bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bacillus Infection Among Children with Hematologic Malignancy, a Single Institution Experience
Authors: Shulman David S , Mehrotra Preeti , Surana Neeraj K. , Blonquist Traci M. , Silverman Lewis B. , Place Andrew E. 
Published: October 2019

Abstract
BACKGROUND: Bacillus species, including B. cereus and other non-anthracis species, are spore-forming, gram-positive rods, found ubiquitously in the environment and cause bacteremia and CNS infection in children with cancer. Case reports have demonstrated that Bacillus spp. infections carry a high morbidity, with rates of CNS involvement of 30%, and mortality as high as 40%. These studies indicate the preponderance of cases occur in children receiving induction chemotherapy for acute lymphoblastic leukemia (ALL). There have been no large, recent studies describing Bacillus spp. infection in children with an underlying oncologic condition.
METHODS: We performed a retrospective medical record review of pediatric cancer patients who received care at the Dana-Farber/Boston Children's Cancer and Blood Disorders Center and developed Bacillus spp. infection between January 1st, 2005 and December 31st 2014. Given that the majority of these infections were found to occur in children with underlying hematologic malignancy, we provide a more detailed description of cases with these underlying conditions.
RESULTS: Twenty-six children developed Bacillus bacteremia during the study period. Of the 26 patients, 21 (81%) had acute leukemia (18 ALL; 3 AML), 3 had neuroblastoma, one had Ewing's sarcoma and one had an optic pathway glioma. The mean age of patients with hematologic malignancies at time of Bacillus spp. infection was 7.3 years [range: 1-17]. Sixteen (76%) children were neutropenic at the time of infection. Of the children with ALL, 11 (61%) developed infection during the remission induction phase of treatment, 3 during post-induction/pre-maintenance treatment phases and 3 after relapse (1 during stem cell transplant, 1 at a year post-transplant and 1 during re-induction). Of the 26 patients, 5 (19%) developed CNS complications, all during remission induction for ALL, and the overall mortality two-weeks following Bacillus infection was 19%.
DISCUSSION: Bacillus spp. continues to cause serious infections in children with cancer, especially in those with underlying hematologic malignancies. While the mortality at our center is lower than that reported in the literature, the rate of death is still higher than what is typically seen with other organisms and CNS involvement remains common. Further study in this area will include identification of risk factors for development of this infection and recommendations regarding use of prophylactic antibiotics.

Disclosures
No relevant conflicts of interest to declare.
IMGN779, a CD33-Targeted Antibody-Drug Conjugate (ADC) with a Novel DNA-Alkylating Effector Molecule, Induces DNA Damage, Cell Cycle Arrest, and Apoptosis in AML Cells
Authors: Krystal Watkins M , Walker Russell , Fishkin Nathan , Audette Charlene , Kovtun Yelena , Romanelli Angela 
Published: October 2019

