bluuebunny/crossref_metadata_2025_split huggingface dataset:
Early Development of Immunity to CMV Following Hematopoietic-Stem Cell Transplantation Is Associated with Graft-Versus Leukaemia Effect
Authors: Khourouj Valérie Guérin-El , Porcher Raphaël , Leveille Sandrine , Le Goff Jérôme , Pédron Béatrice , Baruchel Andre , Dalle Jean-Hugues , Sterkers Ghislaine 
Published: October 2019

Abstract
Abstract 4214
Relapse of disease remains the most common cause of failure in children undergoing hematopoietic-stem cell transplantation (HSCT) for acute leukaemia. A favourable impact, on graft-versus leukaemia effect (GVL), from recipient CMV-seropositivity before HSCT and from CMV-reactivations in the recipient after HSCT has been suggested. The potential role, in this process, for the immune response triggered by CMV has not been directly addressed so far.
108 children (median age 8 years) were included at HSCT following myeloablative conditioning for primary acute leukaemia (lymphoblastic 54%, myeloblastic 42%, biphenotypic 4%). HSCT were from HLA-matched related (41%) or unrelated (44%) donors. 15% patients received cord blood units. CMV- DNAemia was programmed weekly for at least 3 months post-HSCT. When PCR showed ≥1000 copies/ml, patients received ganciclovir as pre-emptive therapy. Immunity to CMV was evaluated sequentially since the first month post-HSCT using 3H-Thymidine incorporation assay (T-cell proliferation) and intracytoplasmic cytokine accumulation assay (IFNg secretion).
Median follow-up from transplant was 40 months. 57% of patients were CMV-seropositive before HSCT. Cumulative incidence of recipients with CMV-DNAemia at day 120 was 31% (median time to onset: 26 days). Cumulative incidence of recipients with immunity to CMV (T-cell proliferation and/or IFNγ secretion assays) at 1 year was 38% (median time to onset: 2 months). As expected, recipient CMV seropositivity represented a major factor contributing to DNAemia (p<0.0001) and to immunity (p<0.001) occurrence as well. The 2 years cumulative incidence of relapse was 26% Among the 89 recipients free of relapse at day +120 and evaluated for immunity before that time, the 2 years cumulative incidence of relapse was 15%. Multivariable analysis revealed a different risk of leukemic relapse according to immunity to CMV and CMV-reactivation (p=0.039), with the lowest risk in recipients with early (before day 120) immunity to CMV but no CMV-reactivation and the highest risk in recipients with early (before day 120) CMV-reactivation but no immunity to CMV (HR: 0.06, 95%CI 0.01–0.69, p=0.024).
In conclusion, early development of immunity to CMV rather than early viremia had a favourable impact on GVL in this pediatric series.

Disclosures:
No relevant conflicts of interest to declare.
Confirmation of A Strong Relationship Between Race and Probability of Transplant Among Patients Referred for Hematopoietic Cell Transplantation (HCT) for Hematological Maliganancies – A 17 Year Experience
Authors: Sharma Manish , Klumpp Thomas R , Ulicny John A , Fasan Omotayo O. , Kropf Patricia , Martin Mary Ellen , Mangan Kenneth F. 
Published: October 2019

Abstract
Abstract 4266

Background
Hematopoietic cell transplantation (HCT) is considered standard of care in patients with numerous types of hematological malignancies. A limited number of large, database derived, retrospective studies have observed the existence of racial disparities between Caucasian and African American patients who are candidates for a transplant for multiple myeloma and other hematological malignancies. We have recently demonstrated that there was no such disparity once a patient with a diagnosis of myeloma was referred to our transplant center. We expanded this analysis to include all patients referred for a transplant with a diagnosis of a hematological malignancy.

Methods
We utilized the existing data in our federally-mandated quality management database to retrospectively analyze the potential associations between race and the following parameters: Age, sex, cancer subtype, stage, best response prior to transplant, best response following transplant, treatment related mortality, overall survival, median interval between date of diagnosis and date of referral, median interval between date of initial visit and date of transplant, probability of actually receiving a transplant following formal evaluation by a transplant physician by race, type of transplant recommended and reasons for not receiving a transplant. We reviewed patients referred to consider a transplant within the time period of July 1st 1993 to December 31st2011.

Results
Total number of patients evaluated was 2009. The pertinent patient characteristics are described in Table 1 for this heterogeneous group of patients. Table 2 describes the univariate analysis of the impact of age, race and sex on obtaining a transplant. Both race and age were statistically significant variables for the probability of making it to transplant. The Kaplan-Meier curve for the probability of undergoing a transplant as per race is shown in Figure 1 and is statistically significant with a p-value of 0.0088. We also determined that patient diagnosis is significant in influencing the probability of making it to transplant, p-value of 0.0001. The era of when a patient was referred for transplant (from July/1993 to June/1998 versus July/1998 to December/2011) was also a significant factor for the probability of receiving a transplant, p-value of 0.0001.

