bluuebunny/crossref_metadata_2025 huggingface dataset:
CREB Deficiency: A Potential Critical Factor for Selective GM-CSF Hypersensitivity in Juvenile Myelomonocytic Leukemia.
Authors: Liu Y. Lucy , Malaviarachchi Priyangi A , Lensing Shelly Y. , Castleberry Robert P. , Emanuel Peter Dean
Published: October 2019

Abstract 2604

Poster Board II-580

Juvenile myelomonocytic leukemia (JMML) is a mixed myelodysplastic /myeloproliferative neoplasm (MDS/MPN) of infancy and early childhood. The pathogenesis of JMML has been linked to dysregulated signal transduction through the NF1/RAS signaling pathway and PTPN11. This dysregulation results in JMML cells demonstrating selective hypersensitivity to GM-CSF in in vitro dose-response assays. Since JMML hematopoietic progenitor cells are selectively hypersensitive to (rather than independent of) GM-CSF, it is rational to hypothesize that the function of the GM-CSF receptor in JMML patients is not constitutively over-active unless stimulated by the cytokine. We previously reported that PTEN is deficient in JMML patients. PTEN expression is up-regulated by Egr-1, which is one of the targets of the cAMP-response-element-binding protein (CREB). CREB, as a transcriptional factor, is expressed ubiquitously and bound to the cAMP-response-element (CRE) of the Egr-1 promoter. After phosphorylation at serine 133, CREB selectively activates the transcription of Egr-1 in response to GM-CSF stimulation in hematopoietic cells. We evaluated the CREB protein level in peripheral blood or bone marrow samples collected from 26 JMML patients. Mononuclear cells (MNCs) were isolated and lysed in lysis buffer at a density of 107/100μl. Protein levels of CREB were evaluated by ELISA and Western-blot. We found that 22/26 (85%) of subjects were substantially CREB deficient while they had constitutively high activity of MAP kinase (Erk-1/2). In comparison to normal controls (n=7), the median level of total CREB protein by ELISA was significantly lower in JMML subjects (0.62 vs 8.85 ng/mg BSA in normal controls; p=0.006). The mechanism that causes CREB deficiency in JMML is under further investigation and further results may be available to present at the meeting. This is the first evidence that CREB, a critical component downstream of the GM-CSF receptor, is highly deficient in the majority of JMML cases.

Disclosures:

No relevant conflicts of interest to declare.
Development of a Novel Treatment Strategy Targeting JAK2 in Acute Myelogenous Leukemia.
Authors: Kojima Shinsuke , Ikezoe Takayuki , Yang Jing , Nshioka Chie , Takeuchi Asako , Isaka Mayuka , Furihata Mutsuo , Yokoyama Akihito
Published: October 2019

Abstract 2619

Poster Board II-595

Somatic mutations in Janus kinase 2 (JAK2) gene activate JAK2/signal transducer and activator of transcriptions (STATs) signaling, leading to proliferation of hematopoietic cells. STAT3 and/or STAT5 were constitutively activated in the majority of patients with acute myelogenous leukemia (AML), although mutation of the JAK2 gene was an extremely rare event in AML. This study performed the immunohistochemichal examination to verify whether JAK2 was activated in AML (n=73, excluding acute promyelocytic leukemia) by utilizing the phosphor-specific antibody against JAK2. p-JAK2 was detectable in all cases examined, although its level varied between each patients (+, n=27; +/−, n=28; −/+, n=18). Statistical examination found that levels of p-JAK2 were correlated with leukocytosis (21.4 × 106/L in patients with high p-JAK2 vs 13.8 × 106/L in those with low p-JAK2, p<0.001) and lower complete remission rate (65.5% in patients with high p-JAK2 vs 83.3% in patients with low p-JAK2, p<0.02). In addition, there was a trend that high expression level of p-JAK2 was associated with poor prognosis in AML patients (median survival time 604 days in patients with high p-JAK2 vs 1431 days in those with low p-JAK2). Moreover, we found that the novel and specific inhibitor of the JAK2 kinase AZ960 potently inhibited the clonogenic growth of freshly isolated CD34+ AML cells from patients (n=6) with IC50 ranging from 0.01 to 0.1 mM. On the other hand, levels of p-JAK2 in CD34+ hematopoietic cells from healthy volunteers (n=3) were lower than those in CD34+AML cells, as measured by FACS, and their colony forming ability was not affected by AZ960. Furthermore, exposure of freshly isolated CD34+ AML cells to AZ960 (0.03–0.1 mM) induced apoptosis as assessed by induction of the cleaved forms of PARP as well as caspase 3, and downregulation of anti-apoptotic protein Bcl-xL. Taken together, JAK2 may be a promising molecular target for treatment of AML. Further studies are warranted to evaluate the efficacy of the JAK2 inhibitor in clinical settings.

Disclosures:

No relevant conflicts of interest to declare.
Aberrant DNA Methylation in Childhood Acute Lymphoblastic Leukemia as a Potential Biomarker Reflecting Disease Status.
Authors: Kwon Seung Yeon , Won Sung Chul , Kim Hyo Sun , Jeung Hei-Cheul , Rha Sun Young , Park Kyu Hyun , Song Jaewoo , Lyu Chuhl Joo
Published: October 2019

Abstract 2637

Poster Board II-613

Background:

Aberrant DNA methylation of promoter-associated cystosine-guanine (CpG) islands is known to play an important role in leukemogenesis and has been reported to have association with poor prognosis in acute lymphoblastic leukemia (ALL). In adult, residual methylation at clinical remission status in patients with acute myeloid leukemia and Philadelphia chromosome-positive ALL showed significant association with poor prognosis in recent studies. We analyzed 47 patients with childhood ALL to evaluate the change of methylation status from the time of diagnosis to the time at morphologic remission.

