bluuebunny/crossref_metadata_2025_split huggingface dataset:
Correlation of Altered Expression of RIZ1 to Diagnosis, Risk Stratification, and Disease Progression in 56 Acute Leukemia Patients.
Authors: Li Qiubai , Zhu Xiaojian , Li Xiaoqing , Chen Xiangjun , You Yong , Huang Shi , Huang Shiang , Zou Ping , Chen Zhichao 
Published: October 2019

Abstract
Abstract 2627
Poster Board II-603
RIZ1 expression is altered in a variety of human cancers and is now considered to be a candidate tumor suppressor in many types of human tumors, including breast cancer, liver cancer, colon cancer, neuroblastoma, melanoma, lung cancer, and osteosarcoma. Previous studies indicate that suppression of RIZ1 expression may have an important role in leukemogenesis and RIZ1 is downregulated during CML progression and displays tumor suppressor properties in CML cell lines. To deeply investigate the expression of RIZ1 and its correlation to diagnosis, risk stratification, and disease progression in human acute leukemia, we analysed the differential expression of RIZ1 by quantitative real-time reverse-transcription polymerase chain reaction assay in 56 acute patients with or without complete remission and in 9 healthy donors. Our results showed that the expression of RIZ1 was significantly decreased in both de novo acute leukemia patients and patients with no remission (n = 35) (P = 0.009, compared with healthy donors) and significantly increased in acute leukemia patients with complete remission (P = 0.001, compared with de novo acute leukemia patients and patients with no remission). When compared with healthy donors, acute leukemia patients with complete remission (n = 21) owned the statistically same expression of RIZ1 (P = 0.595). The expression of RIZ1 was significantly higher in acute myeloid leukemia (AML, n = 17) than acute lymphoblastic leukemia (ALL, n =15) (P = 0.009), with a good correlation to diagnosis of AML or ALL (r = 0.514). The patients (n = 16) with high-risk leukemia had significantly higher expression of RIZ1 than the patients with standard-risk (n = 18) (P = 0.031), with the correlation (r = 0.431) of RIZ1 expression to disease risk-stratification. In addition, the weak correlations of RIZ1 expression were shown to both age and gender ( r = 0.158 and 0.003, respectively). This relatively simple analysis provides an important role of RIZ1 expression in acute leukemia. Taken together, our results suggest the potential for using RIZ1 expression in predication of disease progression or recovery in acute leukemia. We demonstrate that RIZ1 expression can contribute to the diagnosis of AML or ALL and the evaluation of risk-stratification in acute leukemia.

Disclosures:
No relevant conflicts of interest to declare.
Glucocorticoid-Induced TNFR-Related Protein (GITR) Ligand Mediates Tumor Immunoediting in Chronic Lymphocytic Leukemia and Impairs Direct and Rituximab-Induced NK Cell Anti-Leukemia Reactivity.
Authors: Buechele Corina , Baessler Tina , Schmiedel Benjamin J , Kanz Lothar , Salih Helmut R 
Published: October 2019

Abstract
Abstract 4403
Members of the TNF/TNF receptor (TNFR) family of proteins govern differentiation, proliferation, activation, and death of both tumor and immune effector cells and thus play an important role in tumor immunoediting, the reciprocal interaction of tumor cells and anti-tumor immunity. Activation of the TNFR family member GITR has recently been shown to stimulate T cell-mediated anti-tumor immunity in mice. However, available data suggest that GITR mediates different effects in mice and men, and may impair anti-tumor immunity of human NK cells. Here we studied the expression and function of GITR ligand (GITRL) in patients with chronic lymphocytic leukemia (CLL) and the consequences of GITR-GITRL interaction for NK cell reactivity against CLL cells. Substantial GITRL expression was detected on primary B-CLL cells in 38 of 48 (79%) investigated patients. Upon interaction with its cognate receptor, GITRL induced the release of immunoregulatory cytokines like TNF by the leukemia cells, which demonstrated that CLL-expressed GITRL is functional and capable to transduce bidirectional signals. Moreover, disruption of GITR-GITRL interaction in cultures of allogenic NK cells with patient CLL cells by addition of blocking antibody caused a significant increase in NK cell granule mobilization, cytotoxicity and IFN-γ production. The inhibitory effect of tumor-expressed GITRL on the reactivity of human NK cells was also confirmed in cocultures of C1R lymphoma cells transfected to express GITRL with mock transfectants serving as control. In addition, blocking GITR-GITRL interaction also considerably augmented both antibody-dependent cellular cytotoxicity (ADCC) and antibody-induced IFN-γ production of NK cells in cultures with allogenic CLL cells upon Rituximab exposure. Of note, GITR blockade also significantly enhanced anti-leukemia reactivity of autologous NK cells among PBMC of B-CLL patients, and this reinforcement of NK cell effector functions was observed both regarding the direct and, more pronounced, Rituximab-induced anti-leukemia reactivity (both n=10, p<0.01, Student's T test). Thus, expression of functional GITRL by CLL cells potently influences tumor immunoediting and impairs anti-tumor immunity by diminishing both direct and Rituximab-dependent anti-leukemia reactivity of NK cells. Modulation of the GITR-GITRL system might therefore serve to enhance the efficacy of therapeutic approaches in CLL which, like Rituximab-induced ADCC or stem cell transplantation, rely on a sufficient NK cell anti-tumor response.