Conclusions
We have demonstrated that race, age, disease type and era of patient referral were significant factors in patients receiving a transplant at our institution. Further study is needed to identify the reasons for these barriers in obtaining a transplant.

Disclosures:
No relevant conflicts of interest to declare.
The Effect of Hyperglycemia On the Outcome of Patients with Acute Myelogenous Leukemia
Authors: Schmidt Shannon Leah , Blust Linda , Knudson Paul , Richter Emily , Fenske Timothy S. , Palmer Jeanne , Zhang Mei-Jie , Eastwood Dan , Atallah Ehab 
Published: October 2019

Abstract
Abstract 4323

Introduction:
Hyperglycemia (HyG) has been shown to be detrimental in acute leukemia. In patients with acute myelogenous leukemia, hyG was associated with increased hospital mortality (Ali, et. al. Cancer 2007) while in patients with acute lymphocytic leukemia, hyG was associated with a shorter duration of complete response (CR) (Weiser et. al. Cancer 2004.) Our aim is to evaluate the effects of hyperglycemia on achievement of CR, disease free survival (DFS) and overall survival (OS) in patients with AML in our institution.

Patients and Methods:
We retrospectively reviewed all patients diagnosed with AML from 1/1/2005 to 1/1/2012 who underwent initial induction chemotherapy with 7+3 at our institution. Responses were defined according to the 2003 International Working Group criteria as CR within 6 weeks or no response. HyG was defined as 2 or more serum blood glucose levels ≥ 200 in the 30 days following induction chemotherapy. OS was determined using the Kaplan Meier method and compared using the log rank test.

Results:
Of the 91 patients identified, 43 (47%) were female. The median age at diagnosis was 53 years old. The cytogenetic categories were good (15 patients, 17%), intermediate (44 patients, 50%), and poor (29 patients, 33%). The median OS for all patients was 321 days. Median OS in the good, intermediate and poor cytogentics group was 423 days, 314 days and 314 days respectively. HyG, as previously defined, was seen in 39 (43%) of patients. CR was achieved in 40 (44%) of patients within 6 weeks of induction. Of the 40 patients achieving CR within 6 weeks, 19 (48%) were HyG and 21 (52%) were normoglycemic (p=0.67). Median OS was 375 days in the normoglycemic group and 210 days in the HyG group (p=0.74). Of the patients achieving CR in 6 weeks, median DFS was 290 days in the normoglycemic group and 243 days in the HyG group (p=0.54).

Conclusions:
Hyperglycemia in the post-induction period does not appear to have an impact on achievement of CR, DFS, or OS in the AML population.

Disclosures:
No relevant conflicts of interest to declare.
GMP-Grade Generation of B-Lymphocytes for Adoptive Immunotherapy in Patients After Allogeneic Stem Cell Transplantation
Authors: Winkler Julia , Mach Michael , Zingsem Juergen , Weisbach Volker , Mackensen Andreas , Winkler Thomas H. 
Published: October 2019

Abstract
Abstract 4352

Background and objectives:
We have recently shown that memory B-lymphocytes from murine CMV immune donor animals adoptively transferred into immunodeficient mice were highly effective in protecting from a viral infection indicating a therapeutic potential of virus specific memory B-cells. These preclinical data provided evidence that a cell-based strategy supporting the humoral immune response might be effective in a clinical setting of post-HSCT immunodeficiency (Klenovsek et al., 2007, Blood 110: 3472–9). As adoptive transfer of B-cells has not been used before in a clinical setting, it is necessary to establish a technology for the generation of GMP-grade B-cell products.

Methods:
Starting from the leukapheresis of healthy donors, B-cells were purified by two different separation strategies using GMP-grade microbeads and the CliniMACS∧TM device. A one-step protocol was used for positive enrichment of B-lymphocytes with anti-CD19 microbeads. In a two-step enrichment protocol, first T-lymphocytes were depleted by anti-CD3 microbeads and the remaining fraction was positively selected by anti-CD19 microbeads.

