bluuebunny/crossref_metadata_2025_split huggingface dataset:
DA-EPOCH Chemotherapy Is Highly Effective in ALK-Positive and ALK-Negative ALCL: Results of a Prospective Study of PTCL Subtypes in Adults
Authors: Dunleavy Kieron , Shovlin Margaret , Pittaluga Stefania , Grant Cliona , Steinberg Seth M. , Jaffe Elaine S. , Wilson Wyndham H 
Published: October 2019

Abstract
Abstract 1618

Background:
Anaplastic large cell lymphoma (ALCL) is a distinct type of peripheral T-cell lymphoma (PTCL) characterized histologically, by large anaplastic lymphoid cells that are CD30 positive. There is biologic heterogeneity within ALCL: ALK (anaplastic lymphoma kinase) positive cases harbor a translocation usually involving chromosomes 2 and 5 resulting in over-expression of ALK (variant translocations also occur) whereas ALK negative cases do not. ALK positive ALCL is also clinically distinctive, with a younger age of onset and better treatment outcomes. In the recent International PTCL and Natural Killer (NK) T-Cell Lymphoma Study (Savage et al. Blood.2008: 111 (12)), the outcome for patients with ALK positive compared to ALK negative ALCL was significantly better (5-year failure-free survival (FFS) 60% versus 36%: p=0.15). Methods: We prospectively investigated the efficacy of 6 cycles of DA-EPOCH chemotherapy in newly diagnosed patients with both ALK positive and ALK negative ALCL and compared their outcome to other subtypes of PTCL. Results: Clinical characteristics of 38 enrolled patients are shown below. 22 patients had a diagnosis of ALCL and other diagnoses were PTCL-NOS (10), hepatosplenic gamma delta T-cell lymphoma (4), enteropathy associated T-cell lymphoma (1) and angioimmunoblastic T-cell lymphoma (1). Patients with ALK positive and ALK negative ALCL had similar characteristics. With a median potential follow-up time of 10.5 years, the 5 year progression-free survival (PFS) probability for ALK positive versus negative patients was 80% versus 71% (p=0.82); 5 year overall survival (OS) was 86% in both groups (p=0.95). For patients with other subtypes of PTCL, PFS and OS were 32% and 50% respectively, at 5-years. Conclusions: In contrast to other reports, patients with ALK negative ALCL had a very favorable outcome following DA-EPOCH chemotherapy that was no different from that of ALK positive cases. This regimen is highly effective in ALCL, independent of ALK expression. Accrual continues.

Disclosures:
No relevant conflicts of interest to declare.
Increasing Grades of Follicular Lymphoma Correlate with Better Prognosis in Patients Treated with Rituximab
Authors: Wahlin Björn Engelbrekt , Sundström Christer , Holte Harald , Sander Birgitta , Østenstad Bjørn , de Nully Brown Peter , Smeland Erlend B. , Delabie Jan , Christensson Birger , Kimby Eva 
Published: October 2019

Abstract
Abstract 1641

Background:
The World Health Organization (WHO) classification allocates indolent follicular lymphoma to grades 1, 2 or 3A according to the proportions of small centrocytes and large centroblasts in the neoplastic follicles. The prognostic value of the WHO's grading system in indolent follicular lymphoma has not been investigated in patients given the anti-CD20 monoclonal antibody rituximab without chemotherapy.

Methods:
We prospectively reviewed the follicular lymphoma grades in 276 grade 1–3A patients who received upfront rituximab without chemotherapy in two randomized trials. Flow cytometry analyses of malignant and nonmalignant lymphocyte subsets in lymph nodes and blood were also assessed.

Results:
In these patients given upfront rituximab-containing therapy, increasing grades of 1, 2, and 3A correlated with longer time to treatment-failure (P =0.002) and overall survival (P =0.045), independently of clinical factors (including the follicular lymphoma international prognostic index). The grades' impact was also independent of the levels of CD3+, CD4+, and CD8+ T cells in lymph nodes and in blood.

Conclusion:
Increasing grades of indolent follicular lymphoma correlate with better outcome in patients treated upfront with rituximab without chemotherapy, independently of clinical and immunologic factors. This suggests that treatment with rituximab acts differentially in tumors depending on the centrocyte/centroblast ratio.

