bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification and Characterization of Recurrent Venous Thrombosis In Cancer Patients
Authors: Weber Catherine , Adel Nelly G. , Riedel Elyn , Soff Gerald A.
Published: October 2019

Abstract 3328

Background:

Venous thromboembolism (VTE) is a common cause of morbidity and mortality in cancer patients. Standard of care for treatment is Low Molecular Weight Heparin, but recurrence of VTE remains a concern. We performed a retrospective analysis of our institutional experience, to characterize the patients who had a recurrence of VTE while on therapeutic doses of Dalteparin.

Objectives:

1. To determine the VTE recurrence rate for cancer patients on therapeutic Dalteparin. 2. To elucidate potential risk factors for recurrence. 3. To determine the impact of recurrent VTE on overall survival.

Methods:

Patients beginning treatment for VTE with dalteparin between 1/1/2008 and 12/10/ 2009 were retrospectively identified through the hospital's electronic medical records system and cases of recurrent VTE were characterized. Overall survival was estimated using the Kaplan-Meier method and the influence of VTE recurrence on overall survival was analyzed as a time-dependent covariate using a Cox proportional hazards model.

Results:

1,392 patients, treated for VTE with dalteparin were included in this study. 34 recurrent VTE episodes were identified. The overall incidence of recurrent thrombosis by six months was 2.3% (95% CI: 1.7%-3.3%). Older age was significantly associated with recurrence (p=0.04). Lung cancer patients had a significantly elevated risk of recurrence (5.6%, p=0.03). No other cancer types were associated with a significant trend to increased recurrent VTE rates. The incidence of recurrent VTE was higher among females compared to males (3.0% vs. 1.6%), although this trend was not statistically significant (P = 0.08). After adjusting for gender, sex and cancer diagnosis, developing a recurrent VTE was associated with a 3.0-fold hazard ratio of death (<0.0001).

Conclusions:

The rate of recurrent VTE in cancer patients at MSKCC is low in comparison with previously published reports. However, we identified both older age and lung cancer diagnosis as statistically significant risk factors for recurrent VTE. Females also experienced a higher rate of recurrent thrombosis when compared to males, although this result was not statistically significant. The hazard ratio for death was three times that for a patient with recurrent thrombosis when compared to one without subsequent VTE, suggesting recurrence of VTE remains an important influence on cancer-associated mortality.

Disclosures:

No relevant conflicts of interest to declare.
Ten Years and Over 3600 Cases of Recombinant Activated Factor VII Use: What Does the Haemostasis Registry Data Tell Us?
Authors: Phillips Louise E , Zatta Amanda J , Isbister James , Dunkley Scott , McNeil John , Cameron Peter
Published: October 2019

Abstract 3352

Background:

Recombinant activated factor VII (rFVIIa, NovoSeven®) is approved for the treatment of spontaneous and surgical bleeding in patients with haemophilia A or B and with antibodies to either factor VIII or factor IX. However rFVIIa has increasingly been used for indications outside the approved areas as a last resort treatment in trauma, cardiac surgery and other critical bleeding episodes despite the absence of conclusive randomized clinical trial (RCT) data.

Aims:

The aim of the Haemostasis Registry was to collect data (including dose, adverse events and outcome) on the off-license use of rFVIIa in Australia and New Zealand.

Methods:

Monash University established the Haemostasis registry in 2005 with an educational grant from Novo Nordisk Pharmaceuticals. More than 100 hospitals (including all major users of rFVIIa in Australia and New Zealand) contributed data to the Registry covering a ten year period (2000 to 2010).

Results:

More than 3600 off-license rFVIIa cases have been reported to the Registry. 65% of cases were male and the median age was 56 years. Major areas of use were cardiac surgery (∼43%), other surgery (18%) and trauma (13%). The majority (∼77%) of patients received a single dose of rFVIIa with a median (IQR) dose of 91 (73-103) mcg/kg. Seventy-four percent of cases documented a response (decrease or cessation of bleeding) following rFVIIa. Patient mortality rate at 28 days was lower if bleeding was reportedly stopped or decreased (88% or 82% vs. 39% no change, respectively) (χ22=533, p<0.001). Stepwise logistic regression analysis identified the number of units of RBC's, pH and context of bleeding as significant independent predictors of patient response to rFVIIa administration and pH, context of bleeding and units of FFP were included in the best predictive model of patient outcome at 28 days. Thromboembolic adverse events were reported in 7.5% of all patients however risk-adjusted adverse event rates in Haemostasis Registry cardiac patients were not significantly different from those seen in non-rFVIIa treated cardiac patients recorded in the ASCTS registry (www.ascts.org).

Conclusions:

The Haemostasis Registry is the largest dataset of its kind and provides critical observational data on the importance of pH, temperature and coagulopathic state in determining the response to rFVIIa. Although the role of rFVIIa in critical bleeding is still not clear, the Haemostasis Registry has been an invaluable resource for rigorously tracking adverse events and helping to guide clinical practice in an arena unlikely to be supported by new RCT data.

Disclosures:

Phillips: Novo Nordisk: Educational Grant. Off Label Use: rFVIIa; used for the treatment of critical bleeding in trauma, cardiac surgery, liver and obstetrics. Zatta:Novo Nordisk: Educational Grant. McNeil:Novo Nordisk: Educational Grant. Cameron:Novo Nordisk: Educational Grant.
Hypomorphic Lig4 Impacts on Igh Class Switching and Translocations.
Authors: Troppito Logan , Muniandy Parames , Hedouin Sabrine , Silva Joshua , Feldman Lauren , Wu Christine , Yan Catherine T.
Published: October 2019

