bluuebunny/crossref_metadata_2025 huggingface dataset:
TNFRSF14 Is Mutated in a Subset of Follicular Lymphoma and Correlated with Inferior Prognosis.
Authors: Cheung K-John , Johnson Nathalie , Affleck Joslynn , Severson Tesa , Steidl Christian , Ben-Neriah Susanna , Schein Jacqueline , Morin Ryan , Moore Richard , Shah Sohrab P , Qian Hong , Paul Jessica , Telenius Adele , Lai Betty , Relander Thomas , Lam Wan L , Savage Kerry J. , Connors Joseph M , Brown Carolyn , Marra Marco , Gascoyne Randy D. , Horsman Douglas E.
Published: October 2019

Abstract 1919

Poster Board I-942

The secondary genetic events associated with follicular lymphoma (FL) development are obscure as to the identification of critical driver genes. Clinical correlative studies have implicated chromosome band 1p36 deletions and linked them to a propensity for transformation and poor outcome. This region also showed a high frequency of copy-neutral loss of heterozygosity as demonstrated by SNP array analysis. In this study, we applied BAC array comparative genomic hybridization (array CGH) to 141 FL specimens and detected deletion of 1p36 in 20% of the cases with a minimum region of deletion (MRD) of ∼100 kb within the band 1p36.32. The majority of cases displayed heterozygous deletion, while two cases showed homozygous deletion. The MRD encompassed five genes: HES5, LOC115110, TNFRSF14, C1orf93 and MMEL1. Methylation status of CpG in the promoter region of genes in the MRD revealed no difference among samples differing in 1p36 status. However, exonic sequencing of the MRD genes identified somatic base mutations only in the TNFRSF14 gene in four of five selected cases with 1p36 deletion. Lower expression of TNFRSF14 was also found in 1p36 deleted cases. Validation of TNFRSF14 mutations was undertaken in an expanded cohort of 251 FL patients which showed that 45 cases (18%) displayed a total of 50 mutations and that inferior prognosis was significantly associated with TNFRSF14 mutation status. We propose that TNFRSF14, a gene previously implicated in growth inhibition and Fas-induced apoptosis, is a candidate tumor suppressor gene in FL.

Disclosures:

No relevant conflicts of interest to declare.
Activation of PI3K/Akt/mTOR Pathway in Diffuse Large B-Cell Lymphomas: Clinical Significance and Inhibitory Effect by Rituximab.
Authors: Li Jun-min , Xu Zi-zhen , Wang Ai-hua , Hu Jiong
Published: October 2019

Abstract 1934

Poster Board I-957

A better understanding of the biology of diffuse large B cell lymphoma(DLBCL) is needed in the developement of potential therapeutic agents that target specific intracellular pathway. In this study, expression of the important members of PI3K/Akt/mTOR signaling pathway and their clinical significance were investigated in 73 cases of DLBCL. Immunohistochemical analyses showed that activation of Akt and its downstream targets such as p-p70S6K, p-4E-BP1, YB-1 and Mcl-1 were present in DLBCL cases. Activation of PI3K/Akt/mTOR pathway was related to poor disease outcome in DLBCL patients treated by CHOP but not in those treated by R-CHOP. Rituximab combined with chemotherapy could down-regulate PI3K/Akt/mTOR activation and reverse its negative effect on chemotherapy-treated patients. The effect of Rituximab alone or combined with the mTOR inhibitor Rapamycin was further evaluated in DLBCL cell line SUDHL-4. Rituximab combined with Rapamycin possessed synergic effect in down-regulating PI3K/Akt/mTOR signaling pathway, inhibited proliferation and caused G1 arrest in DLBCL cell line. The results showed that PI3K/Akt/mTOR signaling pathway activation presented in DLBCL may be considered as a prognostic biomarker and a promising target for therapeutic intervention.

Disclosures:

No relevant conflicts of interest to declare.
A Comparison of Gene Expression Pattern in Major Histocompatibility Class II-Low Diffuse Large B-Cell Lymphoma with Plasmablastic Lymphoma.
Authors: Wilkinson Sarah T. , Bob Roshanak , Stein Harald , Schwartz Mark , Braziel Rita M. , Gascoyne Randy D. , Rimsza Lisa M.
Published: October 2019

Abstract 1941

Poster Board I-964

Multiple studies have repeatedly shown that loss of MHC II expression correlates with poor patient prognosis in diffuse large B-cell lymphoma (DLBCL). Major histocompatibility complex class II (MHCII) molecules present peptides for antigen recognition and are important for the adaptive immune response. Loss of MHCII expression is also one of the changes seen during normal B-cell differentiation into plasma cells. Plasmablastic lymphoma (PBL) is another B-cell lymphoma characterized by a proliferation of large B-cells with a plasma cell immunophenotype and very poor prognosis. In this study, we questioned whether DLBCL cases that have low MHCII expression have a similar gene expression pattern to PBL. Unstained cuts from formalin-fixed, paraffin-embedded tissue blocks of 101 DLBCL and 76 PBL cases were analyzed for gene expression using a quantitative nuclease protection assay (qNPA, ArrayPlateR). The 42 genes on the array were previously identified as B-cell lineage-related or prognostically important in DLBCL. DLBCL cases were divided into low [MHCII(-)] and high [MHCII(+)] MHC II expression using a 20% cutoff for expression of HLA-DRB by qNPA, as previously described (L Rimsza et al, Blood 2008). Genes that differed significantly between lymphoma types were determined using the Partek Genomics SuiteR software, using ANOVA tests with a false discovery rate of 0.05. Thirty of the 42 genes on the array (71%) were differentially expressed between DLBCL as a whole and PBL. As expected from the literature, the PBL cases had less expression of B-cell antigen, MHCII, and germinal center-related genes as compared to DLBCL. Of these 30 genes, 29 were also different between MHCII(+) and PBL. In contrast, only 21 genes of the 42 on the array (50%) were differentially expressed between MHCII(-) and PBL, indicating a less dissimilar expression pattern between these two sets of cases. Of the 21 genes, two were uniquely different between MHCII(-) and PBL. Both of these, FN1 and CTGF, are found in the extracellular matrix and were low in the MHCII(-) cases. This finding, that the MHCII(-) cases are similar, but not identical to PBL, agrees with our previous immunohistochemistry studies suggesting MHCII(-) cases may be invoking selected mechanisms of differentiation (S Wilkinson et al, AACR Annual Meeting 2009, #2712). Our findings confirm the hypothesis that MHCII(-) DLBCL have a more plasma cell-like expression pattern than MHCII(+) DLBCL. These findings may have implications for pathogenesis and treatment.

