bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of recipient's Age On the Outcome of HLA-Matched Sibling Transplants in Adult Patients with Severe Aplastic Anemia Who Conditioned with Fludarabine-Based Regimen
Authors: Shin SeungHwan , Yoon JaeHo , Yahng SeungAh , Lee SungEun , Cho ByungSik , Eom KiSung , Kim YooJin , Lee Seok , Min ChangKi , Kim Heeje , Cho SeokGoo , Kim DongWook , Min WooSung , Park ChongWon , Lee JongWook 
Published: October 2019

Abstract
Abstract 1921

Background:
There is a controversy concerning upper age limit of recipient in allogeneic stem cell transplantation (allo-SCT) of severe aplastic anemia (SAA) because older patients have an increased risk of transplant-related mortality (TRM). Recently, a less toxic regimen comprising reduced dose of cyclophosphamide (CY), fludarabine (Flu), and ATG (Flu/CY/ATG) was introduced for conditioning the patients with SAA scheduled for HLA-identical sibling allo-SCT. We analyzed the outcome of these patients after conditioning with Flu/CY/ATG regimen according to recipient's age.

Method:
We analyzed 82 consecutive adult patients transplanted from March 2002 to June 2011, followed conditioning with CY (50 mg/kg/day × 2 days), Flu (30 mg/m2/day × 6 days), and ATG (2.5 mg/kg/day × 4 days).

Results:
The median age of patients was 39 years (range, 13–58 years). 29 (35.4%) patients were very SAA at the time of allo-SCT. Stem cell sources were bone marrow (BM, n=59), peripheral blood stem cell (PBSC, n=12), and BM+PBSC (CD34+ cell selection, n=11). The conditioning regimen was well tolerated, with low TRM (4.9%). Neutrophil engraftment was observed in all patients; the median time to engraftment of neutrophils and platelets was 12 and 17 days, respectively. The 100-day cumulative incidence (CI) of acute graft-versus-host disease (GVHD, grade °Ã2) was 3.7% and 2-year CI of chronic GVHD was 4.4%. With a median follow-up of 3 years, overall survival (OS) and failure-free survival was 93% and 83%, respectively. Seven patients (8.5%) developed delayed graft failure and 6 patients of them have successful durable engraftment after second allo-SCT without TRM. Seven patients died of veno-occlusive disease (n=1), cytomegalovirus pneumonia (n=2), sepsis (n=2), clonal evolution after allo-SCT (n=2, 1 acute myeloid leukemia and 1 myelodysplastic syndrome), respectively. 3-year probability of OS by age group were 88% at less than 20 years old (n=8), 97% at 20–39 (n=34), 92% at 40–49 (n=26), 86% at 50–59 (n=14). There is no significant difference in OS according to age group (p=0.426).

Conclusion:
These data indicate that the Flu/CY/ATG conditioning regimen is well tolerable with low TRM and CI of GVHD in all age group. Similar OS according to 4-divided age group suggest that patient's age more than 50 years old might be possible candidate for allo-SCT in SAA with Flu/CY/ATG conditioning regimen.

Disclosures:
No relevant conflicts of interest to declare.
Unmanipulated Graft Transplantation From Family Haploidentical Donors: A Survey On 183 Adult Patients with Acute Leukemias On Behalf of the Acute Leukemia Working Party of the European Group for Blood and Marrow Transplantation (EBMT)
Authors: Ciceri Fabio , Labopin Myriam , Di Bartolomeo Paolo , Arcese William , Santarone Stella , De Angelis Gottardo , Peccatori Jacopo , Mohty Mohamad 
Published: October 2019

Abstract
Abstract 1987

Background.
Allogeneic stem cell transplantation from an haploidentical family donor has been recently developed through unmanipulated graft platforms.

Methods.
We collected in 57 EBMT centers 183 haploidentical transplants (haploSCT) from unmanipulated peripheral blood (PB) and bone marrow (BM) graft in adults patients (pts) with de novo acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) reported to EBMT registry from 2007 to 2010 and analysed the outcome according to the known risk factors.

