bluuebunny/crossref_metadata_2025_split huggingface dataset:
IgD Amyloidosis: An Unrecognized Entity
Authors: Gertz Morie Abraham , Buadi Francis K , Hayman Suzanne R , Dingli David , Dispenzieri Angela , Greipp Philip R. , Kumar Shaji , Lacy Martha Q , Lust John A , Leung Nelson , Rajkumar S. Vincent , Russell Stephen J. , Zeldenrust Steven R , Mikhael Joseph R. , Roy Vivek , Kyle Robert A 
Published: October 2019

Abstract 5079

Introduction:
IgD monoclonal proteins are rare. They are not seen as a MGUS and are present in 1% to 2% of patients with myeloma. In light chain amyloidosis (AL), IgD monoclonal proteins are rare. When an IgD protein is found, amyloidosis is often omitted from the differential diagnosis. An IgD protein in amyloidosis has been reported in single cases but never as a patient series. We report IgD AL in 53.

Patients & Methods:
Clinical and demographic data for patients were retrieved from the patient records. Factors of interest were compared between patients who did and did not have an IgD protein.

Results:
Among 3,955 patients with AL amyloidosis seen, 53 patients (1.3%) had a serum IgD monoclonal protein. (Table 1) A serum monoclonal protein peak was visible on SPE in only 14, and only 5 had an M spike greater than 1 g/dL. On immunofixation of the serum, the IgD light chain was k in 11, λ in 35, and uncertain in 6; 1 patient had a biclonal D λ and G k protein. A urine monoclonal protein was detected in 43 of 51 patients; urinary immunofixation detected a λ light chain in 33 and a k light chain in 10. Biopsy of tissues showed amyloid deposits in the bone marrow in 47% and in the fat aspirate in 73%.
Six patients (age 47–63 years) underwent autologous SCT. Four had renal & two had cardiac AL. All 6 had hematologic PR, 4 CR, and 4 had organ response. One patient had relapse of disease and is now on dialysis, and another had relapse and is alive with salvage chemotherapy. One patient had disease relapse and died of progressive GI amyloidosis at 22 months. The other 5 are alive at a median of 68 months (range, 7.5–83.5 months). We compared the 53 patients with IgD amyloidosis with 144 patients with non-IgD amyloidosis. (Table 2) Findings that were significantly different between groups included a lower frequency of renal amyloidosis (P=.005) and a lower prevalence of cardiac amyloidosis (P=.047). There was a higher serum albumin level (P=.04) related to the lower level of proteinuria. No difference in survival was seen between the groups. (Figure). Variables that might affect survival—liver size, performance status, septal thickness, serum creatinine level, and β2-microglobulin level—were not different between groups.

Conclusions:
IgD AL patients have a lower frequency of renal involvement and possibly also of cardiac involvement. The overall survival of these patients does not appear to be different from that of patients who have AL associated with another monoclonal protein. IgD monoclonal proteins are so closely linked to the diagnosis of multiple myeloma in the mind of a clinician that the possibility of amyloidosis may be overlooked.

Disclosures:
No relevant conflicts of interest to declare.
The Human CD38 Monoclonal Antibody Daratumumab Improves the Anti-Myeloma Effect of Lenalidomide with Dexamethasone in Vitro
Authors: Weers Michel de , Veer Michael van der , van Kessel Berris , Bakker Joost M , Wittebol Shulamiet , Parren Paul WHI , Lokhorst Henk M. , Mutis Tuna 
Published: October 2019

Abstract
Abstract 5106
Multiple myeloma (MM) represents an incurable malignancy of antibody-producing clonal plasma cells. Over the past decade significant progress has been made in MM treatment using novel immunomodulating agents such as lenalidomide (LEN) and bortezomib (BORT). Daratumumab (DARA) is a human CD38 antibody with broad spectrum killing activity. DARA mediates MM cell death via ADCC (antibody dependent cellular cytotoxicity), CDC (complement dependent cytotoxicity) and apoptosis. We are currently exploring the possibility to further improve MM therapy by combining novel MM therapeutics with DARA. Our initial in vitro work already showed significantly improved MM cell killing by combining DARA with LEN and BORT treatment, especially in patient samples which showed poor responses to the LEN-BORT combination. We now investigated whether DARA can also further improve therapy of lenalidomide or bortezomib in combination with corticosteroids. In ex vivo assays, which allow us to address MM cell lysis directly in BM-MNC isolated from MM patients, DARA significantly enhanced killing of MM cells that were treated with LEN or dexamethasone (DEX). Importantly, DARA was also able to enhance lysis of MM cells that were poor responders to the LEN-DEX combination. This suggests that patients might benefit from a DARA-LEN-DEX combination therapy. Experiments showing effects of DARA on killing of BORT-DEX treated cells are currently underway. The results of this study extend our previous results with LEN-BORT-DARA, showing that MM cells lysis is enhanced by DARA, especially in in samples from patients that are refractory or poorly responding to existing and novel emerging combination therapies. These results support the hypothesis that powerful and complementary effects may be achieved when DARA is combined with LEN and cortocosteroids in clinical MM studies.