Disclosures:

Schwartz: High Throughput Genomics: Employment. Gascoyne:Roche Canada: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Rimsza:High Throughput Genomics: Memorandum of understanding with HTG to run qNPA assay at no cost..
CD80 (B7.1) Is Expressed On Both Malignant B Cells and Tumor Infiltrating T Cells in Non-Hodgkin's Lymphomas.
Authors: Tangri Shabnam , Dakappagari Naveen , Estrellado Annalee , Weng Andrew P. , Holmes Elizabeth , Saville M. Wayne , Hariharan Kandasamy , Ho Steffan
Published: October 2019

Abstract 1953

Poster Board I-976

CD80 is a member of the B7/CD28 family of regulatory proteins. B7/CD28 proteins are expressed on the surface of cells of the adaptive and innate immune system (i.e. lymphocytes, monocyte/macrophages, dendritic cells, myeloid-derived suppressor cells). These proteins function to establish a biologically optimal and dynamic balance between immune activation and inhibition or self-tolerance. Interactions between CD80 and its receptors, which include CD28, CTLA4 and PD-L1, contribute to both stimulatory as well as inhibitory or homeostatic regulation. Galiximab, an antibody directed against CD80, is currently under investigation for the treatment of follicular NHL. Initial clinical trials demonstrated that galiximab is well tolerated and suggest that combining galiximab with rituximab may provide clinical benefit. While expression of CD80 by malignant B cells in non-Hodgkin's lymphoma (NHL) has been reported, these studies utilized poorly quantitative immunohistochemical methods. To gain further understanding of the potential role of CD80 as a therapeutic target in NHL, CD80 expression was evaluated by six-color flow cytometric analysis of primary lymphoma cell suspensions generated from diagnostic biopsies of patients presenting with lymphadenopathy. Results obtained to date confirm that CD80 is uniformly expressed by malignant cells in a large majority of cases of follicular lymphoma (N=63), diffuse large B cell lymphoma (N=38), mantle cell lymphoma (n=7), marginal zone lymphoma (n=12) and small lymphocytic lymphoma (n=9). Furthermore, CD80 expression was also observed on tumor-infiltrating, non-malignant T cells.

These results confirm the nearly ubiquitous expression of CD80 by malignant B cells in follicular, diffuse and other low grade NHL. Furthermore, these data demonstrate expression of CD80 by non-malignant cells (e.g. T cells) that define the tumor microenvironment. Further work to expand this dataset and to evaluate the expression of CD80 in non-T, non-B cells is ongoing. The expression of CD80 by malignant cells as well as non-malignant cells in NHL provides an opportunity to not only employ therapeutic antibodies to direct anti-tumor effector function such as antibody-dependent cellular cytotoxicity, but to also potentially interfere with interactions involving CD80 that might be involved in establishing an immune suppressive microenvironment supportive of tumor growth.

Disclosures:

No relevant conflicts of interest to declare.
Cooperation of MLL/AF10(OM-LZ) with K-Ras Mutation Induced Myeloid Sarcoma in a Mouse Bone Marrow Transplantation Model.
Authors: Fu Jen-Fen , Shih Lee-Yung
Published: October 2019

Abstract 1964

Poster Board I-987

We analyzed genetic mutations in a large cohort of AML patients and found that two of the five patients with MLL/AF10 and N-/K-RAS mutations had cutaneous tumors (myeloid sarcomas). To study the cooperative role of MLL/AF10 and N-/K-RAS in the formation of myeloid sarcoma, we established two cell lines by retroviral transduction of MLL/AF10(OM-LZ) and K-RASG12C into GFP-B6 mouse bone marrow cells. Flow cytometric analysis revealed that the cells with MLL/AF10(OM-LZ) and K-RASG12C showed a decreased Mac-1 and CD115 expression when compared with the cells with a single MLL/AF10(OM-LZ) mutation. Microarray and RT-PCR analyses revealed an increased gene expression in Hoxa10 and Meis1, but not Hoxa9. In addition, the phagocytosis related genes, Cybb and Lyz were decreased in the cells harboring MLL/AF10(OM-LZ) and K-RASG12C. These results suggested that cooperation of MLL/AF10(OM-LZ) and K-RASG12C mutations blocked the cells in a more primitive hematopoietic stage. When the two cell lines were intra-peritoneally injected into B6 mice, the mice developed myeloproliferative disease-like myeloid leukemia as that of the mice transplanted with cells carrying a single MLL/AF10(OM-LZ) fusion gene. The median survival time were 33±4.2 and 31.6±5.1 days, respectively, which were shorter than that of the mice transplanted with cells carrying a single MLL/AF10(OM-LZ) fusion gene (49.8±5.0 days). We found that the majority (84%) of mice transplanted with cells harboring both MLL/AF10(OM-LZ) and K-RASG12C mutations formed multiple tumor masses involving gastrointestinal tract, kidney, peritoneum, paraspinal soft tissue, and/or skin. Cytological examination from the imprint smears of tumor masses showed massive infiltrates of leukemia blastic cells. Immunohistochemical stains of the paraffin-fixed histological sections of tumor masses were positive for GFP, confirmed that the tumor cells were generated from the transplanted cell lines. We have established a mouse model which can be used for further study of the myeloid sarcoma formation.