Results.
Overall, 120 AML patients underwent transplantation in CR1 (39), CR2 (22) or in advanced disease (54). Overall, 63 ALL pts underwent transplantation in CR1 (26), CR2 (14) or in advanced disease (22). Median age was 42y (18–75). Graft composition was based on non ex-vivo T-cell depleted BM in 52 (28%) or PB in 131 (72%). Conditioning regimen was myeloablative (MAC) in 95 and reduced-intensity (RIC) in 88 pts. Primary engraftment was documented in 160 pts (88%), with ANC 0.5 ×109/L in a median of 19 days (BM) and 16 days (PB). Graft-versus-Host Disease (GvHD) prophylaxis was based on Anti-thymocyte globulins (ATG) + cyclosporine-methotrexate (24%) or cyclosporine-mycophenolate (18%), rapamycine-mycophenolate (25%), tacrolimus-mycophenolate (15%), others (7%). The cumulative incidence of acute GvHD >=II was 26%. With a median follow-up of 13 months (1–49), the estimated leukemia-free survival (LFS) at 1 years i was 53 +/−7%, 36 +/−8% and 22 +/−5% for CR1, CR2 and advanced patients respectively. In multivariate analysis for competing risks, relapse incidence (RI) at 1 y was 23 +/−5%, 20 +/−7%, 48 +/−6% for CR1, CR2 and advanced. The non-relapse mortality (NRM) at 1 y was 23 +/−6%, 43 +/−5%, 29 +/−6% for CR1, CR2 and advanced patients. On multivariate analysis, the only factor relevant for LFS was disease status at transplant.

Conclusion.
EBMT registry analysis of haploidentical transplantation from unmanipulated donor graft confirms relevant LFS for patients with high risk acute leukemia. These results suggest that this procedure should be considered prospectively int treatment algorithm for high risk adults patients in early stages.

Disclosures:
No relevant conflicts of interest to declare.
Impact of CD3/T Regs Ratio in Donor Graft On Survival Rates in Allogeneic Peripheral Blood Stem Cell Transplantation
Authors: Delia Mario , Pastore Domenico , Mestice Anna , Carluccio Paola , Perrone Tommasina , Gaudio Francesco , Curci Paola , Ricco Alessandra , Rossi Antonella Russo , Giordano Annamaria , Carluccio Vera , Di Tardo Ilaria , Angarano Rosa , Longo Maria Chiara , Specchia Giorgina 
Published: October 2019

Abstract
Abstract 2030

Background:
The therapeutic efficacy of allogeneic stem cell transplantation (alloSCT) for hematological malignancies relies largely on the graft versus leukemia (GvL) effect exerted by the donor CD3 cells, but an uncontrolled graft-versus-host-disease (GvHD) bears a risk of complications. On the other hand, T regs cells (CD4+CD25high Foxp3+) are believed to maintain tolerance and to inhibit GvHD after alloSCT; also, the Foxp3 gene encodes a transcription factor that is a key for thymic development, so T regs cells could preserve an optimal microenviroment for the reconstitution of functional immunity after alloSCT. Moreover, when looking at post allotransplant patients' outcomes, while it is largely known the impact of acute GVHD (triggered by CD3 donor T cells) on survival, there is no evidence that donor graft CD3/T regs ratio may determine an effect in terms of OS, NRM and relapse free survival rates so far.

Patients and Methods:
In this study we analyzed the graft CD3+/Tregs ratio (gCD3/Tregs R) and determined its impact on acute GVHD (aGVHD), immunological recovery and survival rates (OS, NRM and Relapse) after myeloablative alloPBSCT. We analyzed 74 consecutive patients transplanted with unmanipulated peripheral blood stem cells from an HLA identical related donor (n=48) or an HLA identical unrelated donor (n=26); diagnoses were acute myeloid leukaemia (n=62), acute lymphoblastic leukaemia (n=13). The median CD3+ and Tregs dose administered was 238 (range (r): 67–550) and 12,5×106̂/Kg (r: 2–21), respectively; the median gCD3/Tregs R was 19 (r: 8–250). Patients were subdivided into a high gCD3/Tregs R (>=36) group (HR group n= 30) and a low gCD3/Tregs R (<36) (LR group n=44).