Abstract 3373

The DNA Ligase IV (Lig4) protein is an essential component of the non-homologous end-joining (NHEJ) repair pathway that plays a key role in the repair of general DNA double strand breaks (DSBs) and those generated during V(D)J recombination and IgH Class Switch Recombination (CSR) in B lymphocytes. Hypomorphic mutations in the Lig4 gene in humans underlies the DNA Lig4 Syndrome, which is associated with radiosensitivity, developmental delay, growth defects, facial dysmorphism and variable degrees of immunodeficiencies. We recently described a mouse model carrying a specific Lig4 hypomorphic mutation in both copies of the Lig4 coding exon that generates an arginine to histidine amino acid #278 (R278H) replacement that corresponds to the first Lig4 mutation reported in humans. Our studies revealed that similar to human patients, the phenotype of homozygous mutant mice Lig4R278H/R278H (Lig4R/R) includes growth retardation, significant decreased life span, severe cellular sensitivity to ionizing radiation, and a severe but incomplete block in T and B cell development. Peripheral T lymphocytes show an activated and anergic phenotype, reduced viability, and a restricted repertoire, reminiscent of human leaky SCID, and high levels of genomic instability associated with increased incidence of thymic and peripheral T lymphomas. Severe defects in B lymphocyte developmental functions include repertoire restriction during aging, spontaneous low affinity antibody production and inability mount high affinity antibody responses. Our studies now reveal that introduction of IgH and IgL knock-in (HL) variable region exon into the R/R mice leads to significant increase in mature B lymphocytes in peripheral lymphoid organs, directly demonstrating that the overall severe reduction in B lymphocytes in the R/R mice is in part due to a block in their developmental progression. We further observe a mild reduction in IgH class switching in the in vitro CSR activated R/RHL B lymphocytes, accompanied by an unusual increase in IgH specific DSBs and translocations, at levels significantly higher than what we previously observed in Lig4 or XRCC4 deficient peripheral B cells, and lower than expected general DSBs. The implications of our findings in the context of B lymphocyte development and CSR, potential altered utilization of alternative end-joining DSB repair mechanisms and on B lymphomagenesis will be discussed.

Disclosures:

No relevant conflicts of interest to declare.
Quantitative Phosphoproteomics Identified a New Syk-Lyn-Axl Signalling Pathway Involved In Resistance to Nilotinib In Chronic Myeloid Leukemia Cells.
Authors: Gioia Romain , Leroy Cedric , Drullion Claire , Lagarde Valérie , Roche Serge , Mahon Francois-Xavier , Pasquet jean-Max
Published: October 2019

Abstract 3376

Nilotinib has been developed to overcome resistance to imatinib, the first line treatment of chronic myeloid leukemia (CML). To anticipate resistance to nilotinib, we generate nilotinib resistant CML cell lines in vitro to characterize mechanisms and signaling pathways that may contribute to resistance. Among the different mechanisms of resistance identified, the overexpression of the Src-kinase Lyn was involved in resistance both in vitro, in a K562 cell line (K562-rn), and in vivo, in nilotinib-resistant CML patients. To characterize how Lyn mediates resistance, we performed a phosphoproteomic study using SILAC (Stable Isotope Labelling with Amino acid in Cell culture). Quantification and identification of phosphotyrosine proteins in the nilotinib resistant cells point out two tyrosine kinases, the spleen tyrosine kinase Syk and the UFO receptor Axl. The two tyrosine kinase Syk and Axl interact with Lyn as seen by coimmunopreciptation. Syk is phosphorylated on tyrosine 323 and 525/526 in Lyn dependent manner in nilotinib resistant cells. The inhibition of Syk tyrosine kinase by R406 or BAY31-6606 restores sensitivity to nilotinib in K562-rn cells. In parallel, the inhibition of Syk expression by ShRNA in K562-rn cells abolishes Lyn and Axl phosphorylation and then interaction between Lyn and Axl leading to a full restoration of nilotinib efficacy. In the opposite, the coexpression of Lyn and Syk in nilotinib sensitive K562 cells induced resistance to nilotinib whereas a Syk kinase dead mutant did not. These results highlight for the first time the critical role of Syk in resistance to tyrosine kinase inhibitors in CML disease emphasizing the therapeutic targeting of this tyrosine kinase. Moreover, Axl, which is already a target in solid tumor, will be also an interesting pathway to target in CML.

Disclosures:

No relevant conflicts of interest to declare.
Effects of the Second Generation Tyrosin Kinase Inhibitors on Osteogenic Differentiation.
Authors: Tibullo Daniele , Barbagallo Ignazio , Giallongo Cesarina , Cava Piera La , Branca Antonio , Conticello Concetta , Stagno Fabio , Chiarenza Annalisa , Palumbo Giuseppe A , Raimondo Francesco Di
Published: October 2019

Abstract 3386

It has been demonstrated that long term treatment of CML patients with Imatinib (IM) is associated with altered bone and mineral metabolism. The mechanisms that are responsible for this effect are not fully understood but an inhibition of the PDGF-Rβ (Platelet Derived Growth Factor- Receptor beta) axis has been documented. In order to evaluate if stimulation of osteoblastogenesis is a common feature of other tyrosine kinase inhibitors (TKIs) approved for the treatment of patients with CML, we evaluated the osteoblatic differentiation of Mesenchymal Stem Cells derived from adult bone marrow donors (BM-MSCs) after in vitro treatment with Dasatinib (DA), Nilotinib (NI) or Bosutinib (BO). BM-MSCs were induced to differentiate in osteoblastic cells by treatment with osteogenic medium (OM) with or without DA, NI or BO. BM-MSCs was induced to differentiate in osteoblastic cells by treatmet with osteogenic medium (0.2 mM ascorbic acid, 0.1 μ m dexamethasone and 10 mM β-glycerophosphate, OM) with or without DA 2nM, BO 5nM or NI 100nM. After 21 days of treatment, in the cultures treated with DA e NI for 21 days we have observed a significant increase of extracellular mineralization and of osteogenic markers such as bone morphogenetic protein (BMP2) (p<0.005), osteocalcin (OCN) (p<0.002), and Runx2/cfba1, (p<0.002) measured by real time PCR. OPG/RANKL ratio (measured by ELISA) was also increased in surnatant of cultures treated with DA and NI (p<0.002). All these phenomena were not observed when BO was added to the cultures.

