bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemokine Receptor Expression, Migration, and Survival of NK Cells Expanded with Mbil-15 or Mbil-21
Authors: Lee Dean , Aliru Maureen , Denman Cecele J. , Somanchi Srinivas S.
Published: October 2019

Abstract 4683

Natural killer (NK) cells can kill malignant or virus-infected cells through the interaction of activating and inhibitory receptors without needing specific antigen recognition of target cells, and therefor have broad therapeutic applications for treatment of human malignancies. However, due to their limited life-span in vivo and poor expansion in vitro, production of sufficient numbers of NK cells for effective adoptive immunotherapy poses an obstacle. Genetically engineered artificial antigen presenting cells (aAPCs) consisting of K562 modified 4-1BBL and membrane bound IL-15 or IL-21 have been reported for their ability to support ex vivo NK cell proliferation. aAPCs with mbIL-21 were shown to promote increased proliferation of NK cells with shorter telomeres, but differences in in vivo survival or tumor or tissue migration have not been assessed. Tumor and/or tissue migration is primarily mediated by the expression of chemokine receptors. Using aAPCs bearing mbIL15 or mbIL21, we expanded NK cells for 3 weeks and assessed their expression of chemokine receptors, organ migration, and in vivo survival in a xenograft model. Propagated NK cells showed relatively similar levels of low to modest expression of CCR2, CCR7, CXCR4 and CXCR5, and high expression levels of CXCR3. Mean CCR5 expression levels were similar on cells that were positive, but CCR5 was expressed on a higher percentage of NK cells expanded with mbIL-15 than those expanded with mbIL-21. In contrast, about 20% of mbIL-21 expanded NK cells expressed CX3CR1 expression whereas mbIL-15 NK cells showed almost no expression of this receptor. Results from ongoing migration and survival experiments will also be presented.

Disclosures:

No relevant conflicts of interest to declare.
Different Strategies for First-Line Treatment of Chronic Myeloid Leukaemia: An Economic Analysis
Authors: Wu Bin , Zhong Hua , Saglio Giuseppe , Chen Fangyuan
Published: October 2019

Abstract 4696

Purpose:

To evaluate the economic outcome of conventional and targeted therapies of patients with chronic myelogenous leukemia (CML).

Methods:

Two Markov simulation models were designed to measure the cost and quality-adjusted life years (QALYs) for newly diagnosed CML patients whether to be administered conventional therapy or six tyrosine kinase inhibitors (TKIs) based strategies. Clinical and utility data were taken mostly from the literature by a MEDLINE search. Costs were based on local charges. The primary output was reported in terms of incremental cost-effectiveness ratios (ICERs). Sensitivity analyses were performed to examine the robustness of the model output. The impact of patient assistance program (PAP) was assessed.

Results:

The imatinib plus peginterferon-Á switch 2nd TKIs strategy yielded the most health benefits for newly diagnosed CML patients when compared with the conventional, imatinib switch 2nd TKIs, imatinib switch conventional, imatinib plus IFN-Á switch conventional, nilotinib switch conventional and dasatinib switch conventional strategies (figure 1). Marginal cost-effectiveness was $79,134 or $17,600 per QALY gained relative to conventional strategy without or with PAP (figure 2). Both the nilotinib and dasatinib based strategies were more expensive yet less effective than the alternative strategies and were therefore dominated. Model outputs were sensitive to the cost of TKIs.

Conclusion:

Imatinib and imatinib plus peginterferon-Á based strategies are potentially more cost-effective and 2nd-generation TKIs may be preferred in the setting of imatinib failure. Patient assistant program in health resource limited setting might notably improve the economic outcome of TKIs based therapies.

Disclosures:

No relevant conflicts of interest to declare.
Use of the Functional Assessment of Cancer Therapy-Anemia (FACT-An) Instrument in Persons with MPN-Associated Myelofibrosis and Anemia
Authors: Hudgens Stacie , Tencer Tom , Gale Robert Peter Peter , Khan Zeba M.
Published: October 2019

Abstract 4706

Background.

Myeloproliferative neoplasm (MPN)-associated myelofibrosis is characterized by anemia in almost all affected persons. The Functional Assessment of Cancer Therapy (FACT) measurement system is a patient-reported outcome (PRO) developed to document symptoms to diverse aspects of cancer treatment. One FACT version, FACT-An, specifically addresses symptoms of anemia related to cancer- therapy. FACT-An has been validated in diverse cancer populations but not in MPN-associated myelofibrosis.

Methods.

Data were from a phase-2 randomized double-blind Bayesian “pick-the-winner” trial of pomalidomide and prednisone in subjects with MPN-associated myelofibrosis and anemia (including RBC-transfusion-dependence). Details of the study, including definitions of anemia, response, RBC-transfusion-dependence and –independence were published previously. Change in quality of life (QOL) from randomization to the last cycle of therapy was evaluated by using the FACT-An physical well-being (PWB), functional well-being (FWB), trial outcome index (TOI) and anemia (An) domains. Minimally clinically important differences (MID) were used to determine the smallest difference in scores which subjects perceived as beneficial in the FACT-An domains of interest. Subjects were classified as meeting MID for responsiveness if their change score from baseline was greater than one standard error of measurement (SEM), indicating improvement.

Results.

85 subjects were studied. All FACT-An domains showed strong reliability as measured by Cronbach's alpha. 31 were classified as anemia responders by clinical and laboratory criteria. Anemia responders showed greater improvement in PWB, FWB and TOI scores than non-responders (TOI presented below) across all FACT-An domains. Improvement began at the 2nd 28 d cycle of therapy and was sustained.

Conclusion.

We show anemia response defined by IWG-MRT criteria correlates with improved QOL measured by the FACT-An instrument in persons with MPN-associated myelofibrosis.