Methods:

We analyzed the methylation status of CDH1, p16 and DAPK genes at the time of diagnosis and at the time of morphologic remission in 47 patients using methylation specific polymerase chain reaction method with genomic DNA extracted from bone marrow (BM) aspirates. All patients were treated with standard chemotherapy and after 4 weeks, every patient achieved morphologic complete remission. Methylation status of above three genes were also analyzed with the same method in 10 BM aspirate samples from healthy BM donor for comparison.

Results:

CDH1 was methylated in 30 (64%) patients, p16 in 2 (4%) patients and DAPK in 6 (13%) patients at the time of diagnosis. Thirty three (70%) patients had methylation at least one gene, and 5 (11%) had methylation of 2 genes. None of the healthy BM donors showed methylation of above genes. At the time of morphologic remission, all patients who had aberrant DNA methylation of any gene at the time of diagnosis had no detectable residual methylation showing complete resolution of aberrant DNA methylation of examined genes. Clinical prognostic factors including initial white blood cell count, immunophenotype and presence of specific translocations (TEL-AML1, BCR-ABL, E2A-PBX1) did not show any association with initial methylation status. Age was the only factor which showed correlation with methylation status; patients under 2 year old showed significantly low frequency of methylation of above three genes (p <0.001).

Conclusion:

Since aberrant DNA methylation of CDH1, p16 and DAPK genes were found in 70% of pretreatment ALL patients and none in healthy BM donor showing complete resolution of methylation at morphologic remission status, we cautiously suggest aberrant DNA methylation as a potential biomarker reflecting disease status in childhood ALL.

Disclosures:

No relevant conflicts of interest to declare.
Contribution of Deregulated miRNAs to the Phenotypic Characteristic of Hodgkin Lymphoma.
Authors: Ping Tan Lu , Kroesen Bart-Jan , Tiacci Enrico , Duns Gerben , Seinen Erwin , Sibon Ody , Kok Klaas , Poppema Sibrand , Van Den Berg Anke
Published: October 2019

Abstract 265

In Hodgkin Lymphoma (HL), the Hodgkin Reed-Sternberg (HRS) cells are a minority of large mono- or multi-nucleated B cells characterized by a loss of B cell phenotype, constitutive NF-kB activation, a disturbed cell cycle and anti-apoptotic features. In this study we investigated the role of deregulated miRNA expression in the pathogenesis of HL. MiRNA in situ hybridization (ISH) in HL tissue was performed to determine expression of miRNAs previously reported to be highly abundant in HL cell lines, in HRS cells. Next we identified the miRNA-targetome of two HL cell lines by immunoprecipitation of RISC in untransfected and transfected cell lines. miRNA ISH confirmed expression of miR-17-5p, miR-24, miR-106a, miR-146a, miR-150, miR-155, miR-181b and miR-210 in HRS cells. Ago2-immunoprecipitation followed by microarray analysis of the co-immunoprecipitated mRNA revealed that the miRNA-targetome of HL comprises of about 2,500 genes. Inhibition of the anti-miR-17 seed family revealed that about 500 of these genes are regulated by miRNAs of the miR-17 seed family. Gene ontology (GO) analysis for the total miRNA-targetome of HL showed a significant enrichment of genes involved in the regulation of cell cycle, apoptosis, immune system development and NF-kB cascade. The miRNA-targetome of HL contained several genes known to be mutated in HRS cells, including A20, FAS, NFKB1A, NFKB1E, PERP and SOCS1. Also, using previously reported gene expression data, we defined a set of genes downregulated in HL cell lines (L428 and L1236) compared to germinal center B cells (GCB) and compared them to the miRNA-targetome of the same cell lines. This resulted in the identification of 149 genes in L428 and 183 genes in L1236 that were subjected to miRNA mediated repression. Unexpectedly, only a few of all the reported inactivated genes in HRS cells that might contribute to loss of B cell phenotype (MYBL1 and CXCR4) were found to be regulated by miRNAs in HL. In conclusion, we confirmed the expression of miRNAs in the HRS cells of HL tissue and identified miRNA repressed genes in HL. Our data indicated that aberrant miRNA expression contributes to the deregulation of apoptosis, cell cycle, and NF-kB pathways but not loss of B cell phenotype in HL.

Disclosures:

No relevant conflicts of interest to declare.
Defective Central Memory CD8+ T Cell Differentiation in the Absence of Eomesodermin.
Authors: Banerjee Arnob , Gordon Scott M. , Intlekofer Andrew M. , Wherry E. John , Reiner Steven L.
Published: October 2019

Abstract 2662

Poster Board II-638

The differentiation of central memory CD8+ T cells after vaccination or primary pathogen encounter is critical for the establishment of long-lasting protection against pathogens including intracellular infectious organisms and malignancies. Unfortunately, the mechanisms of immune memory establishment are unclear, preventing the development of effective vaccines to many emerging pathogens. Naïve CD8+ T cells responding to intracellular pathogens undergo rounds of cell division and progressive differentiation to give rise to terminally differentiated effector cells and memory cells to provide acute and long-lasting immunity, respectively. T-bet and Eomesodermin (Eomes), key transcription factors in this differentiation, share significant DNA binding domain sequence and functional homology, although their distinct expression patterns and non-DNA binding domains suggest potential non-redundant functions. T-bet drives effector and effector-memory differentiation, suppressing the formation of long-lasting central memory CD8+ T cells. We now show that CD8+ T cells responding to acute infection with the lymphocytic choriomeningitis virus (LCMV) display significant heterogeneity in the relative expression levels of T-bet and Eomes on a single cell level. Using mice with a tissue specific deletion of Eomes in T cells, we show defective central-memory differentiation in CD8+ T cells lacking Eomes after infection with LCMV. We observe defects in both long-term persistence and re-expansion on re-challenge, two defining characteristics of central-memory T cells, in memory CD8+ T cells lacking Eomes. These results demonstrate that, in direct contrast to T-bet, Eomes promotes central-memory CD8+ T cell differentiation. Thus, the balance of T-bet and Eomes expression may determine the propensity for CD8+ T cell terminal effector differentation versus long-lived memory differentiation. Our findings demonstrate a crucial role for Eomes in the differentiation of pathogen specific central memory CD8+ T cells which can provide life-long immune protection.

