bluuebunny/crossref_metadata_2025 huggingface dataset:
Caphosol Mouth Rinse Diminishes Oral Mucositis In Allo-HSCT Recipients.
Authors: Markiewicz Miroslaw , Monika Dzierzak Mietla , Zielinska Patrycja , Kruzel Tomasz , Czerw Tomasz , Kyrcz-Krzemien Slawomira
Published: October 2019

Abstract 3498

Introduction:

Oral mucositis is a complication of conditioning treatment that produces pain and morbidity in allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients. The rationale of this study was to evaluate the efficacy of a calcium phosphate mouth rinse (Caphosol) vs standard regimen in 40 adult patients undergoing allo-HSCT.

Patients and Methods:

40 patients treated with allo-HSCT (31 from unrelated donors, 9 from siblings) performed in Hematology and BMT center in Katowice in 2009 were randomized and stratified by the conditioning regimen (busulfan-, treosulfan- or TBI- based), type of transplant (unrelated or related) and age into two equal groups. Treatment group received Caphosol washes 4 times daily from first day of conditioning until reaching ANC 0.2 G/l. Control group received standard topical mouth care with salvia, antibacterial and antifungal solutions. During the trial patients subjectively assessed level of pain in mouth and in pharynx using 0–10 scale and swallowing problems using 0–5 scale. Mucositis was judged by experienced physician. Nonparametric Mann-Whitney U-tests were used for statistical analysis.

Results:

Average oral toxicity in WHO scale in Caphosol vs control group was 0.9 vs 1.8 (p=0.02), duration of mucositis was 3.2 vs 7.1 days (p=0.02). Total parenteral nutrition (TPN) due to mucosits was required in Caphosol vs control group in 0 vs 6 pts, average duration of TPN was 0 vs 1.9 days (p=0.009). Analgetics were required, respectively, in 3 vs 9 pts and analgesy lasted for 1.1 vs 3.4 days (p=0.047). Average subjective peak pain in mouth was 0.85 vs 1.75 (p=0.005) and in pharynx 1.95 vs 2.2 (NS) in Caphosol vs control group, average pain intensity was lower in Caphosol group throughout the whole period of mucositis. Intensity of swallowing problems tended to be lower in Caphosol group (NS). Acute GVHD was observed in 7 vs 9 pts in Caphosol vs control group and its average degree was 0.5 vs 0.9 (NS).

Conclusions:

Caphosol mouth rinse in the allo-HSCT recipients is associated with decrease of oral toxicity, lower peak pain due to mucositis and its shorter duration. In consequence, comfort of life is improved and the incidence of acute GVHD is reduced, as well as the requirement of TPN and analgetics.

Disclosures:

No relevant conflicts of interest to declare.
The Impact of Center Experience on Results of Reduced Intensity – Allogeneic Hematopoietic Stem Cell Transplantation. A Survey From the Acute Leukemia Working Party (ALWP) of the European Group for Blood and Marrow Transplantation (EBMT)
Authors: Giebel Sebastian , Labopin Myriam , Mohty Mohamad , Blaise Didier , Craddock Charles , Nagler Arnon , Frassoni Francesco , Sadus-Wojciechowska Maria , Rocha Vanderson
Published: October 2019

Abstract 3517

Allogeneic hematopoietic stem cell transplantation with reduced intensity conditioning (RIC-HSCT) is increasingly applied for the treatment of patients with acute myeloid leukemia. However, the procedure is heterogeneous with no standards based on randomized trials being elaborated so far. Hence, particular therapeutic decisions are in major part based on individual experience.

The goal of this study was to evaluate the impact of center experience on outcome of RIC-HSCT. Based on the registry of ALWP of the EBMT, we analyzed results of 1413 HLA-matched related (n=1058) or unrelated (n=355) transplantations performed in 203 European centers between 2001 and 2007. Only patients with AML in first complete remission were included. Median recipient age was 55 years (range, 18–77 y.). Centers were categorized by quintiles according to the number of RIC-HSCT procedures in a study period.

The 2 years probability of leukemia-free survival (LFS) after RIC-HSCT performed in centers with the lowest activity (1st quintile, ≤ 15 procedures/7 years) equaled 43% compared to 55% in the remaining ones (p<0.001). The incidence of non-relapse mortality (NRM) was 24% and 15%, respectively (p=0.004). In a multivariate model adjusted for other potential prognostic factors low RIC-HSCT activity was associated with decreased chance of LFS (HR=0.69, p<0.001) as well as increased risk of NRM (HR=1.69, p=0.001) and relapse (HR=1.37, p=0.01). No significant differences were found between centers belonging to the 2nd -5th quintile.

We conclude that center experience is a strong predictor of outcome and should be considered for future analyses evaluating results of RIC-HSCT.

Disclosures:

Off Label Use: Dasatinib as first line therapy in Ph ALL.
Critical Functions for Notch Dimerization In T Cell Transformation.
Authors: Liu Hudan , Chi Anthony , Arnett Kelly , Chiang Mark , Xu Lanwei , Shestova Olga , Wang Hongfang , Bhandoola Avinash , Aster Jon C , Blacklow Stephen C. , Pear Warren S.
Published: October 2019

Abstract 3647

Notch1 encodes an essential transmembrane receptor that is frequently mutated in T-ALL. Notch signaling regulates cell fate decisions, proliferation, survival and metabolism by activating transcription; yet the mechanism by which Notch selectively activates different transcriptional targets is poorly understood. After ligand-induced proteolysis, the intracellular part of Notch (ICN) generates signals by entering the nucleus and forming a transcriptional activation complex with the transcription factor CSL and the co-activator Mastermind (MAML). This complex can bind DNA as a monomer [1-3], however it can also dimerize on sites in which a pair of head-to-head CSL binding sites is properly spaced (so-called paired sites) [4, 5]. Whether Notch dimerization is physiologically important is unknown. Using T cell development and transformation as models, we now report that dimeric Notch transcriptional complexes are required for leukemic transformation but dispensable for T cell fate specification from a multipotential precursor. The varying requirements for Notch dimerization within the T cell lineage result from the differential sensitivity of specific Notch target genes. One particularly important dimerization-dependent target of Notch, required for both T cell maturation and leukemogenesis, is the proto-oncogene c-Myc, whereas other well-characterized target genes, such as Hey1, show no dimerization-dependence. These findings identify functionally important differences in the responsiveness among Notch target genes attributable to the formation of higher-order complexes. Our data suggest that it may be possible to develop a new class of Notch inhibitors, which selectively block outcomes that are dependent on Notch dimerization (e.g., leukemogenesis).