Disclosures:

No relevant conflicts of interest to declare.
Loss of L3MBTL1, a Candidate 20q12 Tumor Suppressor Gene, Leads to DNA Damage.
Authors: Gurvich Nadia , Voza Francesca , Menendez Silvia , Nimer Stephen
Published: October 2019

Abstract 1974

Poster Board I-997

The L3MBTL1 gene is located on the long arm of chromosome 20 (q12), a region commonly lost in several myeloid malignancies, including myeloproliferative diseases (MPD), myeloprodysplastic disorders (MDS), and acute myeloid leukemias (AML). MDS and AML frequently have complex cytogenetic profiles, and are thought to arise due to accumulation of several cooperating mutations. We have previously reported that L3MBTL1 is highly expressed in human hematopoietic progenitor cells. L3MBTL1 is a homolog of Drosophila polycomb L3MBTL tumor suppressor protein. Thus, L3MBTL1 is a candidate gene in 20q12 myeloid disorders. We have depleted L3MBTL1 by RNAi in several human cell lines, and find that loss of L3MBTL1 leads to a decrease of cells in the S phase of the cell cycle and accumulation in G2/M phase. Cells with depleted L3MBTL1 have an increase of spontaneous DNA breaks, as evidenced by accumulation of γH2A.X foci and comet assay. The presence of DNA breaks leads to activation of DNA damage response, as the L3MBTL1 knockdown cells have increased levels of phosphoChk1 (Ser317 and Ser345), phosphoChk2 (Thr68), phosphoATM (Ser1981), p21 and p53. The DNA damage in the L3MBTL1-depleted cells activates DNA repair machinery, as shown by the increase in Rad51 levels. We propose that the spontaneous DNA damage caused by depletion of L3MBTL1 could contribute to the development of 20q12 myeloid malignancies.

Disclosures:

No relevant conflicts of interest to declare.
Shortened Lifespan of Red Blood Cells and the Effects of Erythropoietin in Rats with Nephrogenic Anemia.
Authors: Iwatsuki Yoshiyuki , Kitamura Koki , Suzuki Ken-ichi
Published: October 2019

Abstract 1977

Poster Board I-1000

Anemia is a common complication of chronic kidney disease (CKD), mainly due to the inability of the kidneys to secrete enough erythropoietin to adequately stimulate hematopoiesis. Further, given that the lifespan of red blood cells (RBCs) has been reported to be reduced in CKD patients, this reduction in RBC lifespan is believed to be a part of the etiology of renal anemia. In the present study, we focused on RBC survival and measured the lifespan of RBCs in rats with nephrogenic anemia. We also examined the effects of erythropoietin on RBC lifespan in this anemia model. Nephrogenic anemia was induced by oral administration of adenine (600 mg/kg/day for 10 days) to male Wistar rats. Progressive, serious anemia associated with increased levels of plasma creatinine was observed in the rats. On Day 40, the number of RBCs and hemoglobin (HGB) levels were lower in the adenine-treated rats than in normal, control rats (normal: 930×104/μL, anemic: 677×104/μL for RBC and normal: 17.2 g/dL, anemic: 13.4 g/dL for HGB). However, the number of reticulocytes did not change in the anemic rats (normal: 299×103/μL, anemic: 329×103/μL, P = 0.102). The percentage of annexin V-binding erythrocytes was increased in anemic rats (normal: 0.77%, anemic 1.76%) and inversely correlated with RBC count and HGB levels, suggesting that apoptosis of RBCs increased as anemia progressed. Taking these findings into account, we measured the lifespan of RBCs in rats with nephrogenic anemia. We transfused 5-chloromethylfluorescein diacetate (CMFDA)-labeled RBCs from normal donor rats into either normal or anemic recipients and determined the number of labeled RBCs present in the peripheral blood at various time points thereafter. The time course of the reduction in the percentage of labeled RBCs in peripheral blood revealed that the half-life (t1/2) of RBCs in anemic rats was shorter than in normal rats (normal: 22.5 d, anemic: 13.3 d). This reduction in RBC lifespan was also observed in a rat model of cisplatin-induced renal anemia. Injection of anemic rats with recombinant human erythropoietin (rhEPO) restored the number of RBCs and HGB concentration to normal levels. However, the t1/2of RBCs in these rats was not changed. The clearance of RBCs in anemic rats does not appear to be influenced by rhEPO injection. In conclusion, the survival of RBCs was reduced in rats with nephrogenic anemia, an observation consistent with the shortened survival time of RBCs in renal failure patients. This finding suggests that this model is suitable for investigating drugs which may be used in the treatment of renal anemia. Further, because EPO therapy did not affect the lifespan of RBCs, agents which improve the shortened RBC survival inherent in CKD patients may be useful in treating renal anemia.