Disclosures:

No relevant conflicts of interest to declare.
Prognostic Value of Angiogenesis Assessment in Chronic Lymphocytic Leukemia: More Data Needed.
Authors: Antic Darko , Cokic Vladan , Fekete Marija Dencic , Perunicic Maja , Mihaljevic Biljana , Boskovic Darinka
Published: October 2019

Abstract 4396

Introduction

The association between angiogenesis and cancer progression in solid tumors has been documented, but its significance in chronic lymphocytic leukemia (CLL) has not been completely evaluated. Vascular endothelial growth factor /VEGF/ is the major pro-angiogenic factor in humans and his transduction pathway may be very active in CLL cells contributes to their enhanced survival. In this context VEGF can be additional tool for predicting the clinical course in early CLL.

Patients and Methods

To predict the risk of disease progression, we analyzed serum levels VEGF (sVEGF) using ELISA tehnique in 33 Binet stage A de novo CLL patients. In addition, We analyzed microvessel density (MVD) of the same patients using immunohistochemical staining with CD34 and vWf. Finally, we explored wheather changes of circulating VEGF concentrations and MVD reflected clinico-biological features of CLL (peripheral blood lymphocytosis (PBL), bone marrow (BM) histology, beta-2 microglobulin (β2m) level, lactat dehidrogenase (LDH) level) and kariotype abnormalities.

Results

The VEGF serum levels (sVEGF) was not significantly elevated (p=0.31) in CLL patients (mean: 70.9 pg/mL; range: 16–483) compared with and age- and sex-matched healthy controls (mean: 44.7 pg/mL; range: 22–69.2). sVEGF level positively correlated with elevated LDH level (p=0.008), but no correlation with other clinico-biological features was found.

Bone marrow MVD was significantly higher (p<0.0001) in CLL patients (mean: 35.91 vessels/field ± 15.71) compared to controls (mean:8.27 vessels/field ±6.19). Also, there was a significant difference between MVD counts according to the antibody used. MVD was higher using CD34 vs vWF (CD34, 35.91 vessels/field ±15.7, vs vWF, 8.15 vessels/field ±4.65, p<0.0001). Bone marrow MVD detected by CD34 was significantlyhigher in patinents with CD38 expression more than 30% (p=0.006). However, no significant MVD differences were detected between CLL subgroups with regard to clinical course, pattern of marrow infiltration, Rai stage and FISH abnormalities.

In univariate analysis sVEGF (p=0.018), Rai substages (p=0.027), PBL (p=0,030), β2m level (p=0.008) and diffuse bone marrow infiltration (p=0.006) were significantly associated with increased risk of disease progression. But, in multivariate analysis only sVEGF (p=0.002) and β2m level (p=0.008) retained their prognostic significance.

Conclusions

Serum VEGF level although not increased in comparasion with healthy controls, may improve the assessment of individual prognosis of patients with early CLL. Assessment of real clinical significance of bone marrow angiogenesis in CLL is required.

Disclosures:

No relevant conflicts of interest to declare.
Treatment of Patients with Autoimmune Cytopenia and Progressive CLL Using Rituximab, Cyclophosphamide, Vincristine, and Prednisone (R-CVP).
Authors: Zent Clive S. , Bowen Deborah , Call Timothy G , Shanafelt Tait D. , Kay Neil E. , Slager Susan L , Schwager Susan , Rabe Kari , Reinalda Megan
Published: October 2019

Abstract 4410

BACKGROUND

Autoimmune cytopenia occurs in 5%-10% of patients with CLL. Treatment for patients with both autoimmune cytopenia and progressive CLL is challenging due to poor tolerance of myelosuppression, and the risk of exacerbation of autoimmune cytopenia by purine analogues.

METHODS

We identified 20 patients from our CLL database of approximately 3000 patients who were treated with a chemoimmunotherapy regimen of rituximab, cyclophosphamide, vincristine, and prednisone (R-CVP) for both autoimmune cytopenia and progressive CLL from January 2000-December 2008 at Mayo Clinic Rochester.

RESULTS

Autoimmune cytopenia responded in 19 patients (14 CR and 5 PR) with a median time to progression (TTP) of 13.6 months (range 5 – 29). Five patients remain in sustained remission at last follow up (range 15 – 30 months) and 4 patients have had recurrent autoimmune cytopenia requiring re-treatment. Six patients required maintenance corticosteroid therapy after completing R-CVP. Progressive CLL responded to treatment in 17 patients (9 CR/CCR, 8 PR by NCI-WG 1996 criteria) with a median TTP of 6.3 months (range 1-40 months). Fourteen patients have required additional treatment for progressive CLL at a median of 5.4 months (range 4-22 months). Five patients have not required additional treatment for either CLL or autoimmune cytopenia at 15 -30 months after completing treatment. R-CVP treatment toxicity included 3 patients with grade 3-4 infections, 2 with grade 1 peripheral neuropathy, and one with grade 3 drug-induced pneumonitis. No patient required blood cell transfusions after the completion of cycle 1 of therapy.

CONCLUSIONS

Although R-CVP is an effective and tolerable therapy for patients with simultaneous autoimmune cytopenia and progressive CLL requiring therapy, the duration of response is suboptimal. Clinical trials testing alternative treatment strategies are needed for this patient population.

Disclosures:

Zent: Genentech, Bayer, Genzyme, Novartis: Research Funding. Shanafelt:Cephalon: Research Funding; Celgene: Research Funding; Polyphenon Pharma : Research Funding; Hospira: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Research Funding; Bayer Health Care Pharmaceuticals: Research Funding. Kay:Biogenc-Idec, Celgene, Genentech, genmab: Membership on an entity's Board of Directors or advisory committees; Genentech, Celgene, Hospira, Polyphenon Pharma, Sanofi-Aventis: Research Funding.
The Alemtuzumab Treatment of Refractory to Fludarabine Chronic Lymphocytic Leukemia Patients.
Authors: Kataeva Elena , Golenkov Anatoly , Triphonova Elena , Buravtsova Iolanta
Published: October 2019

Abstract 4415

The aim of this study was to explore the efficiency of treatment with Alemtuzumab (A.) of chronic lymphocytic leukemia (CLL) patients (pts) refractory to Fludarabine(F.).