Results:
The leukapheresis contained a mean of 9.0×10∧8 CD19-positive B-cells (4.5–12.4 ×10∧8). After the one-step positive purification strategy a mean purity of CD20∧+ B-lymphocytes of 78.1% with a recovery of 32–41% was obtained. With the two-step T-cell depletion/B-cell enrichment protocol we achieved a mean purity of 96.4 % (93.4–97.8%) with a slightly lower recovery of 14–37%. The absolute B-cell numbers obtained in the product were 1.3 to 4.0 ×10∧8 and 1.7 to 2.6 ×10∧8 for the one-step positive enrichment and the two-step protocol, respectively. Importantly, the absolute number of T-cells was lower in cell products after the two-step protocol (0.1 to 0.9 ×10∧6 T-cells) as compared to the one-step positive CD19-enrichment (1.6 to 3.4 ×10∧6 T-cells). Assuming a patient with 70 kg body weight, the B-cell products obtained after the combined CD3-depletion and CD19-enrichment contained less then 4×10∧4 T-lymphocytes/kg bodyweight, which is a critical threshold number of T-cells in haploidentical HSCT. The B-cell products showed antibody production after in vitro stimulation in a limiting dilution assay and showed excellent viability after cryopreservation.

Conclusions:
A GMP-grade B-cell product can be obtained with high purity and very low T-cell contamination using the two-step enrichment protocol based on CliniMACS∧TM technology. (Supported by BayImmuNet)

Disclosures:
No relevant conflicts of interest to declare.
Assessment of Cross-Reactivity in Three Different Fecal Occult Blood Test Systems with Dabigatran and Dabigatran Etexilate: Identification of Useful Test Methods
Authors: Goss Ashley M , van Ryn Joanne , Schurer Johanna , Clemens Andreas 
Published: October 2019

Abstract
Abstract 4360
Anticoagulant therapy can elevate the risk of gastrointestinal (GI) bleeding and may affect its management. Fecal occult blood tests (FOBT) are non-invasive, widely-used tests that may be useful in detecting early and thus treatable stages of GI lesions or bleeding in patients on these therapies. The literature suggests that use of anticoagulants does not diminish the positive predictive value of FOBT, however a potential limitation and concern of these tests is the possibility for drug interactions with test components which may lead to false results.
Dabigatran is a new oral, reversible, direct thrombin inhibitor currently approved for stroke prevention in patients with atrial fibrillation. Dabigatran etexilate (DE) is the prodrug of the active ingredient dabigatran, and is converted by non-specific esterases in plasma and liver to dabigatran. Approximately 6.5% of DE in Pradaxa® is bioavailable and absorbed in the gut with the remaining eliminated in the feces. The purpose of this study was to investigate any potential cross-reactivity of dabigatran, DE or Pradaxa® with three commonly-used commercial FOBTs with different detection methods.
Common methods of detection in FOBTs used worldwide include guaiac oxidation in hemoccult tests, immunochromatographic methods with a membrane strip precoated with hemoglobin antibody, or the benzamidine method where heme in hemoglobin induces a blue/green color change. Examples of each method were tested. The Hemoccult II® SENSA® (Beckman Coulter Inc.), EZ DETECT (Biomerica Inc.), and BioNexia® Hb/Hp Complex Professionell (FROST Diagnostika GmbH) FOBT were used for this study and all tests were conducted according to manufacturer's protocol. DE, dabigatran or the contents of a single Pradaxa® capsule were suspended in a 0.5% cellulose solution. Vehicle solution was used as negative control and human blood used as a positive control.
Isolated human blood samples generated positive results as expected in all three FOBTs whereas the negative controls did not. Exposure to DE, dabigatran or Pradaxa® suspensions did not result in positive readouts with any detection method of the tested FOBTs.
In conclusion, these studies demonstrate that the prodrug DE and its active drug form dabigatran, as well as any further excipients in the Pradaxa® formulation do not cross-react with a set of commonly-used fecal occult blood tests. This supports the usefulness of these 3 tests in dabigatran etexilate-treated patients.

Disclosures:
Goss: Boehringer Ingelheim Pharmaceuticals Inc.: Employment. van Ryn:Boehringer Ingelheim: Employment. Schurer:Boehringer Ingelheim: Employment. Clemens:Boehringer Ingelheim (Anticoagulant Therapy): Employment.
Prevalence of Allo and Auto Antibodies in Adults with SCD
Authors: Kumar Mukesh , Shelia Palmer , Eckman James R. 
Published: October 2019

Abstract
Abstract 4379

Introduction:
Allo- and auto- antibody formation is one of the major and serious complications of RBC transfusion in patients with sickle cell disease. This problem appears to be more common than in other diseases requiring chronic transfusion that leads to acute and delayed hemolytic transfusion reactions, serious morbidity and occasional life threatening problems. Although there have been reports describing prevalence of immunization in SCD patients, data specific for adult population with SCD is lacking. We report the prevalence of allo- and auto-immunization in adult SCD patients.