Disclosures:

Iwatsuki: Astellas Pharma Inc.: Employment. Kitamura:Astellas Research Institute of America LLC: Employment. Suzuki:Astellas Pharma Inc.: Employment.
TRIB3 Pseudokinase Is Induced Via An EPO/EPOR/STAT5 Pathway, Markedly up-Modulated in Late-Stage Erythroblasts, and Plays An Essential Non-Redundant Role During Stress Erythropoiesis.
Authors: Dev Arvind , Wojchowski Don M.
Published: October 2019

Abstract 1985

Poster Board I-1007

TRIB pseudokinases have been implicated as pro-leukemogenic factors, and candidate regulators of insulin-dependent glucose utilization, adipogenesis and obesity. In a hematopoietic context, we have discovered that TRIB3 is a major new EPOR/JAK2/STAT5 response factor which furthermore is selectively elevated (among TRIB-1, -2 and -3) ≥ 10 fold in late-stage murine and human erythroblasts. We therefore have hypothesized that TRIB3 may selectively affect stress erythropoiesis, and have critically addressed this problem by generating novel TRIB3flox/flox and TRIB3-null mice. At steady state, hematopoiesis among TRIB3-null mice is largely unperturbed. When challenged with hemolytic anemia, however, TRIB3- deficient mice exhibit worsened anemia (increased severity, and recovery time). Analyses of possible stage-specific effects further indicate faltered erythropoiesis at relatively late Kitneg CD71high Ter119pos erythroblast stage. Recently, TRIBs have been revealed to act as apparent E3 ubiquitin ligase coupling factors. It is therefore intriguing to speculate that TRIB3 may act selectively during stress erythropoiesis to target and decay a key late-stage negative regulator.

Disclosures:

No relevant conflicts of interest to declare.
Chronic Deferasirox Administration Decreases Hepatic Oxidative Stress and Apoptosis in the Iron Overloaded Gerbil.
Authors: AL-Rousan Rabaa , Katta Anjaiah , Paturi Satyanarayana , Kidd Brent , Manzoor Kamran , Walker Ernest , Blough Eric
Published: October 2019

Abstract 1996

Poster Board I-1018

Background:

Iron overload occurs under conditions such as primary (hereditary) hemochromatosis and secondary iron overload (hemosiderosis) and is associated with an increased risk of developing liver fibrosis, cirrhosis, and hepatocellular carcinoma. Deferasirox is a novel oral chelator with high iron-binding potency and selectivity. Here we investigate the ability of deferasirox to remove excessive hepatic iron and prevent or reverse iron induced hepatic injury.

Methods:

Adult male Mongolian Gerbils were randomly divided into three groups: control, iron overload, and iron overload + deferasirox treatment (n = 8 / group). Iron overload animals received iron dextran 100mg/kg i.p /5d for 10 wks while deferasirox was given 100mg/kg/d p.o for 1-,3-, or 9- months. Hepatic iron levels were determined by inductively coupled plasma atomic emission spectrometry and Prussian blue staining was performed to examine iron deposition in the corresponding tissues. Immunoblot and immunohistochemical analyses for markers of oxidative stress were employed to assess effects of deferasirox treatment on hepatic protein oxidation and superoxide levels. TUNEL assay was employed to examine the extent of hepatic apoptosis.

Results:

Compared to the non-treated iron overload group, deferasirox treatment reduced hepatic iron levels by 21.3%, 43.5%, and 47.4% after 1, 3, and 9 months of treatment, respectively (p<0.05). Prussian blue staining and histological analysis detected frequent iron deposition, evidence of hepatic damage, and lipid accumulation in hepatic tissue of the iron overloaded group. Iron deposition was significantly diminished with deferasirox treatment and no evidence of lipid accumulation was observed. Immunoblotting demonstrated that iron overload caused 2- fold increase in hepatic ferritin expression (p< 0.05) which was reduced by 47.5% following three months of deferasirox treatment (p< 0.05). In addition, deferasirox significantly reduced hepatic protein oxidation and superoxide abundance. The percentage of TUNEL-positive nuclei in the deferasirox treated livers was 41.0% lower than that of iron overloaded group (p<0.05).

Conclusions:

These findings suggest that chronic deferasirox treatment may decrease iron-induced hepatic oxidative stress and apoptosis. Decrease in ROS accumulation in the liver may be the possible mechanism of this protective effect. Further studies are underway to delineate specific mechanisms.

Disclosures:

No relevant conflicts of interest to declare.
Evaluation of Alternative, “Low-intensity” Induction Regimens in Elderly Adults with Acute Myeloid Leukemia (AML).
Authors: Feldman Eric J. , Ritchie Ellen , Gergis Usama , Mayer Sebastian , Scandura Joseph M. , Christos Paul J. , Wissa Usama , Roboz Gail J.
Published: October 2019

Abstract 2066

Poster Board II-43

From 1999 to 2009, 298 adults, age 60 yrs and above, received initial induction therapy for untreated AML at Weill-Cornell Medical College/New York Presbyterian Hospital. Based on physician/patient preference and/or protocol eligibility, patients received either a traditional cytosine arabinoside/anthracycline-based induction regimen (n= 103) or an alternative, low-intensity regimen(n=195); either low-dose ara-C +/- arsenic trioxide (n=88) or tipifarnib +/- oral etoposide (n=107). Overall the median age was 72 yrs (range 60-89), 47% had an antecedent hematological disorder (AHD) and 42% had an unfavorable karyotype. Patients treated with low-intensity regimens were significantly older compared to those given standard induction (median age 75 vs 67 yrs) and had a higher percentage of unfavorable karyotypes (46% vs 33%). Complete remissions (CR) were achieved in 23% of patients receiving low-intensity regimens and 53% of patients treated with standard therapy. Thirty and 60 day mortality rates were 9.7% and 20.5% versus 14.5% and 25% for low-intensity and standard regimens respectively (p=0.29). Seventy two of the initial 195 patients (37%) treated with a low-intensity regimen received a second induction regimen for primary resistance or relapse; either a standard ara-C-anthracycline regimen (n=38) or a second non-intensive regimen (decitabine +/- gemtuzumab ozogamicin, low-dose ara-c, SGN-33,) (n=34). Overall 25/72 (35%) achieved a CR with salvage therapy; 16/38 CR's (42%) with standard induction and 9/34 CR's (26%) with a second low-intensity regimen. Median overall survival for all 298 patients was 6.7 months. By univariate analysis, no significant difference in survival was seen for patients initially treated with a low-intensity regimen compared to those receiving standard induction (median 6.2 vs 7.7 months; p=0.82 by log-rank test). By multivariate analysis, age over 75, prior AHD, unfavorable karyotype, ECOG performance status > 2, and male gender all predicted for shorter survival, whereas intensity of initial treatment did not. These results suggest that older patients with AML may receive initial therapy with a non-traditional, low-intensity induction regimen and have similar survival outcomes compared to patients given standard induction. A comparison of the quality of life of patients, as manifested by the percentage of days spent in hospital, frequency of transfusion support, and number of outpatient visits, will be presented. Death due to resistant disease remains the major problem for older patients with AML