Meterials and methods

We observed 6 pts (3 male and 3 female). The median age was 56 years old(52-69). 4 of the pts had Rai stage I desease, 1 patient had Rai stage III, 1 had Rai stage IV. We revealed that 4 pts had 17p deletion with high level, 1 patient did not have del 17p, 1 - was not assessed. High level of the expression of CD38+ was determined, the median number was 37,3%(15-82). All pts were pretreated with Chlorambucil, COP, CHOP, FC for 18 months(7-48). All pts were refractory to F. 5 pts received A. monotherapy during median 9 weeks (2-18). Subcutaneous(SQ) A. dose escalation: 3mg-10mg-30mg on days 1,3,5, followed by 30mg Monday, Wednesday and Friday for 17 weeks. 1 patient received 5 courses FluCam(A. 30 mg 1,2,3 days IV after dose escalation 3mg-10mg-30mg, F. 25mg/m2 1,2,3 days). All pts received PCP, herpes and cytomegalovirus(CMV) and fungal prophylaxis as well as CMV viral DNA monitoring.

Responses were based on NCI-WG 1996 criteria. Minimal residual disease (MRD) was measured in peripheral blood and bone marrow aspirate using flow cytometry for CD19+/CD5+/CD23+ lymphocytes.

Results

The efficiency of the treatment of CLL pts was following: 2 pts (33,3%) displayed disease progression(PD) in 2 and 4 weeks of A. monotherapy, 2 pts achived (33,3%) CR in 14 and 16 weeks, 2 pts (33,3%), achived PR, among them 1 patient showed PR after 5 FluCam courses, the other — after 14 weeks of A. monotherapy. At the completion of the study 4 pts (66,6%) had no evidence of MRD by flow cytometry(<0,01%).

Conclusion

Obtained results showed high effectiveness of A. and acceptable toxity, among resistant to F. CLL pts (66,6% responded), the majoority of them had unfavourable del 17p.

Disclosures:

No relevant conflicts of interest to declare.
MYC Translocations Are Associated with Poor Overall Survival in DLBCL Patients in Both the Chemotherapy and Immunochemotherapy Eras.
Authors: Dogan Ahmet , Maurer Matthew J , Macon William R , Inwards David J , Micallef Ivana N , Johnston Patrick L , Law Mark , Ristow Kay , Witzig Thomas E , Cerhan James R , Habermann Thomas M
Published: October 2019

Abstract 443

Background:

MYC translocations have been reported to have inferior outcome in aggressive non-Hodgkin lymphomas. Here we present MYC translocation prevalence and outcome from two cohorts of newly diagnosed diffuse large B-cell lymphoma (DLBCL) patients treated in the chemotherapy (C) and immunochemotherapy (IC) eras.

Methods:

Tissue microarrays were created from 302 newly diagnosed DLBCL patients evaluated at the Mayo Clinic with availabel paraffin tissue. 233 DLBCL patients first diagnosed from March 1986-July 2001 were retrospectively identified based on a diagnosis of DLBCL and treatment with anthracycline-based chemotherapy. 69 DLBCL patients diagnosed from March 2002-October 2005 and treated with immunochemotherapy were prospectively enrolled in the University of Iowa / Mayo Clinic Lymphoma SPORE Molecular Epidemiology Resource. Central pathology review was performed on all samples to confirm the diagnosis of DLBCL. Interphase FISH was performed using a breakapart strategy for MYC and BCL6 gene regions and a dual fusion strategy for t(14;18)(IGH&/BCL2).

Results:

Chemotherapy (C) era patients were primarily treated with CHOP (88%); immunochemotherapy (IC) era patients were all treated with an R-CHOP based regimen. The median age at diagnosis was 65 years (range, 22-92) for C patients and 65 years (range, 20-82) for IC patients. Median follow-up for C patients was 11.3 years (range, 2.7-21.3) with 145 (62%) deaths; for IC patients, the median follow-up was 5.0 years (range, 2.1-6.4) with 17 deaths (25%). FISH was successful in 195 of 302 patients (65%). MYC translocations were identified in 6 of 141 C patients (4%) and 3 of 54 IC patients (6%). MYC translocations were associated with inferior overall survival in the C patients (p=0.001), the IC patients (p=0.04), and in the combined group (p≤0.001). Median survival of patients with MYC translocations was 19 months and 16 months for C and IC respectively, compared to 112 months (C) and unreached (IC) for DLBCL patients without MYC translocations. 4 of the 9 MYC translocation patients had a double hit (2 with both MYC and BCL2 translocations and 2 with translocations of MYC, BCL2, and BCL6). Associations of MYC and outcome remained significant in all patients after adjusting for treatment and IPI (p<0.05).

Conclusions:

MYC translocations are present in approximately 5% of DLBCL patients and are associated with poor outcome in patients treated with C or IC. New treatment approaches are needed for DLBCL patients with MYC translocations.

Disclosures:

No relevant conflicts of interest to declare.
Effect of YC-1, a HIF Inhibitor,On Apoptosis of Leukemia Cell.
Authors: Chen Bao-An , Wang Fei , Cheng Jian , Ding Jia-Hua , Xu Wen-Lin , Wang Xue-Mei , Gao Chong , Wang Jun , Zhao Gang , Bao Wen , Song Hui-Hui , Gao Feng , Zhang Wei , Xia Guo-Hua , Pei Xiao-Ping , Wu Wei-Wei , Chen Ning-Na
Published: October 2019

Abstract 4432

Object

This study was purposed to investigate the expression of HIF-1α and VEGF in leukemia cell lines and the effect of YC-1 on the regulation of HIF-1α and VEGF and the induction of apoptosis in U937 cell, exploring the mechanism of apoptosis after treatment of YC-1.

