bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Metabolic SYNDROME and the RISK of Venous Thrombosis: RESULTS of AN Individual LEVEL Patient Meta-ANALYSIS
Authors: Dentali Francesco , Ay Cihan , Jang Moon , di Minno Matteo , Pabinger Ingrid , Oh Doyeun , di Minno Giovanni , Squizzato Alessandro , Grandi Anna Maria , Ageno Walter 
Published: October 2019

Abstract
Abstract 3177

Background:
The metabolic syndrome (MS) is a cluster of interrelated risk factors that identify patients at increased risk of cardiovascular events. Recent studies also suggested an association between MS and venous thromboembolism (VTE). However, the role of the individual features of MS and whether MS and its features are more important than obesity alone to predict VTE remain to be established.

Methods:
We performed an individual patient level meta-analysis of case-control studies comparing the prevalence of MS in patients with unprovoked VTE and in controls. MEDLINE, EMBASE databases, and abstract books were searched up to January 2010. Odds ratios (OR) and 95% confidence intervals of pooled results were calculated. The influence of individual variables (age, sex, BMI and MS) on the likelihood of VTE was compared using logistic regression analysis. Multivariate analysis was subsequently performed including the individual components of MS in the place of MS. The impact of increasing number of individual components of MS on the risk of VTE was investigated.

Results:
Four studies were identified and analyzed, for a total of 1332 patients (479 cases and 833 controls). Mean age was 53.3 and 52.7, respectively (p=n.s.), 49.5% cases and 42.4% controls were males (p=0.0003), 38.8% and 30.0% were obese (p=0.0001). MS was significantly associated with VTE (OR 1.97, 1.57–2.47), and the association linearly increased with the number of MS features (p for trend <0.001). At multivariate analysis, MS but not obesity remained associated with VTE (OR 1.92, 1.50–2.46 and 1.14, 0.88–1.47, respectively). All individual features of MS, but HDL cholesterol, were independently associated with VTE.

Conclusions:
The results of this meta-analysis confirm the association between MS and VTE and suggest that MS (and visceral obesity defined by increased waist circumference) could be a more important predictor of VTE than obesity defined by BMI.

Disclosures:
No relevant conflicts of interest to declare.
Differential Pathogenesis of Bernard-Soulier Syndrome-Associated Mutations In the Platelet Glycoprotein Ibβ Ectodomain
Authors: Yang Wenjun , McEwan P.A , Mo Xi , Emsley Jonas , Li Renhao 
Published: October 2019

Abstract
Abstract 3202
Eight missense mutations in the ectodomain of glycoprotein (GP)Ibβ have been identified in patients with Bernard-Soulier syndrome (BSS) that is characterized by the deficiency of functional GPIb-IX complex on the platelet surface, clearly highlighting the importance of GPIbβ ectodomain in assembly of the GPIb-IX complex. To understand the molecular pathogenesis of these mutations, we have characterized their effects on the expression, secretion, folding of the isolated GPIbβ ectodomain as well as its interaction with GPIX ectodomain in the context of full-length complex. Each of the 8 mutations — C5Y, R17C, P29L, N64T, P74R, Y88C, P96S, and A108P — was constructed into genes encoding HA-tagged GPIbβ ectodomain or full-length GPIbβ subunit, and the mutant gene transfected transiently, along with GPIba and GPIX genes if desired, into Chinese hamster ovary (CHO) cells. Flow cytometry and Western blot analysis indicated that while all 8 mutations impeded formation of the disulfide bonds between GPIba and GPIbβ and significantly decreased the surface expression level of GPIb-IX complex comparing to the wild-type, the extent of disruption varies with each mutation. Further characterization in the context of isolated GPIbβ ectodomain revealed that the majority of 8 mutations — C5Y, R17C, P29L, N64T, Y88C, P96S — are detrimental to proper folding of the GPIbβ ectodomain, resulting in secretion defects and/or domain misfolding. In contrast, two mutations, P74R and A108P, preserved structural integrity of the GPIbβ ectodomain since the mutant ectodomains exhibited wild-type-like secretion levels and formed no inter-molecular disulfide bonds. However, neither of the two mutations, in the context of full-length GPIbβ, were able to support surface expression of GPIX in transfected CHO cells as the wild-type, indicating that P74R and A108P disrupt the interaction between GPIbβ and GPIX ectodomains. Thus, our results demonstrated although all 8 BSS mutations in GPIbβ share the same phenotype, they impair expression of the GPIb-IX complex by two different mechanisms — disrupting folding of the GPIbβ ectodomain or disrupting interactions between GPIb-IX subunits. Furthermore, our results suggest that Pro74 and Ala108 may be located in the interfacial region between GPIbβ and GPIX ectodomains, helping to shed light on the structure of GPIb-IX complex.