In conclusion, we show that besides IM, other TKIs such as DA and NI, but not BO, increase osteogenic markers in hBM-MSCs. Since BO differs from the other TKIs because of its low affinity to PDGF-R, these experiments suggest that inhibition of PDGF-R is a major pathway in the induction of osteoblastogenesis by TKIs. In addition, a perturbation of bone metabolism induced by TKi may interfere with physiological growth and have negative consequences in children and adolescents. In this subset of patients, treatment with BO could became the first choice because we have demonstrated that this drug does not affect osteoblastogenesis.

Disclosures:

No relevant conflicts of interest to declare.
Role of Stromal Microenvironment In Non-Pharmacological Resistance of CML to Tyrosine Kinase Inhibitors through Lyn/CXCR4 Interactions In Lipid Rafts.
Authors: Tabe Yoko , Jin Linhua , Yixin Zhou , Ichikawa Naoki , Iwabuchi Kazuhisa , Miida Takashi , Cortes Jorge , Andreeff Michael , Konopleva Marina
Published: October 2019

Abstract 3390

In chronic myeloid leukemia (CML), the mechanisms of resistance to tyrosine kinase inhibitors (TKIs) beyond the Bcr-Abl mutations are not well understood. We have previously reported that TKI imatinib induces cell-surface expression of the chemokine receptor CXCR4, which results in enhanced migration towards CXCL12-producing BM stromal cells, promotes cell quiescence and development of the microenvironment-mediated, non-pharmacological drug resistance (Jin, Mol Cancer Ther 2008;7:48). Bcr-Abl tyrosine kinase directly activates Src-related kinase Lyn known to frequently localize in lipid raft plasma membrane microdomains and interact with CXCL12/CXCR4 signaling and is directly activated by p210Bcr-Abl. In this study, we investigated the effects of TKIs on the localization and interaction of CXCR4 and Lyn in the lipid rafts, and the role of lipid rafts as the signal transduction platform for CML cell migration. Confocal microscopy and discontinuous sucrose density gradient fractionation demonstrated that in CML cells CXCR4 primarily localized in the non-raft cell surface regions, while Lyn was present both in the lipid raft and non-raft fractions. In turn, the active, phosphorylated form (p-)LynTyr396 is present within the lipid rafts, while inactive p-LynTyr507 in non-raft fractions. Imatinib treatment under co-culture with mesenchymal stem cells (MSC) induced CXCR4 clustering in lipid raft fractions, which was directly co-immunoprecipitaed with Lyn. Under these culture conditions, imatinib repressed p-LynTyr507, but failed to deplete p-LynTyr396. Knock-down of Lyn by siRNA, Src inhibitor treatment, or lipid raft destruction by methyl-b cyclodextrin (MbCD) abrogated imatinib-induced KBM5 migration to MSCs and CXCL12 without affecting CXCR4 surface expression. Consistent with its effects on Src, dual Src/Abl kinase inhibitor dasatinib induced significantly less migration of CML cells to CXCL12 compared with imatinib or nilotinib (p =0.04). In summary, our data indicate that stromal cells interfere with inhibitory effects of TKI on active Lyn (p-Lyn)Tyr396 in CML cells and promote clustering of CXCR4 in lipid rafts where it co-localizes with p-LynTyr396 and facilitates migration of CML cells to the MSC monolayer. Lipid raft disruption by cholesterol depletion inhibit CML cells migration, suggesting that lipid rafts represent one of the key signaling modules responsible for interactions of CML cells with cells of BM niche. We propose that pharmacological disruption of lipid rafts may eliminate BM-resident CML cells through interference with microenvironment-mediated resistance.

Disclosures:

No relevant conflicts of interest to declare.
Role of Protein Disulfide Isomerase In Thrombus Formation In a Collagen-Induced Pathway of Thrombus Formation
Authors: Martin Lola Bellido , Furie Bruce , Furie Barbara C.
Published: October 2019

Abstract 345

We have demonstrated that platelet activation in vivo can take place via two pathways, one initiated by the generation of thrombin and the other initiated by the exposure of collagen on the injured vessel wall (Furie & Furie, 2008). In our laser-induced model of thrombosis, in which the endothelium is activated but intact, platelet activation by thrombin dominates and collagen is not required. In the widely used ferric chloride model of thrombosis the endothelium is denuded exposing collagen which leads to initial platelet activation. Using our laser-induced thrombosis model we previously demonstrated that protein disulfide isomerase is expressed on the vessel wall and within the platelet thrombus at the site of injury. Both bacitracin A, a non-specific inhibitor of thiol isomerases, and an inhibitory antibody specific for protein disulfide isomerase (RL90) block platelet thrombus formation and fibrin generation. Here we extend our study of the role of protein disulfide isomerase in thrombus formation to the ferric chloride model of thrombosis. We used intravital fluorescence microscopy in mouse arterioles exposed to filter paper saturated with 10% ferric chloride for 3 minutes. Protein disulfide isomerase, detected with a non-inhibitory polyclonal anti-protein disulfide isomerase antibody, accumulated in ferric chloride-induced platelet thrombi in cremaster arterioles. Bacitracin A (5 mg/mouse) delayed initiation of thrombus formation in mesenteric arterioles. Median time to initial platelet accumulation increased from 1 min in the absence of inhibitor to 4 min in the presence of inhibitor. In 4 out of 8 mice treated with 7 mg of bacitracin A platelet accumulation was completely inhibited. Similarly, bacitracin A prolonged the time to occlusion of ferric chloride-injured arterioles. Less than 50% of injured arterioles in mice treated with 5 mg of bacitracin A and only 25% of injured arterioles in mice treated with 7 mg of bacitracin A occluded after 30 minutes compared to a 100% of arterioles occluded in control saline treated mice. Pretreatment of mice with RL90 at 0.3, 1 or 3 μg/g mouse delayed the appearance of the first aggregates of platelets. Median time to initial platelet accumulation was prolonged from 0.6 min in the presence of isotype-matched control antibody (1 ug/g mouse) to 1.5 min in the presence of 0.3 mg/g mouse of RL90. Platelet accumulation was not observed in 1 out of 7 animals treated with RL90 at 1 mg/g mouse and in 3 out of 7 animals treated with RL90 at 3 mg/g mouse. RL90 also inhibited fibrin deposition after ferric chloride injury. Minimal fibrin was detected in the presence of RL90 at 1 μg/g mouse while fibrin appeared rapidly in mice treated with a control antibody. These data indicate that PDI is a component of a general regulatory pathway for initiation of thrombus formation.