Disclosures:
No relevant conflicts of interest to declare.
Lymphoplasmacytic Differentiation Associated with Lenalidomide Therapy in Patients with Chronic Lymphocytic Leukemia.
Authors: Veliz Marays , Moscinski Lynn C. , Zhang Ling , Sotomayor Eduardo M. , Pinilla-Ibarz Javier 
Published: October 2019

Abstract
Abstract 4412

Background
Due to significant activity of lenalidomide in chronic lymphocytic leukemia (CLL), research is ongoing to better characterize its mechanism of action. Recent laboratory studies of cells from CLL patients have shown that lenalidomide could exert its antiproliferative activity by decreasing the presence of survival-promoting cytokines. It has also been shown to facilitate immune-mediated ADCC by restoring the defective ability of T- and NK-cells to form immune synapses with tumor B-cells (Ramsay et al JCI 2008). However, no direct cytotoxic effect of lenalidomide has yet been demonstrated in CLL cells. Here, we suggest a new potential mechanism of action based on morphologic evaluation of bone marrow samples from patients with CLL receiving treatment with lenalidomide.

Methods
Bone marrow biopsy and aspirations from 13 patients with relapsed or refractory CLL, who are participating in a phase II clinical trial of lenalidomide and rituximab, and 1 patient who received lenalidomide outside of study, were reviewed before initiation of therapy and every 2 months thereafter.

Results
Of 14 CLL samples evaluated, 3 samples contained cells with lymphoplasmacytoid features in both bone marrow (figure 1) and peripheral blood, which had not been present prior to initiation of treatment. Of the 3 samples containing lymphocytes with plasmacytoid features, 2 were obtained from patients who received more than 6 months of therapy with the lenalidomide/rituximab combination, and 1 was taken from the patient receiving lenalidomide, after one month of therapy. Long term morphologic effects of lenalidomide therapy on lymphocytes from patients with CLL remain unknown. However, we hypothesize that the observed changes in morphology after lenalidomide treatment could represent either a differentiation phenomenon, as a potential antitumor mechanism in CLL cells, or perhaps represent just a selection effect.

Conclusions
An exact direct antitumor mechanism of lenalidomide on CLL cells remains unknown. Our observations suggest that lenalidomide may promote terminal differentiation of lymphocytes thus proposing an additional mechanism by which lenalidomide exerts its anti-tumor activity in CLL.

Disclosures:
No relevant conflicts of interest to declare.
IL-27 Induced Apoptosis and Promoted Antitumor Cytokines Secretion in Human Monocytic Leukemic Cell Line U937.
Authors: Liu Bin-Bin , Fan Rui-Fang , Zheng Yong-Jiang , Guo Xiao-Yan , Lin Dong-Jun 
Published: October 2019

Abstract
Abstract 4418
IL-27 acts as a critical regulator in many pathological processes. Although IL-27 has been studied in many solid tumors, its effect on leukemia remains elusive. Here, we investigated expression of IL-27 receptor (WSX-1 and gp130) on bone marrow mononuclear cells (BM-MNCs) of 31 patients with acute myeloid leukemia (AML) and 8 controls (including patients with IDA, ITP and non-hematological diseases) by RT-PCR, exploring IL-27's property in malignant hematological diseases. In addition, we detected the secretion of antitumor cytokines, cell proliferation and apoptosis in human monocytic leukemic cellline (U397 cells) treated with IL-27. We found that expression rate of IL-27 receptor subunits in AML patients was significantly higher than those with benign hematological diseases, especially on the acute monocytic leukemia subtype (AML-M5 subtype). ELISA assay revealed that antitumor cytokines, including TNF-α and IL-12, were produced by IL-27 stimulated-U937 cells, with an optimal concentration of IL-27 at 60ng/mL and an optimal time at 24h. U937 cells' growth inhibition and apparent apoptosis was induced by IL-27 in a dose dependent manner. U937 cells displayed apparent apoptosis when treated by IL-27 over 40ng/ml. The apoptosis rate of U937 tumor cells reached peak level while the stimulation concentration was 100ng/ml. Hoechst 33258 staining also presented typical apoptotic bodies in U937 cells treated with IL-27. Based on the high expression of IL-27 receptor in BM-MNCs of AML patients, our data provided the first evidence that IL-27 functioned as an anti-leukemia cytokine, suppressing cell growth and inducing apoptosis, offering a new anticancer agent in leukemia therapy.