Disclosures:
No relevant conflicts of interest to declare.
A Reassessment of the Red Blood Cell Folate Assay
Authors: Hoyer James , Oliveira Jennifer , Baumann Nikola , Saenger Amy 
Published: October 2019

Abstract
Abstract 3209

Background:
The red blood cell folate (RCF) assay has historically been recommended as a more reliable indicator of tissue folate stores compared to the serum folate (SF) assay, as it is not affected by recent ingestion of food. However, the RCF assay suffers from inherent problems with imprecision and accuracy, which are not encountered with SF measurements. Furthermore, following the advent of required folic acid supplementation of many foods by the Food and Drug Administration (FDA) in 1992, folate deficiency is increasingly rare. Very few studies have looked at the value of the RCF versus the SF. We undertook a 10 year retrospective analysis of RCF and SF results to determine the clinical utility of RCF beyond that of SF.

Methods:
We retrieved all RCF and SF results from the laboratory information system at Mayo Clinic (Rochester, MN) ordered on inpatients and outpatients between 1999–2009. Data for patients who had concurrent orders for SF and RCF were analyzed and chart reviews were conducted on those patients with normal SF but low RCF. Abnormal values were defined by the National Health and Nutrition Examination Surveys (NHANES)/Center for Disease Control (CDC) criteria for folate deficiency (SF< 3.0 ng/ml, RCF < 140 ng/ml).

Results:
A total of 152,166 SF and 15,708 RCF were performed over the decade of the study. The prevalence of folate deficiency using only SF values was 0.39% and 0.27% using only RCF values. There were 1082 patients in which SFA and RCFA were ordered concurrently (Table 1).
Only 1 patient (0.09%) had both abnormal SF and RCF. Chart reviews of the 4 patients with a normal SF but low RCF were as follows: 1) a 6 year old (yo). male with known folic acid transporter deficiency treated with Leucovorin. 2) a 58 yo male with history of gout, hypertension, psoriasis, and hyperlipidemia with normal hemoglobin (Hb) and MCV. 3) a 65 yo male with chronic diarrhea and suspected alcohol abuse; slight macrocytosis (MCV=100.3 fL) but normal Hb. 4) a 51 yo male with multifactorial gait disorder and alcohol abuse. There was a previous history of vitamin B12 deficiency but B12 levels were normal at this time. The CBC was notable for macrocytosis (MCV=115.1 fL) without anemia. Only in patient 4 did the RCF value result in the institution of folic acid supplementation.

Conclusions:
The RCF provides no additional information beyond that provided by the SF in virtually all situations. Thus SF alone is sufficient for assessment of folate stores. However, there is no evidence to support routine ordering of either SF or RCF, as true folate deficiency in the current era of FDA mandated folic acid supplementation is exceedingly rare.

Disclosures:
No relevant conflicts of interest to declare.
Connectivity Mapping Identifies HDAC Inhibitors as Suitable Candidates for the Treatment of t(4;11)-Positive Acute Lymphoblastic Leukemia In Infants
Authors: Stumpel Dominique JPM , Schneider Pauline , Seslija Lidija , Osaki Hikari , Williams Owen , Pieters Rob , Stam Ronald 
Published: October 2019