References:

1. Nam, Y., et al., J Biol Chem, 2003. 278: 21232.

2. Nam, Y., et al., Cell, 2006. 124: 973.

3. Wilson, J.J. and R.A. Kovall, Cell, 2006. 124: 985.

4. Bailey, A.M. and J.W. Posakony, Genes Dev, 1995. 9: 2609.

5. Nam, Y., et al., Proc Natl Acad of Sci USA, 2007. 104: 2103.

Disclosures:

No relevant conflicts of interest to declare.
Dysregulation of Inflammatory and Hemostatic Markers In Disseminated Intravascular Coagulation.
Authors: Hoppensteadt Debra , Cunanan Josephine , Sadeghi Nasiredin , Kaul Inder , Fareed Jawed
Published: October 2019

Abstract 3656

Disseminated intravascular coagulation (DIC) represents a complex polypathologic syndrome where marked alterations in the hemostatic system are manifested. As a result several inflammatory mediators are upregulated through multiple mechanisms. The upregulation of inflammatory mediators such as anaphylatoxin C5a (C5a), procalcitonin (PCT), interleukin 6 (IL-6), interleukin 10 (IL-10), myeloperoxidase (MPO) and c reactive protein (CRP), and circulating levels of hemostatic markers including protein C inhibitor (PCI), plasminogen activator inhibitor 1 (PAI-1), prothrombin fragment1.2 (F1.2), thrombin antithrombin complex (TAT), antithrombin (AT), activated protein C (APC) and protein C (Pr C) were evaluated in the baseline samples of an initial cohort of provisionally diagnosed DIC and sepsis patients enrolled in an ongoing clinical trial designed to assess the safety and efficacy of r-thrombomodulin (ART-123) (n=100). The control group consisted of normal male and female volunteers (n=30). Commercially available ELISA methods were used to measure the various mediators. Marked deviations in the circulating levels of these markers, as compared to controls, were noted as shown in the following table. Compared with normal volunteers, patients showed a 5–10 fold increase in the circulating level of most inflammatory markers, with the exception of PCT, IL-6 and CRP, where the increase was over 50 fold. PCI, Pr C and AT exhibited slight decreases. Wide individual variations were obvious. These results clearly indicate that inflammation, thrombin generation, impairment of fibrinolysis and impairment of endogenous anticoagulants play a key role in the pathogenesis of DIC.

Marker Normal Human Volunteers (n=30) DIC with Sepsis Patients (n=100) Fold Change PCT (ng/ml) 0.1 ± 0.04 (0.01) 18.7 ± 31.2 (3.1) 187× Increase C5a (ng/ml) 6.7 ± 1.7 (0.5) 15.5.7 ± 14.9 (1.5) 2× Increase PCI (% NHP) 138.9 ± 71.1 (8.8) 106.9 ± 33.4 (7.1) 1.3× Decrease IL-6 (pg/ml) 2.5 ± 1.2 (0.3) 522.5 ± 881.5 (88.2) 210× Increase IL-10 (pg/ml) 9.8 ± 5.23 (1.7) 46.9 ± 73.3 (8.8) 5× Increase MPO (ng/ml) 15.1 ± 10.1 (2.7) 111.4 ± 74.9 (7.5) 7× Increase PAI-1 (ng/ml) 31.7 ± 8.9 (3.1) 130.2 ± 178.1 (22.1) 4× Increase F1.2 (pM) 108.6 ± 46.2 (12.3) 473.7 ± 320.2 (32.0) 4× Increase TAT (ng/ml) 4.4 ± 1.1 (0.3) 17.0 ± 30.8 (3.1) 5× Increase AT (% NHP) 94.2 ± 10.3 (2.7) 80.4 ± 30.7 (3.1) 1.2× Decrease APC (ratio) 2.23 ± 0.3 (0.1) 2.48 ± 0.4 (0.04) 1.1× Increase CRP (ug/ml) 0.5 ± 1.1 (0.3) 38.4 ± 3.9 (0.4) 76× Increase Pr. C (% NHP) 78.3 ± 13.3 (3.6) 41.3 ± 17.4 (1.7) 2× Decrease

Disclosures:

Kaul: Artisan Pharma: Employment.
Incidence of Venous Thromboembolism In Korea: From Health Insurance Review and Assessment Service Database.
Authors: Jang Moon , Bang Soo-Mee , Oh Doyeun
Published: October 2019

Abstract 3676

Background:

Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), represents a major health concern with an annual incidence of 70 to 113 cases per 100,000 Caucasians. Although historically lower than in Caucasians, its incidence among Asians is anticipated to increase rapidly with widespread Westernization of diet and lifestyle.

Methods:

This population-based study investigated the incidence of VTE in Korea. The National Health Insurance (NHI) is the only public medical insurance system operated by the Ministry of Health and Welfare in Korea. All Korean are required to possess NHI service. Health Insurance Review and Assessment Service (HIRA) is a government-affiliated organization to build an accurate claims review and quality assessment system for the NHI. Using the Korean HIRA database, VTE patients from 2004 to 2008 were retrospectively identified by both diagnostic codes and medication codes for drugs used in initial treatment of VTE.

