bluuebunny/crossref_metadata_2025_split huggingface dataset:
Atomic-Level Dissection of the Polyclonal Immune Response to the Human Platelet Alloantigen, HPA-1a (PlA1)
Authors: Zhi Huiying , Ahlen Maria Therese , Thinn Aye Myat Myat , Weiler Hartmut , Curtis Brian R. , Skogen Bjorn , Zhu Jieqing , Newman Peter 
Published: October 2019

Abstract
Alloantibodies to platelet-specific antigens are responsible for two clinically-important bleeding disorders: Post-transfusion purpura and fetal/neonatal alloimmune thrombocytopenia (FNAIT). The HPA-1a/1b (also known as PlA1/A2) alloantigen system of human platelet membrane glycoprotein (GP)IIIa is controlled by a Leu33Pro polymorphism, and is responsible for ~80% of the cases of FNAIT. Local residues surrounding polymorphic residue 33 are suspected to have a profound effect on alloantibody binding and subsequent downstream effector events. To define the molecular requirements for HPA-1a alloantibody binding, we generated transgenic mice that expressed murine GPIIIa isoforms harboring select humanized residues within the PSI and EGF1 domain, and examined their ability to support the binding of a series of monoclonal and polyclonal HPA-1a-specific antibodies. Humanizing the PSI domain of murine GPIIIa was sufficient to recreate the HPA-1a epitope recognized by some HPA-1a-specific antibodies, however humanizing distinct amino acids within the linearly distant, but conformationally close, EGF1 domain was required to enable binding of others. Using a series of transgenic mice and recombinant constructs, we reveal previously unsuspected, complex heterogeneity of the polyclonal alloimmune response to this clinically important human platelet alloantigen system. High-resolution mapping of this alloimmune response may improve diagnosis of FNAIT by providing cells that distinguish specific alloantibody subpopulations, and should facilitate the rational design and selection of contemplated prophylactic and therapeutic anti-HPA-1a reagents.

Disclosures
Curtis: Ionis Pharmaceuticals: Consultancy.
The Clinical Significance of Tumor Associated Macrophages in Myelodysplastic Syndromes
Authors: Yang Yan , Wu Yu 
Published: October 2019

Abstract
Objective:
The purpose of this study is to investigate the relationship between the infiltration of tumor associated macrophages (TAMs) and the disease risk stratification and survival of patients with myelodysplastic syndrome (MDS) and to explore the role of TAMs in the clinical prognosis.
Methods:
We retrospectively collected and analyzed 115 patients initially diagnosed wih myelodysplastic syndromes from January, 2010 to July, 2017 in West China Hospital of Sichuan University. Both bone marrow biopsy specimens and clinical data of the patients enrolled were collected. All patients were assessed prognosis by international prognostic scoring system (IPSS). We quantified the involvement of macrophage (MΦ), alternatively activated macrophage (M2 MΦ) and classic activated macrophage (M1 MΦ) in bone marrow specimen by staining with anti-CD68 monoclonal antibody, anti-CD163 monoclonal antibody, and anti-iNOS monoclonal antibody respectively. Log-rank test was used to evaluate the difference of overall survival (OS) among different subgroups. Logistic regression was used to evaluate the effect of clinical parameters on patients' OS. Cox proportional-hazards models were used to estimate the independent risk factors influencing the prognosis of patients.
Results:
1 In the high risk group of MDS, the composition of CD163+MΦ was higher than that of the low risk group(p < 0.001). In the low risk group of MDS, the composition of iNOS+ MΦ was higher than that of the group with high risk(p < 0.001).
2 The median survival time and 3-year survival rate in the high CD163+MΦinfiltration group were significantly lower than those in the low infiltration group (13 months vs 43 months, 27% vs 64%, Log-rank test, P<0.001). The median survival time and 3-year survival rate in high iNOS+MΦ infiltration group were significantly higher than those in low infiltration group (42. 5 months vs 11 months, 65% vs 27% Log-rank test, P< 0.001).
3 According to the infiltration degree of iNOS+MΦ and CD163+MΦ, the M1 (iNOShigh/CD 163low)and M2 TA(iNOSlow/CD163high) MΦ were further distinguished (The median OS were 53m and 15m respectively, p< 0.001).
4 In multivariate analysis, high infiltration of CD163+MΦ and CD68+MΦ, low infiltration of iNOS+MΦ and low PLT level were independent risk factors for patients' OS .
Conclusion and Discuss:
The degree of bone marrow TAMs subtype infiltration in MDS patients was associated with disease risk group. CD163+M Φ was the main TAMs in the high risk group of MDS,while iNOS+M Φ was the main TAMs in the low risk group. There was a positive correlation between the infiltration of M1-TAMs and OS. On the contrary, there was a negative correlation between the infiltration of M2-TAMs and OS. Analyzing TAMs subsets in bone marrow of patients with MDS is helpful to evaluate disease risk and prognosis.