Disclosures:

Off Label Use: arsenic trioxide to be used to enhance the effects of low-dose ara-C as part of a clinical trial.
Prevalence of Anti-Heparin Platelet Factor 4 Antibodies in Patients with Disseminated Intravascular Coagulation.
Authors: Fareed Jawed , Zhu He , Cunanan Josephine , Jeske Walter , Hoppensteadt Debra , Arif Hussain , Harry Messmore , Walenga Jeanine M.
Published: October 2019

Abstract 2094

Poster Board II-71

Disseminated intravascular coagulation (DIC) represents a complex syndrome with multiple pathophysiologic components. Most patients with DIC exhibit thrombocytopenic responses due to endogenous consumption of platelets. A systematic study on the prevalence on anti-heparin platelet factor 4 (AHPF4) antibodies and HIT syndrome in DIC patients has not been presented. To determine the prevalence of AHPF4 antibodies in patients with suspected DIC syndrome a total of 25 plasma samples were retrospectively analyzed utilizing the two commercially available methods (GTI, Brookfield, WI and Hyphen Biomedical, Paris, France). Out of 25 patients, 24 samples were positive for the AHPF4 antibody in the GTI method (OD>0.400), whereas only 16 were positive in the Hyphen Biomedical assay (OD>0.500). Interestingly, only 9 samples were positive in both of these assays. None of the positive samples in either the GTI or the Hyphen assay exhibited a positive 14C serotonin response. Additional analysis of these samples revealed that only 8 of these patients were previously exposed to heparin. Only 4 of the baseline samples were found to contain low levels of heparin as measured by anti-Xa method (< 0.2 U/ml). Additional analysis of these samples revealed the presence of platelet activation products such as platelet factor 4 (PF4), selectin and p-selectin. These studies suggest that circulating AHPF4 antibodies are non-functional and do not produce any thrombocytopenic responses. The elevated circulating PF4 levels and other cytokines may be contributory to the generation of these antibodies in the DIC patients.

Disclosures:

No relevant conflicts of interest to declare.
Persistant Inhibition of Thrombin Generation After Intravenous Administration of Enoxaparin in Primates.
Authors: Litinas Evangelos , Gray Angel , Sadeghi Nasir , Cunanan Josephine , Hoppensteadt Debra , Fareed Jawed
Published: October 2019

Abstract 2095

Poster Board II-72

The biologic half life (T12) of low molecular weight heparin (LMWH) is usually measured in terms of the circulating anti-Xa levels. Enoxaparin represents an unique LMWH whose biologic T12 is relatively longer than most LMWHs. Moreover, it is known that the antithrombotic effects of this agent last longer in comparison to the measurable circulating anti-Xa levels. Therefore besides the anti-Xa activity, additional non-measurable biologic effects are contributory to the clinical effects of this agent. Plasma based thrombin generation assays have recently become available to assess the effects of LMWHs such as enoxaparin. In these assays blood plasma samples are activated using different activators and the generated thrombin inhibition is measured. To measure the time course of thrombin generation inhibitory activity after an IV bolus dose of 0.5 mg/kg of enoxaparin into groups of primates (n=6-8), a commercially available thrombin generation method was employed (Technoclone, Vienna, Austria/DiaPharma, West Chester,OH). Blood samples were drawn from each of the primates injected at varying time points for up to 28 hours. A thromboplastin/phospholipids based reagent was used to generate thrombin and the results were recorded in terms of nm of thrombin formed. The baseline values ranged from 500-900 nm (710±60 nm), although a complete inhibition of thrombin generation was noted at 1 hour (24±8 nm), a slow and gradual reduction in the thrombin generation inhibition was noted with a T12 of 9 hours. Even at 28 hours after the administration of enoxaparin, sustained inhibition of thrombin generation was noted (30-50%). Interestingly, the circulating anti-Xa and anti-IIa activity gradually diminished to an almost non-detectable level at 6 hours. These studies suggest that enoxaparin produces antithrombotic actions by multiple mechanisms. Furthermore thrombin generation methods in plasma samples may provide a more sensitive assay for the monitoring of the effect of LMWH.