Methods

RT-PCR was used to determine the levels of HIF-1α mRNA and VEGF mRNA in K562,U937 and Jurkat cells. After treatment of U937 cell with 4μmol/L YC-1 for 0 hour, 8 hours,16 hours and 24 hours respectively, the changes of morphologic features were observed by DAPI staining under fluorescent microscope and the apoptotic rates were assayed by flow cytometry with Annexin V-FITC/PI staining; the levels of HIF-1α mRNA and VEGF mRNA were measured with RT-PCR ; the protein expression of HIF-1α, VEGF, Bax,Bcl-2 and Caspase-3 were measured by Western blot.

Results

HIF-1α mRNA and VEGF mRNA were expressed in all three leukemia cell lines. After treatment of U937 cell with 4μmol/L YC-1 for 0 hour,8 hours,16hours and 24hours respectively, the typical apoptotic morphologic features of U937 cells were observed under fluorescent microscope and the apoptotic rates were significantly increased in a time-dependent manner, they were (4.87±0.70)%, (27.27±2.00)%, (51.53±2.81) and (60.5±3.20)% respectively, the level of VEGF mRNA reduced, while the level of HIF-1α mRNA had no obviously changes. Furthermore, the expression of HIF-1α, VEGF and Bcl-2 decreased, while the expression of Bax and Caspase-3 increased in a time-dependent manner.

Conclusion

HIF-1α mRNA and VEGF mRNA are expressed in leukemia, YC-1 has significant effect of down-regulation the protein expression of HIF-1α and VEGF and induction of apoptosis in U937, its mechanisms may involve in up-regulating Bax/Bcl-2 ratio and expression of Caspase-3.

Disclosures:

No relevant conflicts of interest to declare.
A Clinical Significance of Helicobacter Pylori Infection in Hemophilic Children with Gastrointestinal Hemorrhage.
Authors: Kim Ji Yoon , Choi Yong-Mook , Lee Kun Soo
Published: October 2019

Abstract 4442

Purpose

For hemophiliacs gastrointestinal hemorrhage is a life-threatening complication and can be caused by the Helicobacter pylori infection. In this study, the prevalence of H. pylori infection among child hemophiliacs with gastrointestinal hemorrhage and the recurrence rate after eradication H. pylori treatment was investigated.

Patients and Methods

Seven children with hemophilia A with hematemesis (age, 5.3∼17.0 year) were evaluated for the causes of gastrointestinal hemorrhage and the detection of H. pylori. Gastroendoscopy was done to find the bleeding focus and for further evaluation including rapid urease test and mucosal biopsy.

Result: Four patients had dyspepsia and abdominal pain for several weeks or months prior to hematemesis. Three patients did not show any signs of bleeding. From gastroendoscopy, four patients were diagnosed as duodenal ulcer, one as H. pylori associated chronic gastritis and one as hemorrhagic gastritis. One patient showing a normal finding was diagnosed with adenoid hemorrhage after nasopharyngoscopy. H. pylori infection was found in four of six patients with GI bleeding (3, duodenal ulcer; 1, H. pylori associated chronic gastritis). The patients with H. pylori infection had an eradication treatment of triple therapy and no recurrence happened.

Conclusion

In child hemophiliacs, H. pylori should also be considered as an important cause of gastrointestinal hemorrhage. The recurrence of the infection and gastrointestinal hemorrhage can be prevented with eradication of H. pylori. Screening test for H. pylori would be needed in child hemophiliacs in endemic area.

Disclosures:

No relevant conflicts of interest to declare.
Rituximab Treatment in Childhood Chronic Immune Thrombocytopenic Purpura (ITP).
Authors: Kim Ji Yoon , Lee Kun Soo , Kang Hyoung Jin , Kook Hoon , Koo Hong Hoe , Kim Sun Young , Park Byung-Kiu , Park Hyeon Jin , Baek Hee-Jo , Seo Jong Jin , Sung Ki Woong , Shin Hee Young , Ahn Hyo Seop , Yoo Keon Hee , Lee Soo Hyun , Im Ho Joon , Choi Yong-Mook , Han Dong kyun , Hwang Tai Ju
Published: October 2019

Abstract 4461

Background

Immune thrombocytopenic purpura (ITP) is characterized by mucocutaneous purpura and thrombocytopenia caused by circulating anti-platelet auto-antibodies. ITP is usually self-limited in children, but around 20% of patients will develop chronic ITP. The conventional treatments for children chronic ITP include intravenous immunoglobulin (IVIG), corticosteroid therapy, anti-D immune globulin, or splenectomy. Some children with chronic ITP are refractory to these treatments and nowadays begun to try new treatment agents such as rituximab. Rituximab as a monoclonal antibody to CD-20, has shown promising reports to these patients with refractory chronic ITP in adults groups and a few children groups. We investigated this study to evaluate the efficacy of rituximab for childhood chronic ITP in Korea.

Methods

We reviewed the questionnaires and medical records about the clinical progresses and results in thirteen children from eight clinical institutes, retrospectively. Complete response (CR) was considered if the platelet count was > 100,000/uL.

Results

Thirteen patients with chronic thrombocytopenia who had been treated with rituximab were investigated. Two patients were lost to follow-up after rituximab. Finally eleven patients were evaluated including one patient with Evans syndrome. Median age was 6.5 year (range, 0.5 ∼ 15.4). Median platelet count at baseline was 13,700/uL (3,000∼46,000). All patients had been treated with conventional therapy including IVIG and steroids. One had done splenectomy. Median follow-up duration was 2.8 years (1.1-5.9). Among 11 patients, CR was achieved in 3 patients (27%). Their platelet count prior to rituximab were < 10,000/uL. They were treated as the regimen of 375 mg/m2/dose weekly for 4 doses. Time from the first rituximab dose to achievement of complete response was 3.9, 4.9 and 5.7 weeks respectively. One patient who was relapsed 6months after the first course of rituximab was received second course of rituximab using the same regimen and achieved a new CR at 9.3 weeks after. There were no reports about severe complication or interruption of medication.