Disclosures
No relevant conflicts of interest to declare.
Intravenous Administration of Recombinant Factor VIII Induces Immune Tolerance to Subcutaneous Turoctocog Alfa Pegol (SC N8-GP) in Humanized Hemophilia A Mice
Authors: Reedtz-Runge Stine Louise , Weldingh Karin , Schiøler Schultz Heidi , Holm Millner Anders , Rode Frederik , Wiinberg Bo , Kjelgaard-Hansen Mads 
Published: October 2019

Abstract
Introduction
Turoctocog alfa pegol (N8-GP) is a glycoPEGylated recombinant factor VIII (rFVIII) under development for treatment of hemophilia A (HA). Patients with severe HA receiving intravenous (IV) replacement therapy have 20-40% risk of developing inhibitory FVIII antibodies. It is unclear whether the absence of inhibitors in some patients is due to lack of response or due to peripheral tolerance. Induction of peripheral tolerance may be dependent on regulatory T-cells (Tregs) since they are suggested to be involved in regulation of the anti-FVIII antibody response.
In this study, tolerance induction following IV rFVIII administration was assessed in humanized HA mice, described as a suitable model for tolerance induction as only a fraction produce anti-FVIII antibodies after IV FVIII exposure (Steinitz KN, et al. Blood 2012;119(17):4073-4082).
Aims
To explore whether IV exposure to rFVIII induces peripheral tolerance to subcutaneous N8-GP (SC N8-GP) exposure in humanized HA mice, and whether Tregs play a role in tolerance induction.
Methods
HLA-DR transgenic FVIII-deficient mice lacking murine MHC class II were treated with rFVIII IV once per week for 8 weeks, then challenged with SC N8-GP once a week for 8 weeks. The role of CD25+ Tregs was studied by treating one group of mice with depleting anti-CD25 antibodies during the IV exposure period.
The presence of anti-FVIII antibodies was measured prior to IV and SC dosing, and at study end. Mice with anti-FVIII antibodies after IV rFVIII exposure were excluded from the analysis.
Results
No anti-FVIII antibodies were detected after challenge with SC N8-GP in mice pretreated with IV rFVIII. Depletion of CD25+ Tregs (confirmed by flow cytometry) during the IV exposure did not significantly affect the anti-FVIII antibody response.
Conclusion
It was demonstrated that peripheral tolerance to SC N8-GP was induced in humanized HA mice not responding to IV rFVIII exposure. Depletion of CD25+ Tregs during IV exposure was insufficient to abolish the induction of tolerance.

