bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular and Cellular Specialization of Iron Regulation In Human Erythroid Progenitor Cells Prior to Hemoglobin Production
Authors: Noh Seung-Jae , Byrnes Colleen , Lee Y. Terry , Miller Jeffery L.
Published: October 2019

Abstract 4255

Based upon the importance of iron for erythropoiesis, it was hypothesized that specific molecular and cellular mechanisms may be manifested during early erythropoiesis in preparation for heme and hemoglobin production. Here iron regulation was studied in immature erythroid progenitor cells prior to the increased production of heme or hemoglobin. CD34+ cells were cultured in SCF, IL-3 and FLT-3 ligand for 7 days, and the erythroid progenitor cells were identified and sorted from three donors according to the differential expression of CD36, CD41, and CD71. Among the sorted populations, the CD71(+)CD36(+)CD41(-)GPA(-) cells grew almost exclusively (>95%) into erythroid colonies in methylcellulose culture. Cytospin examination of those erythroid progenitor cells demonstrated large blasts with deep blue cytoplasm and blebbed membranes consistent with pre-proerythroblasts. Furthermore, heme accumulation and hemoglobin were absent. Western analyses revealed that ferritin, transferrin receptor 1 (TfR1), and transferrin receptor 2 (TfR2) expression were regulated by dosed titrations (0, 10, 20, 40, 60, and 100 %) of iron-saturated transferrin in the culture medium. The intracellular iron-storage protein, ferritin, showed increased expression with higher holo-transferrin saturation. Opposite patterns of iron-dependent regulation for the transferrin receptors was identified. TfR1 protein decreased and TfR2 increased with increased transferrin saturation. While TfR1 was detected at high levels on the plasma membranes, immunofluorescence studies showed TfR2 co-localization with lysosomes (correlation with LAMP1, a lysosomal marker, R = 0.53 ± 0.11, n=22). Decreased holo-transferrin in the culture medium resulted in no significant reduction in the proliferation of these cells until hemoglobin production was induced by erythropoietin. Confocal microscopy demonstrated a distinct peri-centrosomal lysosomal compartment surrounded by mitochondria. Coincidentally, upon sulfide-silver staining, it was observed that iron accumulated within the lysosomal compartment in a transferrin-dependent fashion. No similar iron-containing lysosomal-mitochondrial structure was identified in non-erythroid cells in the same cultures. These results suggest that functional, lineage-specific differentiation occurs at the progenitor stage of hematopoiesis, and that iron import and regulation is highly developed during erythropoiesis prior to hemoglobin production.

Disclosures:

No relevant conflicts of interest to declare.
Adoptive Immunotherapy with Haploidentical Kir Ligand-Mismatched Natural Killer Cells In Elderly High Risk Acute Myeloid Leukemia Patients: Biological and Clinical Results of A Pilot Study
Authors: Curti Antonio , Ruggeri Loredana , D'Addio Alessandra , Bontadini Andrea , Giudice Valeria , Dan Elisa , Motta Maria Rosa , Rizzi Simonetta , Trabanelli Sara , Urbani Elena , Martinelli Giovanni , Paolini Stefania , Fruet Fiorenza , Isidori Alessandro , Casadei Beatrice , Bandini Giuseppe , Baccarani Michele , Velardi Andrea , Lemoli Roberto M.
Published: October 2019

Abstract 4287

Purpose:

To evaluate safety, feasibility and anti-leukemia potential of haploidentical KIR-L mismatched natural killer (NK) cell infusion in elderly high risk acute myeloid leukemia (AML) patients.

Patients and Methods:

Thirteen patients (5 active disease, 2 molecular relapse and 6 complete remissions) with median age 62 years (range 53–73) received NK cell infusion after immunosuppressive chemotherapy (fludarabine/cyclophosphamide), followed by interleukin-2. Highly purified CD56+CD3- NK cells from haploidentical KIR-L mismatched donors were used. The median number of infused NK cells was 2.74 × 106/Kg. T cells were less than 105/Kg. NK cell chimerism, phenotyping, and functional assays were performed.

Results:

No significant toxicity, including graft versus host disease, related to NK cell infusion was observed. Among patients with active disease, 1/5 obtained transient complete remission (CR), whereas 4/5 patients had no clinical benefit. Both patients in molecular relapse obtained CR, which lasted 9 and 4 months. Three/6 patients in morphologic CR are disease-free after 34, 32 and 18 months. Donor NK cells were demonstrated in the peripheral blood (PB) of all evaluable patients with a peak at day 10 after infusion and, in some cases, also in the bone marrow (BM). NK alloreactivity was demonstrated in vivo by the detection of donor-derived postinfusion NK clones capable of killing recipient targets.

Conclusion:

Infusion of purified CD56+CD3- NK cells is feasible and safe in elderly high risk AML patients. Adoptively transferred NK cells, which can be detected in PB and BM after infusion, are alloreactive against recipient cells and may induce an anti-leukemic activity.

