjamin A , Ohgami Robert S. 
Published: November 2019

Post-transplant lymphoproliferative disorders (PTLD) are diverse in morphology, immunophenotype and clinical outcomes, occurring in immune compromised patients after hematopoietic stem cell transplantation (HCT) or single organ transplantation (SOT). Predicting the outcome of PTLDs is complex. In most of cases PTLD is driven by Epstein-Barr virus (EBV) infection, though the etiology of EBV negative cases is unknown. There have been only few studies investigating the mutational landscape and gene expression of PTLD.
In our study we performed targeted DNA deep sequencing and RNA expression profiling (RNA-Seq) on the hematopoietic lymphoid tissues of 15 post-transplant patients with PTLD and 16 post-transplant patients with follicular hyperplasia (FH) after HCT or SOT.
Recurrent mutations in JAK3 were identified in five of 16 PTLD cases and one of 16 follicular hyperplasia cases. We additionally identified mutations in the PIK3CD gene in four PTLD cases and NOTCH1 mutations in 2 PTLD and four FH cases. 17 other genes were commonly mutated in both groups. Gene expression profiles differed between both groups. Genes involved in regulating the immune system were unregulated in PTLD. We also saw a stronger expression of T-cells and a weaker expression of B-cells within the PTLD group when compared with FH.
Our findings suggest an important role for immune regulatory pathways in the pathogenesis of PTLD, with the JAK/STAT pathway being a central recurrent key metabolic pathway.
Figure

Disclosures
Ohgami: Agilent technologies: Other: received support/funding.
RNA-Sequencing Based Assessment of Targets, Risk and Long Term Survival for Personalized Treatment of Multiple Myeloma
Authors: Emde Martina , Beck Susanne , Benes Vladimir , Moreaux Jerome , Seckinger Anja , Hose Dirk 
Published: November 2019

Aim of our study is to implement RNA-sequencing as basis for risk adapted and targeted treatment-strategies in multiple myeloma. We establish assessment of malignant plasma cell proliferation and risk-stratification de novo (HDHRS) by RNA-sequencing, transfer microarray-based risk scores to RNA-sequencing, and report expression of actionable including immune-oncological targets.
Methods. Transcriptome profiling was performed on CD138 purified malignant plasma cell samples from previously untreated symptomatic multiple myeloma patients undergoing high-dose melphalan treatment and autologous stem cell transplantation. RNA-sequencing was performed on an Illumina NextSeq500-platform using 5ng of total RNA (n=535), and, in the same cohort, by gene expression profiling using Affymetrix U133 2.0 DNA-microarrays (n=534). iFISH was performed using a ten-probe panel (n=535). Clinical data and survival of patients treated with high-dose therapy and autologous stem cell transplantation were assessed (n=534/533/534 for RNA-seq/GEP/iFISH) with median follow up of 64 months. Data were validated using the independent COMPASS cohort (n=767 pts., median follow up of 31 months).
Results. RNA-sequencing is feasible in more than 90% of myeloma patients. It allows assessment of proliferation (RPI) and risk, both de novo (HDHRS) and regarding microarray-based scores (UAMS GEP70-, EMC92-, Rs-score). All scores are significantly predictive for overall and event-free survival in GEP are likewise in RNA-seq with hazard ratio for high risk to low risk group of 3.06, 4.3, 2.84, 3.93 and 3.30 in overall survival of test group. (See as example gene expression based proliferation index / RNA-seq based proliferation index, Fig. 1). The de novo RNA-seq risk stratification (HDHRS) superiorly delineates three significantly different groups of 40%, 38%, and 22% of patients with 5-year survival rates of 84%, 67%, and 32%, respectively (Fig.2). It likewise discerns a group of long term surviving patients with a survival rate of 57% and 49%, at 10 and 12 years, respectively. Targets expressed in normal plasma cells with varying expression height in malignant include BCMA and CD38, those aberrantly expressed CSF1, CD20 and HGF. Mutated actionable transcripts include BRAF V600E/K (target), the proteasome and cereblon (resistance).
In conclusion, RNA-seq allows assessment of risk, long term survival and targets in multiple myeloma both in phase III multicenter trials as well as in clinical Routine.