Disclosures
Reedtz-Runge: Novo Nordisk A/S: Employment. Weldingh:Novo Nordisk A/S: Employment. Schiøler Schultz:Novo Nordisk A/S: Employment. Holm Millner:Novo Nordisk A/S: Employment. Rode:Novo Nordisk A/S: Employment. Wiinberg:Novo Nordisk A/S: Employment. Kjelgaard-Hansen:Novo Nordisk A/S: Employment.
Daratumumab for Delayed Red Cell Engraftment after Hematopoietic Stem Cell Transplant
Authors: Chapuy Claudia I , Kaufman Richard M , Alyea Edwin P. , Connors Jean M. 
Published: October 2019

Abstract
Allogeneic stem cell transplantation represents a curative treatment option for patients with malignant hematologic diseases, including myelodysplastic syndrome (MDS). In 25-50% of transplants, HLA-matched allogeneic stem cell donors have some degree of ABO incompatibility with the recipient. Major ABO incompatibility is caused by recipient antibodies directed against donor red blood cells (RBCs) and may lead to delayed RBC recovery and transient pure red cell aplasia (PRCA). We describe a case of treatment-refractory pure red cell aplasia following a major ABO-mismatchedallogeneic stem cell transplant successfully treated with daratumumab.
The 72-year-old patient with MDS received a matched unrelated donor transplant with a major ABO incompatibility, recipient blood group O from blood group A donor. Despite prompt engraftment with WBC and platelet recovery he remained anemic and RBC transfusion dependent. Bone marrow biopsy showed <1% erythroid elements concerning for post-transplant PRCA. 200 days post-transplant he had persistent circulating anti-A antibodies and no signs of red cell recovery. Standard treatments including tapering of immunosuppression, steroids, rituximab and erythropoiesis stimulating agents had no effect. The patient remained transfusion dependent with 1-2 units per week. Following treatment with daratumumab 390 days post transplant, he achieved transfusion-independence promptly within one week of treatment with daratumumab and continues to have normal erythropoiesis 10 months after daratumumab treatment. Anti-A antibodies became undetectable. The patient tolerated daratumumab well and no signs of GVHD or opportunistic infections were observed.
We describe the use of daratumumab in patients with PRCA after major ABO mismatch allogeneic stem cell transplant. We hypothesized that a selective treatment targeting the CD38 positive plasma cells would decrease anti-A antibody production and allow for RBC recovery. Our findings suggest that direct targeting of residual host plasma cells with an anti-CD38 targeted agent such as daratumumab might be a valid treatment option that needs to be considered for patients refractory to standard treatments.
Figure. Figure.

Disclosures
No relevant conflicts of interest to declare.
PD-L1 Expression Is Low in Large B-Cell Lymphoma with MYC or Double-Hit Translocation
Authors: Elbæk Mette Vestergaard , Pedersen Mette Ø , Breinholt Marie Fredslund , Reddy Anupama , Love Cassandra , Clasen-Linde Erik , Knudsen Helle , Nielsen Signe Ledou , Gang Anne Ortved , Hogdall Estrid , Dave Sandeep , Norgaard Peter H. 
Published: October 2019

Abstract
Introduction: In large B-cell lymphoma (LBCL) MYC translocation and MYC/BCL2 or BCL6 double hit (DH) is associated with poor prognosis and there is an unmet need for novel treatment targets in this patient group. Treatment targeting the PD-L1/PD-1 pathway has been successfully introduced in Hodgkin lymphoma and solid cancers but are still poorly elucidated in LBCL. PD-L1 expression might predict response to treatment targeting the PD-L1/PD-1 pathway. We therefore investigated the relationship between PD-L1 protein and mRNA expression levels and MYC and DH translocation in LBCL.
Material and Methods: MYC, BCL2 and BCL6 translocations were detected by fluorescent in situ hybridization in tissue samples from 130 patients randomly selected from two cohorts of patients with LBCL: 49 patients with MYC translocation of whom 36 patients had DH and 81 without MYC translocation. PD-L1 protein expression was detected by immunohistochemistry (IHC) in tissue samples from 77 patients and PD-L1 mRNA expression by next-generation RNA sequencing (NGS) in another 77 patients. 24 patients overlapped, i.e. were analysed with both IHC and NGS. Nonparametric tests were performed to evaluate intergroup differences.
Results: PD-L1 protein expression level was lower in patients with MYC translocation (n=42, median=3,3%, IQR 0,0-10,8) or DH (n=31, median=3,3%, IQR 0,0-10,0) compared to patients with no MYC translocation (n=35, median=16,7%, IQR 3,3-30,0) or DH (n=46, 13,3%, IQR 2,5-30,0), P=0.004 and P<0,001 respectively (Fig.1). PD-L1 mRNA expression was also significantly lower in patients with MYC translocation or DH, P=0,001 and P=0,006 respectively. Higher PD-L1 protein and mRNA expression levels were associated with non-GC-type compared to GC-type DLBCL, P= 0,004 and P=0,002 respectively.
Conclusions: We report a highly significant association between low PD-L1 expression and MYC and DH translocation in patients with LBCL. Our findings may indicate that patients with MYC or DH translocation may benefit less from treatment with PD-L1/PD-1-inhibitors compared to patients without these translocations. This should be evaluated in larger, prospective, consecutive trials.