Disclosures:

No relevant conflicts of interest to declare.
Anticoagulation does Not Prevent Venous Thromboembolism Following IVC Filter Placement: A Retrospective Study of 702 Patients.
Authors: Narayan Anand , Streiff Michael B. , Hong Kelvin , Lee Adrea , Kim Hyun
Published: October 2019

Abstract 2104

Poster Board II-81

Purpose:

Inferior vena cava filters (IVCF) are extensively used in the United States to treat venous thromboembolism (VTE). Although IVCF prevent pulmonary embolism (PE), IVCF are associated with an increased incidence of deep vein thrombosis (DVT) and IVC thrombosis (IVCT). It remains unclear whether anticoagulation (AC) could reduce thrombotic events post-filter placement. The purpose of this study was to examine the impact of AC on clinical outcomes post-IVCF placement

Materials and Methods:

After institutional review board approval was obtained, consecutive patients who received an IVCF at the Johns Hopkins Hospital were identified using Current Procedural Terminology (CPT) codes. Demographic and clinical data were retrieved from the institutional electronic medical record (EMR). Clinical events including objectively-documented VTE were confirmed by an independent EPR review by two investigators. Clinical outcomes with and without AC were compared using non-parametric and parametric statistics. Marginal structural models were used to model the impact of anticoagulation on VTE

Results:

Between January 1, 2002 and December 31, 2006, 702 patients had an IVCF placed at the Johns Hopkins Hospital. AC was used in 276 patients(39.4%) post-filter placement. 46.8% of patients were female and 60.1% were white and these parameters did not differ based upon AC status (p > 0.45). Patients on AC were younger than patients not on AC (54.9 years versus 59.0 years, p = 0.0025). The most common reason for IVCF placement in both groups was a contraindication to AC. Patients subsequently treated with AC were equally likely to present with DVT (p = 0.852) but were more likely to present with PE (p < 0.001) and IVC thrombus (p = 0.043). Retrievable filter use was more common in patients who were treated with AC. (p = 0.002). The mean duration of follow up was 434 days (range 1 - 2638 days). Follow up was longer for patients on AC than patients not on AC (576 versus 341 days, p < 0.001). All-cause mortality was lower for patients treated with AC (37.7% versus 56.0%, p <0.001). Post-filter placement, VTE occurred in more patients on AC than off AC (63/235, 26.8% versus 54/378, 14.1%, p<0.001). DVT (20.3% versus 11.1%, p = 0.001), PE (7.3% versus 3.5%, p=0.027) and IVCT (6.9% versus 2.1%, p=0.002) were more common in patients who were treated with AC.

Conclusions:

In a large retrospective single center cohort study, AC use was associated with a reduced all cause mortality but an increased frequency of VTE in patients after IVCF placement. These data suggest AC may not protect patients from thrombotic complications associated with IVCF placement and warrant prospective confirmation. IVCF should be reserved for patients who have acute VTE and a contraindication to anticoagulation.

Disclosures:

No relevant conflicts of interest to declare.
Feedback Activation of Factor XI by Thrombin Is Essential for Hemostasis In Vivo.
Authors: Spronk Henri M. H. , Wilhelm Sabine , Van Oerle Rene , Knetsch Menno L. , Gailani David , Pawlinski Rafal , Mackman Nigel , Cate Hugo ten , Renné Thomas
Published: October 2019

Abstract 2127

Poster Board II-102

Background: The revised model of coagulation proposes that factor XI (FXI) can be activated by thrombin, which is generated upon activation of the tissue factor (TF) pathway. This concept, however, has not been tested in vivo. A recent study questioned the existence of this feedback loop and suggested that factor XII (FXII) is the sole activator of FXI. Here, we analyze the feedback activation of FXI in plasma and in genetically altered mice. Methods and results: Fluorescence-based assays indicated that particle-bound thrombin caused thrombin generation in plasma both in the absence of TF and in the presence of active site inhibited factor VIIa. Thrombin failed to activate FXII and thrombin generation was almost completely abolished by an anti-FXIa antibody and in FXI-deficient plasma. Surface bound thrombin induced complex formation of FXI, with its major inhibitor C1 inhibitor, even in FXII-deficient plasma in a time and dose dependent manner. To determine if thrombin-driven FXI activation is important for hemostasis in vivo we used TF deficient mice (low TF), which have severely reduced thrombin formation. Low TF mice were crossed with mice deficient in one of the intrinsic pathway proteases FXII, FXI, or FIX. Double deficiency in TF and either FIX or FXI resulted in the intrauterine death of embryos due to hemorrhage. In contrast low TF/FXII-null mice were viable and the bleeding phenotype was unchanged from low TF animals. Conclusions: Surface-bound thrombin, a model for fibrin clot-protected thrombin, generates thrombin in a FXI dependent manner, independently from FXII. In addition to corroborating an amplifying role of FXI in thrombin generation, we provide the first evidence that at low TF levels FXI is essential in generating a sufficient ambient level of thrombin to permit embryonic development.

Disclosures:

No relevant conflicts of interest to declare.
Clinical Impact and Resource Utilization After Stem Cell Mobilization Failure in Patients with Multiple Myeloma and Lymphoma.
Authors: Gertz Morie A , Wolf Robert , Micallef Ivana N. , Gastineau Dennis A.
Published: October 2019