Disclosures:

No relevant conflicts of interest to declare.
Decreased Expression of KLF2 and KLF4 Induced by Antiphospholipid Antibodies Promotes NF-Kb-Mediated Endothelial Cell Activation and Is Modulated by CBP/p300
Authors: Allen Kristi L , Jain Mukesh K , McCrae Keith R
Published: October 2019

Abstract 4315

Antiphospholipid syndrome (APS) is characterized by thrombosis and/or pregnancy loss in the presence of antiphospholipid antibodies (APLA). These antibodies are directed primarily against phospholipid-bound β2-glycoprotein I (β2GPI). Anti-β2GPI antibodies activate endothelial cells, enhancing the expression of adhesion molecules and tissue factor, and the secretion of proinflammatory cytokines. Krüppel-like factors (KLF) regulate endothelial cell inflammatory responses. KLF2 and KLF4 mediate anti-atherosclerotic and anti-inflammatory effects in endothelial cells, and we have hypothesized that alterations in the expression or activity of KLF2 or KLF4 may modulate the endothelial cell response to APLA. In preliminary studies, we have observed that endothelial cell activation induced by APLA/anti-β2GPI antibodies inhibits the expression of KLF2 and KLF4, and as demonstrated by our laboratory and others, is accompanied by activation of NF-kB. However, forced expression of KLF2 or KLF4 by plasmid-mediated transfection of endothelial cells inhibits neither the phosphorylation of ser536 of the p65 subunit of NF-kB, nor the nuclear translocation of p65 in response to APLA/anti-β2GPI antibodies. Despite the lack of effect on forced KLF2 or KLF4 expression in endothelial cells on p65 phosphorylation, expression of either of these factors inhibits NF-κB transcriptional activity with corresponding inhibition of cellular activation as measured by inhibition of cell-surface E-selectin expression as well as E-selectin promoter activity. Inhibition of NF-kB transcriptional activity by KLF2 and KLF4 appears to be due to recruitment of the CBP/p300 cofactor away from NF-kB by KLF2 or KLF4, since augmenting the cellular pool of CBP/p300 by transfection restores NF-κB activity and endothelial cell activation responses. Similarly, treatment of APLA-activated endothelial cells with CBP/p300 siRNA inhibits NF-kB transcriptional activity regardless of the levels of KLF2 or KLF4. These data suggest that APLA inhibit KLF expression and that these changes promote the acquisition of a prothrombotic endothelial cell phenotype. CBP/p300 may serve as a molecular switch that determines the relative antithrombotic activities of KLFs versus the prothrombotic, inflammatory responses induced by NF-kB in APLA/anti-β2GPI antibody activated endothelial cells.

Disclosures:

No relevant conflicts of interest to declare.
Atypical T Cell Prolymphocytic Leukemia – One Case Report
Authors: He Xuefeng , Depei Wu , Ma Xiao , Zhou Yanan , Fu Chengcheng , Li Weiyang
Published: October 2019

Abstract 4332

Here we reported one case of atypical T cell prolymphocytic leukemia. The 38-year female was admitted to our hospital for fatigue and night sweat. She complained of fatigue and night sweat for one month and accompanied by gum bleeding. Physical examination showed anemia and massive spleen extending to umbilical level. Blood routine test indicated pancytopenia (detailed info: Wbc 0.66×109/L,Hb 82g/L,Plt 60×109/L)and elevated proportion of lymphocytes. Blood biochemistry and routine serum tumor marker were normal. Mutation of JAK2V617F was negative. Marrow film showed many atypical mature lymphocytes which expressed mature T cell markers. Marrow biopsy showed a SLL-like scene and accompanied by local fibrosis, immunochemical stains strong CD3, CD45-R0, CD43 and weak CD5, MPO. Repeated TCR β rearrangement indicated positive. PET/CT scan could not find specific elevated SUV lesions. This patient may be diagnosed as atypical T cell prolymphocytic leukemia despite her lymphocytopenia and unpalpable peripheral lymph nodes. She received one cycle of CVP (cyclophosphamide, Vincristine and prednisone) and another cycle of CHOP(cyclophosphamide, Adriamycin, Vincristine and prednisone). Her blood cell count partly recovered and she was preparing for following high dose chemotherapy.

Disclosures:

No relevant conflicts of interest to declare.
Triptolide Exerts a Cytotoxic Effect on Human Acute Myeloid Leukemia Cell Lines
Authors: McCormack Jennifer M.H. , Feldberg Tanya , Lamba Jatinder
Published: October 2019

Abstract 4352

Background:

Triptolide, a diterpenoid derived from the Chinese herb Tripterygium wilfordii Hook f., has shown anti-tumor effects in various leukemia and solid tumor cell lines in vitro. Previous studies have shown that triptolide synergizes with various chemotherapeutic agents in both leukemia and solid tumor cell lines. Triptolide has been shown to synergize with cytarabine in the THP-1 acute myeloid leukemia (AML) cell line (Pigneux et al 2008). This is of particular interest because cytarabine forms the backbone of AML therapy in both children and adults, and cytarabine resistance poses a significant challenge in the setting of refractory or relapsed AML. Therefore, an agent that works synergistically with cytarabine is of particular interest as a potential new agent for the treatment of relapsed or refractory AML. The aim of this study was to assess the cytotoxicity of triptolide, both as a single agent and in combination with cytarabine, in human AML cell lines representing low-, intermediate-, and high-relapse risk groups.

Methods:

The following cell lines were selected: Kasumi-1 (low risk, t(8;21)), HL-60 and THP-1 (intermediate risk), and MV4-11 (high risk, FLT3 ITD). Kasumi-1 and HL-60 cells were cultured in RPMI 1640 media with 20% fetal bovine serum (FBS). MV4-11 cells were cultured in IMDM media with 10% FBS and THP-1 cells were cultured in RPMI with 10% FBS. We performed the following drug treatments: triptolide alone; cytarabine alone; co-treatment with triptolide and cytarabine. Drug-induced cytotoxicity after 48 hours of treatment was assessed using the MTT assay. The combination index (CI) was determined using Calcusyn software (Biosoft, Cambridge, UK).

Results:

Single-agent triptolide induced cell death in all human AML cell lines tested, including cytarabine-resistant Kasumi-1 cells, at low nanomolar concentrations (average Ic50 ranging from 6–15 nM). The combination of triptolide and cytarabine acted synergistically to induce cell death in THP-1 cells as has been previously reported. Interestingly, the combination of triptolide and cytarabine acted in an antagonistic fashion in all other cell lines tested, except for at low drug concentrations in MV4-11 cells.