Conclusions

Therefore, we suggest that rituximab is effective treatment choice in childhood refractory chronic ITP and well tolerated.

Disclosures:

No relevant conflicts of interest to declare.
Response to Anti D immunoglobulin in Adults with Chronic Immune Thrombocytopenic Purpura in a Minority Cohort with Long Term Follow up.
Authors: Sreenivasappa Shylendra B , Braik Tareq , Sandhu Sonia , Yim Barbara , Catchatourian Rosalind
Published: October 2019

Abstract 4465

Background

Immune Thrombocytopenic Purpura (ITP) is a common hematological disorder. We sort to characterize the risk profiles and efficacy of anti D immunoglobulin in chronic ITP in a largely minority cohort.

Methods

31 patients (pts) with chronic immune thrombocytopenic purpura treated 2003-2008 were studied as a retrospective cohort for clinical presentation, prognostic characteristics, time to next therapy and long term survival. Prognostic factors, time to relapse and overall survival was analyzed using fisher's exact test, logistic regression, Kaplan Meier survival analysis and Cox Proportional Hazards model.

Results

31 pts 19(61.3%) female and 12(38.7%) male. 11 (35.5%) African Americans, 12(38.7%) Hispanic, 5 (16.2%) Asians and 3 (7.8%) Caucasians. Median age at diagnosis was 44 yrs (21-66). 25 (80.5%) were HIV negative and 6 (19.5%) had HIV. 16 (51.6%) had O positive blood group, 9 (29.6%) had A positive and 4 (12.9%) had B positive. The median number of co-morbidities at diagnosis was 1(0-6). Median age at which anti D immunoglobulin was initiated was 45 yrs. Pt had received a median of 3 (2-6) therapies prior to anti D therapy. All patients had received steroids, 17 (54.8%) had immunoglobulin therapy, 2 (6.5%) had vincristine and 6(19.3%) had splenectomy prior to anti D therapy. The median duration to anti D therapy was 6 months (0-228). Anti D therapy was given in the dose of 50-75mcg/kg IV weekly. Median number of doses given was 2 (1-7) doses.

The response rate was 64.5%. Response was defined as Complete response, platelet count of > 100 × 109/L, Partial response >30 × 109/L. 17 (54.8%) achieved complete response, 3 (9.7%) achieved partial response. 11(35.5%) did not respond. Median time to relapse was 4 months (0-79). 9 (29%) achieved a complete response for over a year.

Pt with HIV (p=0.013), O blood group (p=0.030) had a significant poor response to anti D therapy on univariate analysis. Pt with HIV (p=0.035) had poor response to therapy on multivariate analysis. O blood group (p=0.001), HIV (p=0.016), > 2 lines of therapy (p=0.007), one dose of anti D (0.037) were associated with shorter time to progression on univariate analysis. On multivariate analysis prior immunoglobulin administration (p=0.039), >2 lines of therapy (p=0.004) and single dose of anti D immunoglobulin (p=0.039) were associated with shorter time to progression.

Conclusion

Anti D immunoglobulin had a response rate of 64.5% which is similar to other studies. About 29% of patients had a complete response for over a year. Pts who not received anti D immunoglobulin, HIV negative and early anti D administration had the best response and longer time to progression.

Disclosures:

No relevant conflicts of interest to declare.
Evaluation of Platelet Indices for Differential Diagnosis of Thrombocytosis by ADVIA 120.
Authors: Song YoungHee , Ahn Jeong-Yeal , Park Soon Ho , Kim Jung Eun , Seo Yiel Hea , Park Pil Hwan , Kim Kyung-Hee , Lee Jae Hoon
Published: October 2019

Abstract 4472

Background

Because there is no single clinical or laboratory finding for the diagnosis of essential thrombocythemia (ET), a differential diagnosis of other myeloproliferative neoplasms or reactive thrombocytosis (RT) is always necessary. Developments in automated blood cell analysers can now measure various platelet indices and were used in this study to differentiate between ET and RT in patients with a platelet count of 600×103/μL or more.

Method

The subjects studied were 31 patients with ET and 224 patients with RT. The platelet counts, mean platelet volume (MPV), plateletcrit (PCT), platelet distribution width (PDW), mean platelet mass (MPM), mean platelet component concentration (MPC) and large platelets (LPLT) were measured by ADVIA 120 (Bayer Diagnostics, USA) and the sensitivity and specificity of the two groups were determined.

Results

In essential thrombocythemia, all parameters except MPC were higher than those of reactive thrombocytosis and were statistically significant. The sensitivity and specificity were 74.2% and 84.4% when the platelet count was more than 820×103/μL. The sensitivity and specificity were 80.6% and 80.0% when the plateletcrit was more than 0.63%. The sensitivity and specificity were 64.5% and 99.1%, respectively, when LPLT was more than 23×103/μL.

Conclusion

The platelet counts and platelet indices are important for the differential diagnosis of thrombocytosis. The comparison of the plateletcrit and LPLT is particularly useful when the platelet count is markedly increased.

Disclosures:

No relevant conflicts of interest to declare.
Study On Mechanism of Bone Marrow Mesenchymal Stem Cell in Treating Patients with Rheumatoid Arthritis.
Authors: Qiao Zhenhua , Ma Lihui
Published: October 2019

Abstract 4486

Objective

To explore mechanism of Mesenchymal stem cells in treating Rheumatoid arthritis.