Disclosures:
Weers: Genmab: Employment, Equity Ownership, Patents & Royalties. Veer:Genmab: Research Funding. van Kessel:Genmab: Research Funding. Bakker:Genmab: Employment, Equity Ownership. Parren:Genmab: Employment, Equity Ownership, Patents & Royalties. Lokhorst:Genmab: Membership on an entity's Board of Directors or advisory committees, Research Funding. Mutis:Genmab: Research Funding.
Long Term Efficacy of Percutaneous Vertebroplasty in Multiple Myeloma (MM) Patients: Experience of the “Gruppo Ematologico Di Romagna” (GER)
Authors: Tosi Patrizia , Molinari Annalia , Sintini Michele , Merli Anna , Ceccolini Michela , Imola Manuela , Savini Paolo , Pasini Silvana , Mianulli Anna M , Castagnari Barbara , Fattori Pier P , Martinelli Giovanni , Zaccaria Alfonso 
Published: October 2019

Abstract
Abstract 5123
Vertebral compression fractures occur in approximately 60% of MM patients and can cause pain, persistent disability and dismail quality of life. Appropriate therapy of MM or radiotherapy can lead to improvement of symptoms in a significant percentage of patients, but these positive effects can take time to be perceived. Vertebral agumentation techniques have been recently proposed as suitable options to relieve bone pain from vertebral compression fractures in patients with benign osteoporosis or neoplastic diseases such as MM. Aim of this study was to analyze the clinical course and outcome of 40 consecutive MM patients (23M, 17F, median age = 67.6yrs) treated in the Centers referring to GER, who underwent percutaneous vertebroplasty from 2006 to 2010. Seventeen patients (43%) were newly diagnosed while 23 patients were relapsed or refractory after 1–3 lines of therapy. All the patients were treated because of severe pain, the extent of vertebral fractures was assessed by nuclear magnetic resonance imaging. Sixty-nine procedures were performed at C2-L5 levels, 51% of the patients were treated at a single level, a maximum of three levels were treated in 6 patients, 13 procedures (32%) were performed at L1 level. Thirty seven patients (92%) experienced reduction of pain, with 55% showing complete disapperance of symptoms prior to any further treatment, 3 patients reported no or little improvement. Responses were durable, after a median follow-up of 14 months no further collapse of the treated vertebrae was observed. After vertebroplasty, first line or salvage therapy was administered to 35 patients, 10 newly diagnosed patients were scheduled to receive autologous stem cell transplant, and peripheral blood stem cell collection was not affected by the procedure.
In conclusion, percutaneous vertebroplasty appears to be useful in MM patients with painful vertebral fractures as it allows rapid and durable achievement of pain control, without interfering with further therapeutic programs
Work supported in part by RiminiAIL

Disclosures:
No relevant conflicts of interest to declare.
Development of a Splenic Marginal Zone Lymphoma Associated with Active Chronic Visceral Leishmaniasis
Authors: Vase Maja Ølholm , Hellberg Ylva Kristina , Larsen Carsten Schade , Petersen Jørgen Eskild , Schaumburg Henrik , Bendix Knud , Ravel Christophe , Bastien Patrick , Christensen Mariann , Nyvold Charlotte Guldborg , d'Amore Francesco 
Published: October 2019