Disclosures:

No relevant conflicts of interest to declare.
Chronic Kidney Disease and That Risk Factor In Patients Alive More Than 10 Years After Allogenic Hematopoietic Stem Cell Transplantation.
Authors: Shimoi Tatsunori , Ando Minoru , Kobayashi Takeshi , Kakihana Kazuhiko , Yamashita Takuya , Ohashi Kazuteru , Akiyama Hideki , Sakamaki Hisashi
Published: October 2019

Abstract 3463

Introduction:

Chronic kidney disease (CKD) is common in survivors of hematopoietic stem cell transplantation (SCT). However, evolution over time of kidney dysfunction and its association with post-SCT acute kidney injury (AKI) are unclear.

Methods:

A retrospective cohort study was performed in 86 myeloablative allogenic SCT patients who received SCT between 1990 and 1999 and lived without relapse for 10 years or more. CKD was defined as a sustained decrease in estimated GFR less than 60 ml/min/1.73 m2 at least for a period more than 3 months. Post-SCT AKI was classified into three stages according to the acute kidney injury network (AKIN) criteria within 100 days after SCT. Incidence of new-onset CKD was studied by 1-year interval along the course of follow-up. Cumulative CKD incidence was evaluated by the Kaplan-Meier analysis. The factors associated with CKD at the time of 10 years after SCT were examined using Cox regression analysis.

Results:

The incident of new CKD was the highest (10.5%) at the first year after SCT and then remained almost constant (2.3 to 3.5%) (Figure 1). The prevalence of CKD increased along the follow-up time (Table 1). The cumulative incidence of CKD increased according to increasing AKI stages with significant difference between stages ≥1 and no AKI (Figure 2). Cox regression showed that each AKIN stage was a significant predictor of CKD: stage 3: hazard ratio (HR) 12.7, 95% confidence interval (CI) 2.42–97.6; stage 2: HR 7.75, 95% CI 1.83–53.6; and stage 1: HR 4.36, 95% CI 1.06–29.5. Other predictors included total body irradiation (TBI) (HR, 4.00; 95% CI, 1.63–10.5) and age on SCT (HR, 1.08; 95% CI, 1.03–1.13).

Conclusions:

CKD accumulated among long-term survivors receiving myeloablative allogenic SCT. Post-SCT AKI, regardless of the AKIN stages, is the most significant risk of CKD in such SCT population.

Disclosures:

No relevant conflicts of interest to declare.
Acute Renal Failure Is a Common Presentation of Engraftment Syndrome In Light Chain Amyloidosis (AL) Patients After Autologous Stem Cell transplantation.
Authors: Irazabal Maria V , Eirin Aflonso , Gertz Morie Abraham A. , Dispenzieri Angela , Kumar Shaji , Buadi Francis , Lacy Martha , Hayman Suzanne R. , Dingli David , Hogan William J , Leung Nelson
Published: October 2019

Abstract 3468

Engraftment syndrome (ES) is a complication of hematopoietic stem cell transplantation classically characterized by fever, rash, diarrhea, weight gain and non-cardiogenic pulmonary edema. Renal failure has been observed but is not considered to be a major part of the syndrome. We have noted that acute renal failure (ARF) is common around the time of leukocyte engraftment in light chain amyloidosis (AL) patients after autologous stem cell transplant (ASCT). We suspect this is due to ES and this retrospective review was conducted to further study this entity. Data were collected from 377 AL patients who underwent ASCT from 7/1997 to 10/2009. Patients who experienced an elevation of serum creatinine (Scr) > 0.5 mg/dl within 4 days of leukocyte engraftment were selected. Patients who carried a diagnosis of ES were also included regardless of Scr elevation. Nephrotoxic insults were reviewed. Vitals were collected. Forty-one patients met criteria. Four patients were found not to have ES, 2 sepsis, 1 allergic interstitial nephritis (AIN), 1 acute cellular rejection. ES was noted in 37 (9.8%) patients, 2 presented with mainly pulmonary ES and 8 had both pulmonary and renal involvement. The degree of renal failure varied from mild and self-limited to severe and requiring dialysis. The renal failure is usually preceded by fever, rash, increasing edema, relative hypotension and low urine sodium (Figure 1). Treatment with glucocorticoids (60 mg/d) was successful in reversing the renal failure in most patients but those with pulmonary involvement required higher doses. Our study showed that ES presents more commonly with renal failure than pulmonary involvement in AL patients. Further complications may be prevented by early treatment with corticosteroids once infection is ruled out. Dosing depends on concurrent pulmonary findings. Distinguishing ES with AIN is difficult as presentations are similar but AIN will continue until the offending drug is removed while ES generally responds quickly to steroids alone.

Figure 1. Figure 1.