Disclosures:

Tencer: Celgene Corporation: Employment. Gale:Celgene Corporation: Employment. Khan:Celgene: Employment.
Bleeding On Anti-Platelets: A Single Center Quality Assurance Project
Authors: Fountzilas Christos , Levine Randy L.
Published: October 2019

Abstract 4708

Background:

Treatment of CNS hemorrhage in patients on anti-platelets usually includes transfusion of platelets. Management of bleeding in other sites has not been thoroughly studied.

Objective:

To identify practice patterns of treatment of hemorrhage in patients on anti-platelets (aspirin and clopidogrel) at a tertiary care hospital within a 3 month period.

Methods:

This is a retrospective chart review. The Emergency Department provided a list of admitted patients. Target population was identified using the Emergency Department computer system. The patients chart was used in order to extract the following data: age, gender, co-mobridities, medications, baseline and lowest hemoglobin, platelet count, international normalized ratio, partial thromboplastin time and thrombin time, source and type (spontaneous vs trauma) of bleeding, use of packed red blood cells transfused within the first 24 hours, transfusion of platelets; prothrombin complex concentrate; fresh frozen plasma; factor VII; use of desmopressin, surgery or endoscopy within 48 hours from admission. Bleeding was categorized as life threatening, major or minor according to the International Society on Thrombosis and Hemostasis criteria. Statistical analysis was performed with the use of Excel (Microsoft).

Results:

31 patients with bleeding on anti-platelets were admitted from April 2012 to June 2012. Baseline characteristics and treatment practices are summarized in Table 1. The majority of the bleeds were due to aspirin alone, and anti-platelet agents were discontinued 93% of the time. Most bleeds requiring admission were classified as either life threatening or major. Frequency of packed red cell transfusion in life threatening bleeds was 5/6 (83%), 11/17 (65%) in major bleeds and 2/8 (25%) in minor bleeds. 4 patients were transfused with platelets (one had a CNS bleed), all had the anti-platelets discontinued and they had lower platelet counts compared to non transfused patients [93.2(84) vs 217(80.3), p=0.02]. No patient required desmopressin. All patients who had their anti-platelets continued had minor bleeds. All the bleedings stopped within 48 hours from admission and no deaths secondary to hemorrhagic shock were recorded.

Discussion:

This is a quality assurance project to assess current physician practices for the management of bleeding in patients on anti-platelet agents. Except for the actual platelet counts, there is no obvious difference between patients transfused with platelets vs non-transfused. At our institutions, anti-platelet related major bleeds are not routinely managed with platelet transfusions. There is a need for additional research to better clarify management. Our study is limited by the fact that it is a retrospective, single institution study. Furthermore, bleeding in inpatients on anti-platelets was not assessed.

Disclosures:

No relevant conflicts of interest to declare.
Comparative Study of the Biological Characteristics of Serum-Free and Fetal Bovine Serum-Contained Medium Cultured Umbilical Cord-Derived Mesenchymal Stem Cells
Authors: Chen Guanghua , Yang Ting , Qiao Man , Liu Huiwen , Depei Wu
Published: October 2019

Abstract 4737

Objective:

To compare the difference of biological characteristics between human umbilical cord-derived mesenchymal stem cells (UC-MSC) cultured by serum free medium and fetal bovine serum-contained complete medium and to create a xenogeneic protein-free UC-MSC culture system.

Methods:

Healthy human umbilical cord segments were digested with collagenase. Umbilical cord-derived mesenchymal stem cells were cultured by serum free MesenCult-XF medium and FBS-based αMEM complete medium. We analysed the morphology, immunophenotype, expansion potential, trilineage differentiation potential, karyotype and immunosuppression of early passage of UC-MSC.

Results:

The average cell diameters of UC-MSC in suspension cultured by serum free medium and FBS-based medium are 26 (18–39) μm and 35 (20–61) μm, respectively. Cell expansion folds with serum free medium and FBS-based medium were (5.2±0.2) and (3.5±0.1) in the first five passage, respectively. The expansion potential of MSCs was significantly higher with serum free medium compared to FBS-based medium (P<0.05). A panel of markers as CD29, CD44, CD90, CD73, CD105 and HLA-ABC were expressed by human UC-MSC. Hematopoietic lineage markers CD34, CD45 and HLA-DR were not detectable on UC-MSC. The cpm were (4.57±0.14)×104, (2.04±0.16)×104 and(0.42±0.04)×104 when serum free medium cultured MSCs were added to the cultures at ratios MSCs/T cell of 1:100, 1:10 and 1:5. While the cpm were (4.57±0.14)×104, (2.04±0.16)×104 and(0.42±0.04)×104when serum free medium cultured UC-MSCs were added to the cultures. The immunosuppressive potential of serum free medium-cultured UC-MSC was higher than that of serum-contained medium cultured UC-MSC at three different ratios MSC/T cell (P<0.05). Conclusion Compare with serum-contained medium cultured early passage of UC-MSC, the cell diameter of serum free medium cultured MSCs was smaller and the expansion potential was higher. No xenogeneic proteins were presented in UC-MSC preparation when UC-MSC was cultured with serum free medium. Human UC-MSC suppresses T-cell proliferation in a dose-dependent manner. The immunosuppressive potential of UC-MSC was higher when cultured in serum free medium compared with FBS-based medium.