Abstract
Abstract 5202
We here report the observation of the development of a splenic marginal zone lymphoma (SMZL) after years of active chronic visceral Leishmania (VL) infection, implying a possible pathogenic link between these two conditions, where the neoplastic process is preceded by a prolonged period of chronic antigen stimulation.
In 2004, a 60-year old male developed attack-like episodes of septic fever with chills, rigor and subsequent profound fatigue. He had a 4 years previous medical history of severe asthma-like symptoms and hypereosinophilia. A bone marrow (BM) and liver biopsy were inconclusive. A whole-body computed tomography showed a moderately enlarged spleen. No evidence of bacterial, fungal or viral infection was found; the symptoms persisted, although mitigated, with occasional exacerbations over the following 3 years.
By 2007 the patient was admitted again and a new BM biopsy was taken, still showing reactive changes. Due to increased splenomegaly, a diagnostic splenectomy was performed. Examination of the spleen revealed a primary splenic marginal zone lymphoma (SMZL).
In 2010 the patient was admitted with septicaemia and constitutional symptoms. A BM biopsy showed the presence of numerous Leishmania amastigotes and a retrospective review of all previous biopsies (since 2004) identified Leishmania amastigotes in all of them.
In fact, a thorough travel history covering the previous two decades revealed several visits, often twice a year, to the Mediterranean basin, e.g. Greece and Malta, areas endemic for Leishmania infantum (L. infantum).
Visceral Leishmaniasis is a frequent opportunistic infection in HIV-infected immunodeficient individuals but uncommon in cancer patients, and only a few cases of VL in patients with already well-established malignant lymphoma have been reported.
Chronic antigenic stimulation by microbial pathogens has been proposed as a pathogenetic factor in a variety of marginal zone lymphomas. Tissue specific immune responses toward Leishmania parasites have been shown in rodents, and the spleen is a ‘safe harbor’ for the long-term persistence of visceralizing Leishmania. Sustained antigenic stimulation with upregulation of critical signaling pathways may result in prolonged polyclonal B-cell proliferation, and a subsequent increased risk of malignant transformation.
This case is the first to provide evidence for a possible link between chronic antigen stimulation by long-lasting L. infantum infection and the development of a SMZL.

Disclosures:
No relevant conflicts of interest to declare.
Subcutaneous Panniculitis-Like T-Cell Lymphoma: A Study of 12 Cases
Authors: Chen Xiaochen , Depei Wu , Sun Aining , Qiu Huiying , Wu Xiaojin , Shi Xiaolan 
Published: October 2019

Abstract
Abstract 5217

Objective:
Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare and distinct type of T-cell lymphoma. The objective of this study was to explore the clinical presentation, treatment, and prognosis of patients with SPTCL.

Methods:
Twelve cases of SCPTCL, treated in our hospital between June 2005 and June 2010, were included in this study. Their clinicopathological data were reviewed and analyzed retrospectively.

Results:
The median age at diagnosis was 41 years (range 25–69 years) and 7 (58%) were women. 9 cases had a CD3+, CD4-, CD8- phenotype; 2 cases, a CD3+, CD4-, CD8+ phenotype; and 1 case, a CD3+, CD4+, CD8- T-cell phenotype. In all cases, strong expression of cytotoxic proteins (granzyme B, TIA-1, perforin) was observed. CD56 was expressed in 8 of 12 cases.
4 patients had presented with solitary or localized skin lesions. Ulceration was observed in 3 patients. B symptoms, such as fever, chills, night sweats, and weight loss, had been recorded in 7 of 12 patients. Laboratory abnormalities, mainly anemia, leucopenia, thrombocytopenia or combined cytopenias, and elevated liver function tests and lactate dehydrogenase, were reported in 4 patients. Bone marrow examination showed histiocytic hyperplasia, hemophagocytosis, or decreased cellularity in 3 cases, but no evidence of lymphoma. A HPS was diagnosed in 4 of 12 patients (33%), and was fatal in 2 of them.
Four patients presenting with solitary or localized skin lesions had been treated with radiotherapy (2 cases) or surgery (2 cases). All 4 patients reached complete remission and only 1 of them showed a skin relapse, which was treated successfully with radiotherapy again. Eight patients with diffused lesions were treated with chemotherapy (CHOP or CHOP-like courses). After initial treatment 5 (63%) of 8 patients had developed new skin lesions, and 2 of them had developed extracutaneous localizations. Then the 3 of the relapsed patients were treated with autologous stem cell transplantation, all of whom obtained complete remission. At the time of last follow-up (median follow-up: 34 months; range: 10–60 months), 5 patients are in complete remission, 4 patients have ongoing skin disease, while 3 patients have died, 2 of the complications of HPS or therapy-related side effects and 1 of unrelated disease. The 3-year OS and DSS of the patients were 75% and 42%, respectively. Patients without HPS had a significantly better 3-year OS (88%) than patients with HPS (50%; P <.001).

Conclusion:
SPTCL seems to be a kind of heterogeneity disease. The factors associated with an unfavorable disease course were: diffuse lesions, a low white blood cell count, elevated lactate dehydrogenase, and combine with HPS. Autologous stem cell transplantation may improve the overall survival of high risk patients.