Methods:
Patients aged 18 and above with diagnoses of SCD, confirmed by standard hemoglobin electrophoresis, who had at least one type and cross match done from 1995 through 2011 were considered eligible. To facilitate patient management all data on antibody identification, screening and transfusions were routinely recorded in the electronic database of the Georgia Comprehensive Sickle Cell Program at Grady Health System. We gathered red cell antigen phenotype, dates and results of antibody screens, antibody specificity, and demographics which include but not limited to age in years and gender of all transfused patients.

Results:
A total of 424 patients 230 females and 194 males were identified with SCD who have been tested for antibodies during this period. The average age of the patients is 34 (range 18–84). A total of 138/32.5% of patients had antibodies. The most common antibodies were E (14%), C (10%) and K (8%). This may be an under estimations because antibodies disappear over time without repeated exposure. A total of 82 (19.3%) of patients developed autoantibodies. Detailed results described in Table 1.

Conclusion:
Allo and auto antibody formation remains significant limiting factor in finding compatible blood resulting in delays in availability of blood for transfusion that can compromise patient care in SCD. With better supportive care and hydroxyurea, adult population is growing resulting in increased need for blood transfusion and risk of antibody formation. Our practice is to do limited phenotypic matching in all patients and extended phenotype matching once antibodies are produced. Despite this practice allo- and autoimmunization continues to be a significant problem. Studies need to be done to understand pathophysiology of antibody formation in SCD and prospective randomized trials are required to define best preventive clinical practices.

Disclosures:
No relevant conflicts of interest to declare.
Antithymocyte Globulin (ATG) Plus Cyclosporine (CsA) and Combined with Cord Blood Infusion Is Superior to ATG Plus Csa for the Treatment of Severe Aplastic Anemia
Authors: Fan Zhiping , Liu Qifa , Sun Jing , Jiang Qianli , Huang Fen , Zhang Xian , Xu Dan , Zhou Hongsheng , Xu Bing , Meng Fanyi , Liu Xiaoli , Feng Ru 
Published: October 2019

Abstract
Abstract 4397

Backgrouds and objectives:
Standard initial immunosuppressive therapy (IST) is ATG and CsA, which produces hematologic recovery in 60% to 70% of severe aplastic anemia (SAA), but the shortcoming is the long duration for hematologic response, the higher relapse rate and clonal evolution. In addition to stem cells, Cord blood contains plenty of mesenchymal cells, regulatory T cells, dendritic cells and hematopoietic factors. So we predicted that cord blood coinfusion could improve the effect of ATG plus CsA for treating SAA. The aim of the current study was to investigate the safety and effect of ATG plus CsA combined with cord blood infusion SAA.

Methods:
From August 2008 to May 2012, nine patients (6 males and 3 females), with a median age of 22 years (14–52) were diagnosed with SAA. They received an IST of rabbit ATG (3mg/kg/d, for 5 days) plus CsA (5mg/d, continuously), and then accepted a five or six loci matched cord blood infusion in 7–10 days after the end of ATG. The median nuclear cells were 4.02 (3.1–5.62) ×107/kg.

Results:
After a median duration follow-up of 38 (1–50) months, the response rate was 88.9% (8/9), the median duration of plantlet transfusion independence was 34(18–72) days and that of red blood cell was 30 (18–56) days, which were shorter than those of standard IST for SAA. Only 2 patients underwent serum sickness, 1 patients was diagnosed as having upper respiratory tract infection, and none underwent sepsis and invasive fungal infection. In addition, EB viremia was found in 3 patients, and all of them were cured by antiviral therapy. Of all 9 patients, only one showed evidence of partly engraftment (the percentage of cord blood was 24.6%) as determined by STR-PCR at 15 days after cord blood infusion, the others had no evidence of engraftment at 15days, 1 month and three months after infusion. No myelodysplastic syndrome or acute myeloid leukemia was found among the patients. No patient relapsed till now.

Conclusions:
ATG plus CsA and combined with cord blood infusion was safe, the rate of hematologic response was higher than traditional IST for SAA. The duration of transfusion independence was shorter than that of traditional IST.