Disclosures:

Dispenzieri: Celgene: Honoraria, Research Funding; Binding Site: Honoraria. Kumar:Celgene: Consultancy, Research Funding; Millennium: Research Funding; Merck: Consultancy, Research Funding; Novartis: Research Funding; Genzyme: Consultancy, Research Funding; Cephalon: Research Funding.
Prognostic Impact of Pretransplant Transfusion Amount on Outcome After Allogeneic Stem Cell Transplantation In Adult Patients with Severe Aplastic Anemia
Authors: Lee Sung-Eun , Lee Jong-Wook , Yahng Seung-Ah , Cho Byung-Sik , Eom Ki-Seong , Kim Yoo-Jin , Kim Heeje , Min Chang-Ki , Lee Seok , Cho Seok-Goo , Kim Dong-Wook , Min Woo-Sung , Park Chong-Won
Published: October 2019

Abstract 3503

Background:

Aplastic anemia (AA) is a life-threatening bone marrow failure disorder. Therefore, many patients with AA require blood transfusions as supportive management. Regular transfusions of packed red cell (PRC) lead to the development of iron overload, which is known to increase the risk of complications after stem cell transplantation (SCT). However, the prognostic impact of pretransplant transfusion history of PRC on outcome in AA has not been completely analyzed. We investigated the impact of pretransplant transfusion amount of PRC on outcome after allogeneic SCT in severe AA (SAA).

Methods:

221 adult patients with SAA who underwent allogeneic SCT between January 1995 and August 2007 who had not received optimal iron chelating therapy were selected for retrospective analysis.

Results:

221 patients were divided into two groups according to the mean amount of pretransplant transfusion (32 PRC units): receiving less than 32 PRC units (n=164), >32 PRC units (n=57) before SCT. The median follow-up duration of survivors after SCT was 47.9 (39.5-56.2) months in ≤32 PRC units of transfusion group and 42.8 (39.7-45.9) months in >32 PRC units of transfusion group. Primary engraftment was achieved in all, but 13 patients (9/164 patient, 5.5% in the ≤32 PRC units of transfusion group, 4/57 patients, 7% in the >32 PRC units of transfusion group, P=0.745) developed secondary graft failure. Acute GVHD (grade II-IV) developed in 27.4% in ≤32 PRC units of transfusion group and 42.1% in >32 PRC units of transfusion group (P=0.04), and extensive type of chronic GVHD occurred in 20.7% and 26.3% among evaluable patients, respectively. In the comparison between two groups, higher pretransplant transfusion group has significantly increased risk of transplant-related mortality (TRM) (<32 PRC units of transfusion: 8.2% vs >32 PRC units of transfusion: 25.2%, P=<0.000), and lower overall survival (OS) (91.8% vs 75.2%, P=0.001) than those with lesser transfusion history. Multivariate analysis revealed that higher pretransplant PRC amount [HR (95% CI) 3.09 (1.44-6.63), P=0.004] and donor type (related vs unrelated) [HR 2.41 (95% CI) (1.10-5.27), P=0.028] were independent prognostic factor for affecting OS.

Conclusion:

These results indicate that higher pre-transplant transfusion history of PRC was associated with increased TRM and decreased OS, and it has shown to have a negative impact on outcome after SCT in SAA.

Disclosures:

No relevant conflicts of interest to declare.
Transplant Conditioning Regimens and Outcomes After Allogeneic Hematopoietic Cell Transplantation (HCT) In Children and Adolescents with Acute Lymphoblastic Leukemia (ALL)
Authors: Tracey James , Zhang Mei-Jie , Sobocinski Kathleen A , Thiel Elizabeth L. , Eckrich Michael J. , Pasquini Marcelo C , Saber Wael , Weisdorf Daniel J. , Horowitz Mary M. , Eapen Mary
Published: October 2019

Abstract 3506

Recurrent disease is the most important cause of treatment failure after HCT. Total body irradiation (TBI)-containing conditioning regimens are associated with fewer relapses and longer leukemia-free survival (LFS) in children and adolescents with ALL. While TBI <13 Gy + cyclophosphamide (Cy) is considered standard, attempts to lower relapse rates have led to addition of a second chemotherapeutic agent (etoposide) or higher dose TBI (≥13 Gy) with or without addition of etoposide. TBI dosing (<13 Gy vs. ≥13 Gy) or the addition of etoposide to TBI + Cy regimen has not been examined in children. We report on 765 patients aged <18 years, who received either an HLA-matched sibling (n=160) or an unrelated donor (URD, n=605) HCT between 1998 and 2007. Seventy percent of patients were in 2nd complete remission (CR), 20% were in 3rd CR, and the remaining 10%, in relapse at HCT. The median age of the study population is 9 years and the median follow-up of surviving patients is 4 years. Transplant outcomes were examined in four treatment groups: 1) TBI <13 Gy + Cy (n=304), 2) TBI <13 Gy + Cy + etoposide (n=108), 3) TBI ≥13 Gy + Cy (n=327), and 4) TBI ≥13 Gy + Cy + etoposide (n=26). Ninety-six percent of patients in the TBI <13 Gy group received 12 Gy and 4%, 10 Gy. Irradiation doses in the TBI ≥13 Gy group were 13.2 Gy (24%), 13.5 Gy (41%) and 14 Gy (35%). Patient and disease characteristics (performance score, disease status, NCI-risk score, duration of first remission and cytogenetic risk) were similar among the treatment groups. The 3-year probabilities (95% confidence interval) of treatment-related mortality (TRM), relapse, and LFS in the four treatment groups are shown in the Table below. Neither higher dose TBI (≥13 Gy) nor the addition of etoposide regardless of TBI dose was associated with lower risks of leukemia recurrence or longer LFS after HCT. In the absence of an advantage for leukemia control, further intensification of the conditioning regimen TBI <13 Gy + Cy is not recommended.