Results:

The respective age- and sex-adjusted annual incidences of VTE, DVT alone, and PE (with or without DVT) per 100,000 individuals increased significantly from 8.83, 3.91, and 3.74 in 2004 to 13.8, 5.31, and 7.01 in 2008 (P = 0.0001) with successive increments each year. The annual incidence of VTE, DVT alone, and PE (with or without DVT) for both men and women steadily increased over time (Fig 1). Specifically, the annual incidence of PE (with or without DVT) for both sexes significantly increased during the last 2 years studied (2007 to 2008). All three annual incidences also increased steadily with age (P = 0.0001 for all) particularly among those over 60 years old.

Conclusions:

This represents the largest epidemiologic study which demonstrate the lower incidence of VTE and increasing incidence of VTE in Korean population.

Disclosures:

No relevant conflicts of interest to declare.
Duration of Corticosteroid Tapering as First Line Treatment In Idiopathic Thrombocytopenic Purpura.
Authors: Lam Selay , Hsia Cyrus C.
Published: October 2019

Abstract 3688

Background:

Idiopathic Thrombocytopenic Purpura (ITP) is a relatively common benign hematologic disorder. Management of ITP is difficult as many treatment regimens present risks that may pose more harm than the disease itself. Typically, corticosteroid is used as first line treatment, but there is currently no evidence-based guideline to direct the optimal duration of therapy.

Objective:

To investigate the effectiveness and relative safety of various lengths of corticosteroid therapy.

Methods:

In a retrospective cohort study, charts of all ITP patients seen in the general hematology clinic at the London Health Sciences Centre (LHSC) from January 1, 2004 to December 31, 2009 were reviewed.

Results

: A total of 312 patients with ITP were reviewed. 128 of the patients (52 male, 76 female), age range 4–94 at time of diagnosis, required corticosteroid treatment. Of those, 35 patients were treated with short term steroid regimen (< 8 weeks); 32 patients had 8–16 weeks of therapy, and 64 patients received long term steroid tapering regimen (>16 weeks). Based on results, 63%, 56% and 39% of patients achieved complete response in each group respectively. The follow-up duration from diagnosis ranged from 1 month to 29 years (with median of 1 year).

Interestingly, the same proportion of patients experienced side effects as a result of steroid use in all groups. However, frequency of serious complications such as avascular necrosis and infections, occurred at a higher rate in the long term therapy group (9%) compared to 0% in short term therapy group.

Conclusions:

Rapid corticosteroid taper is as effective as a slow corticosteroid taper and has less serious side effects.

Disclosures:

No relevant conflicts of interest to declare.
Kinetics of Engraftment and Graft Versus Host Disease After Cotransplantation of Ex Vivo Expanded and Unexpanded Cord Blood Units In Immunodeficient Mice.
Authors: Ong Li Ming , Fan Xiubo , Chu Pak Yan , Gay Florence , Ang Justina , Li Zhihong , Chen Jianzhu , Lim SaiKiang , Bunte Ralph , Hwang William
Published: October 2019

Abstract 3722

Ex vivo expansion of cord blood (CB) hematopoietic stem cells (HSCs) and cotransplantation of two CB units can enhance applicability of CB transplants to adult patients. This is the first study on cotransplantation of ex vivo expanded and unexpanded human CB units in immunodeficient mice, simulating conditions for ex vivo CB expansion clinical trials.

CB units were cultured in serum-free medium supplemented with Stem Cell Factor, Flt-3 ligand, Thrombopoietin and Insulin Growth Factor Binding Protein-2 with mesenchymal stromal co-culture. Cotransplantation of unexpanded and expanded CB cells was achieved by tail vein injection into forty-five sublethally irradiated nonobese diabetic SCID-IL2γ−/− (NSG) mice. Submandibular bleeding was performed monthly and mice were sacrificed 4 months following transplantation to analyze for human hematopoietic engraftment.

CB expansion yielded 40-fold expansion of CD34+ cells and 18-fold expansion of HSCs based on limiting dilution analysis of NSG engraftment. Mice receiving expanded grafts had 4.30% human cell repopulation, compared to 0.92% in mice receiving only unexpanded grafts at equivalent starting cell doses (p = 0.07). Ex vivo expanded grafts with lower initiating cell doses also had equivalent engraftment to unexpanded grafts with higher cell dose (8.0% vs 7.9%, p= 0.93). However, the unexpanded graft, richer in T-cells, predominated in final donor chimerism.

Ex vivo expansion resulted in enhanced CB engraftment at equivalent starting cell doses, even though the unexpanded graft predominated in long-term hematopoiesis. The expanded graft with increased stem/progenitor cells enhanced initial engraftment despite eventual rejection by the unexpanded graft.

Disclosures:

No relevant conflicts of interest to declare.
G-CSF as Secondary Prophylaxis of Febrile Neutropenia In the Management of Advanced-Stage Hodgkin Lymphoma Treated with ABVD Chemotherapy: A Decision Analysis.
Authors: Graczyk Joanna , Cheung Matthew , Buckstein Rena , Chan Kelvin
Published: October 2019

Abstract 3831

Background:

ABVD is the standard treatment for advanced stage Hodgkin Lymphoma (HL) with rates of complete remission achieved in the majority of patients treated. Current practice guidelines (American Society of Clinical Oncology, Smith TJ et al. JCO 2008) recommend the use of granulocyte colony stimulating factor (G-CSF) in secondary prophylaxis despite lack of a survival benefit and potential toxicities, including bleomycin pulmonary toxicity (BPT). Recently, small retrospective series and expert opinion (Horning S, ASH Education Program Book 2007) advocate for the omission of G-CSF, although this approach has not been prospectively studied. The purpose of this study was to perform a decision analysis that compared the life expectancy and quality-adjusted life expectancy of advanced-stage HL managed with and without secondary prophylactic G-CSF.

Methods:

We constructed a decision-analytic model to compare the strategy of secondary prophylaxis with G-CSF to a strategy of no G-CSF with severe neutropenia for a hypothetical cohort of 40 year-old patients with clinical stage IIB to IV Hodgkin Lymphoma treated with 8 cycles of ABVD chemotherapy. Markov models were used to simulate a 2-year clinical course of patients. Baseline probability estimates were derived from a systematic review of relevant published studies. Utilities for various health states were derived from expert opinion. One-way sensitivity analysis was performed on key variables such as severe neutropenia, febrile neutropenia and bleomycin pulmonary toxicity, as well as the utilites associated with these health states.