Disclosures:
No relevant conflicts of interest to declare.
CD109 Deficiency Induces Preferential Proliferation of the Piga Mutant Leukemia Cell Line TF-1 in the Presence of TGF-β
Authors: Hosokawa Kohei , Katagiri Takamasa , Saito Chizuru , Espinoza Luis J. , Sasaki Yumi , Seiki Yu , Yamamoto Yasuhiko , Yamazaki Hirohito , Nakao Shinji 
Published: October 2019

Abstract
Abstract 4399

Background:
An increase in glycosylphosphatidylinositol-anchored protein-deficient (GPI-AP−) blood cells is a significant predictor of a good response to immunosuppressive therapy in patients with aplastic anemia (AA) and low-risk myelodysplastic syndrome (MDS). Immune mechanisms are therefore thought to be involved in the increase of GPI-AP− cells in such bone marrow (BM) failure, though the exact mechanisms are unknown. The lack of GPI-APs due to PIGA mutations may render hematopoietic stem cells (HSCs) resistant to myelosuppressive cytokines such as TGF-b. This may lead to preferential activation of PIGA mutant HSCs in immune-mediated BM failure, although little is known about the GPI-APs involved.

Objectives/Methods:
We assessed the roles of GPI-APs in TGF-b-mediated inhibition of cell proliferation, cell cycle, and signal transduction in the myeloid leukemia cell line TF-1, TF-1 with a PIGA mutation (PNH-TF-1), and TF-1 cells transfected with siRNA against CD109, a GPI-AP that serves as a TGF-b co-receptor in human keratinocytes. We used flow cytometry to study expression of CD109 in BM CD34 cells of healthy individuals and other hematopoietic cell lines.

Results:
TGF-b inhibited PNH-TF-1 proliferation to a lesser degree (percentage of inhibition, 19±13%) than wild-type TF-1 cells (67±3%) in an MTT-based proliferation assay. Transfection of PIGA into PNH-TF-1 cells restored GPI-AP expression as well as sensitivity to TGF-b (53±10% versus 19±13% in PNH-TF-1 cells). CD109 coimmunoprecipitated with TGF-b in TF-1 cells, and its expression was confirmed on BM CD34+ cells of healthy individuals, particularly on CD34+CD38+CD123−CD45RA− megakaryocyte-erythroid progenitor cells, and also on TF-1 and KG1a cells. CD109 knockdown rendered TF-1 cells less sensitive to TGF-b-induced inhibition of proliferation (26±10% versus 67±3%), TGF-b induced cell cycle arrest (a relative increase in the G0/G1 phase of the cell cycle, 6.9% versus 20.7%, Figure) and TGF-b-induced SMAD2 phosphorylation (a relative increase in pSMAD2 MFI, 1±0.3% versus 16%±3%) compared to non-transfected TF-1 cells.

Conclusions:
The lower sensitivity of PIGA mutant TF-1 cells to TGF-b compared to wild-type TF-1 cells is partially due to CD109 deficiency. This deficiency may also account for the preferential activation of PIGA mutant HSCs in immune-mediated BM failure, in which TGF-b suppresses activation of wild-type HSCs.

Disclosures:
No relevant conflicts of interest to declare.
Dasatinib Restores Full Donor Chimerism in Animatinib - Resistant Ph+ ALL Childwith E255K Gene Mutation Relapse Dafter Allo HSCT
Authors: Peng Ching-Tien , Tamamyan Gevorg , WU Kang-Hsi 
Published: October 2019

Abstract
Abstract 4827
Philadelphia chromosome positive acute lymphoblastic leukemia is uncommon among children and very tough to treat. With chemotherapy alone, only 20–30% of children are cured, but tyrosine kinase inhibitors (TKIs) plus chemotherapy and allogeneic hematopoietic stem cell transplantation in 1st complete remission has gradually high possibility of cure. Some recent papers also suggest that chemotherapy plus tyrosine kinase inhibitors (TKIs) may be the initial treatment of choice. Despite this, there is a few data about treatment after relapse.
We introduce a case of 15 years old boy with Philadelphia chromosome positive acute lymphoblastic leukemia early relapse after full-match related donor hematopoietic stem cell transplantation from his mother.
Both at the time of diagnosis and at relapse time the patient had various cytogenetic abnormalities and also at relapse he revealed with imatinib-resistant E255K gene mutation, which is a common mutation that occurs frequently after imatinib therapy in Ph-positive ALL patients is the glutamic acid to lysine mutation at codon 255.
After the relapse the boy received high-dose chemotherapy and dasatinib and obtained complete molecular remission and restored full donor chimerism. There were no observed side effects of dasatinib treatment. The patient is now still in complete molecular remission and is continuing maintenance chemotherapy with dasatinib.
Thus, this case suggests that chemotherapy plus dasatinibcould be a treatment of choice for the children with relapsed Philadelphia chromosome positive acute lymphoblastic leukemia after allogeneic hematopoietic stem cell transplantation, which alsohas E255K gene mutation and various cytogenetic abnormalities.

Disclosures:
No relevant conflicts of interest to declare.