Disclosures
No relevant conflicts of interest to declare.
Regulation of Homeostatic and Malignant B Cell Development By the Tetraspanin CD53
Authors: Greenberg Zev J. , Monlish Darlene A. , Bartnett Rachel L. , Schuettpelz Laura G. 
Published: October 2019

Abstract
Acute lymphoblastic leukemia (ALL) is the most frequent pediatric malignancy, most commonly originating from the transformation of progenitor cells of the B cell lineage (B cell precursor-ALL; BCP-ALL). Treatment of patients with high-risk or relapsed disease is difficult and prognosis remains poor in pediatric patients, with an even worse survival rate for adult BCP-ALL. Previous studies have shown an association of enhanced CD53 expression with many B cell malignancies, suggesting upregulation of CD53 may be implicated in carcinogenesis or maintenance of malignant cells. CD53 is a member of the tetraspanin family of transmembrane proteins, classically involved in cell adhesion, proliferation, and survival, and expressed exclusively on hematopoietic cells. While several studies have implicated a role for CD53 in regulating mature B cell proliferation, its role in early B cell development is not yet known. To elucidate the contribution of CD53 to normal and malignant B cell development, we have generated a CD53 knockout mouse.
In our CD53-/- mouse, we observe no differences in total white blood cell counts, yet the fraction of peripheral blood B cells is significantly reduced by 31% compared to wild-type (WT) controls (28.3% vs. 19.5%; p<0.005). During homeostatic B lymphopoiesis, CD53 increases through development, beginning at the pre-pro-B cell stage and reaching highest expression on mature B cells. Further investigation into the loss of B cells revealed that immature pre-B cells in the bone marrow and mature B cells in the spleen and lymph nodes are significantly diminished upon loss of CD53, resulting from increased apoptosis in CD53-/- mice. B cell differentiation of CD53-/- hematopoietic stem cells (HSCs) in vitro corroborates the dependence on CD53 for normal differentiation, as CD53-/- cultures have 26% fewer B cells than controls (p=0.033). Investigation into the signaling differences between WT and CD53-/- B cell progenitors by mass cytometry (CyTOF) suggests that decreased PI3K/Akt and MAPK signaling could be driving this loss.
With the observed loss of both B cell progenitors and mature B cells in CD53-deficient mice, CD53-/- mice were recently crossed to Eμ-Myc transgenic mice, a model of B-lineage leukemia/lymphoma, to generate WT, CD53-/-, Eμ-Myc+;CD53+/+, and Eμ-Myc+;CD53-/- groups to assess whether loss of CD53 alters the pathology or survival of these mice. As observed in human patients, moribund Eμ-Myc+ mice significantly upregulate CD53 on malignant cells, suggesting a potential role for CD53 during pathogenesis. Ongoing experiments are aimed at elucidating the mechanism by which CD53 promotes homeostatic B cell development and determining the potential of CD53 as a therapeutic target for B lineage malignancies.