Results:

The life expectancy was 1.858 years for the G-CSF strategy and 1.875 years for no G-CSF, yielding a net expected benefit of 0.017 years for no G-CSF use in severe neutropenia. The quality-adjusted life expectancy was 1.371 years for the G-CSF strategy and 1.408 years for no G-CSF with a net expected benefit for no G-CSF of 0.037 QALYs. On microsimulation (10,000 trials), 96% of the simulations showed that the no G-CSF strategy is preferred to the use of G-CSF. This analysis was not sensitive to the odds ratio of lung toxicity with G-CSF, the hazard ratios of febrile neutropenia and severe neutropenia, the probability of death from febrile neutropenia, or the utilities associated with bleomycin pulmonary toxicity, hospitalization for febrile neutropenia and musculoskeletal pain from G-CSF.

Conclusions:

While the difference between the two strategies is small, our model predicted that for a 40 year-old patient with advanced-stage Hodgkin Lymphoma treated with ABVD chemotherapy, the strategy of avoiding use of G-CSF with severe neutropenia is preferred. This finding is robust across a wide range of sensitivity analyses.

Disclosures:

No relevant conflicts of interest to declare.
Mesenchymal Stem Cells Express the Surface Receptor Calreticulin (cC1qR) and Complement C1q Chemoattracts Them.
Authors: Qiu Yuanyuan , Marquez-Curtis Leah A. , Janowska-Wieczorek Anna
Published: October 2019

Abstract 3855

Complement cleavage fragments play an important role in the trafficking of hematopoietic stem/progenitor cells as reported by us (Blood 2003;101:3784; Exp Hematol 2010;38:321; Transfusion Sept 2010), as well as of mesenchymal stem cells (MSC) as reported by others (J Immunol 2009;182:3827). Because MSC have a great potential for tissue regeneration and cellular therapies, in this study we investigated the mechanisms of migration of MSC to injured sites. As complement cascade is activated upon tissue injury we examined whether complement component 1 subcomponent q (C1q), the initiator of the classical pathway of complement activation, plays a role in the migration of MSC, and which C1q receptors (CR1, gC1qR, calreticulin (cC1qR), CD93) are expressed on MSC and could be involved in their migration. We previously reported that matrix metalloproteinases (MMPs), especially membrane type 1 (MT1)-MMP and MMP-2, regulate the migration of MSC (Stem Cells, 2006, 24:1254); therefore in this study we examined the effects of C1q on MMP expression and migration of MSC. Human MSC isolated from cord blood and bone marrow were maintained for 3–6 passages and characterized by adipocyte and osteoblast differentiation. We used chemoinvasion across the reconstituted basement membrane Matrigel to evaluate the migration of MSC, RT-PCR and flow cytometry to determine the expression of C1q receptors and, upon stimulation with C1q, zymography and Western blot to examine the expression of MMPs and ERK1/2 and PI3K/Akt signaling pathways. We found that MSC were chemoattracted by a C1q gradient in a dose-dependent manner, and MSC expressed transcripts for gC1qR, CD93 and cC1qR, but only calreticulin protein was detected on the surface of MSC. Specific antibody against calreticulin (anti-cC1qR antibody) inhibited the trans-Matrigel chemoinvasion of MSC towards C1q. Moreover, stimulation of MSC with C1q (10 μ g/mL) increased MT1-MMP expression, but no changes in MMP-2 secretion were observed. Trans-Matrigel migration of MSC towards C1q was also reduced by the MT1-MMP inhibitor EGCG. Further, the ERK1/2 inhibitor PD98059 and the PI3K inhibitor Ly294002 decreased the chemoinvasion of MSC towards C1q. In conclusion, this study indicates that: 1) C1q exerts chemoattractant activity towards MSC through its surface receptor calreticulin; 2) MT1-MMP regulates the C1q-induced trans-Matrigel migration of MSC; and 3) both the ERK1/2 and PI3K/Akt signaling pathways are involved in this process. These findings demonstrate a broader regulatory role for C1q, which functions as a chemotactic factor for MSC through its binding to surface calreticulin, and suggest a newly-found mechanism for the migration of MSC which may be important for its clinical use.

Disclosures:

No relevant conflicts of interest to declare.
Distribution of Bim Determines MCL-1 Dependence or Co-Dependence on BCL-xL/BCL-2 In Multiple Myeloma
Authors: Boise Lawrence H. , Morales Alejo A , Kurtoglu Metin , Matulis Shannon M , Markovitz Rebecca , Lee Kelvin P , Lonial Sagar
Published: October 2019