Disclosures
Moreaux: Diag2Tec: Other: Co-founder of Diag2Tec company.
VISTA Is a Novel Regulator of Macrophage Biology
Authors: Shah Parth , Eltanbouly Mohamed , Smits Nicole , Sarde Aurelien , Noelle Randolph , Mabaera Rodwell 
Published: November 2019

Background:V-domain Ig suppressor of T cell activation (VISTA) is an immune checkpoint receptor with an established role as an inhibitory receptor on T cells. However, its role in myeloid cell biology remains unclear. Owing to the much higher expression of VISTA on monocytes and macrophages, we investigated its role in regulating myeloid biology.
Methods: Mouse bone marrow-derived macrophages (BMDMs) were differentiated and treated with agonistic anti-VISTA mAb under steady-state and conditions of M1 inflammatory polarization (LPS + IFN-𝛾). Human CD14+ monocytes were isolated from peripheral blood and treated with anti-VISTA in vitro. Phosphoarrays were used to assess signaling downstream of VISTA engagement and Luminex analysis was used to evaluate cytokine production. Time-course total RNA-seq was performed on BMDMs (at 1, 2, 4, 8 and 16 hours of anti-VISTA treatment). To evaluate the effect of anti-VISTA in vivo, single-cell RNA-seq (scRNA-seq) was performed on FACS sorted CD11b+ myeloid populations 12 hours after mice were treated with intravenous anti-VISTA.
Results:
Anti-VISTA treatment of BMDMs and human monocytes in vitro induced rapid phosphorylation events including robust phosphorylation of Raf-1 kinase at the suppressive serine residue 43.Next, we generated a comprehensive timestamp of VISTA activation in BMDMs in vitro by time-course deep RNA-seq analysis of agonistic anti-VISTA treated cells under rigorous M1 inflammatory polarization. This revealed a unique activation state marked by the upregulation of inhibitory cytokines IL-10 and IL1RA as well as ablation of IL-12 family cytokines, suggestive of an M2-like signature. The presence of an M2-like immunoregulatory signature defined by upregulation of the IL-10 was also seen in macrophages identified post clustering of in vivo scRNA-seq data on myeloid cells.
Conclusion:
Using novel agonistic anti-VISTA antibodies, we reveal that VISTA triggering on myeloid cells can induce an alternative anti-inflammatory cell-state, even under conditions of strong inflammatory polarization. This introduces VISTA as an intrinsic checkpoint of macrophage tolerance.

Disclosures
Noelle: Immunext: Employment, Equity Ownership, Patents & Royalties, Research Funding.
Acquired Dysfibrinogenemia Krakow III after Everolimus Therapy
Authors: Merkulova Alona A. , Mitchell Steven C. , Merkulov Sergei , Wolberg Alisa S. , Marguerite Neerman-Arbez , Schmaier Alvin H. 
Published: November 2019