Disclosures:
No relevant conflicts of interest to declare.
ProatherogenIc Inflamatory mRNAs Have structural Features for Being Regulated by MicroRNAs
Authors: Yang Xiao-Feng , Virtue Anthony , Mai Jietang , Yin Ying , Jiang Xiaohua , Wang Hong 
Published: October 2019

Abstract
Abstract 5316
The current literature focusing on miRNAs has failed to adequately address two important questions - how miRNAs modulate atherogenic inflammatory genes from a panoramic viewpoint and whether the augmented expression of the atherogenic inflammatory genes is the result of miRNAs suppression. To resolve these knowledge gaps, we have employed a novel database mining technique in conjunction with statistical analysis criteria established from experimentally verified miRNAs. Utilizing this strategy we were able to conclude that the expression of 33 inflammatory genes is upregulated in atherosclerotic lesions and that these genes contain structural features in the 3'UTR of their mRNA for potential miRNAs regulation. Additionally, the binding features governing the interactions between the miRNAs and the inflammatory genes were statistically identical to the features of experimentally verified miRNAs. It was also determined that 21 (64%) of the 33 inflammatory genes were targeted by highly expressed miRNAs while the remaining 12 genes (36%) were targeted by normally expressed miRNAs. In addition, 10 of the 21 highly expressed miRNA-targeted inflammatory genes (48%) were targeted by a single miRNA, suggesting miRNA regulation specificity. Furthermore, 12 (48%) out of the 25 miRNAs found to meet our criteria targeted individual inflammatory genes while the other 13 miRNAs targeted multiple inflammatory genes. These results indicate a critical role of miRNAs in regulating proatherogenic inflammatory gene expression.

Disclosures:
No relevant conflicts of interest to declare.
“Rolling Recruitment” of Endothelial Cell (EC) Activation in the Prothrombotic Nature of Heparin-Induced Thrombocytopenia (HIT)
Authors: Hayes Vincent M , Cines Douglas B. , Poncz Mortimer , Rauova Lubica 
Published: October 2019

Abstract
Abstract 536
HIT is an iatrogenic, prothrombotic, immune-mediated disorder associated with antibodies directed against platelet factor 4 (PF4) and heparin complexes. Once these pathogenic anti-PF4/heparin antibodies develop, they recognize and bind to antigenic complexes formed on cell surfaces composed of PF4 released from platelets bound to cell membrane glycosaminoglycans (GAGs). Unlike platelets, which have only chondroitin sulfate on their surface, endothelial cells express mainly heparan sulfate resulting in a very high capacity to form PF4/GAG complexes and become targets for HIT antibodies. In fact, activation of endothelial cells by HIT antibodies was recognized almost 25 years ago (Cines et. al., 1987). We now show direct interaction of the HIT-like monoclonal antibody KKO with perithrombus endothelial cells, which propagates thrombosis following laser induced cremaster vessel injury in a passive immunization murine model of HIT. PF4 released from activated platelets at the site of laser injury binds rapidly and predominantly to the adjacent endothelium and is recognized by KKO in both transgenic mice expressing only human PF4 (hPF4+) and mice expressing hPF4 and human FcgRIIA on platelets (hPF4+/FcgRIIA+). These studies show that HIT-like antigenic complexes are present within thrombi prior to antibody exposure, predominantly localized to endothelial cells, which is consistent with their surface GAGs having higher affinity for PF4 than platelets. These endothelial cell surface PF4/GAG complexes, and with it KKO binding, are dissociated by high concentrations of intravenous heparin. Infusion of KKO in hPF4+/FcgRIIA+ mice but not in control mice, reinitiates growth of previously stable thrombi at sites of laser injury, leading to a significant increase in vascular occlusion (24/33 injuries, 73%, compared to 0/30 in control mice; P<0.0001). Clot extension is followed by dissemination of endothelial activation, demarcated by binding of annexin V and Factor Xa, and extension of the endothelial surface that binds KKO. Based on these studies, we propose a model of feed-forward rolling recruitment to explain how the endothelial lining contributes to the prothrombotic state in HIT: PF4 released from activated platelets at a site of injury or disease binds to the surface of perithrombus endothelial cells, which then binds HIT antibodies followed by endothelial cell activation. These activated endothelial cells then bind and activate additional platelets, leading to the next round of PF4 release, more extensive endothelial cell activation and platelet recruitment into thrombi.