TRM Relapse LFS 1) TBI dose <13 Gy + Cy 25 (21–31)% 30 (24–35)% 45 (39–51)% 2) TBI dose <13 Gy + Cy + etoposide 29 (21–38)% 26 (18–34)% 45 (35–54)% 3) TBI dose ≥13 Gy + Cy 23 (19–28)% 33 (28–39)% 43 (38–49)% 4) TBI dose ≥13 Gy + Cy + etoposide 35 (17–52)% 31 (15–69)% 35 (17–52)%

Disclosures:

No relevant conflicts of interest to declare.
Trend towards Improved Day 100 and 2-Year Survival After SCT for AL Amyloidosis: Outcomes Before and After 2006
Authors: Gertz Morie Abraham , Lacy Martha , Dispenzieri Angela , Kumar Shaji , Buadi Francis , Dingli David , Leung Nelson , Hogan William J , Hayman Suzanne R.
Published: October 2019

Abstract 3554

Introduction:

The role of SCT in the management of Ig light chain (AL) amyloidosis remains undefined.

Patients:

We report 422 patients (Table 1) who received SCT for AL amyloidosis to compare outcomes of patients treated before January 2006 with those of patients treated from January 2006 until December 1, 2009.

Results:

Day 100 all-cause mortality decreased over this time period from 12% to 7% (P=.09) figure 1. Survival at 2 years increased from 78% to 82%. Figure 2 The major determinants of early mortality (before day 100) were the presence of cardiac involvement with amyloid and increased levels of cardiac biomarkers, lower serum albumin, higher serum creatinine, and a higher number of organs involved. (Table 2) On multivariate survival analysis, higher levels of serum troponin T and N-terminal pro–brain natriuretic peptide were the only predictors of early mortality after SCT.

Conclusion:

Improved supportive care and refined patient selection has improved the safety margin for patients undergoing SCT; short-term mortality showed a more than 40% decrease after 2005. Recognition of this decrease in mortality is important for physicians caring for these patients as they weigh the pros and cons of SCT vs novel agent-based treatment in management of amyloidosis.

Disclosures:

Gertz: Celgene: Honoraria; Millenium: Honoraria, Membership on an entity's Board of Directors or advisory committees. Lacy:Celgene: Research Funding. Dispenzieri:Celgene: Honoraria, Research Funding; Binding Site: Honoraria. Kumar:Celgene: Consultancy, Research Funding; Millennium: Research Funding; Merck: Consultancy, Research Funding; Novartis: Research Funding; Genzyme: Consultancy, Research Funding; Cephalon: Research Funding.
Impact of the Presence of An Internal Tandem Duplicate of FlT3 Receptor (ITD) on the Outcome of Adult Patients with Acute Myelocytic Leukemia (AML) Autografted In First Remission (CR1)Norbert-Claude Gorin, Myriam Labopin, Jordi Esteve, and Mohamad Mohty, on Behalf of the Acute Leukemia Working Party of the European Group for Blood and Marrow Transplantation (EBMT)
Authors: Gorin Norbert C. , Labopin Myriam , Esteve Jordi , Mohty Mohamad
Published: October 2019

Abstract 3556

The prognosis of patients with AML harbouring the FlT3 ITD is known to be poor in patients treated with chemotherapy only. However it remains uncertain whether it also has an impact on outcome following high dose intensification and autologous stem cell transplantation (ASCT).We adressed the question using the EBMT data base. Information on the presence or the absence of FlT3ITD was available in 134 adult patients with AML who were autografted in CR1 in the period of January 1999 to December 2009. 76 patients (42 with normal karyotypes) were ITD negative and 58 (36 with normal karyotypes) were ITD positive. 90% of the patients received peripheral blood as a source of stem cells. The follow up was 30 mo (1-139).Patients ITD positive were older than patients ITD negative (52.8 vs 47.4 years; p=0.009)and their White cell counts at diagnosis were higher (52 vs 10.9 109/l; p<0.0001).For the 134 patients, the 3 year leukemia free survival (LFS) was 42 ± 5%, the relapse incidence (RI) 53 ± 4% and the non relapse mortality (NRM) 6 ±3%.Patients positive for Flt3ITD had a 3 year LFS of 34±7% vs 46±6% in those with no ITD (p=0.12), and a RI of 62±7% vs 45±6% (p=0.051). In Patients with ITD, age was the only significant poor risk factor with a LFS of 20 ± 9% in those older than 53 years (median) vs 46±10% in those younger. Further studies are needed with a larger patient population to draw valuable conclusions. However, these results suggest that while ASCT is of little benefit to older patients, it remains valuable in younger patients with AML harbouring the FlT3ITD, in whom the outcome does not differ from the ITD negative population.

Disclosures:

Mohty: Genzyme: Consultancy, Honoraria, None, Research Funding, Speakers Bureau; Amgen: Consultancy, Honoraria; Janssen Cilag: Consultancy, Honoraria; Celgene: Honoraria.
High Dose Therapy with Autologous Stem Cell Transplantation Vs Standard Dose Chemotherapy In Multiple Myeloma: A Meta-Analysis
Authors: Faußner Florian , Pfirrmann Markus , Dempke Wolfram
Published: October 2019

Abstract 3559

Introduction.

Myeloablative high dose chemotherapy (HDT) followed by single autologous stem cell transplantation is currently the standard treatment for patients younger than 65 years in newly diagnosed multiple myeloma (MM). Several randomized controlled trials (RCTs) comparing HDT with standard dose therapy (SDT) have shown some benefit in overall survival (OS) and progression free survival (PFS), whereas other RCTs did not confirm this finding. Koreth et al. (2007) performed a metaanalysis summarizing the existing data of the RCTs including 2,411 patients. These authors found a significant superiority for HDT in PFS but not in OS. Since a number of new studies have been published recently, we attempted to re-analyze the current data in terms of the endpoints OS and PFS.

Methods.

We searched PubMed, Embase, abstracts of former ASH meetings and ClinicalTrials.gov as well as bibliographies of included trials and recent reviews from september 2009 until may, 20th 2010. Amongst the 3,484 results in this search we identified 10 RCTs comparing HDT with SDT on an intent-to-treat-basis. Treatment characeristics and outcomes of OS and PFS were calculated using R. Furthermore, we tested for statistical heterogenity, publication bias and performed subgroup analyses.