Disclosures:
No relevant conflicts of interest to declare.
Prognostic Significance of Gelsolin and MMP12 in Langerhans Cell Histiocytosis.
Authors: Kim Sun Young , Kim Hee Jin , Bae Keun Wook , Im Ho Joon , Kim Ji Yoon , Jeong Dae-Chul , Lee Mee Jeong , Park Eun Sil , Seo Jong Jin 
Published: October 2019

Abstract
Abstract 4431

Background
Langerhans cell histiocytosis (LCH) pathogenesis is hypothesized a genetic change may have a significant effect on the cellular mechanisms controlling proliferation and apoptosis of LCs. In LCH, the expression of MMP12 was observed most abundantly in multi-system disease, which has the poor prognosis, and high expression of GSN was reported but the clinical significance of GSN was unveiled until now. We will investigate the association between these proteins and clinical outcomes in patients diagnosed with LCH.

Methods
Archival paraffin block were retrieved from children diagnosed with LCH and followed up at Asan medical center and Chungnam National University Hospital between 1998 and 2008. Available formalin-fixed, paraffin-embedded specimens from these patients will be used for GSN, MMP12 immunohistochemistry. We will analyze the correlations between protein expression states and clinical features.

Results
The medical records of the patients with LCH was analyzed for the factors that affect relapse and overall survival. The specimens from 49 patients were available for immunohistochemistry. Of these, 2 slides were not suitable because the quality of staining was not good for evaluation or the tumor cells are too difficult to be differentiated. The median age of 49 patients was 9.5 years, range 5 months to 22 years with a definite diagnosis of LCH based on CD1a positivity. The gelsolin and MMP12 were expressed in various degrees except eight specimens and overexpression had a tendency of correlation with multisystem and risk organ involvement.

Conclusion
Gelsoin and MMP12 might be associated with the pathogenesis of LCH and the high expressions in LCH have a possibility of playing a role in the progression of LCH.

Disclosures:
No relevant conflicts of interest to declare.
Safety and Efficacy of Plasma Derived Factor IX in Patients with Hemophilia B Undergoing Surgical Intervention: A Single Institution, Retrospective Analysis.
Authors: Logan Laurence , Quon Doris V. 
Published: October 2019

Abstract
Abstract 4438

Introduction
Hemophilia B patients often require orthopedic surgical intervention for the improvement of function and quality of life. In these patients, coagulation factor replacement is essential, but the safety and efficacy of plasma-derived factor IX in controlling bleeding during surgeries has been little studied. Issues of particular concern for surgical intervention include appropriate dosing of factor concentrate, pharmacokinetics, and safety considerations.

Objective
The purpose of this study was to examine outcomes in patients with hemophilia B following surgical intervention and treatment with plasma-derived factor IX.

Method
Following IRB approval, 22 patients who underwent 31 surgical procedures at the Hemophilia Treatment Center at Orthopedic Hospital or its affiliates in Los Angeles, CA, during the period 1996 to present, were identified. Once identified, inpatient charts for these patients were reviewed and abstracted. Outcomes of interest included pre- and post operative dosing of factor IX, perioperative blood loss and use of blood products, pharmacokinetics factors, and hemostatic response.

Results
For identified patients, 9.1% were diagnosed with mild hemophilia B (factor IX levels > 5%), 13.6% had moderate hemophilia B (factor IX levels between 1% - 5%), and 77.3% had severe hemophilia B (factor IX < 1%). The mean age at surgery was 48.0 years old. All but 3 surgical procedures were orthopedic (90.3%) and most frequently involved the knee (38.7%), elbow (16.1%), hip (12.9%), or shoulder (9.6%). All surgeries were completed under general anesthesia and average time in surgery was 3:15 hours. Dose of factor IX averaged 238 IU/kg on the day of surgery and was adjusted over the course of the hospital stay. Selection of replacement factor IX was by patient choice and AlphaNine® SD was the most common factor IX concentrate used (94% of procedures). Mean perioperative blood loss was 283ccs (range 0-1000) and blood replacement was required in only 2 surgeries (6.5%). Pharmacokinetic analysis performed pre-operatively related well to factor IX levels obtained peri- and post-operatively. Average hospital length of stay was 10.7 days and all patients were discharged to home.