Abstract 4054

The inappropriate activation of oncogenes can result in the up-regulation of pro-apoptotic signals often in the form of BH3-only proteins such as Bim, Noxa or Puma. This renders cells dependent on anti-apoptotic proteins including BCL-2, BCL-xL and MCL-1. Thus cancer cells would be predicted to be more susceptible to inhibition of BCL-2 family proteins, prompting the development and testing of several small molecule inhibitors of this class of proteins. Multiple myeloma is a plasma cell malignancy of the bone marrow and like normal plasma cells, myeloma plasma cells express MCL-1. A search of gene expression profile data from normal plasma cells (n=22), MGUS plasma cells (n=12), plasma cells from patients with asymptomatic (smoldering) myeloma (n=44) or newly diagnosed multiple myeloma (n=538) revealed no significant difference in MCL-1 mRNA expression associated with progression of disease. We then determined MCL-1 dependence through the introduction of siRNA in 4 MM cell lines and consistent with previous findings using anti-sense oligonucleotides in additional lines, we demonstrated that all cell lines tested were MCL-1 dependent. However using the BCL-2/BCL-xL/BCL-w-selective inhibitor ABT-737 we found that 3 of the 6 MCL1-dependent cell lines tested were sensitive (IC50 for Annexin V-FITC positive at 24 hrs of 300 – 600 nM) and therefore also dependent on BCL-xL/BCL-2. Taken together this is the first formal demonstration that cells can be co-dependent on multiple Bcl-2 family members. We have previously reported that ABT-737 sensitivity, and what we now refer to as co-dependence on MCL-1 and BCL-xL/BCL-2, is determined by the distribution of BIM on the anti-apoptotic BCL-2 proteins in these cells. We have now expanded these findings to patient samples that displayed sensitivity to ABT-737 that is similar to what we have observed in the co-dependent cell line MM.1s. Consistent with these findings co-immunoprecipation revealed BIM binding predominantly to BCL-xL. Additionally we have now demonstrated that BIM binding is not simply controlled by the expression levels of BCL-xL or MCL-1 as enforced over-expression of each protein could alter the sensitivity of co-dependent cell lines to ABT-737 but did not alter the initial distribution of BIM amongst these proteins. These data suggest that additional factors regulate the association of BIM with anti-apoptotic BCL-2 proteins. These factors could include differences in cellular localization of these proteins as well as differences in post-translational modifications of either pro- or anti-apoptotic BCL-2 family proteins.

Disclosures:

Boise: University of Chicago: Patents & Royalties.
Primary Pulmonary MALT Lymphoma: Clinical Characteristics and Treatment Outcomes – Single Institution Experience
Authors: Nowakowski Grzegorz S. , Ristow Kay , Kurtin Paul , Allen Mark S , Micallef Ivana N , Colgan Joseph , Inwards David James , McPhail Ellen , Markovic Svetomir , Ansell Stephen M. , Porrata Luis , Johnston Patrick B , Thompson Carrie A , Witzig Thomas E. , Habermann Thomas M.
Published: October 2019

Abstract 4168

Background:

Primary Pulmonary MALT lymphoma represents 15–20% of Extranodal Marginal Zone Lymphomas of Mucosa Associated Lymphoid Tissue (MALT). In contrast to the more common gastric MALT lymphoma, natural history, prognosis and treatment outcomes for primary pulmonary MALT lymphoma are not well defined. Herein, we report a single institution experience.

Methods:

Consecutive patients with primary pulmonary MALT lymphoma registered in the Mayo Clinic Lymphoma Database, which includes all consenting patients with lymphoma seen at Mayo Clinic Rochester, were reviewed for clinical features, treatment outcome progression free survival (PFS) and overall survival (OS). The pathology for all patients was centrally reviewed by hematopathologist and the diagnoses were based on WHO lymphoma classification criteria. PFS and OS were assessed using the Kaplan–Meier method and the Cox proportional hazard model was used to assess the impact of variables on PFS and OS.

Results:

Between December 1986 and June of 2009, ninety-seven patients with primary pulmonary MALT lymphoma were enrolled. The median age at diagnosis was 63 years (range 31–87). There were 43 (44%) males. The initial presentation was a unilateral pulmonary lesion (n=47, 48%), bilateral pulmonary lesions (n=41, 42%), and pulmonary lesion with intrathoracic lymphadenopathy (n= 4, 4%). Bone marrow involvement and presence of B symptoms were 4, 4% and 5, 5%, respectively. International Prognostic Index (IPI) was 0–1, 2–3 and 4–5 in 69, 25 and 1 patient(s) respectively. The median follow-up was 10.4 years. The estimated median OS was 13. 6 years and the median PFS was 5.5 years (Figure). In a multivariate analysis, age >60 (p=0.02) and ECOG PS>2 (p=0.01) were associated with shortened survival. The IPI and age adjusted IPI were not predictive of overall survival. The treatment outcomes for the most common treatment modalities are summarized in the Table below. The median PFS of the 38% of patients who had a complete surgical resection was excellent at 11.2 years; whereas for observed patients with residual disease after biopsy was 3.2 years. Only 8 patients received single agent rituximan with relatively low response rate.

The prognosis of primary pulmonary MALT lymphoma is favorable, with a median survival of over 13 years. In patients with resectable disease, surgery alone is associated with excellent disease control. Further prospective studies are needed to define the optimal treatment of primary pulmonary MALT lymphoma.

Disclosures:

No relevant conflicts of interest to declare.
Fibrinogen γ' In the Budd-Chiari Syndrome: Results From a Multicenter Case-Control Study
Authors: Smalberg Jasper , Koehler Edith , Murad Sarwa Darwish , Plessier Aurelie , Garcia-Pagan Juan-Carlos , Seijó Susana , Langlet Philippe , Trebicka Jonel , Primignani Massimo , Maat Moniek De , Rijken Dick , Valla Dominique , Janssen Harry , Leebeek Frank
Published: October 2019

Abstract 4213

Primary Budd-Chiari syndrome (BCS) is a rare disorder characterized by thrombosis of the hepatic outflow tract anywhere from the level of the hepatic veins to the suprahepatic inferior vena cava. Thrombophilic factors or prothrombotic disorders are found in the majority of patients. However, in around 20% of primary BCS patients still no cause can be identified, which highlights the need to further explore the etiology of this disorder. The fibrinogen γ' variant is a thrombosis risk modifier and may thus contribute to BCS. The aim of this study was to determine the role of fibrinogen γ' levels and common variations in the fibrinogen γ gene (FGG) in the etiology of BCS. Patients were recruited from the EN-Vie cohort, consisting of 163 consecutive BCS patients, enrolled in nine European countries between October 2003 and October 2005. Plasma and/or DNA was available from 118 BCS patients (50 males and 68 females; median age 37.9) and 104 healthy controls (43 males and 61 females; median age 36.8). We measured fibrinogen γ' levels by ELISA and genotyped two haplotype-tagging single nucleotide polymorphisms (SNPs): rs2066865 (10034C>T) tagged FGG H2 and rs1049636 (9340T>C) tagged FGG H3. All statistical analyses were adjusted for differences in age and sex. Fibrinogen γ' (0.50 vs 0.42 g/l; p=0.02) and total fibrinogen levels (3.0 vs. 2.8 g/l, p=0.04) were significantly elevated in BCS patients compared to controls. Also the fibrinogen γ'/total fibrinogen ratio, which adjusts for a potential acute phase induced increase of fibrinogen, was significantly elevated in BCS patients (0.17 vs. 0.15; p=0.03). Logistic regression showed a significant association between an increasing fibrinogen γ'/total fibrinogen ratio and risk of BCS (p=0.03). FGG H2 (OR 0.97; 0.96–0.98) and H3 (OR 1.02; 1.01–1.03) were significantly associated with fibrinogen γ'/total fibrinogen ratios. FGG H2 (OR 0.96; 0.64–1.46) and H3 (OR 0.86; 0.62–1.21) were not associated with BCS. In conclusion, fibrinogen γ' levels and the fibrinogen γ'/total fibrinogen ratio are significantly elevated in BCS patients. Common FGG gene variations determine the fibrinogen γ'/total fibrinogen ratio in these patients. We did not observe an association between FGG gene variations and risk of BCS.