Results:
The incidence of aGVHD (grade II-IV) in the low gCD3/Tregs R (LR) group was lower than in the high gCD3/Tregs R (HR) group (4/30 or 13% vs 36/44 or 82%, p<.001). The OS, NRM and relapse rate at 3 years was 54,29 and 34%, respectively. Comparing LR with HR group a statistically significant difference is demonstrated for OS and NRM rates (65 vs 31%,p<.004; 3 vs 71%, p<.001), respectively, but not for the R one (35 vs 30%, p=ns). Comparing aGVHD+ with aGVHD- group OS, NRM and relapse were always statistically significant different (39 vs 65%,p<.005; 61 vs 7%,p<.001; 9 vs 53%,p<.002).

Conclusions:
Taken together, our data may suggest that Tregs content is able to mediate protective effects against aGVHD, while preserving GvL effects as demonstrated by relapse rate comparison between H and LR groups. However, larger studies are needed to understand the real contribution of gCD3/Tregs R on survival rates.

Disclosures:
No relevant conflicts of interest to declare.
Three Novel EPAS1/HIF2A Somatic and Germline mutations Associated with Polycythemia and Pheochromocytoma/Paraganglioma.
Authors: V Felipe R Lorenzo , Zhuang Zhengping , Yang Chunzhang , Fui Mark Ng Tang , Vankayalapati Hariprasad , Pacak Karel , Prchal Josef T. 
Published: October 2019

Abstract
Abstract 2080
Congenital polycythemias have diverse etiologies, including mutations in the hypoxia sensing pathway leading to increased levels of hypoxia inducible factors (HIF) and erythropoietin. These include mutations of negative regulators of HIFs, such as germline von Hippel-Lindau (VHL) gene heterozygous mutations (Chuvash polycythemia), HIF-prolyl hydroxylase 2 (PHD2) gene mutations, and gain-of-function mutations of HIF-2-alpha (HIF2A) (exon 12). Mutation of the PHD2 gene in one family was associated with polycythemia and recurrent pheochromocytoma/paraganglioma (PHEO/PGL) a neuroendocrine tumor commonly found in so called VHL tumor predisposition syndrome. Over the past two decades, we have studied six unrelated patients with sporadic congenital polycythemia who subsequently developed PHEO/PGLs without till now discernible molecular basis. We now report on these three patients, two with different tumor somatic codon A530 HIF2A mutations in exon 12 and one with germline mutation F374Y inherited from his mother, in a unique domain (exon 9) of HIF2A, all three cases later developed multiple recurrent neuroendocrine tumors and were subjects of our study.
In search of species homology, codons F374 and A530 of the HIF2A are highly conserved among man, chimpanzee, mouse, horse, cattle, chicken and zebrafish, suggesting this serves an important function for the gene. These mutations were identified in the vicinity of the primary hydroxylation site (exon 12) and novel domain (exon 9) of the HIF2A protein which affects VHL protein binding, Functional studies of the HIF2A mutants shown that three HIF2A variants have increased half-life consistent with gain-of-function of the HIF2A due to disruption in the VHL binding to these mutant residues impairing ubiquitination and proteasomal degradation. This results in increased transcription of genes downstream of HIF2A including erythropoietin. Further examination did not reveal any evidence of loss-of-heterozygosity, nor an additional mutation of HIF2A, or other HIF-pathway genes in their tumor tissues. The fact that two patients with polycythemia and PHEO/PGL had somatic and one germline HIF2A mutations, albeit at different locations, underscore the PHEO/PGL promoting potential of gain-of-function mutations of HIF2A that alone, either as somatic or germline mutations can contribute to, but are not sufficient for PHEO/PGL development but is sufficient for inducing polycythemic phenotype.