Conclusion:

Single-agent triptolide exerts a cytotoxic effect on human AML cell lines, including those that are relatively resistant to cytarbine. The effect of the combination of triptolide and cytarabine was cell-line dependent. The results of this study warrant further investigation on the potential role of triptolide as an anti-leukemic agent in combination with cytarabine.

Disclosures:

No relevant conflicts of interest to declare.
Clofarabine, Etoposide and Mitoxantrone In the Therapy of Relapsed and Refractory Acute Myelogenous Leukemia
Authors: Ehmann W. Christopher , Ibrahim Sulfikar , Rybka Witold , Claxton David F.
Published: October 2019

Abstract 4353

Currrent therapy for acute myelogenous leukemia depends on the activity of cytosine arabinoside (ara-C). The development of regimens without this agent would potentially provide non-crossresistant treatment options for these disorders. Clofarabine, a novel agent showing significant single agent activity in AML, provides a platform for potentially effective treatment independent of ara-C. We treated 10 patients ages 30–67 (median 51) with relapsed or refractory AML with a phase I dose finding protocol employing a three drug combination based on clofarabine. The objectives were to define a maximally tolerated and recommended phase 2 dose and identify early phase 2 activity. Seven patients (70%) were refractory to 1 or 2 treatment regimens immediately prior to enrollment, the other 3 pts (30%) were relapsed following a remission. All patients had relapsed following or were refractory to standard 7+3 chemotherapy and 7/10 had received intermediate or high dose cytarabine within <52 weeks of enrollment. Patients received clofarabine 20mg/m2 (Dose level 1 – DL1 – 4 patients treated) or 25mg/m2 (DL2 – 6 patients) days 2–6, etoposide 100mg/m2 days 1–5, and mitoxantrone 8mg/m2 days 1–3. Treatment emergent non-hematological toxicities included mucositis (4 patients, ≤ grade 2) and diarrhea (2 patients, ≤ grade 3). Two out of 6 patients (33%) at DL2 failed to recover absolute neutrophils (ANC) to 500/mcL by Day 42, and this was judged a potentially treatment related toxicity given lack of residual leukemia in day 14 marrows. Seven of 9 (78%) day 14 marrows were markedly hypocellular or aplastic, and two showed residual leukemia. Four out of 10 patients (40%) showed complete remission (CR – 2 patients) or remission with incomplete hematopoietic recovery (CRi – 2 patients). Three patients survive in remission 34, 98, and 236 days from enrollment.

We conclude that the clofarabine, etoposide and mitoxantrone combination has acceptable toxicity and is an active regimen for significantly pretreated acute myelogenous leukemia. The total response rate compares favorably with other AML salvage regimens. As there has been delayed myeloid recovery at higher doses, we are pursuing DL1. The activity of this regimen is potentially non-crossresistant with ara-C, therefore larger studies are justified. Currently, patients are enrolling in an expanded cohort at the recommend phase 2 dose.

Disclosures:

Claxton: Genzyme: Research Funding. Off Label Use: Clofarabine for AML therapy.
The Histone Methyltransferase Inhibitor, DZNep, Upregulates TXNIP, Increases ROS Production and Targets Leukemia Cells In AML
Authors: Zhou Jianbiao , Bi Chonglei , Liu Shaw-Cheng , Tay Kian-Ghee , Cheong Lip-Lee , Koh Tze-Loong , Yu Qiang , Chng Wee-Joo
Published: October 2019

Abstract 4355

Background/Hypothesis:

Targeting epigenetic abnormalities is an emerging therapeutic strategy in AML. Unlike inhibition of DNA methylation and histone deacetylase, inhibition of histone methylation, has been under-explored in AML.

Methods:

A novel histone methytransferase inhibitor, DZNep, was used to treat a panel of AML cell lines (in vitro and in mouse models), primary patient cells and leukemia stem cells (LSCs). Flow cytometry was used to determine apoptosis and reactive oxygen species (ROS) production. RNA interference (RNAi), gene expression profiling (GEP), and chromatin immunoprecipitation (ChIP) were used to study the molecular mechanism of DZNep.

Result:

DZNep depleted EZH2, a histone methyltransferase, and induced robust apoptosis in AML cell lines, both in vitro and in mouse model, in primary AML cells, and targeted LSCs while sparing normal haematopoietic stem cells. On GEP, polymerase chain reaction (PCR) and western blot, TXNIP, a major redox control molecule, was one of the most upregulated molecules upon DZNep treatment. Either DZNep treatment or EZH2 knockdown reactivated TXNIP and increased ROS, leading to apoptosis. TXNIP over-expression also produced the same phenotype. Furthermore, TXNIP was downregulated in AML and a direct target of EZH2-mediated gene silencing. We also saw a signature of downregulation of endoplasmic reticulum (ER)-stress regulated pro-survival genes, suggesting a novel function of EZH2 in regulation of stress response.

Discussion and Conclusion:

DZNep and EZH2 inhibition has therapeutic potential in AML, in which treatment has not change in 20 years. We delineated that the effect of DZNep is specifically mediated through EZH2 and TXNIP, and highlighted the importance of histone methylation, redox regulation and ER stress in AML biology.

Disclosures:

No relevant conflicts of interest to declare.
Clofarabine In Combination with Cyclophosphamide for Treatment of Relapsed/Refractory Acute Leukemia In Adult Patients
Authors: Chawla Bobby , Kanate Abraham Sebastian , Osman Salman , Tse William , Hamadani Sayed Mehdi , Craig Michael , Cumpston Aaron
Published: October 2019

Abstract 4367

Introduction:

Clofarabine is a purine nucleoside analogue which is approved for pediatric patients with relapsed or refractory acute lymphoblastic leukemia. A number of small phase I and II studies have shown activity in adult patients with newly diagnosed and relapsed/refractory acute myeloid leukemia (AML). Promising activity of clofarabine in combination with cyclophosphamide and etoposide has been reported in the pediatric setting (Hijiya et al., Leukemia 2009; Locatelli et al., Br J Haematol 2009). This combination has limited data in adult patients. We present a series of five cases in which clofarabine was combined with cyclophosphamide in adult patients with relapsed or refractory acute leukemia.