Abstract
Abstract 3222
To date, MLL-rearranged infant Acute Lymphoblastic Leukemia (ALL) remains the most aggressive type of childhood leukemia characterized by a high rate of early relapses and a grim prognosis. This type of leukemia arises from chromosomal translocations involving the Mixed Lineage Leukemia (MLL) gene. The genesis of such translocations seems to be initiated in utero. Hence, MLL-rearranged ALL is typically diagnosed in infants at or shortly after birth. The most common MLL translocation among infant ALL patients, occurring in about 50% of the cases, is t(4;11) generating the oncogenic fusion product MLL-AF4.
MLL-rearranged ALL is distinguishable from other ALL subtypes by unique gene-expression profiles. While inappropriate gene activation seems to be largely driven by specific histone modifications, we recently showed that gene inactivation in MLL-rearranged infant ALL can be explained by aberrant promoter hypermethylation. Focusing on genome-wide DNA methylation, we here uncovered that MLL-rearranged infant ALL is characterized by the activation of particular set of (proto-onco)genes as a result of abnormal promoter hypomethylation.
In search for therapeutic agents capable of targeting these potential cancer-promoting genes, we applied connectivity mapping on a gene expression signature based on the genes most significantly hypomethylated in t(4;11)-positive infant ALL as compared with healthy bone marrows. Connectivity map analyses revealed that histone deacetylase (HDAC) inhibitors represent the most suitable compounds to reverse this gene signature. We show that six different HDAC inhibitors effectively induce leukemic cell death in primary t(4;11)-positive infant ALL cells in vitro. These cytotoxic responses were accompanied by down-regulation of MYC, SET, RUNX1 and RAN, and were preceded by degradation of the oncogenic MLL-AF4 fusion product.
Our data shows that DNA methylation profiles allow the identification hypomethylated proto-oncogenes, and underlines the essential role for epigenetic de-regulation in MLL-rearranged ALL. Furthermore, we show for the first time that connectivity mapping can indirectly be applied on DNA methylation patterns, providing a rationale for HDAC inhibition in t(4;11)-positive leukemias. Given the presented potential of HDAC inhibitors to target important proto-oncogenes including the leukemia-driving MLL fusion in vitro, these agents should urgently be tested in in vivo models and subsequent clinical trials.

Disclosures:
No relevant conflicts of interest to declare.
Adolescent and Young Adult Patients Treated with Modified Augmented Berlin-Frankfurt-Muenster Therapy
Authors: Rytting Michael E. , Kantarjian Hagop M. , Thomas Deborah A , Jabbour Elias , Franklin Anna , Ravandi Farhad , Faderl Stefan , Garris Rebecca , Kadia Tapan , Schroeder Kurt , O'Brien Susan 
Published: October 2019

Abstract
Abstract 3250
Pediatric protocols for acute lymphoblastic leukemia (ALL) are currently employed by many groups to treat adolescents and young adults (AYA) with ALL. Adults up to age 55 are presently enrolled in such treatment regimens, and investigators have reported excellent results in these young adult patients (pts). Augmented Berlin-Frankfurt-Muenster therapy has been shown to be effective therapy for adolescents with ALL. To evaluate the efficacy and toxicity of this therapy in young adults, we designed a protocol of modified augmented Berlin-Frankfurt-Muenster (ABFM) therapy for patients with ALL from age 12 to 40. 70 pts have been enrolled on protocol and are evaluable for toxicity. 60 pts with de novo Philadelphia chromosome negative ALL have completed at least 29 days of therapy (induction) on protocol. They have the following characteristics: 52 (87%) pts have pre-B ALL and 8 (13%) have T-ALL. The median age is 20 (mean=22; range=13-39). The median presenting WBC=5.2 (mean=32; range= 0.4–494). 58/60 (97%) pts have achieved a remission. There have been no induction deaths. 49(82%) pts have attained remission by 15 days of induction, while 11 (18%) have been slow responders. 5/60 (8%) pts have required an extension of induction by 2 weeks. At day 29 of therapy, 38 (63%) pts had negative minimal residual disease (MRD) by flow cytometry, 15 (25%) patients were positive for MRD, 7 were suspicious or not available. By day 84 of therapy, 46 (77%) pts were negative for MRD and 9 (15%) were positive. Currently, there have been 10 relapses and 9 deaths. Toxicities in the entire group include severe asparaginase allergy in 15 (21%) pts, thrombus formation in 15 (21%) pts, hyperbilirubinemia grade III-IV in 19 (27%) pts, ALT/AST grade III-IV in 20 (28%) pts, CNS stroke-like symptoms in 6 (8%) pts, and avascular necrosis in 6 (8%) pts. Hepatic toxicity has resolved completely within two weeks in almost all pts as has the CNS toxicity. Grade III-IV hepatic toxicity have been transient. For pts 25 years of age and younger (n=25), the overall survival (OS) and disease free survival (DFS) at 2 years are 91% and 85% respectively. For pts > 25 years of age (n=15), the OS and DFS at 2 years are 55% and 61% respectively. This difference is statistically significant for the two groups; p=0.04 for DFS and p=0.004 for OS. Continued enrollment is anticipated to further evaluate the survival differences between these two patient groups.