Conclusion
The results of this study demonstrated that patients with Hemophilia B undergoing major surgery who were treated with plasma derived factor IX had little unexpected blood loss perioperatively, seldom required blood replacement, and had no bleeding related surgical complications. These results suggest that pre- and postoperative treatment with plasma derived factor IX is both safe and effective for patients with hemophilia B undergoing surgical intervention.

Disclosures:
Logan: Grifols, S.A.: Consultancy. Quon:NovoNordisk: Speakers Bureau; Grifols, S.A.: Honoraria.
FactorVIII Gene Modifications Observed in Acquired Hemophilia.
Authors: Hwang Sung Ho , Kim Hugh C , Lim Jeonga , Lee Hyun Woo , Jeong Seong Hyun , Park Joon Seong , Kim Hye Sun 
Published: October 2019

Abstract
Abstract 4450
Acquired hemophilia is a rare bleeding disorder caused by autoantibodies directed against the coagulation factor VIII (FVIII). Usually acquired hemophilia is found in the elderly person, autoimmune disorder or women in the postpartum. Incontrast to alloantibody inhibitors of hereditary hemophilia, acquired inhibitor is presumably due to a spontaneous autoimmune disorder in which patients with previously normal hemostasis develop autoantibodies against FVIII. However, the precise cause of the antibody formation remains obscure and the possibility of abnormal FVIII protein derived from the FVIII gene mutation might have caused the antibody formation was investigated by direct FVIII gene sequencing method. Blood samples were obtained from a 72 year old male who initially presented with a large hematoma in the Rt. Shoulder, and had a prolonged aPTT (46 sec), FVIII level of 14%, and VIII inhibitor titer 2∼5 BU/ml. Direct sequencing of FVIII was performed via amplification for all 26 exons, including the 5′-UTR and 3′-UTR region, using the 35 synthesized primers. Sequencing was conducted using BigDye Terminator cycle sequencing kit on an ABI 3730XL DNA analyzer (Applied Biosystems, Foster City, CA). Sequence variations were analyzed with CLC main workbench program (CLC, Aarhus. Denmark). Firstly, we analyzed translational region of FVIII gene. But we couldn't find any sequence variation. Then we analyzed the sequence of untranslationed region, 5′-UTR and 3′-UTR. As a result, we identified gene variation of substitution to c.8889G>A in the 3′-UTR. We speculate that this variation may have affected the RNA processing or mRNA stability. Thus we need to study about the relationship between this sequence variation and FVIII function. Also, we will investigate whether this gene variation is functional mutation. The cause of acquired hemophilia remains obscure. Variations in FVIII molecules including in untranslatable 5′- or 3′-region should be studied further to delineate the cause of antibodies in acquired HA. We expect that the accumulation of sequence variation can help to understand the cause of acquired hemophilia through this study.

Disclosures:
No relevant conflicts of interest to declare.
An in-Vivo Model of T Cell-Mediated Rejection of Human Hematopoietic CD34+ Stem Cells Using NOD/SCID γnull (NOG) Mice.
Authors: Nicolini Benedetta , Mahmud Dolores , Mahmud Nadim , Nucifora Giuseppina , Rondelli Damiano 
Published: October 2019