This study was carried out on behalf of the European Network for Vascular Disorders of the Liver (EN-Vie).

Disclosures:

No relevant conflicts of interest to declare.
A Stapled BIM BH3 Helix Restores Apoptosis In Bim-Null Mantle Cell Lymphoma
Authors: Katz Samuel G , Labelle James L , Godes Marina , Fisher Jill , Bird Gregory H. , Walensky Loren D.
Published: October 2019

Abstract 437

Mantle cell lymphoma (MCL) is a highly aggressive B-cell lymphoma resistant to conventional chemotherapy. Although defined by the characteristic t(11;14) translocation, a variety of genetic aberrations have been indentified in MCL and may contribute to its pathogenesis and chemoresistance. Of particular interest is the frequent biallelic deletion of the pro-apoptotic BCL-2 family protein BIM. BIM exerts its pro-death function via its alpha-helical BH3 death domain that has the dual capacity to inhibit anti-apoptotic proteins such as BCL-2 and MCL-1 and directly trigger pro-apoptotic proteins such as the mitochondrial executioner BAX. In an effort to replace the deleted BH3 functionality in Bim−/− MCL, we generated stabilized alpha-helix of BCL-2 domains (SAHBs) modeled after the BIM BH3 alpha-helix. BIM SAHBs are helical, protease-resistant, and cell permeable peptides that recapitulate the pro-apoptotic activity of BIM. Indeed BIM SAHB, but not a negative control point mutant, dose-responsively activated caspase 3/7 and correspondingly inhibited the viability of a panel of MCL cell lines with IC50s in the single digit micromolar range. To extend these studies to an in vivo model of Bim−/− lymphoproliferative disease, we reconstituted Rag2-deficient mice with the bone marrow from Bim−/− mice and documented the development of splenomegaly and massive organ infiltration by B220-positive lymphocytes. Mice treated with intravenous BIM SAHB exhibited TUNEL positivity within the aberrant organ infiltrates, but not in the surrounding normal parenchyma. Importantly, vehicle and point mutant SAHB had no such effect, highlighting the specificity of BIM SAHB activity. Thus, therapeutic replacement of BIM's pro-apoptotic functionality using BIM SAHB has the potential to restore apoptosis in hematologic cancers that mount an apoptotic blockade by deleting Bim.

Disclosures:

Walensky: Aileron Therapeutics: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees.
Indications for Platelet Transfusions: How Well Do Physicians Comply with Professional Guidelines
Authors: Katz Elena , Klek Malgorzata , Levine Randy L. , Graham Robert E
Published: October 2019

Abstract 4402

Background:

Professional, evidence-based guidelines are developed to help physicians implement best practice care. Unfortunately, guidelines are not followed. Platelet transfusion guidelines have recently changed to a prophylactic transfusion threshold of 10, 000/μ L from the older threshold of 20,000/μ L. We conducted a retrospective analysis at a metropolitan teaching hospital to assess how well physicians comply with the new professional guidelines as well as the older, less stringent criteria to administer platelet transfusions.

Methods:

All patients admitted to the medical service who received platelet transfusions over a two month period in 2010 were reviewed. These patients represented the following services: ICU, general medicine, medical step down, interventional cardiology, CCU, and the cardiac step down unit. The indication selected in the computerized physician order entry (CPOE) system was compared to the clinical indication found in the patients’ medical record. The medical record clinical indication was then evaluated against the American Society of Hematology (ASH) 2007 “Evidence-Based Platelet Transfusion Guidelines” (Slichter SJ. Hematology 2007): bleeding and platelets ≤50, 000/μ L, pre-invasive procedure and platelets ≤50, 000/μ L, prophylactic transfusion for platelets ≤10, 000/μ L and WHO bleeding grade ≥ 2. We also assessed how the patients’ clinical indication met the older less stringent prophylactic threshold for platelet transfusion of ≤20, 000/μ L laid forth by the landmark study by Gaydos LA. et. al. (The quantitative relation between platelet count and hemorrhage in patients with acute leukemia. N Engl J Med 1962).

Results:

A total of 108 patients received platelet transfusions; 29 were medicine patients to tally 95 platelet transfusions. The most common patient clinical indication was “platelets ≤ 20, 000/μ L without bleeding” (27%), while the clinical indication was not specified in 16% of cases. The CPOE documented indication coincided with the patient's clinical indication from the medical record in 23% of cases. Sixty five percent of the time the patient's clinical indication failed to meet the currently accepted 2007 ASH guidelines and 36% of cases failed to meet the older less stringent guidelines.

Conclusions:

A majority of platelet transfusions did not meet the current professional guidelines for indication. Our pilot study suggests the need for more physician education regarding evidence-based guidelines for platelet transfusions, and in a larger context, initiatives to enhance compliance. We are currently developing an educational intervention and plan to reassess compliance with indications pre and post intervention.