Results.

9 RCTs including 2,600 patients were fully analyzed. Patients undergoing HDT with stem cell transplantation did have significant PFS benefit (Hazard Ratio 0.73; 95% conficence intervall 0.56–0.95; P=0.02) but not OS benefit (HR 0.90; 95% CI 0.74–1.10; P=0.32) compared to patients undergoing SDT. Additional data from ongoing clinical trials are expected, thus updated results at the meeting including 10 RCTs with about 3,400 patients will be presented.

Conclusion.

Although there is only a trend to OS benefit with HDT, it is currently still the first line treatment. Additional data from ongoing clinical trials and new studies using novel agents like thalidomide, lenalidomide and bortezomib are egerly warrented to finally evaluate the role of HDT in the treatment management of patients with newly diagnosed MM.

Disclosures:

No relevant conflicts of interest to declare.
Characteristic Proinflammatory Serum Cytokine Profiles In Patients with B-Cell Chronic Lymphocytic Leukemia
Authors: Harding James J. , Yeh Raymond , Nikhamin Yan , Frattini Mark , Lamanna Nicole , Jurcic Joseph G , Heaney Mark , Brentjens Renier
Published: October 2019

Abstract 3595

Background:

Cytokines are posited to play a critical regulatory role on the survival of the B-cell neoplastic clone in Chronic Lymphocytic Leukemia (CLL). AIM: The primary goals of this study were 1) to define additional relevant cytokines, growth factors and chemokines in CLL pathophysiology and 2) to correlate abnormal cytokine levels with disease stage, relevant hematological data and multiple prognostic factors. METHODS: A novel bead-based protein array system was employed to simultaneously measure 38 proinflammatory cytokines in the sera of CLL patients (N=116) and healthy age and sex matched controls (N=30). These results were correlated with Rai stage, β2-microglobulin level, LDH, CD38 expression and cytogenetic abnormalities. RESULTS: We first confirmed previous observations that TNFα, IL-1α, IL-1RA, IL-10, sIL-2Rα, VEGF and sCD40 ligand are significantly elevated in patients with CLL as compared with healthy controls. Expanding on the current literature, we demonstrated perturbations in an additional 15 serum cytokines in affected individuals. Compared to healthy controls, CLL patients had an increase in serum levels of IL-3 (p=0.002), IL-7 (p=0.008), INF-2α (p<0.0001), MCP-1 (p<0.0001), MIP-1β (p=0.002), MDC (p<0.0001), Fractakine (p<0.0001), EGF (p<0.0001), FGF-2 (p<0.0001), GRO (p<0.0001), Eotaxin (p<0.0001) and FLT-3 ligand (p<0.0001). Patients with CLL also exhibited significantly lower levels of INF-γ (p<0.01), IL-6 (p<0.005) and IL-8 (p<0.002) when compared to healthy individuals. Advanced Rai stage and high risk chromosomal abnormalities (del 11q and del 17p) strongly correlated with higher serum levels of TNFα, soluble IL-2Rα, IL-10, MCP-1, MIP-1α, MIP-1β and IP-10. Finally, serum levels of TNFα, MIP-1α and MIP-1β correlated with other adverse prognostic markers, including total white blood cell count, serum β2-microglobulin and LDH levels as well as CD38 expression. CONCLUSION: We have demonstrated numerous previously unrecognized cytokine abnormalities in patients with CLL and described a unique cytokine signature associated with advanced disease. Supported by the current understanding of cytokine biology and CLL pathophysiology, our observations suggest an important regulatory role for hematopoietic cytokines, such as IL-3 and IL-7, in promulgating survival of the aberrant B-cell clone. Likewise, the profoundly high levels of chemokines (i.e. MCP-1, MIP-1α, MIP-1β, IP-10) and their association with high risk prognostic factors argue for their role in sustaining the neoplastic microenvironment. Finally, the altered levels of IL-10, IL-6 and INF-γ observed in patients with CLL likely contribute to the immunosuppressive phenotype of the disease state.

Disclosures:

No relevant conflicts of interest to declare.
T Cells From CLL Patients Recognize Spontaneously Peptides Derived of the Receptor Tyrosine Kinase Ror1
Authors: -Farsangi Mohammad Hojjat , Daneshmanesh Amir Hossein , Jeddi-Tehrani Mahmood , Osterborg Anders , Shokri Fazel , Mellstedt Håkan , Rabbani Hodjattallah
Published: October 2019

Abstract 3603

Background:

The receptor tyrosine kinase Ror1 is a tumor-associated molecule over-expressed in chronic lymphocytic leukemia (CLL) and a variety of other malignancies with potential implication for targeted immunotherapy. Little is known about the functional role of Ror1 in the leucomogenesis of CLL. Aims: To assess spontaneous T cell response against Ror1 in CLL patients.

Methods:

Autologous T cell response against Ror1 was studied in 9 CLL patients and 6 healthy subjects expressing the HLA-A2 allele. Four synthetic 9-mer HLA-A2 restricted peptides selected from different parts of the Ror1 molecule were loaded on dendritic cells and co-cultured with enriched autologous T cells. T cell response was determined by enumeration of the frequency of IFN-γ, IL-5 and IL-17A secreting T cells by ELISPOT. Cell proliferation was determined by 3H-thymidine incorporation.

Results:

Our results demonstrated a significantly higher frequencies of IFN-γ producing T cells (p<0.05-0.0001) and to a lesser extent IL-17A secreting autologous T cells (p<0.05) in response to Ror1 peptides in CLL patients compared to healthy controls. No IL-5 secreting T cells were noted. The frequency of IFN-γ secreting T cells was significantly higher in non-progressive as compared to progressive CLL patients (P<0.05). No differences were observed between patients with mutated and unmutated immunoglobulin heavy chain variable region (IGHV) genes.