Methods:

We retrospectively reviewed patient charts of five patients treated with clofarabine in combination with cyclophosphamide.

Results:

Three patients received clofarabine 30mg/m2 + cyclophosphamide 340mg/m2, both on Days 1–5. Two patients received clofarabine 40mg/m2 + cyclophosphamide 440mg/m2 + Etoposide 100mg/m2, each drug on Days 1–5. Median age was 21 (range: 17 – 54). Patients had received 2 to 4 prior induction regimens (median of 3). Three patients were AML, one ALL, and one biphenotypical acute leukemia. Two patients were primary refractory and the other three were relapsed disease. Two out of the five patients achieved a morphologic complete remission (CR), one patient had a morphologic complete remission with incomplete blood count recovery (CRi) and the other 2 patients had treatment failure per Cheson criteria. Three patients went on to receive allogeneic transplants after clofarabine salvage therapy. Two patients that received allogeneic transplant had achieved complete remission (CR) after clofarabine/cyclophosphamide. The third patient was transplanted with a hypocellular marrow 38 days after clofarabine therapy. This patient ultimately achieved CR that was documented post-transplant, making it difficult to determine if the clofarabine regimen or allogeneic transplant achieved the remission status. Event-free survival ranged from 5 to 265+ days (median: 82 days). Treatment was complicated by neutropenic fever (n=5), grade III-IV mucositis (n=4), prolonged aplasia >30 days (n=4). One patient died of sepsis before completing the regimen.

Conclusion:

Clofarabine in combination with a cyclophosphamide-containing regimen appears to have anti-leukemic potential in adult patients. This regimen might be used to achieve cytoreduction before considering allograft transplant with refractory disease, in selected patients. More studies with this combination in adults are warranted.

Disclosures:

Hamadani: Celgene: Honoraria, Speakers Bureau; Otsuka: Research Funding, Speakers Bureau.
Hematology Experience with Perioperative Anticoagulation at a Tertiary Hospital
Authors: De Sancho Maria Teresa , Bardarova Svetoslava
Published: October 2019

Abstract 4399

Introduction:

The purpose of our study was to evaluate the peri-procedure management of patients on chronic vitamin K antagonists (VKA) and to assess adherence to the 2008 American College of Chest Physicians (ACCP) guidelines.

Methods:

We retrospectively reviewed the electronic medical records of patients on chronic VKA who required temporary discontinuation of anticoagulation due to an invasive or surgical procedure at New York Presbyterian Hospital from January 2006 to June 2010. Dermatological or oral procedures were excluded. Demographics, indications of VKA, underlying thrombophilia, cancer or inflammatory bowel disease, type of invasive or surgical procedure, method of bridge therapy and complications were recorded. When the ACCP guidelines were published, we compared our previous practice and modified our management accordingly.

Results:

A total of 48 procedures where performed in 34 patients. The demographic and clinical characteristics of these patients are shown in Table 1. The type of procedure, anticoagulant bridge therapy and complications are shown in Table 2. The majority of the procedures were managed using bridge therapy with low molecular heparin (LMWH) treatment dose. There were no thrombotic episodes, however there were 3 bleeding complications. All occurred prior to the publication of the 2008 ACCP guidelines. The patients who had bleeding complications were on therapeutic dose LMWH/Fondaparinux bridge therapy. One patient with the antiphospholipid syndrome developed severe thrombocytopenia after surgery that responded to intravenous gamma globulin.

Conclusion:

Adherence to the ACCP guidelines for the perioperative management of anticoagulation minimizes bleeding complications and improves patient outcomes.

Disclosures:

No relevant conflicts of interest to declare.
Pro–angiogenic Induction of Myeloid Cells for Therapeutic Angiogenesis Can Favor MAPK p38–dependent Foam Cell Formation
Authors: Rohde Eva , Schallmoser Katharina , Reinisch Andreas , Hofmann Nicole A , Pfeifer Thomas , Rechberger Gerald , Kratky Dagmar , Fröhlich Eleonore , Strunk Dirk
Published: October 2019

Abstract 4442

Background:

Clinical trials for therapeutic angiogenesis use blood- or marrow-derived transplants containing hematopoietic cells, endothelial progenitor cells (EPCs) and mesenchymal stem and progenitor cells (MSPCs) to support vascular regeneration. Recently concerns have emerged, as bone marrow-derived stem cell preparations also include these three cell types which probably may contribute to atherosclerosis. We therefore asked whether human myelomonocytic hematopoietic cells, EPCs or MSPCs after pro-angiogenic induction can accumulate lipid droplets (LDs) and develop into foam cells.

Method:

LD accumulation was quantified by flow cytometry, confocal microscopy and cholesterol measurement in each of the tested cell types. The impact of an initial three-day pro-angiogenic culture on subsequent foam cell formation was studied to mimic a relevant setting already being used in clinical trials. The phosphorylation state of intracellular signaling molecules in response to pro-angiogenic stimulation was determined to delineate the operative mechanisms and to establish a basis for interventional strategies.

Result:

Foam cells were formed by monocytes but neither by EPCs nor by MSPCs after pro-angiogenic induction. Mitogen-activated protein kinase (MAPK) p38 phosphorylation was enhanced in monocytes after pro-angiogenic stimulation. Kinase inhibition almost abrogated intracellular LD accumulation.