Abstract 2142

Poster Board II-119

High-dose chemotherapy in conjunction with autologous SCT is the preferred treatment of relapsed Hodgkin disease and non-Hodgkin lymphoma and newly diagnosed multiple myeloma. Failure to achieve optimal stem cell mobilization results in multiple subsequent attempts, which consumes large amounts of growth factors and potentially requires antibiotics and transfusions. We retrospectively reviewed the natural history of stem cell mobilization attempts at our institution from 2001 through 2007 to determine the frequency of suboptimal mobilization in patients with hematologic malignancy undergoing autologous transplant and analyzed the subsequent resource utilization in patients with initially failed attempts. Of 1,775 patients undergoing mobilization during the study period, stem cell collection (defined by the number of CD34+ cells/kg) was “ optimal” (≥5×106) in 53%, “low” (≥2 to 5×106) in 25%,“ poor” (<2×106) in 10%, and “failed” (<10 CD34+ cells/mL) in 12%. In the 47% of collections that were less than optimal, increased resource consumption included increased use of growth factors and antibiotics, subsequent chemotherapy mobilization, increased transfusional support, more apheresis procedures, and more frequent hospitalization. Other costs often omitted include the need for hospitalization, which was seen in 5% to 11% of the patients in our study. Parenteral antibiotics were needed when fever developed in 7% of patients with Hodgkin disease, 4% with non-Hodgkin lymphoma, and 24% with multiple myeloma who underwent mobilization using a chemotherapy pulse. When stem cell mobilization was not immediately optimal, subsequent attempts to mobilize failed completely in 3 of 42 patients (7%) with Hodgkin disease (3% of the original Hodgkin disease cohort), 56 of 157 (36%) with multiple myeloma (6% of the original myeloma cohort), and 50 of 328 (15%) with non-Hodgkin lymphoma (7% of the original non-Hodgkin lymphoma cohort). These usually unappreciated costs of stem cell mobilization failure highlight the need for more effective mobilization strategies.

Disclosures:

Gertz: genzyme: Research Funding.
Mobilization of Allogeneic Peripheral Blood Stem Cells in Family Donors with Single-Dose Pegfilgrastim.
Authors: Vucinic Vladan , Basara Nadezda , Stiegler Runa , Bartsch Kristina , Kliem Constanze , Leiblein Sabine , Niederwieser Dietger
Published: October 2019

Abstract 2148

Poster Board II-125

Introduction:

The standard procedure for obtaining peripheral blood stem cells (PBSC) is donor mobilization with G-CSF. Pegfilgrastim is a covalently bound conjugate of filgrastim and monomethoxypolyethylene glycol with longer half-life elimination due to decreased plasma clearance and could represent an alternative approach for PBSC mobilization in healthy donors.

Design and Methods:

From July 2006 till August 2009 28 related healthy donors (50% male, 50% female) were treated with single dose of 12 mg pegfilgrastim for mobilization of allogeneic PBSC. The harvests were performed as large-volume, continuous-flow collections using a Cobe Spectra blood cell separator on day 4 and if necessary on day 5 of the mobilization regimen. In case of inadequate CD34+ counts (less than 4×106/kg body weight of recipient on day 5), stimulation was continued with filgrastim. In addition, the serum level of filgrastim was determined twice daily.

Results:

We present the results of 27 donors (the results of the 28th donor are still pending). In all 27 cases the harvests were successful. In 22 out of 27 donors (82%) only a single apheresis was needed to reach the target. Two of the donors required additional treatment with non-pegylated filgrastim.

The maximal concentration of circulating CD34+ cells was achieved on day 4 (median 74.3/μl; range 24.6-136.6). The median yield of CD34+ cells was 5.9×106/kg of the recipients body weight (range 3-14.5), and the median CD3+ count was 9.1×108/kg of the recipient body weight (range 1.4-6.2). Serum filgrastim level peak was on day 2 of the mobilization regimen with a median level of 226 ng/ml (range 35 to 1123 ng/ml), thus preceding the increase of CD34+ cells in blood. The main adverse events were WHO grade 1 and included headaches, bone pain and transient elevations of alkaline phosphatase and lactate dehydrogenase.

Conclusion:

PBSC mobilization with a single dose of pegfilgrastim is feasible for healthy donors. The graft composition was comparable to that obtained with the conventional regimen of short-term G-CSF. Long-term follow-up of healthy donors treated with pegfilgrastim should be further investigated.

Disclosures:

No relevant conflicts of interest to declare.
The Expression Pattern of TCR Vγ I∼III Subfamilies in GVHD Patients After Allogenic Hematopoietic Stem Cell Transplantation.
Authors: Wu Xiuli , Liu Can , Zhang Yu , Fan Zhiping , Liu Qifa
Published: October 2019

Abstract 2219

Poster Board II-196

Objective

The γΔ+ T cells can act as a vast functional setting of immune defense against pathogenic invaders in chronic inflammatory reactions, as well as in modulating systemic and organ-specific autoimmune diseases. Recently, it was reported that γΔ+ T cells might play an important role in regulation of graft versus host disease (GVHD), mediation of graft versus leukemia effect, anti-virus infection, anti-cancer effect and so on. But the frequency of T cell receptor (TCR) Vγ repertoire and the expression patterns of TCR Vγ subfamilies in GVHD remain unknown. To further study on the characteristics of TCR Vγ subfamilies in GVHD, we investigated the frequency of TCR Vγ repertoire and the expression of TCR Vγ I∼III subfamilies genes in the patients with GVHD after allogenic hematopoietic stem cell transplantation (allo-HSCT).

Methods

The expression and cloanlity analysis of TCR Vγ repertoire was detected in peripheral blood mononuclear cells (PBMNCs) from 25 patients with GVHD by RT-PCR and genescan technique. The TCR Vγ I∼III genes expression levels of PBMNCs from patients with GVHD were detected using the real-time fluorescence quantitative polymerase chain reaction with SYBR Green I technique and relative quantification method. Twelve healthy individuals served as normal controls.

Results

The RT-PCR results showed that in GVHD patients, the expression frequency of TCR Vγ I was 88.0% (22/25), TCR Vγ II was 72.0% (18/25), and TCR Vγ III was 96.0% (24/25). All of the three TCR Vγ subfamilies could be detected in PBMNCs from the normal controls. TCR Vγ repertoires with polyclonal pattern were identified in normal controls. However, the skew expression pattern of TCR Vγ repertoire could be detected in patients with GVHD even more than 4 year after allo-HSCT. Oligoclonal or monoclonal expanded T cells were identified in TCR Vγ I∼III subfamilies in GVHD patients. The expression level of TCR Vγ II gene in the PBMNCs from patients with GVHD was significant lower than the normal controls (P<0.05). The pattern of TCR Vγ gene expression levels in GVHD was TCR Vγ I> TCR Vγ III> TCR Vγ II, however, the expression pattern in normal controls was TCR Vγ II> TCR Vγ I > TCR Vγ III.