Methods

(1) MSCs were isolated from Bone marrow samples of Rheumatoid arthritis(RA)patients and purified by density gradient centrifagation and cultured in vitro. Morphology, immunophenotype, and proliferative property of bMSC and colony forming unit-fibroblast (CFU-F) were measured and analyzed. (2) In an in vitro co-culture system, MSCs were observed to modulate proliferation,activation, and maturation of T and B lymphocytes of Rheumatoid arthritis(RA)patients. The expression of IL-1?ATNF-a?ATGF-β were obviously changed.(3) Bone marrow- derived BMSCs of wistar rats were isolated and cultured in vitro routinely and the fourth passage as taken for identification of specific surface antigens by flowcytometry, then were labled with 5- BrdU in vitro. The model of collagen-induced arthritis (CIA) rats were established. 5- BrdU labled BMSCs were implanted through tail vein to model rats. At 4 weeks after BMSCs transplantation, immunohistochemical examinations were used to investigate BMSCs aggregate around the knee joints.and identify the contribution of bone marrow– derived cells to joints damage repair.

Results

(1) The culture expanded cells from RA patients presented a typical fibroblast-like morphology. Cells were positive for SH2(CD105),CD71,and CD44, but negative for CD45.Their proliferative capacity and CFU-F number were similar to those of bMSCs from healthy donors. (2) MSCs significantly inhibited T,B cell proliferation. MSCs also could down-regulating the levels of IL-1, TNF and up-regulating TGF-β. (3) Flow cytometry showed that BMSCs expressed CD44, CD71and CD105, but no CD45,CD34. At 4 weeks after the cells transplantation, the implanted cells were detected in the damaged joints of the model rats, which is not founded in normal knee joints of the rats'.and at same time there are more OPG(osteoprotegerin) positive.

Conclusion

(1) In the aspect of morphology, immuno -phenotypen, proliferative property and colony forming unit-fibroblast (CFU-F),MSCs from bone marrow of RA patients are not different from those of MSCs isolated from bone marrow of normal donors,MSCs from the bone marrow of RA patients have the potentiality in clinical application.(2) Human bone marrow MSCs inhibited Tcell and Bcell activation and proliferation in patients with RA in vitro. And these immuno –modulatory effects were not MHC-restricted. (3) bone marrow mesenchymal stem cells prevents tissue damage in arthritis. Allogeneic MSCs can engraft at sites of tissue damage,and prepair damage. That provided positive results for developing effective therapy for Rheumatoid arthritis.

Disclosures:

No relevant conflicts of interest to declare.
No Impact of Dectin-1 Polymorphism Y238X On the Outcome of Hematopoietic Stem Cell Transplantation, but a Role for Candida in Acute Graft-Versus-Host Disease.
Authors: van der Velden Walter J.F.M. , Plantinga Theo , Feuth Ton , Donnelly Peter , Netea Mihai , Blijlevens Nicole N.A.
Published: October 2019

Abstract 4498

Dectin-1 is a C-type lectin receptor that recognizes b-1,3-glucan, and plays an important role in antifungal immunity. The recently discovered dectin-1 Y238X polymorphism, which results in “loss-of-function” has been shown associated with increased Candida colonization of stem cell transplantation (SCT) recipients. Besides its role in antifungal immunity Dectin-1 exhibits a broader function in immunity. Stimulation of Dectin-1 with β-glucan affects antigen presentation, modulates T-lymphocytic (CD4+, both Th1 and Th17, and CD8+) and B-lymphocytic responses, and induces cytokine production including interleukin (IL) 10, IL-12 and IL-23. These specific T-cell responses and cytokines are of particular interest in SCT because they are involved in graft-versus-leukemia (GvL) effects as well as in the pathogenesis of graft-versus-host disease (GvHD). Therefore we now performed a retrospective study in 140 patients on the impact of the Y238X polymorphism on the outcome of myeloablative T cell-depleted matched related SCT. The allele frequency of the Y238X polymorphism was 6.6%, with 10.7% of patients and 15.7% of donors bearing the polymorphism. All were heterozygous and at least one polymorphism was present in 28 of 140 (20%) patient-donor pairs. We found no impact of the polymorphism on the occurrence of acute and chronic GvHD, non-relapse and relapse related mortality, nor disease-free and overall survival. Interestingly, patients from patient-donor pairs bearing the wild-type allele who were colonized with Candida had an increased incidence of acute GvHD compared to non-colonized patients (41.9% vs. 20.4%, OR=2.6 95%CI:1.02-6.58, P=0.04). However, this seemed to be the other way round for patients from pairs with the Y238X polymorphism (23.5% colonized vs. 30% not colonized, OR=0.7, ns). Therefore we hypothesize that the loss-of-function of dectin-1 increases colonization through deficient mucosal immunity, but prevents inflammatory complications resulting from colonization (Figure 1). This might explain the lack of an effect of the Dectin-1 Y238X polymorphism on outcome measures of SCT.

Figure 1: Simplified hypothesis on the role of dectin-1, polymorphism Y238X, and Candida colonization on acute GvHD and possibly GvL. Figure 1:. Simplified hypothesis on the role of dectin-1, polymorphism Y238X, and Candida colonization on acute GvHD and possibly GvL.

In case of Candida colonization (left) activation of the dectin-1 receptor influences immune responses and allo-reactivity increasing the incidence of acute GvHD. In the presence of the loss-of-function polymorphism Y238X (right), although Candida colonization is increased, due to the loss-of-function of dectin-1, no changes in the allo-reactive T-cell responses occur.