Disclosures:

No relevant conflicts of interest to declare.
Hemoglobin Agenogi in Argentina: Case Report
Authors: Martin Ana Paula , Gargallo Patricia Martha , Bragos Irma Margarita , Abbate Alejandro , Ojeda Mara Jorgelina , Montero Verónica Susana
Published: October 2019

Abstract 4776

Hb Agenogi [b90(F6)Glu–>Lys], a beta chain variant was detected in a 44-years-old female patient of italian ancestry. She showed a hypochromic microcytic anemia and was treated as ferropenic anemia since she was 27 years old. The complete cell blood count revealed the following results: RBC: 4.01× 1012/L, PCV:30.9%, Hb:10.4 g/dl, MCV: 77fl, RDW 13.5%, MCH: 25.9 pg, MCHC:33.7%; reticulocytes: 0.6% and the peripheral blood smear showed no basophilic stippling. Serum vitamin B12, folate, iron, transferrin, transferrin saturation and ferritin were normal. The electrophoresis performed on agarose (alkaline pH) revealed a band of 44.5% with a mobility between Hb C and S. The unstable hemoglobin test was positive and the P50 was 31.3 mmHg (NR: 24 –28 mm Hg). This slow-moving hemoglobin, mild unstable and with decreased oxygen affinity was further characterized by sequencing of the amplified DNA, showing the substitution of glutamic acid (GAG) to lysine (AAG) at position 90 of the β globin chain This mutation has been described in only nine families, this is the second affected case in Argentina.

Disclosures:

No relevant conflicts of interest to declare.
The Feature of MALT1-A20-NF-κB Expression Pattern Provide Important Insights Into the Therapeutic Benefit for T-ALL
Authors: Ma Yu , Wu Xiuli , Wang Xu , Zhang Fan , Yang Lijian , Chen Shaohua , Li Bo , Li Yangqiu
Published: October 2019

Abstract 4810

The knowledge of oncogenic signaling pathways of T-cell acute lymphoblastic leukemia (T-ALL) is still limited. Constitutive aberrant activation of NF-κB signaling has been detected in various lymphoid malignancies and plays a key role in the development of these malignancies. The zinc finger-containing protein A20 (also known as Tumor Necrosis Factor Alpha-Induced Protein 3 or TNFAIP3) is a central regulator of multiple NF-κB activating signaling cascades. A20 is inactivated and results in constitutive NF-κB activation in tumor cells. A20 is now known to act as a crucial tumor suppressor in various hematological malignancies like lymphomas. MALT1 (mucosa-associated lymphoid tissue lymphoma translocation protein 1) plays a critical role in the regulation of NF-κB pathways, and mediated rapid proteolytic cleavage and inactivation of A20. To further characterize the function of these signal molecules, we analyzed the expression levels of A20, NF-κB and MALT1 genes in peripheral blood mononuclear cells (PBMCs) of 19 patients newly diagnosed with T-ALL (aged 4–70 years, median 25), and investigated the relationship between the aberrant expressions of these genes and T-ALL. Twenty-nine healthy individuals (aged 20–57, median 28) served as controls. We found that the expression levels of A20 in T-ALL patients (6.057±5.275) were significantly lower than healthy group (9.865±5.370) (P=0.020), while the expression levels of NF-κB (0.560±0.425) and MALT1 (2.712±3.127) in T-ALL patients were significantly higher than healthy group (0.337±0.311, 0.713±0.464) (P=0.041, P=0.001). The expression levels of A20 had a significant negative correlation with the expression of MALT1 (r=−0.628, P=0.009), and the reduced levels of A20 had a positive correlation with the increased expression of NF-κB in T-ALL (r=0.588, P=0.017). In conclusion, the overexpression of MALT1 in T-ALL causes constitutively cleavage and inactivation of A20 to enhance NF-κB signaling, and may contribute to the pathogenesis of T-ALL. Thus, MALT1 may consider as a potentially attractive target for the development of T-ALL therapeutics.

Disclosures:

Ma: National Natural Science Foundation of China (No. 91129720): Research Funding. Wu:National Natural Science Foundation of China (No. 91129720): Research Funding. Wang:National Natural Science Foundation of China (No. 91129720): Research Funding. Zhang:National Natural Science Foundation of China (No. 91129720): Research Funding. Yang:National Natural Science Foundation of China (No. 91129720): Research Funding. Chen:National Natural Science Foundation of China (No. 91129720): Research Funding. Li:National Natural Science Foundation of China (No. 91129720): Research Funding. Li:National Natural Science Foundation of China (No. 91129720): Research Funding.
Pediatric Mixed Phenotype Acute Leukemia-41 Cases Report
Authors: Gao Huifang , Liu Yi , Zhang Ruidong , Xie Jing , Shi Huiwen , Wu Minyuan , Huang Pengli , Zheng Huyong
Published: October 2019

Abstract 4811

Background:

Mixed phenotype acute leukemia (MPAL) is a rare type of acute leukemia with a poor clinical outcome, defined by the blasts express antigens of more than one lineage. MPAL was also named as mixed lineage leukemia, bilineal leukemia, biphenotype leukemia historically. The properly diagnosis of MPAL is crucial for the treatment. The scoring system proposed by European Group for Immunological Characterization of Leukemia (EGIL) in 1995 was the first standard criteria to diagnose MPAL. In 2008, WHO proposed a new scoring criteria to define MPAL. But both of these two systems have their limitation.

Methods:

We retrospectively analyzed 41 pediatric patients with mixed phenotype acute leukemia from 2000 to 2010 according to EGIL scoring system. All the 41 patients were reclassified according the 2008 WHO classification. Diagnosis, cytogenetics, immunophenotype, treatment and prognosis were analyzed.

Results:

There were 25 male and 16 female with the mean age of 8 years old. According to EGIL scoring system, the phenotype included T/myeloid (n=16), B/myeloid (n=13), T/B(n=11) and T/B/AML(n=1), respectively. Among the patients, there were 4 MPAL with t(9;22)(q34;q11), 5 with t(12;21)(p13;q22), 1 with inv(16)(p13;q22) and 1 with t(9;9). The overall complete remission (CR) rate was 47% treated by ALL regimen (n=19) and 17% by the AML+ALL combined therapy (n=6). MPAL with t(9;22)(q34;q11) showed poor response (4/4). MPAL with t(12;21)(p13;q22) had a good response to the treatment(4/5). Based on the 2008 WHO criteria, 24 of the 41 MPAL patients were reclassified as MPAL, including T/myeloid type(n=11), B/myeloid type(n=6), T/B(n=7). Three MPAL patients with t(12;21)(p13;q22) diagnosed by EGIL system were excluded by 2008 WHO criteria.