Conclusions

The expression patterns of TCR Vγ I∼III subfamilies were changed in GVHD. The low expression of TCR Vγ II subfamily might be related with the pathogenesis of GVHD.

Disclosures:

No relevant conflicts of interest to declare.
Low Sensitivity of the (1-3)-Beta-D-Glucan Assay for Diagnosis of Invasive Aspergillosis in Hematologic Malignancy Patients.
Authors: Yonezumi Masakatsu , Kurosawa Mitsutoshi , Fukuhara Takashi
Published: October 2019

Abstract 2242

Poster Board II-219

Invasive aspergillosis (IA) is a common opportunistic infection in hematologic malignancy patients. The diagnosis of IA is difficult and the outcome is poor despite recent progress in treatment. The detection of galactomannan antigen is useful in diagnosis of IA and is defined as one of EORTC/MSG diagnostic criteria. The (1-3)-beta-D-glucan assay is also used in diagnosis of invasive fungal disease, but the sensitivity and specificity of these tests for IA are variable in recent reports. To evaluate the correlation of them, we analyzed retrospectively the results of these tests in IA cases of hematologic malignancy patients.

From January 2006 to December 2008, we reviewed 2914 hematologic malignancy patients (AML=492, ALL=198, MDS=284, NHL=1373, HL=92, MM=375) retrospectively who were recieved chemotherapy or stem cell transplantation(SCT). 607 cases received SCT are included in this study. We diagnosed IA according to the EORTC/MSG criteria, and extracted the data of galactomannan antigen and (1-3)-beta-D-glucan assay examined at diagnosis of each case.

43 cases(1.5%) are diagnosed as invasive fungal disease (Aspergillus=24, Candida=9, Mucor=6, Trichosporon=2, Cryptococcus=1, Geotrichum=1). 23 IA cases are analyzed (proven: 3 cases, probable: 20 cases). All cases are positive for galactomannan antigen test(range, 0.5-5.0< ODI, cut-off value:0.5), but only 9 cases for (1-3)-beta-D-glucan assay (range, 24.5-313pg/ml, cut-off value:20). In the three cases of proven IA, only one case are positive for this assay. There is no difference in patient characteristic and prognosis between the positive and negative group.

We conclude that the (1-3)-beta-D-glucan assay is not useful tool for diagnosis of invasive aspergillosis.

Disclosures:

No relevant conflicts of interest to declare.
Prospective Evaluation of Proteomic Screening with An Agvhd-Specific Proteomic Pattern MS-17.
Authors: Mischak-Weissinger Eva M. , Metzger Jochen , Krons Annika , Kontsendorn Julia , Krauter Jürgen , Stadler Michael , Mischak Harald , Ganser Arnold
Published: October 2019

Abstract 2246

Poster Board II-223

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only curative treatment for many hematologic malignancies or hematopoietic dysfunction syndromes in adults, but the application is still limited due to major complications, such as severe graft versus host disease (GvHD) and infectious complications. Diagnosis GvHD is based on clinical features and biopsies, a non-invasive, unbiased laboratory test using proteomics was published previously and evaluated in a multicenter setting (Weissinger et al., 2007). In order to maintain good quality data of the proteomic pattern data and due to the fact that the electrospray ionization time of flight mass spectrometer (ESI-TOF) from ABI (mariner) is no longer produced, we applied a more sensitive mass spectrometer (MS; ESI-TOF/Bruker). In order to validate the quality of the data produced with the Bruker, ESI-TOF was used since December 2007 in parallel to the mariner. Our first and previously published “aGvHD-specific pattern” (Weissinger et al., 2007) was used to evaluate and improve the pattern with the more sensitive decreased (6) or increased (11) signal intensity in patients with GvHD grade II to IV. Patients post HSCT and patients with GvHD grade I have the same pattern. In addition, the MS-17-pattern yielded at least comparable if not superior results to the previous one yielding sensitivities around 95% and specificity about 80%.

To date the proteomic pattern specific for aGvHD MS17 was evaluated blindly on 400 samples collected from about 90 patients undergoing allo-HSCT at MHH since Dec. 2007.

The peptide pattern MS-17 consists of 17 peptides - either absent/decreased (6) or present /increased (11) in aGvHD grade II to IV when compared to patients with clinical aGvHD grade I or without GvHD. Prospective and blinded evaluation of the patients included in this parallel diagnostic study revealed the correct classification of patients developing aGvHD about 7 days prior to the development of clinical signs and symptoms for aGVHD with a sensitivity and specificity of about 85%. Sequencing 3 of the 17 markers yielded the following results:

Peptide No 5: Albumine fragment (N-terminus); Peptide No 7: ψ2 microglobulin; Peptide No 10: fragment of CD99 (MIC2; a single-chain type-1 glycoprotein). CD99 and β-2 microglobulin are particulary interesting because of their involvement in immune responses, both being expressed on leukocytes and CD 99 especially on thymocytes with involvement in apoptosis of double positive T-cells and binding cyclosporin A. Data on the pattern, signal intensity (3 dimension, mass and charge are shown in Figure 1)

Disclosures:

Metzger: mosaiques-diagnostics GmbH: Employment. Krons:mosaiques-diagnostics GmbH: Employment. Mischak:mosaiques-diagnostics GmbH: Patents & Royalties, coowner and founder of mosaiques-diagnostics.