Disclosures:
No relevant conflicts of interest to declare.
Rituximab Cerebrospinal Fluid Levels in Patients with Primary Central Nervous System Lymphoma Treated with Intravenous High Dose Rituximab
Authors: Larouche Jean-Francois , Bergeron Marc , Hampson Grace , Illidge Tim , Delage Robert 
Published: October 2019

Abstract
Abstract 1644

INTRODUCTION:
Rituximab penetration in central nervous system is largely unknown in human. Experiments in monkeys showed that 0,1% of serum rituximab concentration was achieved in cerebrospinal fluid. Reports in patients are limited (Rubenstein JL, Blood 2003 and Petereit HF, Multiple Sclerosis 2009). They demonstrated similar low levels of cerebrospinal fluid penetration with standard dose (375 mg /m2) rituximab in patients with central nervous system (CNS) lymphoma or multiple sclerosis.

METHOD:
We conducted a phase 2 trial in patients with primary CNS lymphoma. Patients were treated with an intravenous combination of high dose methotrexate (8 g/m2), high dose cytarabine (2 g/m2) and high dose rituximab (750 mg/m2 every 1–2 weeks × 13 infusions). We obtained from four patients paired cerebrospinal fluid and serum samples and rituximab concentration were determined in each. Samples were collected at different time points just before rituximab infusion and represent trough levels.

RESULTS:
11 cerebrospinal fluid samples were available and their 11 paired serum samples. Mean cerebrospinal fluid and serum levels were 2,04 ug/mL (0,49–4,08) and 297,09 ug/mL (211,26–504,47) respectively. Mean cerebrospinal fluid levels were 0,71% (0,18–1,5%) of serum levels. No relationship was made between cerebrospinal fluid level and the number of rituximab dose administered.

CONCLUSION:
In patients with primary CNS lymphoma receiving high dose 1–2 weekly rituximab. cerebrospinal fluid concentration achieve is low compared to serum levels. However, administration of higher dose of intravenous rituximab can increase penetration in central nervous system but its clinical impact is unknown as cerebrospinal fluid levels are still low.

Disclosures:
No relevant conflicts of interest to declare.
Doxycycline Reduces Fibril Formation in a Transgenic Mouse Model of AL Amyloidosis
Authors: Seldin David C , Ward Jennifer , Ren Ruiyi , Toraldo Gianluca , SooHoo Pamela T , Guan Jian , O'Hara Carl , Jasuja Ravi , Trinkaus-Randall Vickery , Liao Ronglih , Connors Lawreen H 
Published: October 2019

Abstract
Abstract 1837
AL amyloidosis results from the production and aggregation of an amyloidogenic immunoglobulin (Ig) light chain (LC) by a clonal bone marrow plasma cell dyscrasia. Currently, there are no genetically reproducible animal models of AL amyloidosis. We engineered transgenic mice to express an amyloidogenic human λ6 LC. We used the cytomegalovirus (CMV) promoter to express the LC in multiple tissues and organs, circumventing the disruption of B cell development by premature expression of recombined LC in the B lineage alone. LC were detected in a number of organs including epithelial tissues of the gastrointestinal and genitourinary tracts, and in the serum. The CMV-λ6 transgenic mice developed neurologic dysfunction. By 2 years of age, >80% of the transgenic mice developed Congo-red staining human LC fibrils in the stomach. Transgenic mice were treated with the antibiotic doxycycline orally for 7 months. Of treated mice, 23% had Congophilic deposits, compared with 69% of controls drinking water for the same time period. Treatment of recombinant LC in vitro with doxycycline reduced fibril formation and the drug also caused to disruption of pre-formed fibrils, producing disordered aggregates. Thus, this transgenic model replicates the process of AL amyloidosis in vivo and is useful for testing the anti-fibril potential of orally available agents. Antibiotics such as doxycycline could prove useful in AL as well as in other amyloidoses.

Disclosures:
No relevant conflicts of interest to declare.
Targeting Leukemias by CD123 Specific Chimeric Antigen Receptor
Authors: Thokala Radhika , Singh Harjeet , Olivares Simon , Champlin Richard , Cooper Laurence J N 
Published: October 2019