Conclusion:

Our results suggest that MPAL is a poor outcome disease requiring more accurate classification based on genetic and gene classification. MPAL with t(9;22)(q34;q11) is a predictor of poor outcome. MPAL with t(12;21)(p13;q22) could be treated only by ALL regimen. MPAL with both lymphoid and myeloid markers appears to achieve a better CR rate if treated by ALL regimens alone than treated by ALL+AML combined regimens. Further studies are needed to determine a standard diagnosis and treatment approach for MAPL.

Disclosures:

Zheng: Beijing Health System High-level Technical Personel Plan: Research Funding.
Clinical Course and Pathological Findings in a Series of Patients with Aggressive Natural Killer (NK) Cell Leukemia
Authors: Liebman Mira F , Sheridan Brian L.
Published: October 2019

Abstract 4823

Background:

NK cell leukemia is a rare, malignant proliferation of NK cells associated with Epstein Barr Virus (EBV). The World Health Organization (WHO) defines NK cell leukemia based on a blood film showing pancytopenia, and circulating leukemic cells, which are positive for CD2, cytoplasmic CD3, CD56, and cytotoxic molecules. The neoplastic cells may have a wide range of appearances, including cells that resemble large granular lymphocytes, highly atypical cells with abundant cytoplasm, and azurophilic granules. Reported cytogenetic abnormalities have included 6q deletion, 11 q deletion and losses of 7p and 17p.

Previous publications in the medical literature have been limited to case reports, mostly from Asian centers.

Methods:

We conducted a retrospective chart review of all aggressive NK cell leukemia diagnoses at an academic medical center, from 2008–2012.

Results:

We identified 4 cases of aggressive NK cell leukemia. The median age at diagnosis was 57 years. 3 out of 4 cases were male, and 3 of 4 were associated with EBV infection. All patients presented clinically with cytopenias, one patient had an elevated white blood cell count, 31 × 10 9per liter with the others presenting with pancytopenia. All had constitutional symptoms (including fever and night sweats) at diagnosis. 2/4 cases had extramedullary involvement, including splenomegaly and lymphadenopathy. One patient presented with hemophagocytic lymphohistiocytosis. 2/4 patients had CNS involvement. All had a large proportion of circulating neoplastic cells (12–80%).

The blood film examination in all cases demonstrated large, pleomorphic neoplastic cells. Most (3/4) had distinct nucleoli and 1/4 had large azurophilic granules in the cytoplasm. The immunohistochemistry profile showed positivity for cytoplasmic CD3, CD56 and CD7 in all cases. 3/4 cases were positive for CD11c. 2/4 patients had unique complex karyotypes including chromosome 3p duplication, deletion of 16q, addition 1p, trisomy 7, trisomy 8, isochrome 17q and near tetraploid karyotype.

All patients received treatment with various chemotherapeutic protocols; however none received radiation therapy, or stem cell transplantation. 2/4 cases achieved a short remission. All patients had poor clinical outcomes with median survival of 12 months (range 2–19 months), which is consistent with prior reports.

Conclusion:

This case series serves to confirm the typical clinical presentation, and poor prognostic outlook, of patients with aggressive NK cell leukemia. This rare malignancy was previously described only in individual case reports. In our patient population, we noted complex, novel cytogenetic findings. Our study reaffirms the need for new therapeutic modalities to improve the poor prognosis for this disease.

Disclosures:

No relevant conflicts of interest to declare.
Viral Ortholog Complements Mir-155 Deficiency-Associated Abnormalities and Together with Additional Viral Mirnas Causes B Cell Hyperplasia and B Cell Lymphoma
Authors: SIN Sang-Hoon , Dittmer Dirk P
Published: October 2019

Abstract 4866

MicroRNA-155 (miR-155) is overexpressed in many types of cancers including B cell lymphomas. It has also an essential function in GC development. These functions are conserved among species and miR-155 knockout (ko) mice are deficient in GC development in Peyer's patches (PP) and lymph nodes. The human tumor virus Kaposi sarcoma associated herpesvirus (KSHV) encodes an ortholog to miR-155, named miR-K12-11. MiR-155 and miR-K12-11 share 100% seed sequence homology (Nature. 2007 Dec 13;450(7172):1096-9, J Virol. 2007 Dec;81(23):12836-45). Another human herpesvirus, Epstein-Barr Virus, induces mir-155 upon infection and immortalization of naïve B cells in culture. To test the hypothesis that miR-K12-11 can complement the normal function of miR-155 in vivo, we generated transgenic mice, which express miR-K12-11, as well as the other 21 KSHV miRNAs. Using this mouse model, we show that KSHV latency locus which contains a viral ortholog of miR-155, KSHV miR-K12-11 complements B cell abnormalities associated with the lack of miR-155. Germinal center (GC) formation is rescued in spleen and PP and lowered immunoglobulin level is also augmented to normal in KSHV latency locus transgenic mice with miR-155 ko background. Furthermore, mature B cells were chronically activated, leading to hyperglobulinemia triggered by increased plasma cell frequency. Marginal zone (MZ) B cells developed hyperplasia and the mice had an augmented response to T-dependent antigen as well as the TLR4 ligand LPS in vivo. This suggests that by mimicking miR-155 (and other functions) this human tumor virus drives the expansion of infected B cells, which if left unchecked can accumulate secondary mutations leading to post-GC lymphoma and multicentric Castleman's disease.