Disclosures
No relevant conflicts of interest to declare.
Functional Analysis of the FOXO3 Gene on the Induction of Fetal Hemoglobin in K562 Cells
Authors: Albuquerque Flávia Peixoto , Franca-Neto Pedro Luis , Franca Rafael de Oliveira , Araujo Aderson da Silva , Costa Fernando F. , Bezerra Marcos , Lucena-Araujo Antonio R. 
Published: October 2019

Abstract
The β-hemoglobinopathies are known as genetic disorders of high impact and wide distribution worldwide, with chronic and variable clinical prognosis. These pathologies have their symptoms and sequelae alleviated by increased levels of fetal hemoglobin (HbF; α2γ2). The Hydroxyurea, a drug used for the treatment of β-hemoglobinopathies, is effective for the maintenance and control of the development of the main clinical manifestations, however, it needs some prerequisites for its use, which indicates the need for new therapeutic approaches for this group of individuals. The family of Forkhead Box O transcription factors (FOXO), composed of FOXO1, FOXO3, FOXO4 and FOXO6, plays a key role in the regulation of several biological processes such as: regulation of the cell cycle, modulation oxidative stress, regulation mechanisms of response to DNA damage, controlling apoptosis and inflammatory response. Among members of the FOXO family, FOXO3 has been described as a physiological regulator of the erythroid maturation process and indicated as a positive regulator of HbF levels. In the present work, we evaluated the expression levels of the FOXO3 gene in patients with hemoglobinopathies and, in an attempt to better understand the pathophysiology of the disease, we performed a subcloning of the FOXO3 gene into a lentiviral expression system for its constitutive expression in vitro and subsequent evaluation of its activity as a possible transcription factor for γ globin genes (HBG1 and HBG2). In our clinical study, FOXO3 expression was significantly higher in patients with sickle cell anemia when compared to healthy donors (HbAA) (P <0.001) . In addition, a differential expression of FOXO3 was associated with the development of lower limb ulcer (P <0.005). Although we observed a tendency to increase FOXO3 expression in patients with 2 or more clinical manifestations, this association was not statistically significant (P = 0.06). The same was observed when we compared the number of clinical complications presented by patients last year with HbF levels: patients with 2 or more complications had lower levels of HbF, although this difference did not reach statistical significance (P = 0.182). There was no correlation between FOXO3 expression levels and HbF dosage (r = -0.12). Because of the activity of the FOXO3 gene in the control of oxidative stress, experiments were performed to evaluate the ROS and NO rates in the cell culture and a significant role was found, the FOXO3 increasing NO production (P = 0.0001) as well as in control of ROS produced in mitochondria.

Disclosures
No relevant conflicts of interest to declare.
Alternate Day Oral Iron Dosing in Iron Deficiency Anemia
Authors: Bulbul Ajaz , Araujo Mino Emilio , Dake Vyas , Bautista Adriana , Lentkowski Lisa , Khorsand-Sahbaie Masoud 
Published: October 2019