Abstract
Abstract 1908
Chimeric antigen receptors (CARs) are employed to genetically modify T cells to redirect their specificity to target antigens on tumor cells. Typically a second generation CAR is derived by fusing an extracellular domain derived from the scFv of monoclonal antibody (CAR) specific to targeted antigen with CD3 zeta, and CD28 endodomains. CD123 (IL3RA) is expressed on 45% to 95%of acute myelogenous leukemia (AML) and B-cell lineage acute lymphoblastic leukemia (B-ALL). Expression of CD123 is high in the leukemic stem cell (LSC) population, but not in normal hematopoietic stem cells. Thus, CD123 appears to be potential target for immunotherapy in leukemias through chimeric antigen receptor (CAR). We hypothesized that the generation of CD123 specific CAR can redirect the specificity of T cells to CD123 and this was tested by cloning the scFv of CD123 mAb in our CAR construct. The sleeping beauty system was used to express the CAR and DNA plasmids were electroporated into peripheral blood mononuclear cells and cells were numerically expanded on artificial antigen presenting cells genetically modified to express co stimulatory molecules CD86, 4-1BBL, membrane-bound IL-15, and CD123 antigen in presence of IL-21 and 1L–2. CAR+ T numerically expanded to clinically relevant numbers and showed antigen specific cytotoxicity in leukemic celllines. CAR+ T cells expressed both effector and memory markers showing the potential for in vivo persistence after T cell infusion. The bonemarrow homing receptor CXCR4 was expressed by CAR T cells shows the potential to target LSC that reside in BM niches. The preliminary data suggests that mirroring an approach we are using to manufacture clinical grade CD19 specific CAR+ T cells.Figure 1:(A) CAR expression on day 35. (B) Cytotoxicity of CD123CAR in leukemic cell lines.Figure 1:. (A) CAR expression on day 35. (B) Cytotoxicity of CD123CAR in leukemic cell lines.CD3CD3

Disclosures:
No relevant conflicts of interest to declare.
High Efficiency Isolation of Alloantigen-Reactive Foxp3+ Natural Regulatory T Cells According to Specific Activation Marker Signatures
Authors: Schoenbrunn Anne , Keye Jacqueline , Kohler Siegfried , Frentsch Marco , Moewes Beate , Scheffold Alexander , Romagnani Chiara , Thiel Andreas 
Published: October 2019

Abstract
Abstract 1915
Transplant tolerance induction and avoidance of exposure to destructive immunosuppressive drugs are still major objectives in transplantation medicine. Many preclinical animal models have proven the adoptive transfer of polyclonal CD4+CD25+Foxp3+ regulatory T (Treg) cells to be an important and effective tool for the prevention of graft rejection or graft-versus-host-disease. However, polyclonal Treg may also modulate immunity to foreign or tumor antigens. It is unclear yet, whether and how their application might lead to an unwanted general immunosuppression. Therefore the selective transfer of alloantigen-reactive Treg represents a very attractive therapeutic option. However, so far this strategy has been hampered so far by the lack of appropriate marker to assess and isolate antigen-reactive Treg cells with high efficiency.
In order to get access to alloantigen-reactive Treg, we established cytometric methodologies allowing a clear dissection between (allo)antigen-specific Treg and Teff based on expression of 4-1BB and the lack of expression of CD40L. After allogeneic stimulation CD4+ T cells expressing 4-1BB but lacking CD40L expression were highly enriched in Foxp3+ T cells. Further molecular analysis of the Foxp3 gene locus revealed that only 4-1BB+CD40L− T cells were characterised by a completely demethylated TSDR (Treg specific demethylated region). 4-1BB+CD40L− T cells highly expressed the transcription factor HELIOS recently demonstrated to specify thymic-derived Treg. Alloantigen-reactive Treg isolated according to 4-1BB and CD40L were superior with respect to their alloantigen-specific in vitro suppression as compared their polyclonal Treg counterparts. Finally 4-1BB+CD40L− alloantigen-reactive Treg could be easily expanded in vitro up to 300 fold during 3 weeks culture, maintaining alloantigen-specific suppression. Our results offer the possibility to improve current approaches for adoptive cell-therapy with alloantigen-specific Treg to achieve transplantation tolerance aiming at a specific inhibition of pathology.