Disclosures:
No relevant conflicts of interest to declare.
A Hepcidin Inhibitor Mobilizes Iron for Incorporation Into Red Blood Cells in an Adenine-Induced Chronic Kidney Disease Model in Rats.
Authors: Vaja Valentina , Sun Chia Chi , Cappellini Maria D , Lin Herbert Yih-Fuu , Babitt Jodie L 
Published: October 2019

Abstract
Abstract 2082

Background:
Anemia is prevalent in patients with chronic kidney disease (CKD). A key feature of the anemia of CKD is limited iron availability for efficient erythropoiesis despite adequate body iron stores. It is now well established that excess levels of the iron regulatory hormone hepcidin in CKD are responsible for decreasing expression of the iron exporter ferroportin, thereby blocking iron absorption from the diet and iron release from body stores. Adenine treatment in rats has been proposed as an animal model of anemia of CKD with high hepcidin levels that mirrors the condition in patients.

Methods:
We developed a modified adenine-induced kidney disease model of anemia in rats by giving a diet supplemented with 0.75% adenine for 3 weeks followed by a normal diet for 3 weeks. We then tested whether the small molecule bone morphogenetic protein (BMP) inhibitor LDN-193189, which has previously been shown to lower hepcidin levels, was able to mobilize iron into the plasma and improve iron-restricted erythropoiesis in adenine-treated rats.

Results:
The modified adenine model had a higher survival rate than previously reported models, while maintaining irreversible renal failure and anemia. Adenine-treated rats had increased hepatic hepcidin mRNA, decreased serum iron, increased spleen iron content, low hemoglobin, and inappropriately low EPO levels relative to the degree of anemia. LDN-193189 lowered hepatic hepcidin mRNA and mobilized stored iron into plasma in adenine-treated rats. Moreover, the iron was efficiently incorporated into hemoglobin in reticulocytes. However, LDN-193189 alone did not prevent anemia progression in our model.

Conclusions:
Lowering hepcidin improved iron availability, but did not improve anemia in an adenine-induced kidney disease model in rats. Co-administration of hepcidin lowering agents with erythropoiesis stimulating agents (ESAs) may be useful as a combination therapy to correct iron balance and thereby reduce the ESA dose needed to achieve target hemoglobin levels.

Disclosures:
Sun: FerruMax Pharmaceuticals Inc: Consultancy. Lin:Ferrumax Pharmaceuticals: Consultancy, Equity Ownership, Patents & Royalties. Babitt:Ferrumax Pharmaceuticals, Inc: Equity Ownership.
Elevated Hematocrit Concentration and the Risk of Mortality and Vascular Events in Patients Undergoing Major Surgery.
Authors: Musallam Khaled M , Porter John B , Soweid Assaad , Hoballah Jamal J , Sfeir Pierre M , Khalife Mohamed , Zeineldine Salah , Tamim Hani M , Richards Toby , Lotta Luca Andrea , Peyvandi Flora , Jamali Faek R 
Published: October 2019

Abstract
Abstract 2088

Background:
Preoperative anemia is associated with adverse outcomes after major surgery. This study evaluates the effect of elevated hematocrit concentration on 30-day postoperative mortality and vascular events in patients undergoing major surgery.

Methods:
We conducted a cohort study using the American College of Surgeons National Surgical Quality Improvement Program database. Thirty-day mortality and vascular events, demographic, and perioperative risk factors were obtained for 197,469 adult patients undergoing major surgery in nonveteran's administration hospitals across the US, Canada, Lebanon, and the UAE during 2008 and 2009. We assessed the adjusted effect of elevated (>0.50) compared to normal preoperative hematocrit concentration (≥0.41–0.50, American Medical Association reference-range) on postoperative outcomes. Separate sex-specific analysis using hematocrit concentration thresholds commonly used in the diagnosis and management of patients with apparent or absolute erythrocytosis was also done.