Conclusion:

These data suggest that hematopoietic cell preparations containing monocytes bear the risk of foam cell formation after pro-angiogenic induction. EPCs and MSPCs instead may drive vascular regeneration without atherogenesis aggravation. A thorough understanding of cell biology is necessary to develop new strategies combining pro-angiogenic and anti-atherogenic cellular effects during therapeutic angiogenesis.

Disclosures:

No relevant conflicts of interest to declare.
Proteasome Inhibition Leads to Dephosphorylation and Downregulation of Protein Expression of Members of the Akt/mTOR Pathway In MCL
Authors: Hutter Grit , Zimmermann Yvonne , Rieken Malte , Hartmann Elena , Hiddemann Wolfgang , Rosenwald Andreas , Dreyling Martin H.
Published: October 2019

Abstract 4449

Background:

Mantle cell Lymphoma (MCL) is a distinct B-cell subtype characterized by the chromosomal translocation t(11;14)(q13;q32), an especially poor clinical outcome and low response to chemotherapy. The proteasome inhibitor bortezomib is approved for treatment of relapsed and refractory MCL and achieves a response rate of 30–40%. However, little is known which molecules represent the critical targets of proteasome inhibition and how different regulators of cell cycle and apoptosis are affected. Bortezomib has been shown to inactivate the NFkB pathway in MCL, but recent findings indicate Bortezomib is also active in a proteasome –independent manner suggesting Bortezomib targets multiple pathways.

Method:

Four MCL cell lines (HBL2, Granta 519, Jeko-1, NCEB-1), two CLL cell lines (Mec1, Mec2) and two hematological control cell lines (Jurkat, Karpas 422) were exposed to Bortezomib at a previously defined cytotoxic concentration (25nmol). Western blot and mRNA analysis were performed for various members of the PI3K/Akt/mTOR and the MEK/ERK pathway after 24h Bortezomib exposure. Results were compared to cell proliferation (WST1, trypan blue staining), induction of apoptosis (Annexin V PE/7-AAD staining) and cell cycle data (FACS).

Result:

Western blot analysis revealed reduced phosphorylation of Akt at Ser473 in all cell lines while autophosphorylation of mTOR at Ser2481 was completely downregulated only in the susceptible cell lines. In addition further members of the mTOR pathway were affected by bortezomib treatment. Dephosphorylation of the 4EBP1, downregulation of p70S6 protein expression was detected in all cell lines whereas EIF4E dephosphorylation was only observed in the sensitive MCL cell lines. In contrast Bortezomib did not affect members of the MEK/ERK pathway (MEK1/2, p42/44MAPK). Interestingly the mRNA and protein expression profile of CCND1 were differently altered suggesting an involvement of bortezomib in the regulation of translation initiation. This data were also confirmed by microarray analysis.

Conclusion:

In this study Bortezomib treatment was shown to target the Akt/mTOR pathway especially by dephosphorylation of the translation initiation factor EIF4E and other molecules of this signal pathway. This knowledge will play a crucial role in the development of future combinations of biologicals to target the molecular pathogenesis of MCL.

Disclosures:

Dreyling: Johnson & Johnson: support of investigators initial trials.
Serious Late Complications After Hematopoietic Stem Cell Transplantation (HSCT) Following Myeloablative Conditioining (MAC) In Infants.
Authors: Yasui Masahiro , Yamada Kayo , Kondo Osamu , Sato Maho , Sawada Akihisa , Tokimasa Sadao , Kawa Keisei , Inoue Masami
Published: October 2019

Abstract 4501

Background:

Recently, HSCT has been widely used as a curative therapy for refractory hematological/malignant diseases. However, late complications after HSCT such as endocrine disorders, infertility, short stature and secondary cancers have been recognized as serious problems in children. Late complications are assumed to be much more serious in younger children, especially in infants. Therefore, we retrospectively evaluated late complications among patients who underwent HSCT before one-year-old age in our institute to clarify this big issue.

Methods and results:

We performed HSCT in 530 children from 1993 to 2009. Among these 530 patients, 33 were infants (younger than 1- year - old) at HSCT. 23 infants with malignant disorders consisted of neuroblastoma 10, hepatoblastoma 2, rhabdomyosarcoma 1, retinoblastoma 1, acute lymphoblastic leukemia 5, myelodysplastic syndrome 2, acute myelogenous leukemia 2, and 10 infants with non-malignant disorders consisted of immunodeficiency 5, familial hemophagocytic lymphohistiocytosis/hemophagocytic syndrome 2, congenital metabolic disorder 1, severe aplastic anemia 1, pure red cell aplasia 1 were included. 9 infants underwent autologous HSCT and 24 underwent allogeneic HSCT. 22 infants received MAC and 11 received reduced-intensity conditioning (RIC). 26 out of 33 patients have been alive (MAC, 18/22 = 81.8 %; RIC, 8/11 = 72.7 %). Body height (BH) of 5 patients in RIC group who have been surviving longer than 5 years after HSCT is equal or taller than -2 standard deviation (SD) of BH. However, BH of 6 out of 13 evaluable patients in MAC group remains shorter than -2 SD (the shortest, -5.3 SD) of BH. All survivors in MAC group are suffering from one or more late complications such as growth hormone secretion insufficiency, premature puberty, hypothyroidism, gonadal failure and secondary cancers, therefore, they needs treatment and support for these late complications.

Conclusions:

The survival rate is similar (81.8 % versus 72.7 %) between MAC and RIC in infants, however, infants who underwent MAC-HSCT are suffering from late complications much more frequently and need treatment and support. These results suggest that less toxic conditioning should be adopted for infants who undergo HSCT to avoid serious late complications.