Disclosures:

No relevant conflicts of interest to declare.
Dengue Virus Associated Hemophagocytic Syndrome with Neurogical Manifestations in Children: A Case Report.
Authors: Soler-Rosario Yadira , Barrios Nilka J. , Garcia Ricardo , Fernandez-Sein Alicia , Rivera Enid
Published: October 2019

Abstract 4516

Dengue fever, caused by dengue virus, can cause increased vascular permeability, which leads to a bleeding diathesis or disseminated intravascular coagulation known as Dengue Hemorrhagic Fever (DHF). Hemophagocytocytic Syndrome (HPS) with neurological manifestations is an uncommon presentation of DHF. There are no reports of virus associated with HPS and neurological manifestations in the pediatric literature. Hemophagocytic Syndrome (HPS) is a clinico-pathologic entity characterized by proliferation of T lymphocytes and macrophages leading to cytokine overproduction. HPS may be diagnosed in association with malignant, genetic, or autoimmune diseases. Dengue virus is considered non-neurotropic, however neuroinvansion has been reported. We present the case of a 10 month old female patient who developed DHF, manifested with upper GI bleeding, hypotension and pancytopenia. The infant subsequently developed dengue shock syndrome, with thrombocytopenia, intravascular hemolysis, coagulopathy, elevated transaminase, hyperbilirubinemia, and creatine kinase (CK) of 2,876U/L. She required artificial hemodynamic and blood components support. During her course of illness, she developed ecchymosed, purpuric bullae lesions of the skin in the distal upper extremities. Her IgM ELISA for Dengue virus was positive. Bone marrow aspiration and biopsy was diagnostic for HPS. The patient was initiated on IV steroids and antibiotics therapy. An improvement was noticed on day 8 of illness and was weaned off completely of all artificial support by the day 9. A complete recovery of her hematological, transaminase, billirubin, and coagulation parameters was noticed on day 12. A repeated bone marrow aspirate and biopsy examination was normal. Patient's recovery was significant by muscle weakness (MCG grade ≤3), hypotonia, reduced tendon reflex and increased CK suggestive of possible myositis. The cerebrospinal fluid and magnetic resonance imaging studies of the brain were normal. She was given IV immunoglobulin (500mg/kg) for 2 consecutive days with remarkable neurological improvement including a normal CK (56U/L).She was weaned of steroids completely on day 20.Dengue virus infection was confirmed by a positive serology result at the convalescent stage. On day 23 she had a complete clinical recovery. To our knowledge, this is the first case reported of dengue virus-associated HPS and neurological manifestations in a pediatric patient with DHF. Clinicians should consider that the occurrence of HPS and neurological manifestations in children could de due to dengue virus infection.

Disclosures:

No relevant conflicts of interest to declare.
Clinical Trial of a Portable Electrical Muscle Stimulator (VeinoPlus®) to Improve Symptoms of Postthrombotic Syndrome.
Authors: Soriano Catherine , Deal Allison , Boles Jeremiah C. , Moll Stephan
Published: October 2019

Abstract 4540

Background

Limited treatment options exist for postthrombotic syndrome (PTS). We performed a trial in patients with PTS of a portable electrical muscle stimulation device, VeinoPlus®, which delivers electrical impulses to leg muscles for 20 minute periods via 2 cutaneously placed electrode pads. Aims were to determine whether use of the device was a “clinical success” (defined by patient reporting improvement of symptoms, plus an interest and willingness to continue using the device) and improved quality of life (QOL) and severity of PTS findings; and to define optimal electrical intensity for greatest symptom relief.

Methods

Patients were told to use different voltages and numbers of treatment periods, and experiment with pad placement, to find intensity, frequency of use, and pad position for optimal PTS symptom relief. Assessments (Villalta score, QOL questionnaire) were obtained at study entry and after 8 weeks of device use.

Results

Twelve patients were enrolled: 3 had severe, 4 moderate, 5 mild PTS. To date, 8 patients have completed the study. Clinical success occurred in 5/8 (63%) of patients. 63% of patients had an improved VEINES questionnaire score on the symptom subscale, 75% on the QOL subscale. Villalta score on the most affected leg improved for 50% of patients. Most patients used the device in the intensity range of 25-35.

Conclusion

The VeinoPlus® electrical stimulation device appears to improve symptoms and QOL for patients with PTS. The study provides the rationale and details needed for a larger follow-up randomized, sham-device controlled, double-blind trial.

Disclosures:

No relevant conflicts of interest to declare.
Erythropoietin Treatment Leads to Reduced Blood Glucose Levels and Body Mass: Insights From Murine Models.
Authors: Katz Odelia , Stuible Matthew , Golishevski Nataliya , Lifshitz Lilach , Tremblay Michel , Gassman Max , Oster Howard S , Mittelman Moshe , Neumann Drorit
Published: October 2019

Abstract 4557

Erythropoietin (EPO) regulates proliferation and differentiation of erythroid precursor cells into erythrocytes. The last decade has revealed non-renal sites of EPO production and extrahematopoietic expression of the EPO-receptor (EPO-R), suggesting that EPO has pleiotropic functions. We have previously shown anti-cancer and immunomodulating effects of the hormone in humans and mice. Here we addressed the interplay among EPO, glucose metabolism, and body weight by employing a panel of relevant experimental murine models. The models focused on situations of increased EPO levels, including EPO-injected C57BL/6 and BALB/c mice, as well as transgenic mice (tg6) constitutively overexpressing human EPO and thus exposed to constantly high EPO serum levels. As experimental models for diabetes and obesity we employed protein Tyr phosphatase 1B (PTP1B) knockout mice associated with resistance to diabetes (PTP1B-/-), and ob/ob mice susceptible to diabetes and obesity. Our data demonstrated an EPO-associated decrease in blood glucose levels in all mice models tested. The tg6 mice, continuously exposed to EPO, were hypoglycemic even under non-fasting conditions. Blood glucose reduction in the experimental models tested was evident already one week following EPO administration in all models, including the PTP1B-/- and ob/ob mice. This conclusion gained further support by the glucose tolerence test (GTT). EPO overexpression or administration led to improved glucose clearance in all the tested murine models. Notably, in the ob/ob mice we observed EPO-associated attenuation of body weight gain and reduction of hemoglobin A1C. Preliminary clinical observations with several diabetic patients support these data and will be discussed further. Taken together our data bear significant clinical implications for EPO treatment in the management of a wide range of metabolic diseases and add an important novel therapeutic potential to this pleiotropic hormone.

Disclosures:

Mittelman: BioGAL- Start up (inactive): Equity Ownership, Patents & Royalties. Off Label Use: Non erythroid effects: immune, anti-cancer (all under investigation).