Disclosures:
Scheffold: Miltenyi Biotec GmbH: Employment.
β-1,4-Galactosyltransferase 1 Expression Is Required for Platelet Production in Vitro and In Vivo
Authors: Giannini Silvia , Grozovsky Renata , Begonja Antonija Jurak , Hoffmeister Karin M. 
Published: October 2019

Abstract
Abstract 192
Platelet turnover requires correct glycan presentation and expression. Deficiency in β-1,4-galactosyltransferase 1 (β4GalT1), the major enzyme that transfers galactose (Gal) from UDP-Gal to terminal N-acetylglucosamine (GlcNAc) to form type-2 lactosaminyl structures, is lethal in embryonic mice. However, E14.5 β4GalT1−/− embryos are grossly indistinguishable from wild type embryos. Here we sought to determine whether platelet formation and survival require β4GalT1. Hepatic stem cells were obtained from embryonic livers at E14.5 and megakaryoctes were differentiated in vitro in the presence of thrombopoietin. β4GalT1−/−megakaryocytes mature and differentiate normally in vitro as judged by their number, morphology and expression of main surface glycoproteins specific for the megakaryocyte lineage (GPIbα/β, GPIX, αIIb and β3). However, following differentiation, β4GalT1−/−megakaryocytes were unable to produce proplatelets and platelets in vitro. Addition of exogenous β4GalT1 and the donor substrate UDP-Galactose did not improve in vitro proplatelet and platelet formation. Importantly, platelet numbers were decreased by ∼ 75% in β4GalT1−/− E14.5 embryos when compared to wild type embryos. Platelet size was increased by ∼ 50% in β4GalT1−/− embryos, indicating that β4GalT1−/− mice have increased platelet clearance and/or that larger platelets are produced in vivo. Our data strongly support the notion that glycosylation mediated by β4GalT1 activity is crucial for platelet production in vitro and in vivo. Our findings demonstrate for the first time a role for posttranslational glycan modification in platelet production.

Disclosures:
No relevant conflicts of interest to declare.
Donor Dual TCR T Cells Preferentially Expand and Mediate Pathologic Alloreactivity in Acute Graft Versus Host Disease
Authors: Morris Gerald P. , Uy Geoffrey L , Donermeyer David L , Allen Paul M , DiPersio John F. 
Published: October 2019

Abstract
Abstract 1972
The nature of the T cell repertoire mediating pathologic in vivo alloreactivity is an important question for understanding the development of acute graft-versus-host disease (aGvHD) following clinical allogeneic transplantation. We have previously demonstrated that the small proportion of T cells that naturally express 2 T cell receptors (TCR) as a consequence of incomplete TCRa allelic exclusion during thymic development contribute disproportionately to the alloreactive T cell repertoire, both in vitro and in vivo in a mouse model of graft versus host disease (GvHD) (J. Immunol., 182:6639, 2009). Here, we extend these findings to human biology, examining dual TCR T cells from healthy volunteer donors (n = 12) and patients who have undergone allogeneic hematopoietic stem cell transplantation (HSCT) (n = 19). Peripheral blood was collected at day 30 post-HSCT or at the time of presentation with symptomatic acute GvHD. Dual TCR T cells were measured in peripheral blood by pair-wise staining with 3 commercially-available and 2 novel TCRa mAbs. Dual TCR T cells were consistently and significantly expanded in patients with symptomatic aGvHD, representing 5.3±3.8 % of peripheral T cells, compared to 1.7±0.8 % of T cells in healthy controls (p < 0.005) (Figure 1). There was no correlation between dual TCR T cell frequency and GvHD severity. Furthermore, sequential analysis of peripheral blood in 2 patients demonstrated expansion of dual TCR T cells concurrent with the development of aGvHD (Figure 2). Dual TCR T cells from patients with symptomatic aGvHD demonstrated increased expression of CD69 as compared to T cells expressing a single TCR, indicative of preferential activation of dual TCR T cells during aGvHD. Similarly, dual TCR T cells isolated from patients with symptomatic aGvHD demonstrate increased production of IFN-g ex vivo, indicative of the ability to mediate pathogenic alloreactive responses. Dual TCR T cell clones isolated from healthy donors and patients post-HSCT by single cell FACS sorting demonstrate alloreactive responses against a range of allogeneic cell lines in vitro. We propose that the increased alloreactivity of dual TCR T cells results from the less stringent thymic selection for secondary TCR, and thus provides a link between thymic selection, the TCR repertoire, and alloreactivity. These findings may lead to simple ways of phenotypically identifying specific T cells predisposed to inducing aGvHD for subsequent examination of T cell repertoires and functional studies. Furthermore, these data suggest that dual TCR T cells represent a potential predictive biomarker for aGvHD and a potential target for selective T cell depletion in HSCT.