Disclosures:

No relevant conflicts of interest to declare.
Linac Based Total Marrow Irradiation and Myeloablative Chemotherapy In Allogeneic Stem Cell Transplantation for High Risk Patients.
Authors: Patel Pritesh R. , Aydogan Bulent , Rondelli Damiano
Published: October 2019

Abstract 4526

Intensity modulated total marrow irradiation (IM-TMI) represents an innovative technique to irradiate the bone marrow in hematologic malignancies. IM-TMI has been performed previously using tomotherapy in combination with a reduced intensity preparative regimen. Here we report 2 cases where IM-TMI 300cGy was delivered using a linear accelerator in combination with fludarabine/IV busulfan.

To plan IM-TMI, 5 mm-slice CT scanning from top of the head to the mid femur was performed with immobilization using a customized whole body alpha cradle. All bones (excluding the arms and lower extremities) were contoured as the clinical target volume. A 3 mm margin was added to obtain the planning target volume (PTV). The organs at risk (OAR) including the brain, lenses, lungs, liver, kidney, small bowel and heart were identified and contoured. The IM-TMI technique consisted of three separate treatment plans: the head and neck; trunk; and pelvis.

Patients received fludarabine 40mg/m2 on days -8 to -5. IV busulfan was given on days -5 to -2 targeting an AUC of 4800microM/min based on a pretransplant test dose. IM-TMI was delivered on day -5. The patients received a total of 300 cGy IM-TMI dose in two fractions, 8 hours apart.

Two patients were treated: one is a 63 year old male with multiple myeloma who relapsed within 6 months after an autologous transplant with new cytogenetic abnormalities; and the second is a 52 years old female with AML who failed initial induction chemotherapy and at the time of transplant was in complete remission after receiving a second induction and one consolidation chemotherapy. Both patients received PBSC from HLA matched siblings.

IM-TMI technique achieved 95% coverage of the PTV. The mean doses to the lenses and lungs were 99 and 195 cGy, respectively. Overall doses delivered to OAR were reduced by 20–67% on average when compared to standard total body irradiation. Treatment time was 44 min and 32 min for the beam-on and set-up, respectively, using the Varian 21 EX linac and MV imaging.

Both patients suffered Bearman grade 1 mucositis. No other extramedullary toxicities were observed. Both engrafted in a timely manner achieving neutrophil >0.5 × 109/L at day 13 and 14, and platelet >20 × 109/L at day 8 and 9, respectively. Full donor chimerism was noted by day +30. After follow up of 246 and 218 days, respectively, both patients are alive and in remission. One developed a grade 2 acute GVHD and none of them has chronic GVHD.

This study demonstrates for the first time the use of IM-TMI using a linear accelerator. The possibility of adding higher doses of IM-TMI to a myeloablative regimen without toxicity will be tested in a dose escalating clinical trial.

Disclosures:

No relevant conflicts of interest to declare.
Evaluation the Risk Factor of Transplantation-Associated Thrombotic Microangiopathy.
Authors: Zheng Weiyan , Luo Yi , Tan Yamin , He Jingsong , Shi Jimin , Wei Guoqin , Sun Jie , Ye Xiujin , Lin Maofang , Cai Zhen , Huang He
Published: October 2019

Abstract 4527

Background:

Transplantation-associated thrombotic microangiopathy (TA-TMA) is lifethrewten though rare complication of allogeneic hematopoietic stem cell transplantation (HSCT). Diagnosis of TA-TMA is difficult due to its variation of criteria. Recently two new diagnositic criteria for TA-TMA have recently been proposed: the Bone Marrow Transplant Clinical Trials Network (BMTCTN) and the International Working Group (IWG) criteria. Our purpose is to investigate the indence and risk facter of TA-TMA in our institute.

Study design and methods:

All 8 cases of TA-TMA previously diagnosed at our institution between October 2005 and August 2010 were retrospectively evaluated and analysised. Table I showed the transplant details and patients characteristics.

Results:

Six patients performed Matched Unrelated Donor HSCT, two were haploidentical donor HSCT. Four patients complicated with hypohepatia, but only three patients had renal insufficient. The incidence of central nervous symptom abnormalities or dysfunction was very high (sever of eight patients). Four of eight patients were CSA linked TA-TMA, withdrawing CSA resulted in complete response. The other four patients were no CSA linked TA-TMA and developed aGVHD or CMV infection before TA-TMA. They had badly response to common treatment including plasma exchange (PE), steroid treatment and immunosuppression decreased. All of them died of multiple organ failure. Table II showed TA-TMA manifestations and associated circumstance of the patient.

Conclusion:

Our experience suggests that CSA linked TA-TMA is totally different from no CSA linked TA-TMA. The former had good response and prognosis, the later were always associated with GVHD, hypohepatia and virus infectious. The mortality of no CSA linked TA-TMA is high, they had poor prognosis and badly response.

Disclosures:

No relevant conflicts of interest to declare.
Pre-Surgical Methylene-Blue “targeting” of Small Intrapulmonary Nodules In Patients with Haematological Malignancies: Preliminary Experience.
Authors: Ceesay M. Mansour , Jaffer Ouni , Lung Phillip FC , Marrinan Michael T , Deshpande Ranjit , Mullholland Nicola , Pagliuca Antonio , Mufti Ghulam J. , Desai Sujal R
Published: October 2019