Disclosures:

No relevant conflicts of interest to declare.
Relative Stability Of Plasma Cells Immunophenotype In Multiple Myeloma Over Time
Authors: Tessoulin Benoit , Legouill Steven , Eveillard Marion , Robillard Nelly , Wuilleme Soraya , Gastinne Thomas , Touzeau Cyrille , Pellat-Deceunynck Catherine , Bene Marie C , Moreau Philippe
Published: October 2019

Emerging evidence indicates that multiple myeloma (MM) can follow a number of evolutionary pathways over a patient’s disease course. Recently, genomic data have shown the coexistence in many patients of several tumour types, which could be either genetically stable, evolving linearly or be constituted of heterogeneous clonal mixtures with predominant clones shifting over time (Keats, Blood 2012;120:1067-1076). Little is known however of immunophenotypic evolution of the myeloma cells (MM cells) during MM progression.

In a retrospective single-centre analysis of tumoral immunophenotypes, we examined sequential bone marrow or peripheral blood samples from 51 MM patients. Multiparameter flow cytometry was performed to assess MM phenotype using CD38 and CD138 expression as well as intracytoplasmic light chain usage restriction in most cases. The presence or absence of CD19, CD20, CD27, CD28, CD56 or CD117 on the MM cells’surface was investigated additionally. A median of 4 of the latter antigens was examined per sample. Most MM cells were homogeneous in the expression or absence of expression of the differentiation antigens investigated. Immunophenotype changes were defined as the loss or gain of at least 1 antigen. Whenever partial expression of one or several antigens was observed on MM cells, indicating MM subsets, the presence of subclones was suspected.

Samples were obtained at diagnosis and relapse for 33 MM patients, and during consecutive relapses for 18. The total amount of analysed samples was 109, with a median of 2 samples per patient (range: 2-3). A modification of immunophenotype occurred in 22 patients (43%), with one antigen change (68%), two antigens changes (18%) or three antigens changes (14%). Immunophenotypic changes are summarized in table 1. For 20% of the cases or more, this involved CD28 (n=11, balanced gain or loss) or CD27 (n=7, mostly loss). CD56 expression, scarcely negative on the first assessment, was gained at relapse in three cases. Other antigens were expressed in a stable fashion over time. Eighteen (35%) of the patients had at least a subclone on the first immunophenotype, which was lost and/or modified in 14 / 18 patients at time of subsequent relapse.

There was no significant impact of immunophenotypic modifications on overall survival rates Similarly, the presence of a subclone at first examination, or the immunophenotypic change of this subclone over time was not associated with differences in overall survival rates.

In conclusion, this retrospective single centre study demonstrates that the immunophenotype of MM cells is mostly stable during the course of the disease. When changes occur, they do not seem to affect the clinical course of the patients. These preliminary results need confirmation on a larger and prospective trial.

Disclosures:

No relevant conflicts of interest to declare.
Identification Of a Novel Small Molecule Inhibitor Of ASK1 As a Potent Anti-Platelet Agent
Authors: Ulhas Naik Meghna , David Maloney , Turaga Ramya , Ichijo Hidinori , Naik Ulhas P
Published: October 2019

Apoptosis signal-regulating kinase (ASK1) is a serine/threonine kinase, belonging to the MAP kinase-kinase-kinase family, which is activated in response to stress. However, its presence and role in platelets are not known. We found that ASK1 is expressed in platelets and is rapidly activated during platelet stimulation by various agonists in a dose-dependent manner. In addition, we found that TRAF2/6, known endogenous activators of ASK1, are expressed in platelets and associate with ASK1 upon platelet activation with agonists. Furthermore, genetic ablation of Ask1 significantly delayed tail-bleeding time (P=0.2x10-9). While WT mice showed an average bleeding time of 100 s, the Ask1 null mice had an average bleeding time of 576 s. A carotid artery injury induced by 10% FeCl3 showed a significantly increased (P=0.0003) time of occlusion and unstable thrombus formation in Ask1 null mice. Furthermore, we found that loss of Ask1 renders significant protection to the mice from pulmonary thromboembolism induced by a mixture of collagen and epinephrine as determined by increased survival and lack of large occlusive thrombi in the lung. We also found that ADP- and AYPGKF (PAR4 receptor peptide) -induced platelet aggregation was diminished in Ask1 null mice compared to WT mice. Furthermore, PAR4 peptide-induced alpha- and dense-granular secretion was also reduced in Ask1 null platelets compared to WT. Interestingly, we also found that Ask1 null platelets bind less FITC-fibrinogen compared to the WT upon activation by PAR4 peptide. Furthermore, thrombin failed to activate MKK6 and p38 in Ask1 knockout platelets, showing that Ask1 is indispensable for p38 activation by thrombin. These results indicated that ASK1 regulates platelet function by augmenting platelet secretion as well as fibrinogen receptor activation, making it an important target for combating thrombosis. We therefore synthesized a novel and highly specific ASK1 inhibitor, N-(6-(1H-imidazol-1-yl)imidazo[1,2-a]pyridin-2-yl)-4-(tert-butyl)benzamide (IPTB) based on the published report. IPTB has been found to be a very potent inhibitor that inhibits ASK1 activity at nM concentrations. IPTB is also highly specific to ASK1 and does not affect activities of related protein kinases such as ASK2, MEKK1, TAK1, and ERK1. We found that in human platelets, IPTB dose-dependently inhibits p38 activation induced by a variety of platelet agonists. Furthermore, IPTB dose-dependently inhibited ADP and PAR4 peptide-induced platelet aggregation. Interestingly, IPTB also dose-dependently inhibited platelet spreading on immobilized fibrinogen. Our results strongly suggest that the dose of IPTB could be adjusted so that it attenuates thrombosis without affecting hemostasis. This development would make IPTB a novel potential therapeutic agent to be used to combat thrombotic disorders.