Disclosures:

No relevant conflicts of interest to declare.
The Interaction of Soluble Phospholipids with Coagulation Factor VIIa
Authors: Sengupta Tanusree , Majumder Rinku , Lentz Barry R.
Published: October 2019

Abstract 4421

Factor VIIa (fVIIa) is one of the key proteins in the blood coagulation cascade. It activates factors IX and × on a negatively charged phospholipid surface in either a TF-dependent or TF-independent fashion (Silverberg et al, 1977; Bom et al, 1990). Monroe et al (1997) demonstrated that fVIIa binds to activated platelets independent of TF and partially restores thrombin generation in an in vitro model of hemophilia. Thus, it appears that interaction of fVIIa with platelet phospholipids plays an important role. We report that binding of 1,2-dihexanoyl-sn-glycero-3-phospholipids -L-serine (C6PS) and 1,2-dihexanoyl-sn-glycero-3-phosphoethanolamine (C6PE) to fVIIa causes changes in its activity as well as structure. Titration with C6PS led to changes in intrinsic fluorescence indicative of two or more binding sites for this lipid. Similar titrations with C6PE indicated that it probably binds to a single site on the protein. Experiments are underway to test this initial conclusion. Both lipids bind with comparable affinity (kd ~ 165 and 160 μ M) when data were analyzed using a single site model. We also examined the effect of the soluble lipids on the activity of fVIIa. Both C6PS and C6PE binding increased fVIIa proteolytic and amidolytic activity, with the effect of C6PS being more pronounced. Based on current data, it appears that both lipids bind to a single weak site, but that binding of either to this site promotes binding of C6PS to a second, tighter, and C6PS-specific site, which seems to be crucial in regulating activity. Further experiments are underway to test this hypothesis.

Disclosures:

No relevant conflicts of interest to declare.
A Novel Case of Hemophilia B Due to a Partial Duplication of the Factor 9 Gene
Authors: Wheeler Ruth , Alamelu Jayanthi , Cutler Jacqueline
Published: October 2019

Abstract 4423

Hemophilia B is an X-linked recessive coagulation disorder. The disease is caused by a deficiency of procoagulant Factor IX and is characterised by easy bruising and prolonged bleeding and oozing after injury or surgery. The severity of the disease and the frequency of bleeding events vary, depending on the FIX clotting activity, and in severe cases males suffer from spontaneous joint and muscle bleeds which significantly impact on their health and quality of life. Hemophilia B is less common than Hemophilia A, with a frequency of approximately 1 in 25000 males worldwide. The F9 gene is located on the long arm of the × chromosome at Xq27. The gene comprises 8 exons, spanning approximately 33.5 kb DNA. The molecular basis of Hemophilia B is heterogeneous and to date over a 1000 different mutations have been reported, including missense and nonsense mutations, splicing mutations and large deletions. Here we report the identification of a previously uncharacterised duplication spanning a large part of the F9 gene in a patient with severe Hemophilia B. The patient, a 6 year old male of mixed Iranian and UK origin, was referred to the centre with severe Hemophilia B. He had a FIX level of less than 1iu/dL. No family history of bleeding diathesis could be confirmed due to loss of maternal family members in an earthquake. Mutation analysis of all exons including immediate flanking regions to allow detection of splice site mutations, and the 5’ and 3’ untranslated regions was performed by direct sequencing but no changes from the normal sequence were identified. There have been several reports of Hemophilia B being associated with partial duplications of the F9 gene so we analysed gene copy number using multiplex ligation-dependant probe amplification (MLPA). A large duplication, involving exons 2 to 6 was identified in the affected male. Subsequent analyses of maternal samples were normal, indicating that the mutation arose de novo.

Disclosures:

No relevant conflicts of interest to declare.
Induction of Apoptosis In Imatinib-Resistant BCR-ABL1-Positive Leukemia Cell Lines by Bortezomib
Authors: Quentmeier Hilmar , Eberth Sonja , Romani Julia , Zaborski Margarete , Drexler Hans G.
Published: October 2019

Abstract 4469

The BCR-ABL1 translocation occurs in chronic myeloid leukemia (CML) and in 25% of cases with acute lymphoblastic leukemia (ALL). We screened a panel of BCR-ABL1 positive cell lines to find models for imatinib-resistance studies. Five of 19 BCR-ABL1 positive cell lines were resistant to imatinib-induced apoptosis (KCL-22, MHH-TALL1, NALM-1, SD-1, SUP-B15). None of the five resistant cell lines carried mutations in the kinase domain of BCR-ABL1 and – consequently – all also showed resistance to the second generation kinase inhibitors, nilotinib or dasatinib. All Philadelphia chromosome (Ph)-positive cell lines demonstrated constitutive phosphorylation of STAT5 and S6. Imatinib induced dephosphorylation of both BCR-ABL1 downstream effectors in responsive cell lines, but - remarkably – induced dephosphorylation of STAT5 in resistant cell lines as well. By administering well-described signalling pathway inhibitors we were able to show that activation of mTOR complex 1 was responsible for the constitutive S6 phosphorylation of imatinib-resistant cells. Neither BCR-ABL1 nor Src kinases or Ras/Rac-GTPases underlie tyrosine kinase inhibitor resistance in these cell lines. In conclusion, none of the five TKI-resistant cell lines showed aberrant activation of previously-described oncogenic pathways which would explain their resistance. These findings raise the question whether these cell lines might help to find a novel – alternative – explanation for TKI resistance. Interestingly, the proteasome inhibitor bortezomib induced apoptosis in TKI-resistant and –sensitive Ph+ cell lines. Bortezomib is being used for the treatment of multiple myeloma. Our findings support the notion that bortezomib might also be useful for the treatment of imatinib-resistant CML.