Abstract 4551

The diagnosis of intrapulmonary nodules in patients with haematological malignancies is problematic as such lesions are often small and impalpable and “non-targeted” surgical biopsy is difficult. The aim was to evaluate the utility of image-guided “targeting” of small pulmonary nodules with methylene-blue before video-assisted thoracoscopic (VATS) biopsy. Eleven patients (8M:3F) with median (range) age of 48 (27-62) years with haematological malignancies (lymphoma, n=6, AML/MDS, n=3, ALL, n=1,Castleman's disease, n=1) were referred for VATS biopsy. Equal volume of iodinated contrast) was injected in the vicinity of the target lesion and along a track (including the pleural surface and the overlying chest wall), using a 20G needle. The platelet count, diameter of targeted nodules, “perpendicular” distance from the pleural surface and complications were recorded. Patients were transferred to surgery from the CT suite. The median (range) platelet count was 256×109/L (54-453). The mean (range) diameter of targeted nodules was 12.5(5-22) mm and these were at a mean distance of 14.3±8.3mm from the pleural surface. Complications included small pneumothoracis in 4/11 (36%) patients and pain in 1/11 (9%). A definitive histopathological/microbiological diagnosis was achieved in 10/11 (91%) patients and included: organising pneumonia (n=4), respiratory bronchiolitis (n=2), Kaposi's sarcoma (n=1), mycobacterium fortuitum infection (n=1) and chronic GVHD (n=1). There were no cases of angioinvasive aspergillosis. This preliminary data suggest that pre-biopsy methylene-blue targeting of intrapulmonary lesions is a safe and promising technique for the diagnosis of indeterminate lung nodules in patients with haematological malignancy.

Disclosures:

Mufti: Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.
Massive Pleural Effusions and Anasarca After Allogeneic Hematopoietic Cell Transplantation.
Authors: Wirk Baldeep
Published: October 2019

Abstract 4556

A 37 year old male with T cell acute lymphoblastic leukemia with normal cytogenetics 46XY in second complete remission (CR2) after 8 cycles of HyperCVAD and 4 cycles of salvage nelarabine underwent myeloablative conditioning with cyclophosphamide TBI for a matched related donor allogeneic stem cell transplant from his brother. His day+100 bone marrow biopsy showed CR2 and was 100% donor. His post transplant course was unremarkable until he relapsed d+162. The immunosuppression was tapered off rapidly and 2 cycles of nelarabine and a donor lymphocyte infusion (1×107 CD3 cells/kg) were completed by d+254 and CR3 was achieved. He did well until d+608 when he presented with a month long history of dyspnea and recurrent bilateral large pleural effusions (despite multiple large volume thoracenteses) and anasarca including facial edema. He had gained 15 kilograms in 2 weeks. He had no fever, skin rash, sicca syndrome or lichen planus. Chest and abdomen CT showed massive bilateral pleural effusions, but no lung infiltrate, pericardial effusion or ascites or lymphadenopathy. The complete blood count, renal function and liver function tests were normal and there was normal hepatopedal flow in the main portal vein and its branches. The echocardiogram showed a left ventricular ejection fraction of 60% (normal) and there were no vegetations. The serum ANA, anti-Ro and anti-La were negative. The bone marrow biopsy showed no evidence of relapse of T cell ALL. The peripheral blood STR was 100% donor. The pleural fluid was transudative and cytology showed no malignancy. Pleural fluid flow cytometry showed no CD20+ B cells but did show polyclonal T cells with a CD4:CD8 ratio of 0.22. The pleural biopsy showed reactive mesothelial cells with mixed acute and chronic inflammation and no malignancy. Ebstein Barr virus in-situ hybridization and HHV-8 immunohistochemistry was negative on the pleural biopsy. All bacterial, fungal and viral (including CMV, EBV, HSV, adenovirus, VZV, HIV, BK) of the blood, urine and pleural fluid were unremarkable. A random skin biopsy of the forearm showed scleroderma. Methylprednisolone 2 mg/kg iv daily and therapeutic tacrolimus with extracorporeal photoporesis was begun with resolution of the pleural effusions and anasarca two months later. On d+903 he remains in CR3 and is on tapering courses of prednisone and tacrolimus without recurrence of the pleural effusions or anasarca. Conclusion: Isolated sterile pleural effusions with anasarca should be recognized as a rare feature of late onset chronic graft versus host disease so as to allow prompt initiation of immunosuppression. The patient shared the HLA antigens HLA DR15 and HLA DQW6 which are associated with autoimmune disease such as systemic lupus erythematosus suggesting that patients with this HLA combination may be more prone to this presentation.

Disclosures:

No relevant conflicts of interest to declare.
Irradiation-Based Myeloablative Cord Blood Transplantation for Hematologic Malignancies In Adults.
Authors: Liu Huilan , Wang Xingbing , Geng Liangquan , Ding Kaiyang , Tang Baolin , Tong Juan , Yao Wen , Wang Zuyi , Sun Zimin
Published: October 2019

Abstract 4583

We retrospectively analyzed of the engraftment, Transplant-related complications and survival after unrelated cord blood transplantation (UCBT) using irradiation-based myeloablative conditioning in adult with hematologic malignancies. Between September 2006 and June 2010, 29 consecutive adult patients with hematological malignancies were treated with UCBT, Thirteen of them were advanced-stage disease and 11 of them were high risk or refractory disease. All patients received four fractionated 12 Gy TBI, total dose 12 g/m2 cytarabine and total dose 120 mg/kg cyclophosphamide as myeloablative conditioning. The median age was 21 years; the median weight was 57 kg. Double or multiple UCB grafts were used for 17 patients, while single UCB graft for 12 patients. the median number of nucleated cells was 3.83×107/kg and 5.25×107/kg. All patients were given a combination of cyclosporine A (CsA) and mycophenolate mofetil (MMF) for graft-versus-host disease (GVHD) prophylaxis. All patients obtained engraftment. Median time to neutrophil≥0.5×109/L was 20 days (range 14–37) and platelet engraftment in 25 patients (≥20×109/L) was 35 days (range 25–49). Chimerism was assessed by PCR analysis of short tandem repeat (STR) sequences on whole blood or bone marrow weekly in cases who were fully donor chimeric from 7 days to 21 days after transplantation. 16 cases developed acute GVHD, more than grade II in three cases. Six of twenty-four patients who survived more than 100 days developed limited chronic GVHD.17 cases were alive and in hematologic remission at a median follow-up of 504 days (range 49 ~ 1245). The probability of over survival at 3 years was 58.6%. Five cases relapsed. Nine of twelve cases died of transplant related complications and infection. These results suggest that UCBT after TBI-based myeloablative conditioning could be safely and effectively used for adult patients with hematologic malignancies.