Results:
A total of 3,961 patients (2.0%) had elevated hematocrit concentration preoperatively. After adjustment, postoperative mortality at 30 days was higher in patients with elevated hematocrit concentration than in those without (odds ratio [OR]: 2.23, 95% CI: 1.77–2.80). 30-day deep vein thrombosis (OR: 1.95, 95% CI: 1.44–2.64) and pulmonary embolism (OR: 1.79, 95% CI: 1.17–2.73), but not myocardial infarction or cerebrovascular events, were also higher in patients with elevated hematocrit concentration than in those without. Similar evaluation of various clinically relevant hematocrit concentrations revealed the following: an effect on mortality was noted beyond the thresholds of 0.48 in women and 0.52 in men, with the effect estimates becoming considerably high for values >0.54. Values between 0.41–0.45 were not associated with increased odds mortality. Similar observations were noted for deep vein thrombosis, although with higher variation and uncertainty especially in women; while the effects on pulmonary embolism were restricted to men.

Conclusion:
Elevated hematocrit concentration is associated with an increased risk of 30-day mortality and venous thrombosis following major surgery. Further investigation of the impact of elevated hematocrit concentration and its reduction on surgical outcomes is warranted.

Disclosures:
No relevant conflicts of interest to declare.
Homozygous Expression of a Novel Senegalese-Type Partial Deletion of the Beta and Delta Genes Causes a Delta0 Beta+ Thalassemia.
Authors: Sabio Hernan , Dixon Natalia , Kutlar Ferdane , Patel Niren , Zhang Hanfang , Zhuang Lina , Kutlar Abdullah 
Published: October 2019

Abstract
Abstract 2128
Clinical phenotype in β-thalassemia syndromes is determined by the degree of chain imbalance. An increase in γ-globin production will compensate for the absent or deficient β-globin synthesis and will result in the amelioration of the chain imbalance, and hence an improvement in clinical features. The known genotypes of δβ-thalassemia are associated with an increase in Hb F production, which results in the amelioration of the clinical presentation. Most δβ-thalassemias result from deletions that remove the δ- and β-globin genes, (δβ)0 with a compensatory increase in γ-globin (Hb F) expression. We report an unusual case of homozygous δ0β+ thalassemia that provides interesting insights into increased γ-globin expression and the regulation of β-globin gene expression. An 8-year old boy of African ancestry presented with lifelong jaundice and pallor. He also experienced episodes of worsening symptoms. He exhibited frontal bossing, pale mucosa, scleral icterus, and moderate splenomegaly. He was known to have G6PD deficiency and was suspected of having additional erythrocyte pathology. The CBC revealed a Hb of 8.7, Hct 26.4, MCV 64.7, WBC 10,700, platelets 283,000, reticulocytes 2.2%, and total bilirubin 5.3. Hemoglobin analysis by HPLC and IEF revealed HbA 13.4%, Hb F 86.6%, and no additional components. Alpha thalassemia −3.7kb deletion was not detected. Globin chain analysis revealed α, β, Gγ and AγI chains. DNA analysis revealed a novel Senegalese-type deletion of the beta and delta genes, resulting in a delta0 beta+ thalassemia. The subject's parents who were both from the same small village in Niger had normal hematology values. Their hemoglobin analyses revealed Hb A 94. 8%, Hb A2 2.0%, Hb F 3.2% and Hb A 93.5%, Hb A2 2.1%, Hb F 4.5% in the father and mother, respectively. They were both heterozygous for the delta-beta deletion identified in their son. DNA analysis revealed a breakpoint in the delta gene at nucleotides 54755–54760 and a breakpoint in the beta gene at nucleotides 62153– 62158 [GenBank Ref ID: HUMHBB] with a 5 nucleotide “CAACA” bp region overlapping area. The subject, who is homozygous for the identified deletions, has a clinical phenotype of thalassemia intermedia. He has not yet required red cell transfusions. This is the first instance of a Senegalese-type deletion occurring in the homozygous state. The genotype provides insights into regulation of globin gene expression. While the ∼7 Kb deletion in the δβ-intergenic region may be responsible for the increased expression of the γ-globin gene similar to Hb Lepore deletions, the continued low level expression of the β-globin gene is most probably the result of the juxtaposition of the inefficient δ-globin promoter brought in the vicinity of the β-globin gene.