Disclosures:

No relevant conflicts of interest to declare.
Donor Specific Tolerance Of Renal Allografts Following Haploidentical In Utero Hematopoietic Cell Transplantation In The Canine Model
Authors: Pearson Erik G. , Vrecenak Jesse D , Bhatti Tricia R , Peranteau William H. , Flake Alan W.
Published: October 2019

Introduction

In utero hematopoietic cell transplantation (IUHCT) can result in allogeneic mixed hematopoietic chimerism and associated donor specific tolerance (DST). We have reported a 1-2% donor chimerism threshold for consistent DST in the murine model as defined by the ability to enhance engraftment postnatally with a same donor minimal conditioning BMT, and have confirmed this finding in the canine model of IUHCT. Recently, we have optimized the canine model and achieved higher levels of chimerism (average>10%). As prenatal tolerance induction for postnatal organ transplantation is one of the clinical goals of IUHCT, we hypothesized that the presence of donor chimerism (>2.0%) after haploidentical IUHCT in the canine model would be sufficient to allow same donor renal transplants without immunosuppression.

Method

Stable mixed hematopoietic macrochimerism was documented by VNTR after haploidentical IUHCT performed at 40 days gestation using maternal donor BM cells in 4 pups (chimerism levels 3-38%). One positive control canine with no detectable chimerism following IUHCT also underwent haploidentical renal transplantation. Renal transplantation was performed from the maternal donor at ages between 12 and 18 months, and the pups were serially followed by ultrasound of the graft, blood chemistry and urinalysis post transplant. At 60 days an open biopsy of the allograft was taken and at 6 months a graft nephrectomy was performed for histologic analysis.

Results

Following transplantation, all recipients demonstrated blood flow to the renal cortex and all laboratory values were within normal ranges. At 60 days and 6 months 3 of the 4 recipients demonstrated a graft without evidence of acute or chronic rejection. The recipient with the lowest level of chimerism (3%) demonstrated evidence of mild interstitial nephritis (Banff class 1 rejection) following transplantation at the time of renal biopsy which increased in severity to severe interstitial fibrosis and moderate tubular atrophy (Banff class 3 rejection) at the time of graft nephrectomy. The positive control canine without detectable chimerism demonstrated clinical and histologic evidence of acute rejection within one week of transplantation.

Conclusion

Our results support the ability of IUHCT to induce DST for haploidentical organ transplantation, in a large animal model, without the need for immunosuppression. In agreement with previous studies in the murine model there appears to be a threshold level of donor chimerism required for associated DST. Although our numbers are not adequate to establish absolute thresholds of chimerism predictive of DST for organ transplantation, it appears to be slightly higher than the 1-2% threshold established for cellular transplantation.

Disclosures:

No relevant conflicts of interest to declare.
Immunologic Effects Of Mesenchymal Stem Cells In The Treatment Of Refractory Acute Graft-Versus-Host Disease
Authors: Liu Qifa , Zhao Ke , Liu Can , Wu Meiqing , Zhang Yu , Huang Fen , Fan Zhiping , Dai Min , Sun Jing
Published: October 2019

Background

Mesenchymal stem cells (MSCs) have been considered as a promising strategy for the prevention and treatment of acute graft-versus-host disease (aGVHD), but the mechanism of MSCs ameliorating GVHD is still not fully understood. A few studies suggested that MSCs ameliorated GVHD via protecting and repairing the function of thymus.

Methods

Twenty refractory aGVHD patients receiving MSCs treatment were enrolled in this study, and twenty grade II to IV aGVHD patients treated without MSCs were matched as non-MSCs group. MSCs were given at a median dose of 1×106 cells/kg once weekly until aGVHD got complete response (CR) or MSCs were infused for a total of 8 doses. Lymphocyte subsets of T-cell, B-cell, and NK-cell in peripheral blood were analyzed by flow cytometry before and 30, 60, 90, 180 and 360 days after the MSC infusion in MSC group and the corresponding period in the control group.

Results

A total of the 33 patients who survived more than 30 days after the study treatments were evaluated for the alterations in cellular immune compartment and cGVHD, including 15 cases in MSCs group and 18 in non-MSCs group. In MSCs group, patients had a significantly higher CD4+/CD8+ T-cell ratio at 60, 90 and 180 day after MSCs treatments, which subsequently equalized at 360 day compared with non-MSCs group. The MSC group presented higher percentages of CD4+CD25+ regulatory T cells (Treg) comparing with non-MSCs group, especially at 90 and 180 day, and approached at 360 day. The proportion of CD4+CD45RO+ and CD4+CD45RA+ naïve T-cells in MSC group were also higher than those in non-MSCs group at 60, 90 and 180 day, but not different at 360 day. The proportion of CD19+ and CD16+CD56+ was not detected striking difference between the two groups. Four patients (26.7%) experienced cGVHD in MSCs group, compared with twelve (66.7%) in non-MSCs group (p=0.02).

Conclusions

In conclusion, our data indicate that MSCs might ameliorate aGVHD and induce longer-lasting immune tolerance by altering cellular immune compartments in peripheral blood. The alteration of the cellular immune compartments is associated with the protecting and repairing role of MSCs to thymus.