Abstract
Introduction
Practice guidelines for Iron deficiency anemia (IDA) suggest taking ferrous iron in divided doses. Recent studies suggest that split daily dosing may increase serum hepcidin which reduces iron bioavailability. Adherence to oral iron supplementation (OIS) can also be a barrier to treatment. In practice iron dosing varies significantly with unclear evidence of benefit from a particular dosing regimen.
Methods
This is a retrospective study evaluating outcomes of different schedules of OIS in 146 patients with IDA (Hb <12.2 and/or ferritin of < 30 ng/mL) treated between June 2017-June 2018. Patients with multifactorial anemia were excluded. Descriptive statistics and Chi-square were used for analysis.
Results
The mean age was 66.8 ± 1.3; women constituted 70% of the cohort (M/F 44/102). Mean Hb was 11.59 ± 0.12; Median ferritin was 22 ng/ml (IQR 10-63). Four different schedules of OIS evaluated were every other day (QOD) 60% (88/146), daily (QD)15% (22/146), twice daily (BID) 12%(18/146) and three times a day (TID) 12% (18/146). After one month of OIS a mean increase in Hb was (0.44 mg/dl + 0.04). GI toxicity occurred in 10.2% (15/146), therapy discontinuation in 4.8% (7/146) and IV iron was required in 9.6 % (14/146) of all cases. Among patients without GI toxicity 65% (85/131) were on QOD vs other schedules (X² 11.7 p=0.008), 63% (87/139) were compliant on QOD (X² 9.05 p=0.029). Salvage IV iron was not required in 64% (84/132) of QOD patients (X² 22.7 p=<0.001). One month post therapy, patients on QOD schedule had ≥1 g/dl improvement in 38% (10/26) (X² 9.18 p= 0.027) and increase of >0.5g/dl in 68% (69/102) of cases (X² 9.63 p= 0.022).
Conclusions
Alternate day iron dosing may optimize iron absorption and is possibly a better tolerated regimen. Larger prospective studies need to confirm these findings

Disclosures
No relevant conflicts of interest to declare.
Programmed Cell Death Receptor (PD-1), PD-1 Ligand (PD-L1) Expression in Philadelphia Chromosome Negative Myeloid Neoplasms
Authors: Chen Chi , Pandey Anita , Kundra Ajay , Kodali Sreenath , Wong Ching , Cheung Tony W. , Gotlieb Vladimir K. , Joseph Gardith , Tribie Sophia , Wang Jen-Chin 
Published: October 2019

Abstract
Introduction : PD-1 and PD-L1 pathway inhibitor therapy has been extensively explored in the field of oncology treatment recently, however there is no information so far about its usefulness in myeloid neoplasms (MPN). We have previously reported on PD-1 and PD-L1 expression in Philadelphia chromosome negative myeloid neoplasm (MPN), but now that we have accumulated more cases , we wish to report the final results.
Materials and Methods: 63 patients with Philadelphia chromosome negative MPN in total were studied which included 16 MF (14 PMF, 2 post-PV-MF, 2 post-ET-MF), 29 ET, 18 PV, and 25 normal volunteer controls.
Flow Cytometry Studies: Leukocytes were obtained from whole blood after RBC lysis using RBC lysis buffer (Qiagen). To quantify surface bound PD-1 and PDL-1, the leukocytes were incubated with CD279-APC and CD274-PE, as well as CD4-FITC, CD8-FITC, CD14-PCP, or CD34-FITC (BD Biosciences) and were subjected to flow cytometric analysis.
Results: PD-1 and PD-L1 positive cells were expressed as a percentage in gated CD4bright, CD8+, CD14+, or CD34+ cells. We found that 1) there was no difference in PD-1 or PD-L1 levels among different groups of MPN, but there was a significant difference when they were grouped of PV, ET and MF as MPN and compared with controls in all the immune cells including CD4+, CD8+, CD14 + and,CD34+ cells.(Representative of CD4+ shown inFig(1a). 2) High expression levels (more than 50% cell positivity) was found on the CD34+ cells with PD-1 and PD-L1 expression of 20% and 26% in MPN patients respectively ( Fig 1b,1c) . 3) We also found that there was no correlation between of the PD-1 or , PD-L1 expression levels with clinical features including such as WBC counts , platelet counts, and hemoglobin levels, , or presence or absence of the JAK2 , MPL, or CALR gene mutations or splenomegaly
Conclusion: We have shown elevated increased expression levels of PD1 and PDL-1 on the immune cells and high expression ( more than 50%) in the CD34+ cells , suggest that PD-1 or , PD-L1 pathway inhibitor therapy maybe worthwhile in Philadelphia chromosome negative Ph(-) MPN ..

Disclosures
Wang: celgene: Other: clinical trial.