Disclosures:
No relevant conflicts of interest to declare.
Leukemia-Specific Ligands Against Childhood Acute Lymphoblastic leukemia
Authors: Satake Noriko , Sarangi Susmita , Chang Astra , McLaughlin Bridget , Zhou Ping , Kenny Elaina , Kraynov Liliya , Arnott Sarah , McGee Jeannine , Nolta Jan A. , Lam Kit 
Published: October 2019

Abstract
Abstract 3269
The one-bead-one-compound (OBOC) combinatorial library method was invented by Kit Lam to identify cancer cell surface targeting ligands (Peng L et al. Nat. Chem. Biol. 2006, Aina OH et al., Mol. Pharm. 2007). Using this method, LLP2A, a ligand against activated a4b1 integrin, was discovered that targets malignant lymphoma with high affinity and specificity (Peng L et al., Mol Cancer Ther. 2008). We tested whether childhood acute lymphoblastic leukemia (ALL) cells expressed activated a4b1 integrin and bound to LLP2A using primary leukemia cells and leukemia cells engrafted in NOD/SCID/IL2Rg null (NSG) mice. Expression of activated a4b1 integrin was observed in three primary leukemia samples (1 T-ALL, 1 precursor B (preB) ALL, and 1 relapsed preB ALL) by the rainbow beads (color-coded polystyrene bead mixture displaying unique ligands against known receptors such as a4b1, a3b1, avb3, a5b1 integrins (Luo J et al., J. Comb. Chem. 2008). To quantify activated a4b1 integrin expression, primary leukemia cells were analyzed by flow cytometry using biotinylated LLP2A/streptavidin-PE. Nine samples (7 preB ALL and 2 relapsed preB ALL) were analyzed. All samples, except for one relapsed preB ALL sample, showed expression of activated a4b1 integrin at different levels. In order to determine the specificity of activated a4b1 integrin expression, hematopoietic stem cells from three normal bone marrow (BM) samples were analyzed and showed very low levels of activated a4b1 integrin expression. Furthermore, we have identified 32 analogues of LLP2A using three fresh preB ALL samples to screen two LLP2A-focused libraries. Peptide microarrays using a polystyrene slide coated with neutravidin and biotinylated ligands will be prepared with these analogues. We will determine the binding affinity and specificity of these analogues to a series of primary ALL cells. Binding specificity to leukemia cells will be determined by excluding ligands which bind to normal hematopoietic progenitor (CD34) cells. The property of the selected ligands will be tested in vivo using NSG mice engrafted with primary ALL cells. Updated results with these new ligands will be presented at the meeting.

Disclosures:
No relevant conflicts of interest to declare.
Development of Impaired Cytochrome C Oxidase Activity In Apheresis Platelets During Storage
Authors: Diab Yaser A. , Thomas Adia , Luban Naomi L.C. , Wong Edward , Wagner Stephen J. , Moroff Gary , Levy Richard J. 
Published: October 2019

Abstract
Abstract 3347

Background:
With current storage requirements, the shelf life of platelet (PLT) products is largely limited by the development of deleterious in vitro changes associated with overall reduction in therapeutic efficacy collectively known as the “Platelet Storage Lesion” (PSL). PSL is characterized by a number of biochemical changes including lactate accumulation, bicarbonate depletion and a fall in pH. We hypothesize that these changes reflect a state of impaired oxidative phosphorylation associated with increased reliance on anaerobic glycolysis that evolves during PLT storage. In this study we evaluated the function and expression of “Cytochrome C Oxidase” (COX), a key mitochondrial enzyme in oxidative phosphorylation, with relation to several in vitro markers of PSL. The studies were performed in apheresis PLT stored for up to 7 days under standard blood bank conditions.