Disclosures:
No relevant conflicts of interest to declare.
Longitudinal Analysis of Body Mass and Composition in Survivors of Pediatric Hematological Malignancies After Allogeneic Hematopoietic Stem Cell Transplantation
Authors: Inaba Hiroto , Yang Jie , Kaste Sue , Hartford Christine , Motosue Megan S , Srinivasan Ashok , Triplett Brandon M. , Shook David R , Pui Ching-Hon , Leung Wing 
Published: October 2019

Abstract
Abstract 1991

Background:
Body mass and composition have been well studied in survivors of childhood cancers, but little is known about these factors in those who have undergone allogeneic hematopoietic stem cell transplantation (allo-HSCT).

Methods:
We prospectively and longitudinally evaluated changes in body mass index (BMI), changes in the proportion of fat and lean body mass, and associated clinical factors in 179 survivors of pediatric hematologic malignancies after allo-HSCT. BMI was analyzed as an ordinal variable (four percentile categories: underweight, healthy weight, overweight, and obese) and as a continuous variable (Z-score); dual-energy X-ray absorptiometry data were used to derive Z-scores for percent total body fat and lean mass/height2 ratio.

Results:
With a median follow-up of 6.6 years (range, 1.0–17.7 years), BMI decreased significantly over time (mean Z-score, 0.32 pre-HSCT and −0.60 at 10 years post-HSCT) (Figure; p<0.001). These longitudinal changes differed among pre-HSCT BMI categories (p<0.001). BMI Z-scores of patients who were underweight before HSCT increased over the first 4 years after HSCT and then declined, while those of patients in the other three pre-HSCT BMI categories continuously declined. Although the mean Z-scores for percent fat mass were higher or similar to those of the general population during follow-up (0.305 at 1 year, −0.272 at 10 years), the mean Z-scores of lean mass/height2 ratio remained below that of healthy controls and diminished significantly over time (-0.296 at 1 year, −1.256 at 10 years post-HSCT) (p=0.002). Pre-HSCT BMI categories were strongly associated with post-HSCT BMI values (p<0.001) and with Z-scores of percent total body fat and lean mass/height2 ratio (both p<0.001). Patients who had extensive chronic graft-versus-host disease were significantly more likely to be in the underweight BMI category (p=0.021) and to have a low Z-scores for lean mass/height2 ratio (p<0.001). Younger patients (less than the median age, 11.3 years, at HSCT) had a higher BMI after HSCT than older patients (p<0.001), and female survivors had higher Z-scores of percent total body fat (p=0.005) and lower Z-scores of lean mass/height2 ratio (p=0.025) than male survivors.

Conclusions:
The finding of a significant decline of BMI and severe loss of lean mass after HSCT indicates a critical need for nutritional education and early intervention for these survivors.

Disclosures:
No relevant conflicts of interest to declare.
Autologous Hematopoietic Stem Cell Transplantation in Multiple Sclerosis: Long-Term Clinical Outcome in China
Authors: Chen Bing , Ouyang Jian , Zhou Min , Shao Xiao-Yan , Xu Yong , Zhou Rong-Fu 
Published: October 2019

Abstract
Abstract 2020

Background
Autologous haematopoietic stem cell transplantation (AHSCT) is a promising treatment of multiple sclerosis (MS) who had not adequately responded to conventional therapies. We retrospectively evaluated the safety and long-term clinical outcome of AHSCT in MS patients in China.

Methods
Twenty-five patients with various types of MS were treated with AHSCT. Peripheral blood stem cells were obtained by leukapheresis after mobilization with granulocyte colony stimulating factor. Then CD34+ cell selection of the graft was performed and anti-thymocyte globulin was given for T-cell depletion. Conditioning regimen was BEAM. Early and late toxicities were also recorded. Long-term outcomes were evaluated by the expanded disability status scale, progression free survival and gadolinium-enhancing magnatic resonance imaging (MRI) scans.

Results
10, 7 and 8 patients experienced neurological improvement, stabilization and progression, respectively. The median EDSS scores at every follow-up year after transplantation (5.5-7.0) were consistently lower than the baseline (8.0). The progression-free survival rate was 74%, 65% and 48% at 3, 6 and 9 years post-transplant. 58% cases (7/12) had active lesions at baseline and all turned to inactive status in the follow-up years. 25% cases (3/12) experienced progression after transplantation but had no active lesions in MRI in the whole follow-up period. 17% cases (2/12) without active lesions at baseline progressed and appeared active lesions in MRI.

Conclusion
AHSCT is a feasible treatment for severe MS and its long-term efficacy is favorable. However, more random and controlled clinical trials are required to fully assess long-term efficacy of AHSCT for MS.

Disclosures:
No relevant conflicts of interest to declare.