Disclosures:

Sun: the Fund of the Key Medical Project of Anhui Provincial healthy department (2010A005): Research Funding; the Clinical Technology foundation of Anhui Provincial healthy department (2008A011): Research Funding; the Fund of Anhui Provincial “115” Industrial Innovation Program: Research Funding.
Stem Cell Transplantation for Relapsed and Refractory Burkitt Lymphoma.
Authors: Kwon Steven , Steinberg Amir , Bresee Catherine , Franco Mercedes , Lopez Angela M. , Lim Stephen , Lill Michael
Published: October 2019

Abstract 4589

Background:

Burkitt lymphoma is a highly aggressive and rapidly proliferating hematologic malignancy. Various chemotherapy regimens (HyperCVAD, CODOX-M/IVAC, REPOCH) have been shown to improve overall survival rate. However, in instances of relapsed or refractory disease, there is no clear-cut standard of care. Hematopoietic stem cell transplantation (HCT) has shown benefit in these patients. Here, we report our institutional experience using HCT for relapsed/refractory Burkitt lymphoma.

Methods:

Between February 1994 and January 2010, 13 patients (10 males, 3 females) with refractory or relapsed Burkitt lymphoma were retrospectively evaluated. The patients in question were administered a particular conditioning regimen followed by stem cell transplantation (11 autologous, 2 allogeneic). The average age at transplant was 41.8± 3.4 years (range 24 to 67). Stem cell source was from peripheral blood in all transplants including allogeneic (2 HLA-identical sibling transplants). The conditioning regimens for HCT consisted of the following: TBI/Rituximab/Cytoxan/VP16, TBI/Cytoxan/VP16, BEAM, Cranial Spinal boost/TBI/Cytoxan/VP16 or Cranial boost/TBI/Cytoxan.

Results:

On average, patients received transplant 299 ± 36 days after initial diagnosis (range 153 to 582). All patients achieved engraftment. For the 5/13 deceased patients (38%), cause of death was attributed to relapsed/refractory disease (n=2) and treatment related causes (n=3). Using the Kaplan-Meier method, the average survival time after transplant was computed at 27.7 ± 5.3 months and 75% were alive 2-years after transplant. Likely due in part to the small sample size, no covariates (age, gender, conditioning regimen, HIV status, presence of B symptoms, and CNS or bone marrow involvement) were found to be predictive of survival rates.

Conclusion:

Patients with Burkitt lymphoma, known for its rapid growth, can achieve long-term complete remission (CR) with intense, combination chemotherapy. Despite successful long-term remission rates, a substantial portion of patients die from uncontrolled disease. At the first sign of refractory or relapsed disease, resources should be mobilized to proceed with HCT. Our study, though limited in size, provides further compelling evidence that long-term CR, and potentially cure, may be achieved using HCT as a treatment modality.

Disclosures:

No relevant conflicts of interest to declare.
Autologous Hematopoetic Stem Cell Transplantation as An Intensive Consolidation Therapy for Adult Patients in Remission from Acute Myeloid Leukemia.
Authors: Genadieva-Stavrik Sonja G , Pivkova Alexandra , Stojanoski Zlate , Krstevska-Balkanov Svetlana , Georgievski Borce
Published: October 2019

Abstract 4595

Despite advances in our understanding of its pathogenesis, acute myeloblastic leukemia remains difficult to treat. Although initial complete remission can be achieved in a high percentage of patients, relapse occurs in 70–80% of the patients. Two main approaches have been the attempt to eradicate the leukemic clonal cells population via chemotherapy with or without autologous stem cell rescue or to pursue a combined approach using an antileukemic therapy combined with an antileukemic immune response via allogeneic bone marrow transplantation. Autologous transplantation compares favorably against allogeneic bone marrow transplant in several ways. Autologous transplantation can be used as a consolidation therapy in the older population, and lack of a matched donor does not preclude the patients from this treatment.

We report a retrospective analysis on 48 patients diagnosed with de novo AML, who did not have an available histocompatible donor, and who underwent autologous transplantation between years 2000–2009 at the University hematology Clinic, Skopje, Macedonia. All patients had ECOG score 1 or less. The patient's age ranged from 17 to 65 years with the median age 41 years. There were 26 males and 22 females. For stem cell mobilization patients received chemotherapy or chemotherapy plus G-CSF. The preparative chemotherapy regimen prior to autologous transplantation consisted of BuCy in 24 patient, BEAM in 22 and BuCyMel was used in the remaining 2 patients. We used bone marrow as primary source of stem cells in 18 patients, and peripheral blood stem cells in remaining 30 patients.

The five years overall survival was 52% and the 5 years disease progression free survival were 42%. We analyzed sever factors that can influence the overall survival and the disease free survival such as: age, disease status, stem cell source, chemotherapy regiments prior to transplantation, conditioning regiments, number of mobilized stem cells. Advanced age and bone marrow stem cell source seems to be more influent factors.

We report that the clinical results of autologous hematopoietic stem cell transplantation are sufficiently encouraging to warrant future trials that include autologous transplantation as an option for appropriately selected patients with AML in CR1. We conclude that autologous hematopoietic stem cell transplantation is a reasonable and save intensive consolidation for patients with acute myeloblastic leukemia who do not have a suitable HLA–matched donor.

Disclosures:

No relevant conflicts of interest to declare.