Methods:
Apheresis PLT concentrates were collected in 100% plasma using a Trima Cell Separator (CaridianBCT, Lakewood CO) to provide products with at least 3 × 1011 PLT. All products were collected in Trima® storage bags and were stored in a flatbed reciprocal agitator at 22 ± 2°C for 7 days. Multiple standard in vitro assays were performed on Days 0 (baseline measurement), 2, 4 and 7 of storage including PLT count, mean PLT volume, pH, pO2, pCO2, bicarbonate, lactate & glucose levels, aggregation and ATP release studies (ADP/Collagen), soluble CD40 ligand levels (supernatant) and total intracellular PLT ATP content. In addition, steady state COX kinetics and protein immunoblotting for COX subunits I and IV, were performed using isolated PLT mitochondria from simultaneously collected samples. Data are reported as mean ± 2 SD (n =10 experiments). One-way Analysis of Variance (ANOVA) and post-hoc Tukey's range test were used to compare data obtained at different time points. Differences were considered statistically significant only if the p value was <0.001 taking into the account that performing such large number of tests in the study increased the probability that a significant p value was incorrectly obtained by random chance.

Results:
PLT COX function declined significantly throughout storage (Table). Steady-state levels of COX I and IV remained essentially unchanged. This decrease in COX function paralleled progressive ATP depletion and time-dependent changes that were consistent with the development of the PSL.

Conclusion:
During storage of apheresis PLT for 7 days, COX function decreased progressively in association with ATP depletion indicating acquired impairment in oxidative phosphorylation. These findings suggest that bioenergetic failure is associated with PSL. Further studies are required to determine if mitochondrial dysfunction is a cause of PSL, and if it can be prevented or is amenable to therapeutic intervention.

Disclosures:
No relevant conflicts of interest to declare.
Interferon Gamma (IFNγ) Interferes with the Effects of Tyrosine Kinase Inhibitors (TKI) In CML Cells.
Authors: Held Stefanie AE , Bringmann Anita , Heine Annkristin , Kock Grethe , Körber Ruth-Miriam , Seltmann Nina Manon , Brossart Peter 
Published: October 2019

Abstract
Abstract 3393

Introduction:
Chronic myeloid leukemia (CML) is a myeloproliferative disease which resolves in the constitutive activity of the BCR-ABL protein. Since the introduction of imatinib as first line therapy for CML, the overall survival of patients could be significantly extended. However, mutations of the BCR-ABL protein and environmental effects mediated by adhesion molecules, cytokines and growth factors were shown to induce resistance to TKIs. For the development of immunotherapeutic approaches that combine TKIs with vaccination strategies or donor lymphocyte infusions it is important to understand the mechanisms of possible interactions and inhibition. Therefore, we thought to determine the role of activated T cells and to analyze a possible antiapoptotic effect of released IFNγ on the CML cells.

Methods:
CML cell lines and primary cells from patients with CML were treated with imatinib or nilotinib and incubated with activated (PMA/ionomycin) or resting T cells in transwell experiments. Induction of apoptosis was analyzed by flow cytometry. In addition, IFNγ was used together with TKIs and apoptotic cell death and proliferation was determined. Immunoblotting was performed to analyze the involved pathways.

Result:
Incubation of CML cells in transwell assays with activated but not resting T lymphocytes resulted in significant inhibition of the apoptosis induction by imatinib and nilotinib. To further determine the mechanisms mediating these effects, CML cells were treated with IFNγ in addition to the TKIs. In line with the results from previous experiments, IFNγ reduced the rate of cell death and proliferation inhibition mediated by imatinib and nilotinib. Interestingly, in contrast to IFNα, IFNγ inhibited the TKIs induced downregulation of MHC-class I molecules on CML cells. In line with these results, Western blot analysis of K-562 cells incubated with imatinib or nilotinib showed an increased caspase-3 activation and PARP cleavage as well as reduced down regulation of anti-apoptotic molecules such as xIAP as compared to IFNγ treated cells. Furthermore, we observed a diminished TKI induced downregulation of Jak-2 and STAT-5 phosphorylation as well as increased nuclear expression of RUNX-1 in cells treated with IFNγ.

Conclusion:
Our results demonstrate that IFNγ released by activated T-cells can interfere with the action of TKIs in CML patients and might have important implications in the development of immunotherapeutic approaches.

Disclosures:
No relevant conflicts of interest to declare.