Abstract
IMGN779 is a CD33-targeting ADC consisting of a humanized anti-CD33 antibody, Z4681A, conjugated to DGN462, a novel DNA-alkylating agent, through a cleavable disulfide linker, sulfo-SPDB. CD33 is broadly expressed on leukemic blasts of patients with AML, making it a promising target for AML therapy. DGN462 is a member of the novel IGN class of DNA-acting cytotoxic agents, that consists of an indolino-benzodiazepine dimer containing a mono-imine moiety.
Potent killing of AML tumor cells by DGN462 and IMGN779 has previously been demonstrated in vitro (K. Whiteman et. al, ASH 2014 #2321). Here we describe studies elucidating the mechanism of action of this novel payload in the AML cell lines: MV4-11, HL60, and EOL-1. The ability of DGN462 to alkylate DNA was demonstrated in an AML cell line by isolation and analysis of the genomic DNA from cells. DGN462 was found to co-purify with DNA, demonstrating that it covalently reacts with cellular DNA. A comet assay was performed confirming that DGN462 does not cross-link DNA.
H2AX is known to be phosphorylated on serine 139 in response to DNA damage. Using flow cytometry, we assessed the phosphorylation of H2AX in AML cell lines following exposure to DGN462 and IMGN779. Increases in phosphorylated H2AX levels were detected as early as 4 hours following exposure to DGN462-SMe and 12 hours following exposure to IMGN779. Additional flow cytometry analysis showed that exposure to DGN462-SMe and IMGN779 leads to S-phase accumulation, G2/M arrest, followed by induction of apoptotic markers (cleaved PARP and cleaved Caspase-3) at later time points. Ex vivo studies using AML patient samples also showed elevation of phosphorylated H2AX and an increase in apoptosis in myeloid blasts following exposure to DGN462-SMe and IMGN779.
As a demonstration of proof-of-mechanism in AML disease models, our results suggest that cell killing by IMGN779 is mediated by DNA damage, as a consequence of DNA alkylation. The DNA damage response is accompanied by cell cycle arrest, which leads to apoptosis. This relationship will be further explored in additional AML preclinical models to support the use of phosphorylated H2AX as a pharmacodynamic biomarker for IMGN779 activity in future clinical studies.

Disclosures
Krystal: ImmunoGen, Inc.: Employment, Equity Ownership. Walker:ImmunoGen, Inc.: Employment, Equity Ownership. Fishkin:ImmunoGen, Inc.: Employment, Equity Ownership. Audette:ImmunoGen, Inc.: Employment, Equity Ownership. Kovtun:ImmunoGen, Inc.: Employment, Equity Ownership. Romanelli:ImmunoGen, Inc.: Employment, Equity Ownership.
Bortezomib, Dexamethasone, Thalidomide and Melphalan (VDT-Mel) Preparative Regimen in Autologous Stem Cell Transplant (ASCT) Results in a Very High Stringent CR (sCR) Rate in Multiple Myeloma (MM)
Authors: Nadiminti Kalyan , Abbi Kamal Kant Singh , Tricot Annick , Schultz Allyson , Dozeman Lindsay , Mott Sarah L , Zhan Fenghuang , Tricot Guido J 
Published: October 2019

Abstract
Background: Melphalan 200mg/m2 is the standard preparative regimen in MM and addition of other cytotoxic drugs has not been found to result in superior activity. The novel agents have improved outcome in MM significantly, but data on their role in preparative regimens are scarce. The purpose of this study was to understand the toxicity and efficacy of triple therapy with VDT in combination with high-dose melphalan.
Methods: An IRB approved retrospective analysis was performed on all patients who received an ASCT with the VDT-Mel during 2012-2014. Mel: 100 mg/m2 was given on days -4 and -1; V: 1 mg/m2 on days -4, -1, +2 and +5; T: 100 mg daily from -5 to +5; and D: 20 mg/day from -4 to -1 and +2 to +5. End points were treatment-related toxicity during the first 100 days and quality of response at 6 months post-transplant; 98 patients had follow-up ≥ 6 months. Patients in sCR were also minimal residual disease negative (MRD-) by 10-color flow cytometry with a sensitivity of 10-4.
Results: 100 patients received 153 transplants; 47 patients underwent single and 53 had tandem transplants (TT); 64 patients received early (≤ 12 months of induction therapy) and 36 salvage transplantation. Median age was 61 y; median followup was 16.2 months. Only 1patient had achieved a sCR and 11 a CR prior to transplantation. Best responses at 6 months were 53% sCR (and MRD-), 24% CR, and 9% VGPR. The sCR rate after single transplant was 47% (overall) and 54% (early transplant) vs 59% and 60% after TT. Grade 3-5 non-hematologic toxicities were almost entirely related to infections (38% and 53% in single and TT, respectively); the 100-day mortality rate was 2.6% (4/153), 1.8% for early transplants and 4.5% for salvage transplants. Median time to ANC recovery > 500/µL was 12 days in both early and salvage transplantation.
Conclusion: VDT-Mel is well-tolerated and resulted in minimal additional toxicity and a similar mortality rate when compared to historic data of MEL alone. Importantly, the sCR rate with MRD- by flow cytometry at 6 months in our study was very high compared to published reports. The ultimate sCR rate will be higher as at this time an additional 13 patients attained a sCR during further follow up past 6 months for a total of 66% sCR. Since both sCR and MRD- are proven early surrogate markers for progression-free and overall survival, it appears highly likely that this regimen will be superior to Mel alone and should become the new standard for ASCT in myeloma.
Figure 1. Figure 1.