Disclosures:
No relevant conflicts of interest to declare.
Trafficking Kinesin Binding Protein Is Essential for Human Erythropoiesis
Authors: Noh Seung-Jae , Lee Y.Terry , Byrnes Colleen , Rabel Antoinette , Miller Jeffery L. 
Published: October 2019

Abstract
Abstract 683
Mitochondrial specialization in erythroblasts is important for efficient heme synthesis, with defects or reduced expression of several mitochondrial proteins causing anemia. Trafficking kinesin binding 2 (TRAK2) is known to participate in mitochondrial movement along microtubule by interacting with kinesin motor protein and making a complex with Miro that is localized on the mitochondrial outer membrane. Transcriptome data suggest that TRAK2 is highly and specifically expressed in early erythroid cells. Here the role of TRAK2 was studied among human CD34+ cells that were grown in ex vivo serum-free cultures supplemented with erythropoietin (EPO, total culture period 21 days). Quantitative PCR studies indicated that TRAK2 expression is highly regulated during erythropoiesis. Its expression pattern was nearly identical to aminolevulinate synthase 2, the erythroid specific enzyme for the committed step of the heme biosynthetic pathway, and mitoferrin 1, the erythroid specific mitochondrial iron transporter. Western analyses revealed that TRAK2 protein is detected as a doublet band with molecular weights of 130kD and 105kD. Mitochondrial co-localization of TRAK2 was verified by confocal microscopy in TRAK2-overexpressing K562 cells. To study a potential role of TRAK2 in erythropoiesis, TRAK2 expression was reduced in cultured human erythroid cells using lentiviral shRNA transduction. TRAK2 knockdown (TRAK2-KD) was confirmed by Western analysis in K562 cells. In primary erythroblasts, TRAK2-KD caused slight reduction of CD36+ immature erythroblasts at culture day 7 prior to the addition of EPO (CD36+ population 58% in control vs 40% in TRAK2-KD). After the addition of erythropoietin to the culture medium, TRAK2-KD severely restricted erythroblast proliferation (5.0 million cells/ml in control vs 0.25 million cells/ml in TRAK2-KD on culture day 18). Flow cytometric analyses showed that <1% of the CD36+ progenitors cells differentiated into glycophorin A erythroblasts compared with >90% in control cultures. Annexin-V staining indicated that more than 90% of cells had undergone apoptosis by day 14. These data suggest that TRAK2 expression is required for erythroid differentiation. As such, defects in TRAK2 expression should be considered in cases of unexplained anemia. The data also support the notion that mitochondrial location or mobility within erythroblasts may be important for iron trafficking or heme synthesis.

Disclosures:
No relevant conflicts of interest to declare.
ENU Mutagenesis in the Mouse for Identification of Genes Regulating Erythropoiesis: a Mouse Mutant with An Activating Mutation of the KCl Cotransporter, KCC1 Causing Dehydrated Red Cells
Authors: Curtis David J. , Brown Fiona , Wiley James , Ho Shwen , Hilton Douglas J. , Kile Benjamin T. , Jane Stephen M 
Published: October 2019

Abstract
Abstract 684
Genome-wide phenotype-driven studies have emerged as a powerful tool for the identification of novel genes in a biological process of interest, new functions for existing genes and the establishment of mouse models of human disease. Recent advances in exomic and whole genome sequencing has simplified mutation detection, making genetic screens in the mouse more facile. We have employed a large-scale mutagenesis screen in mice using the chemical mutagen N-ethyl-N-nitrosourea (ENU) to identify genes regulating erythropoiesis. In this dominant screen, G1 progeny were screened at 7 weeks of age by automated hematological analysis for isolated abnormalities of red cell indices (HCT, RCC and MCV) defined as greater than three standard deviations from the wild type population. Here, we describe the RBC10 mouse line, in which homozygotes had mild anemia with microcytosis, target cells, spherocytes, reticulocytosis and increased resistance to osmotic stress. A combination of SSLP and SNP mapping isolated the genetic mutation to a 3.65 Mb region on chromosome 8. Whole genome Next Generation Sequencing of the mapped interval identified an A to T nucleotide substitution within the coding region of the potassium chloride (KCl) co-transporter, Slc12a4 (KCC1), resulting in a non-conservative amino acid substitution from methionine to lysine at position 935 within the C-terminal cytoplasmic domain. KCC1 and KCC3 function are the major erythroid KCl co-transporters that export KCl in response to hypotonic swelling. We hypothesized that the M935K was an activating mutation of KCC1, based upon the microcytosis and resistance to osmotic stress, which contrasts with the macrocytic phenotype of red cells lacking both KCC1 and KCC3. 86Rb efflux assay confirmed increased KCC1 activity of RBC mutant red cells. We propose that the M935K mutation increases activity of KCC1 by preventing phosphorylation of the nearby threonine reside, a critical regulatory target of the serine-threonine kinase, WNK1.

Disclosures:
No relevant conflicts of interest to declare.