Disclosures:

Liu: 863 Program (No. 2011AA020105): Research Funding; National Public Health Grand Research Foundation (Grant No. 201202017): Research Funding; National Natural Science Foundation of China (Grant No.81000231, No.81270647): Research Funding; Science and Technology Program of Guangzhou of China (11A72121174) : Research Funding.
Circulating Endothelial Cells Enumeration Is a Helpful Tool In The Diagnosis Of GvHD In Patients Undergoing Allogeneic Hematopoietic Stem Cells Transplantation
Authors: Almici Camillo , Skert Cristina , Verardi Rosanna , Di Palma Andrea , Bianchetti Andrea , Russo Domenico , Marini Mirella
Published: October 2019

Allo-HSCT can be burdened by life-threatening complications, being GvHD the major cause of morbility and mortality. Clinical and physio-pathological evidences showed that vascular endothelium could be a target of GvHD in very early phase; therefore markers of endothelial damage are warranted as valuable support in GvHD diagnosis. We conducted a study with primary endpoint to identify and count circulating endothelial cells (CEC) in peripheral blood of patients undergoing allo-HSCT as a function of endothelial damage.

The CellSearch System® is used to capture and enumerate CEC. Enriched and stained cells are dispensed into a MagNest® cartridge that is scanned and individual images of cells are scored as CEC, based on CD146+, CD105+, DAPI+ and CD45- phenotype. Patients undergoing allo-HSCT were tested before (T1), after the conditioning regimen (T2), at engraftment (T3), at GvHD onset (T4) and at 1 weeks after steroids treatment (T5). Ten healthy subjects served as controls.

We enrolled 40 patients with hematologic neoplastic diseases (7 HD, 13 AML, 5 ALL, 8 MM, 3 CLL, 1 NHL, 1 CML, 2 SAA) undergoing allo-HSCT from either HLA-matched familial (n=12) or unrelated donor (n=28). GvHD (grade I-IV) manifested in 19/39 patients. No clinical and transplant characteristics differences were present between patients with and without GvHD. The median CEC/ml pre allo-HSCT was 20 (n=40, range 4-718), in comparison to a value of 2 (range 1-14) in the 10 healthy subjects. At time of engraftment CEC/ml were 47 (range 16-148) in patients with GvHD and 92 (range 23-276) in patients without GvHD (P=0.006). This difference remained significant in multivariate analysis by logistic regression model (OR 0.97, 95% C.I. 0.96-0.99; P=0.02). At GvHD onset, the relative increase of CEC counts (T4 vs T3) was 44% (range, -43 - 569%) in GvHD patients versus 0% (range, -49 – 2%) in patients without GvHD (P=0.003), being confirmed in multivariate analysis (OR 1.04, 95% C.I. 1.0-1.08; P=0.04).

Circulating endothelial cells can represent a promising marker to monitor endothelial damage in patients undergoing allo-HSCT. The confirmation of the clinical utility of CEC counts in a larger series of patients, together with the use of a semi-automatic, standardized and reproducible technology, will allow a valuable help in the diagnostic definition of GvHD in early phase, and moreover could be a valid complement in the prognostic stratification of patients candidates to allo-HSCT.

Disclosures:

No relevant conflicts of interest to declare.
Adolescents and Young Adults With Hemophagocytic Lymphohistiocytosis Who Undergo Allogeneic Hematopoietic Cell Transplantation Are At Increased Risk Of Mortality Compared To Younger Patients
Authors: Chandrakasan Shanmuganathan , Marsh Rebecca , Grimley Michael , Bleesing Jack , Jordan Michael , Filipovich Alexandra H.
Published: October 2019

Hemophagocytic lymphohistiocytosis (HLH) is a potentially life-threatening disorder of immune deregulation characterized by overwhelming immune activation and inflammation. Primary HLH was once thought to affect predominantly infants and young children. However, with increasing awareness, HLH is being diagnosed in adolescents and young adults. Currently, allogeneic hematopoietic cell transplantation (HCT) is the only curative therapy available for primary hemophagocytic lymphohistiocytosis (primary HLH). There is limited data on HCT outcome for adolescents and young adults with HLH. We reviewed the allogeneic HCT outcomes of 19 adolescents and young adults with HLH (12 males and 7 females) who underwent HCT from January 2000 to June 2013 at our center. The median age at transplantation was 18.2 years (range: 15.2 -27.2). The Majority (15/19) underwent reduced-intensity conditioning (RIC) regimen consisting of alemtuzumab, fludarabine, and melphalan. Thirteen patients received transplants from HLA- matched donors (10 MUD and 3 MSD). Bone marrow was the source of stem cells in 15 patients. The HCT outcome of this group was compared to outcome of children with HLH less than 15 years of age. Median follow up of adolescent and young adult patients following HCT is 280 days (range 9-1643 days). Mixed donor chimerism was noted in 20% (3/15) of patients who received RIC. Acute GVHD grade II-IV was noted in four patients. Overall survival for adolescent and young adult patients was 42.1% (8/19). In patients who received RIC, Kaplan Meier analysis revealed a long term estimated survival of 57%, compared to 75% for children less than 15 years of age (p=0.03). Cox proportional hazard modeling revealed a reduced risk of mortality in young patients undergoing RIC HCT compared to adolescent and young adult patients (HR 0.379 [0.154-0.933], p=0.035), controlling for donor match and source. Deaths in adolescent and young adult patients occurred from days +9 to +568 following HCT. The cause of death varied from fulminant bacterial sepsis (n=4), acute refractory GVHD (n=2), disseminated aspergillus and fungal sepsis (n=2), viral infection (n=2), and refractory chronic GVHD (n=1). In conclusion, adolescents and young adults with HLH who undergo allogeneic HCT are at increased risk of mortality compared to younger patients. Further studies are needed to identify risk factors and potential interventions to improve HCT outcome for adolescents and young adults with HLH.