Disclosures:
No relevant conflicts of interest to declare.
Platelet ERp57 Is Required for Hemostasis and Thrombosis.
Authors: Wang Lu , Wu Yi , Zhou Junsong , Ahmad Syed S. , Mutus Bulent , Essex David W 
Published: October 2019

Abstract
Abstract 2168
Several members of the protein disulfide isomerase family of enzymes are important in platelet function and in thrombosis. Platelet protein disulfide isomerase (PDI) has been shown to have an important role in platelet function but is reported to not be required for thrombus formation in vivo. A novel platelet PDI called ERp57 mediates platelet aggregation but its role in thrombus formation is unknown. To determine the specific role of platelet-derived ERp57 in hemostasis and thrombosis we generated a megakaryocyte/platelet specific knockout. Despite normal platelet counts and platelet glycoprotein expression, mice with ERp57-deficient platelets had prolonged tail-bleeding times and thrombus occlusion times, and defective activation of the αIIbβ3 integrin and platelet aggregation. The aggregation defect was corrected by addition of exogenous ERp57 implicating surface ERp57 in platelet aggregation. Platelet surface ERp57 protein and activity increased substantially with platelet activation. We conclude that platelet-derived ERp57 is required for hemostasis and thrombosis and platelet function.

Disclosures:
No relevant conflicts of interest to declare.
Effect of Increased Tissue Factor Pathway Inhibitor (TFPI) Levels On Factor Xa Inhibition and Global Hemostasis in the Presence of TFPI-Antagonistic Aptamer BAX 499.
Authors: Dockal Michael , Hartmann Rudolf , Knappe Sabine , Palige Michael , Kammlander Willibald , Kunckova Klara , Ehrlich Hartmut J. , Scheiflinger Friedrich 
Published: October 2019

Abstract
Abstract 2207
In a recent hemophilia clinical trial, patients' TFPI plasma levels substantially increased after intravenous or subcutaneous administration of TFPI-inhibitory aptamer BAX 499. To better understand the consequences of elevated plasma full-length (fl)-TFPI and the potency of BAX 499, the TFPI-inhibitory activity of a wide concentration range of BAX 499 was tested at levels up to 10 nM fl-TFPI in two model systems and in two global hemostatic coagulation assays.
Factor Xa (FXa) inhibition assay measured the influence of BAX 499 on the interaction between TFPI and FXa. BAX 499 at 1000 nM efficiently inhibited fl-TFPI within the physiological concentration (< 0.5 nM). However, with increasing TFPI, inhibition of TFPI by BAX499 became considerably less efficient, reflected by increasing EC50 and decreasing maximum inhibition. At substantially elevated TFPI concentrations (10 nM) EC50 increased ∼20-fold, with TFPI retaining ∼70% of its FXa inhibitory activity. Similar results were observed in a more complex reaction system (TF-FVIIa-catalyzed FX activation). These results suggest that BAX 499 is a partial inhibitor of TFPI, efficiently neutralizing TFPI at low concentrations and less efficiently inhibiting TFPI at high TFPI levels.
In thrombin generation assays with FVIII-inhibited plasma, a substantial excess of BAX 499 was required to compensate the anticoagulant activity of increasing fl-TFPI. Based on peak thrombin values, fl-TFPI levels that could be neutralized by a given BAX 499 concentration were determined. For example, a ∼50-fold excess of BAX 499 neutralized 0.2 nM TFPI added to FVIII-inhibited plasma, whereas a 140-fold excess was required for neutralization of 7.3 nM fl-TFPI added. An equivalent ROTEM experiment performed in FVIII-inhibited whole blood confirmed these findings.
In summary, the data showed that even a high concentration of BAX 499 (1 μM) was not able to counteract the strong inhibitory effect of 10 nM fl-TFPI on FXa, on TF-FVIIa-catalyzed FX activation, on thrombin generation in plasma and clot formation in whole blood, due to the partially inhibitory properties of BAX 499. The current study offers an explanation for increased bleeding tendency in hemophilia patients associated with the ≥25-fold elevated fl-TFPI plasma levels after BAX 499 administration. BAX 499 does not appear to be able to compensate the anticoagulant activity of increased TFPI levels caused by partial inhibition in patients treated with BAX 499.

Disclosures:
No relevant conflicts of interest to declare.