A 45 yo woman with a medical history of common variable immunodifficiency (CVID) was referred for a bleeding disorder. The bleeding was manifested daily with ecchymosis and epistaxis, but prior to the visit, she developed a lower pelvic mass that was a massive hematoma requiring transfusion. In 2011 she had a splenectomy for thrombocytopenia. After splenectomy, her liver enlarged and one year prior to being seen, she was started on everolimus as part of a protocol to reduce her liver size.
Bleeding started 3-6 months after starting everolimus treatment, first manifesting with recurrent lower gastrointestinal hemorrhage. In 2011 she had normal PT and aPTT. At the present time her PT remains normal at 11.43+0.67 (Mean+SD) (normal 9.7-12.7 sec); but her aPTT is abnormal at 43+6.1 (normal 28-38 sec); clottable fibrinogen (Fb) 305+72 (normal 200-400 mg/dl); Fb antigen, 428+115 mg/dl (normal 196-441); ratio of clottable Fb/Fb antigen = 0.71+ 0.06; reptilase time 20+2.2 (normal 14-23 sec); and her thrombin time of 19+1.6 is prolonged (normal 10-16 sec). Blood coagulation factors XI, IX, VIII, VII, X, V, II, and XIII were normal. Further, she did not have excess alpha-1-antitrypin, antithrombin, or protein C to suppress thrombin generation. On a 1:1 mixing study of normal plasma:patient plasma, her thrombin time corrected to normal. Since the patient had an abnormal thrombin time with serious, spontaneous, clinical bleeding with a normal reptilase time, we postulated a fibrin polymerization defect. On a fibrin polymerization assay, the patient required 4-fold greater amounts (32 nM vs 8 nM) of human alpha thrombin to achieve complete fibrin polymerization (See Figure 1 below). On complete fibrinogen sequencing, the patient was found to have a pathologic mutation [Fb gamma chain exon 3, 124G>A, Gly42Ser (Gly16Ser in the mature gamma chain without the signal peptide)]. This defect had been previously described as Fibrinogen Krakow III (Pietrys D et al. Thromb Haemost. 2011;106:558-60). However, neither parent of the patient has a bleeding disorder. Sequencings of her parents' Fb gamma chains show no mutation.
Since first being seen, the patient had a serious bleed into her right sacral plexus leaving her with a permanent foot drop. We managed her bleeding with cryoprecipitate replacement acutely and oral tranexamic acid as an outpatient. Everolimus is an mTor inhibitor which is a regulator of protein synthesis. We postulated that everolimus therapy produced the acquired abnormal Fb gamma synthesis, producing the fibrin polymerization defect associated with bleeding. Upon urging, the patient stopped everolimus therapy and has not had a major bleeding incident in 8 months although the abnormal thrombin time persists.
Figure 1

Disclosures
Wolberg: Novo Nordisk: Research Funding.
Cross-Reactivity of Drug-Dependent Antibodies in Patients with Immune Thrombocytopenia Induced By Beta-Lactam Antibiotics
Authors: Slaught Matthew John , Bougie Daniel W. , Aster Richard H. 
Published: November 2019

More than 50 beta lactam (BL) antibiotics are now in active use for treatment of a wide range of bacterial infections. BL antibiotics are among the most common drugs capable of inducing antibodies (DDAbs) that cause drug-induced immune thrombocytopenia (DITP). Most DDAbs are highly specific for the sensitizing drug but beta lactams all have a common core structure and many similarities among side groups that are added to augment potency and modify specificity, raising the possibility that a DDAb specific for one BL may cross-react with another. We studied DDAbs from 33 patients with DITP induced by 9 commonly used BL drugs to determine whether patterns of cross-reactivity exist that might influence the choice of an alternative antibiotic in a patient with BL-induced DITP.
DDAbs were demonstrated in a flow cytometric assay considered to be "positive" when immunoglobulins in patient serum but not normal serum react with normal platelets in the presence, but not in the absence of drug (Blood 2018;131:1486). DDAbs detected in the 33 patients were specific for 9 different BL drugs that were divided into two groups, "penicillins" (Group 1) and cephalosporins (Group 2) on the basis of structural similarities (Figure 1). In Group 1 were 19 DDAbs specific for amoxicillin (2), nafcillin (4) and piperacillin (13). Structurally similar ampicillin and penicillin were also tested with these abs. In Group 2 were 14 DDAbs specific for cefadroxil (1), cefepime (2), ceftazidime (2), ceftizoxime (1), ceftriaxone (7) and cephalexin 1). Cross-reactions identified within these groups of DDAbs are shown in Tables 1 and 2.
Cross-reactions, many quite strong (S) were observed among DDAbs specific for drugs in both structural groups (Tables 1 and 2). Particularly noteworthy were cross-reactions of the 19 Group 1 DDAbs with ampicillin (6) and penicillin (6) (Table 1) and of the 14 Group 2 DDAbs with cefepime (6), ceftizoxazole (6) and ceftriaxone (3) (Table 2). The findings show that platelet-specific DDAbs induced by beta lactam antibiotics, in contrast with those induced by medications like quinine, sulfamethoxazole and vancomycin, commonly cross-react with other antibiotics of this class. In patients with immune thrombocytopenia induced by a beta lactam antibiotic, it may be prudent to avoid switching to another beta lactam or, if this is necessary, to monitor platelet counts carefully.

Disclosures
No relevant conflicts of interest to declare.