Abstract
Abstract 4474
We have previously demonstrated that human CD34+ cells include subsets of antigen presenting cells capable of stimulating anti-stem cell T cell alloreactivity in-vitro. In this study we transplanted human CD34+ cells and allogeneic T cells in a NOD/SCID γnull (NOG) mouse model and evaluated the occurrence of stem cell rejection as well as xenogeneic graft-versus-host disease (GVHD) following the infusion of different doses of T cells. After sublethal irradiation NOG mice were cotransplanted with 2×105 CD34+ cells and HLA mismatched CD4+CD25- T cells at 1:0 (control), 1:2 or 1:10 CD34+ cell: T cell ratio (n=5-10 mice per group). Hematopoietic stem cell and T cell engraftment was assessed in the bone marrow and in the spleen 6 weeks following transplantation or earlier in case the animals died. Control mice transplanted with CD34+ cells alone showed a high level of stem cell engraftment (huCD45+ cells: 60±10%) in the bone marrow, encompassing CD19+ B cells (64±4%), CD34+ cells (18±1%), CD33+ myeloid cells (7±1%), CD14+ monocytes (3±1%), and no T cells within huCD45+ cells. In contrast, mice that were transplanted with CD34+ cells and 4×105 (1:2 ratio) or 2×106 (1:10 ratio) T cells had only 9±2% and 3±1% huCD45+ cells, respectively, in the bone marrow (p=0.01). Moreover, marrow samples of mice cotransplanted with CD34+ cells and T cells at 1:2 or 1:10 ratio included >98% huCD3+ T cells and no CD34+ cells. Spleen engraftment of huCD45+ cells was lower (25±8%) in control mice (1:0 ratio) as compared to 66±10% and 36±11% in 1:2 and 1:10 groups, respectively (p=0.05). As observed in the marrow, also the spleen of animals receiving CD34+ and T cells included >98% CD3+ T cells. Among the T cells, both in the marrow and in the spleen of mice in the 1:2 and 1:10 ratio groups, 60-70% were CD4+CD8- cells, 22-25% CD8+CD4- cells, 1-3% CD56+ cells, and 2-5% CD4+CD25+ cells. In mice receiving 4 ×105 T cells (1:2 ratio), on average 12±6% of the T cells in the bone marrow and spleen were CD4+CD8+. Only mice receiving 2×106 T cells (1:10 ratio) showed GVHD. This was demonstrated by fur changes, reduced survival (p=0.02) and weight loss (p=0.0001) compared to control mice or mice receiving a lower dose of T cells (1:2 ratio). The marrow engraftment of CD3+ cells with disappearance of CD34+ cells in mice receiving low doses of allogeneic T cells, in the absence of evident xenogeneic GVHD, suggests that NOG mouse model represents a useful tool to study human stem cell rejection. This model will be also utilized to investigate new strategies of immunosuppressive cell therapy applied to stem cell transplantation in an HLA mismatched setting.

Disclosures:
No relevant conflicts of interest to declare.
Natural Killer (NK) Cell Recovery After Bone Marrow Transplantation in Mice: Early Emergence of a Novel Ly49+ Stage in Differentiation Independent of MHC Haplotype.
Authors: Murphy William , Redelman Doug , Barao Isabel 
Published: October 2019

Abstract
Abstract 4477
NK cells play critical roles in resistance to viral infections and in cancer. NK cells exist as subpopulations of cells that bear inhibitory and/or activating receptors to MHC. In mice, these are the Ly49+ subsets which have been shown to play a role in the rejection of bone marrow allografts as well as resistance to CMV. These Ly49 receptors also play a central role in the “education”, “arming” or “licensing” of NK cells. NK cell recovery after bone marrow transplantation is thought to proceed quickly but the acquisition of the Ly49 receptors has been incompletely characterized. NK cell differentiation has for the most part been characterized through in vitro models. We therefore examined the recovery of NK cells after syngeneic BMT in mice and assessed the effects of MHC on the recovery of the Ly49+ subsets using congenic recipients. NK cells were rapidly detected in mice as early as 14 days after BMT. Interestingly, the dominant population observed had a mature NK cell phenotype based on the expression of CD94, CD43, CD11b, etc. However, the majority of NK cells had a unique expression of Ly49G2 single positive NK cells with median fluorescence intensity (MFI) approximately twice as high as on NK cells from normal animals. This phenotype was not observed in untreated normal mice and occurred in B6 and B10 (H2b) as well as B10.D2 (H2d) strain mice showing independence from MHC. When these cells were sorted and assessed for cytotoxic activity, the cells had comparable killing efficiency as NK cells from untreated mice. Over time, NK cells with normal Ly49 subset distribution and phenotype were observed with the disappearance of this earlier subset. However, total splenic NK cell numbers remained significantly reduced in the BMT recipients as long as 120 days after BMT and despite normal recovery and numbers of T cells. These results demonstrate the existence of novel stage(s) in NK cell differentiation that occur independently of MHC and that can be characterized by sole expression of Ly49G2 at high levels. However, deficits in NK cell numbers persist in mice for extended periods of time. These findings suggest that NK cell recovery may occur in waves with some inhibitory receptors programmed to repopulate first and that surface expression intensity also needs to be assessed. Furthermore, the long-term deficits in total numbers suggest that overall activity may be compromised for extended periods clinically post-BMT.

Disclosures:
No relevant conflicts of interest to declare.