Disclosures:

No relevant conflicts of interest to declare.
Association Of Health Care Expenditure With Results Of Allogeneic HSCT For Adults With ALL: An Analysis From Acute Leukemia Working Party Of The EBMT
Authors: Giebel Sebastian , Labopin Myriam , Ibatici Adalberto , Browne Paul , Czerw Tomasz , Socié Gérard , Unal Ali , Kyrcz-Krzemien Slawomira , Bacigalupo Andrea , Goker Hakan , Potter Michael N , McQuaker Grant , Beelen Dietrich , Milpied Noel , Campos Antonio , Craddock Charles , Mohty Mohamad
Published: October 2019

Background

Results of allogeneic hematopoietic stem cell transplantation (aloHSCT) depend on many patient-, donor- and procedure-related factors. In recent years, in a setting of AML we demonstrated that also socio-economic status of a country and center experience may influence outcome. The goal of the current analysis, focused on patients with acute lymphoblastic leukemia (ALL), was to evaluate specific effects on non-relapse mortality (NRM) related to health care expenditure (HCE) of a country as well as distribution of transplant centers in addition to previously studied human development index (HDI) and center activity.

Patients and methods

Results of myeloablative alloHSCT from HLA-identical siblings performed between 2004-2008 for adults with ALL in CR1 were analyzed. Among 983 individuals treated in 27 European countries the median age was 35 (18-55) years and the interval from diagnosis to alloHSCT – 158 (42-831) days. TBI was used for conditioning in 820 (83%) cases and peripheral blood was a source of stem cells in 656 (67%) cases. The following factors were studied for their impact on outcome: current HCE, HCE as % of gross domestic product, public HCE, private HCE, no. of teams per country area and population, HDI and center activity (no. of alloHSCT for ALL in a study period). All variables were categorized by medians. The median follow-up was 34 months.

Results

In a univariate analysis the probability of day 100 NRM was increased for countries with lower current HCE (p=0.06), lower HDI (p=0.02) and for centers with lower experience (p=0.04). Also overall NRM was affected by current HCE (p=0.09), HDI (p=0.03) and center activity (p=0.07). In a multivariate model adjusted for recipient age, interval from diagnosis to HSCT, source of stem cells, type of conditioning, and donor/recipient gender, the variables of interest were included separately due to strong internal correlations. The best predictive model for day 100 NRM included HDI < median (HR = 2.38, 95%CI = 1.3-4.35, p=0.005). The overall NRM was most strongly predicted by current HCE < median (HR = 2.56, 95%CI = 1.41-4.76, p=0.002). In a univariate analysis lower values of HDI and current HCE were also associated with decreased probability of the overall survival (p=0.004 and p=0.006, respectively).

Conclusion

Both macroeconomic factors and the socio-economic status of a country influence strongly non-relapse mortality and overall survival after alloHSCT for adults with ALL. Our findings should be considered in interpretation of clinical studies in the field of alloHSCT.

Disclosures:

No relevant conflicts of interest to declare.
Adverse Pregnancy Outcomes In High Risk Sickle Cell Women
Authors: Saraf Pankhoori , Jacoby Sari H , Shah Shailja , Nazir Habib , Gimovsky Martin , Cohen Alice J.
Published: October 2019

Background

Life expectancy in patients with sickle cell disease (SCD) has increased with the institution of newborn screening, antibiotics and Hydroxyurea (HU). Prior studies have reported maternal mortality rate to be 2.2 times that of normal pregnancies. With improved high risk obstetrical services and hematological care, more women with SCD are choosing to carry a pregnancy (P). In order to see if outcomes have improved, we performed a review of women with SCD who had recent P at our hospital with a focus on maternal and fetal outcomes.

Methods

Patients (pts) were identified by a chart review of all women of childbearing age followed at both the Comprehensive Sickle Cell Center and the high risk obstetrics clinic. Data included: genotypes of SCD, fetal complications, P outcomes, transfusions (T), hospital admissions, previous HU use.

Results

71 pregnancies were identified in 53 women from 2008 to 2013.

Pregnancy outcomes

See Table 1. Live births rates were equal in both GR I and GR II. The mean gestational age (weeks) in GR I was 35.13 and GR II 38.28 (p=0.0077) with more preterm births in GR I 16/36 (44%) compared to GR II 2/18 (11%). The most common mode of delivery was C-section in both GR I and II. Reasons for C- section were fetal distress 60% (20), repeat C-section 27% (9), other (5% or less) for breech, elective, preeclampsia, placenta previa. There were equal numbers of induced and spontaneous labor in each group. Complications in GR I 8/36 (22%) and GR II 2/18(11%) included PIH, Chorioamniotis, placenta previa, death (cardiac arrest).

Fetal outcomes

Low birth weight occurred in 20/33(61%) of GR I and 3/18(17%) of GR II (p= 0.0016) births. Other complications (41 % of births) including IUGR, meconium aspiration, oligohydramnios and Apgar scores <7 @ 1 min occurred equally in both GRs.

Maternal outcomes: During P mean values for events in GR I and GR II respectively were: transfusions 5.56 units (U) and 1.22 U (p=0.0022), admission for vasoocclusive crisis (VOC) 3.33/pt and 1.44/pt (p=0.0173). Other complications were urinary tract infection (7), pneumonia (4), acute chest syndrome (4), cardiomyopathy (1), renal failure (1), hepatic crisis (2), DVT (1). Six patients were on HU pre- pregnancy (PP). In these patients 13 simple blood T were required PP and 56 during P (p=0.0297). VOC events increased from 13 PP to 35 during P (p=0.1011). 2 patient required exchange T during P.

Conclusion

Despite improved antenatal care for SCD women, P remains a high risk event for mother and fetus, with lower birth weights and more preterm deliveries in SS/SB 0 thal pts compared to SC/SB+ thal. Prior use of HU PP was not protective. New insights and studies are warranted to understand the pathophysiology of SCD causing adverse pregnancy outcomes and possible effects of HU withdrawal.

Disclosures:

No relevant conflicts of interest to declare.