Conclusion:

Ror1 may spontaneously induce mainly a type 1 T cell response in CLL patients, particularly in those with non-progressive disease as compared to progressive disease. Ror1 may be an immunodominant antigen in CLL which, has also been suggested by Fakuda et al. PNAS, 105, 3047, 2008. Active immunotherapy using Ror1 as a target might be an interesting approach to test in the clinic.

Disclosures:

No relevant conflicts of interest to declare.
Epigenetic Silencing of Bcl-2, C/Ebpa and p14ARF by the AML1/ETO Oncoprotein Contributing to Growth Arrest and Differentiation Blockage
Authors: Zhuang Wen-yue , Chen Zi-Xing
Published: October 2019

Abstract 3617

The t(8; 21) is one of the most frequent chromosomal translocations associated with acute leukemia. The AML1(RUNX1)-ETO(MTG8) fusion transcription factor generated by the t (8; 21) translocation is believed to deregulate the expression of genes that are crucial for normal differentiation and proliferation of hematopoietic progenitors, resulting in acute myelogenous leukemia by recruiting co-repressor complexes to DNA. To investigate the role of AML1-ETO in leukemogenesis, we transfected the cloned AML1-ETO cDNA with plasmid and expressed the AML1-ETO protein in U937 myelomonocytic leukemia cells. Interestingly, we found dichotomous phenomena in these transfected leukemic cells, i.e. growth arrest versus differentiation block (detailed data?). The AML1-ETO transfected U937cells were growing significantly slower than that of empty vector-transfected cells and nontransfected cells (P<0.01). As the surface markers for myeloid differentiation, the expression of CD11b and CD14 measured by flow cytometry demonstrated that the percentage of CD11b+ cell was 4.1%-7.0% in U937-A/E1-4 cells, which was significantly lower(P<0.01) than those in U937-Mock cells (11.4%) and U937-WT cells (11.0%). Moreover, the expression of CD14 antigen was decreased by 1.5–2-fold as compared with the control cells. By focusing on the anti-apoptotic gene (Bcl-2), a key transcription factor (C/EBPA) which regulates granulocytic differentiation and a tumor suppressor gene (p14ARF), we found that AML1-ETO- expressing cell subclones displayed low levels of these three genes in comparison with the non-transfected U937 (P<0.001). In primary bone marrow cells of acute myeloid leukemia containing t(8;21)/AML1-ETO, levels of Bcl-2, C/EBPA and p14ARF mRNA were markedly lower (P<0.001) when compared with other acute myeloid leukemias lacking this translocation (n=10). Chromatin immunoprecipitation assays (ChIP) demonstrated that Bcl-2, C/EBPA and p14ARF were among the direct transcriptional regulating targets of AML1-ETO. The universal binding of AML1-ETO to genomic DNA resulted in MeCP2 recruitment (P<0.01), reduction of histone H3 (P<0.0 1) or histone H4(P<0.01) acetylation and increased tri-methylation on histone H3 lysine 9 (P<0.01)as well as histone H3 lysine 27 (P<0.01), indicating that AML1-ETO induced heterochromatic silencing of Bcl-2, C/EBPA and p14ARF. These results suggested that the aberrant transcription factor AML1-ETO epigenetically silences the function of Bcl-2, C/EBPA and p14ARF gene by inducing repressed chromatin configurations at their promoters through histone modification. Considering that apoptosis-enhancing effect of AML1-ETO would not be favorable to the leukemogenesis, it must be compensated by some other effects to permit its leukemogenic potential.

Disclosures:

No relevant conflicts of interest to declare.
The Transcriptional Network Governed by Interferon Regulatory Factor (IRF8) In Germinal Center B Cell Lymphomas.
Authors: Shin Dong-Mi , Lee Chang-Hoon , Morse Herbert
Published: October 2019

Abstract 3638

The transcription factor IRF8, is highly expressed in germinal center (GC) centroblastic B cells and diffuse large B cell lymphomas (DLBCL). IRF8 is known to play roles in GC formation as well as in early B cell fate commitment, functioning both as a transcriptional activator and repressor; however, the transcriptional network regulated by IRF8 has not been elucidated yet. To identify direct targets of IRF8 on a genome-wide scale, we used ChIP-chip and expression profiling to study human and mouse lymphoma cell lines of GC origin – human Ly1, Odh1 and Val and mouse NFS201, NFS202, and NFS205. The IRF8-negative human multiple myeloma cell line, MMS1, and mouse plasmacytoma cell line, MPC11, were used as negative controls. For the human lines, 271 IRF8 target genes with common binding sites in all three cell lines, but not in negative cell line, were highly enriched for genes involved in innate immunity and adaptive immunity. Two well-established IRF8 target motifs- GAAANNGAAA and GGAANNGAAA - were significantly enriched in promoters of these genes compared to sequences 1kb upstream. Studies of the mouse lines identified 871 IRF8 targets with the lowest number found in NFS205. NFS205 expressed little PU.1, a common partner of IRF8 in DNA binding. PU.1 ChIP-chip analyses of the mouse lines allowed us to classify IRF8 targets into those that are PU.1-associated and PU.1-independent. Analyses of expression profiling of siIRF8-treated cells were used to identify transcriptionally active IRF8 targets. Gene Set Enrichment Analysis (GSEA) revealed significantly high enrichment of IRF8 ChIP targets as well as significant enrichment of genes involved in hematopoietic development. Finally 52 IRF8 targets common to human and mouse GC neoplasms were identified and characterized as contributing to antigen presentation, BCR and CD40 signaling, and interferon signaling, which can contribute differentially to the normal GC reaction and B cells transformation. These results define the contribution of IRF8 to the transcriptional network in GC B cells and provide new insights into the workings of the GC reaction in health and disease.

This work was supported by the Intramural Research Program of the NIH, National Institute of Allergy and Infectious Diseases.

Disclosures:

No relevant conflicts of interest to declare.