Disclosures:

No relevant conflicts of interest to declare.
A Cell Line SYRMO Derived From AML with EVI 1 Rearrangements Following Imatinib Mesylate Therapy for Chronic Myeloid Leukaemia
Authors: Kottaridis Panagiotis , Brazma Diana , Howard-Reeves Julie , Mazzullo Helen , Nacheva Elisabeth P
Published: October 2019

Abstract 4470

Chronic Myeloid Leukaemia (CML) is a malignant disorder of the haematopoeitic stem cell, usually characterised by the t(9;22) giving rise to the Philadelphia chromosome (Ph), and by the BCR-ABL gene rearrangement at the molecular level. Imatinib mesylate (IM), which targets the tyrosine kinase (TK) activity of BCR-ABL, has become the first line therapy for CML patients. Dasatinib or Nilotinib is now indicated as a second line therapy for patients who develop resistance or intolerance to IM.

Here we report the case of a 51 year old woman who was diagnosed in Cyprus (2007) with BCR/ABL1 positive CML. After failing to respond to IM therapy, she was treated with Dasatinib achieving complete cytogenetic remission (CCR), and subsequent complete molecular remission. In July 2009 the patient presented with 88% blasts in the bone marrow. Immunophenotyping showed the presence of CD34+, CD117+ myeloblasts, and a diagnosis of AML was confirmed. Analysis of G banded metaphases from cultured peripheral blood revealed a complex karyotype: 46,XX, t(2;3)(p21;q26),t(4;8)(q12;q22), del(6)(q13;q23)[1]/45,idem,der(6)ins(6;6)(q23;),-7[9]. FISH revealed EVI 1 rearrangement resulting from the t(2;3) in the absence of BCR/ABL1 fusion and confirmed the secondary monosomy 7. The patients failed to respond to treatment and passed away shortly afterwards. Whole genome screening by aCGH using a 244K platform (Agilent) confirmed the loss of chromosome 7 and the 6q22/23 region.

Clonal cytogenetic abnormalities (CCA) in Ph-negative metaphases are known to develop in some patients during IM therapy. The most frequent of these abnormalities are trisomy 8, -7, del(7q), and del(20q), which are also associated with MDS and AML. These abnormalities are usually transient and disappear after a short time, or have no clinical consequence (Deininger et al., Cancer 2007). However, reports of development of high risk MDS or AML in association with CCA in Ph-negative cells are rare, but patients with chromosome 7 abnormalities appear to be at greater risk. The t(2;3) is a non random abnormality in MDS and AML, including therapy-related leukaemias, frequently associated with -7 and a complex karyotype with a poor prognosis (Stevens-Kroef et al Leukemia 2004).

This is the first report of a CML patient on TKI treatment with t(2;3) and EVI1 gene rearrangements in Ph(-) cells. This cryptic translocation could easily be overlooked in the presence of a monosomy 7 with a dramatic effect on patient management.

Disclosures:

No relevant conflicts of interest to declare.
Incidence and Clinical Features of Idiopathic Pneumonia Syndrome and Diffuse Alveolar Hemorrhage After Unrelated Cord Blood Transplantation.
Authors: Nishida Aya , Wake Atsushi , Yamamoto Hisashi , Ishiwata Kazuya , Nakano Nobuaki , Tsuji Masanori , Asano-Mori Yuki , Uchida Naoyuki , Izutsu Koji , Masuoka Kazuhiro , Yoneyama Akiko , Makino Shigeyoshi , Taniguchi Shuichi
Published: October 2019

Abstract 4535

Incidence and clinical features of idiopathic pneumonia syndrome and diffuse alveolar hemorrhage after unrelated cord blood transplantation.

Aya Nishida 1, Atsushi Wake 1, Hisashi Yamamoto 1, Kazuya Ishiwata 1, Nobuaki Nakano 1, Masanori Tsuji 1, Yuki-Asano Mori 1, Naoyuki Uchida 1, Koji Izutsu 1, Kazuhiro Masuoka 1, Akiko Yoneyama 3, Shigeyoshi Makino 4, Shuichi Taniguchi 1.

1 Department of Hematology, Toranomon Hospital, Tokyo, Japan; 2 Department of Pathology, Toranomon Hospital, Tokyo, Japan; 3 Department of Infectious Diseases, Toranomon Hospital, Tokyo, Japan; 4 Department of Transfusion Medicine, Toranomon Hospital, Tokyo, Japan [Background] Idiopathic pneumonia syndrome (IPS) and diffuse alveolar hemorrhage (DAH) are non-infectious pulmonary complications of hematopoietic stem cell transplantation (HSCT) with unclear pathogenesis and treatment. [Objective and method] To investigate the incidence and clinical features of IPS/DAH after unrelated cord blood transplantation (uCBT), we retrospectively analyzed 370 patients underwent uCBT from January 2005 to June 2010 at Toranomon Hospital. Diagnosis of IPS/DAH was made by multilobar infiltrates on CXR or CT, clinical signs of pneumonia: cough, dyspnea, or rales, abnormal physiology: increased arterial-alveolar oxygen gradient, or the needfor supplemental oxygen support, and no evidence of respiratory tract infection. [Result:] Twenty five cases of IPS/DAH were identified, with incidence of 6.8%. The median-age was 59 years (range; 26–72). Nineteen patients underwent transplantation for leukemia, 4 for malignant lymphoma, and 2 for aplastic anemia. IPS/DAH was diagnosed at a median of 34 days (range; 8–93) after uCBT. All patients were administered mPSL therapy. Nine of 25 patients were administered etanercept combined with mPSL pulse therapy. Five of 9 had not responded, while 4 responders had worse their respiratory condition after discontinuation of etanercept therapy. Twenty four of 25 died of respiratory failure. [Conclusion] IPS/DAH after uCBT are fetal pulmonary complications. It is suggested that the incidence of IPS/DAH after uCBT appears similar to that observed after transplantation using other sources. But our results suggested that the existing treatment such as etanercept combined mPSL pulse have only limited efficacy as a therapy for IPS/DAH after uCBT. Further research is needed to characterize the condition of this syndrome and to investigate the optimal therapy and prophylaxis.

Disclosures:

No relevant conflicts of interest to declare.