Disclosures
No relevant conflicts of interest to declare.
Disease Risk Index Is the Major Predictor of Outcome Following Myeloablative Haploidentical Hematopoietic Stem Cell Transplantation (haplo-HSCT) and Post-Transplant Cyclophosphamide (PT/Cy)
Authors: Solomon Scott R. , Sizemore Connie , Zhang Xu , Solh Melhem , Morris Lawrence E. , Holland H. Kent , Bashey Asad 
Published: October 2019

Abstract
Disease Risk Index is the Major Predictor of Outcome Following Myeloablative Haploidentical Hematopoietic Stem Cell Transplantation (haplo-HSCT) and Post-Transplant Cyclophosphamide (PT/Cy)
Although non-myeloablative (NMA) haplo-HSCT utilizing PT/Cy results in low rates of GVHD, infection, and non-relapse mortality (NRM), relapse remains the predominant cause of treatment failure, occurring in up to 50% of patients. To reduce the risk of relapse often associated with the use of NMA preparative regimens, we have developed a myeloablative haplo-HSCT utilizing PT/Cy. Sixty-four patients have been transplanted following either Busulfan-based (n=20) or TBI-based (n=44) myeloablative conditioning, T-cell replete PBSC infusion, PT/Cy, and tacrolimus/mycophenolate mofetil. Median age was 43 (range 21-60). Patient characteristics included a high/very high disease risk by the Dana-Farber/CIBMTR disease risk index (DRI) in 32 patients (50%), KPS<90 in 69%, and comorbidity index (CMI) of ≥2 in 58% of patients. The most common indications for transplant were AML, ALL, and advanced-phase CML in 55%, 20% and 12% of patients respectively. Median follow-up for surviving patients was 24 months. All patients have engrafted with no late graft failure. Grade II-IV, III-IV acute GVHD and moderate-severe chronic GVHD occurred in 46%, 23%, and 30% respectively. One-year NRM was 10%. Predicted three-year overall survival (OS), disease-free survival (DFS), and relapse are 53%, 53%, and 26% respectively. In multivariate analysis, high/very high DRI was the most significant negative predictor of OS (HR 13.26, p<0.001), followed by CMI≥2 (HR 3.54, p=0.01) and age (HR 1.26, p=0.038, per each 5 year increase in age). DRI was also significantly associated with DFS (HR 10.84, p<0.001), NRM (HR 15.0, p=0.004), and relapse (HR 8.85, p=0.004). In the 32 patients with standard risk disease (low/intermediate DRI), outcomes were significantly improved with one-year NRM of 0% and predicted 3-year OS, DFS, and relapse of 79%, 74% and 9% respectively. Conditioning regimen (TBI vs. Busulfan) had no significant impact on outcome. This analysis confirms that DRI is a strong predictor of outcome following myeloablative haplo-HSCT and PT/Cy and adds to a growing body of literature suggesting that haplo-HSCT is a safe and effective transplant option for patients lacking a matched sibling donor.
Figure 1. Figure 1.

Disclosures
No relevant conflicts of interest to declare.
The Role of Mitochondrial Metabolism and Redox Signaling in Iron Deficiency Anemia
Authors: Bullock Grant C , Richardson Chanté L , Schrott Valerie , Gunawardena Naomi D , Cole Teague Nolan , Corey Catherine G , Shiva Sruti S 
Published: October 2019

Abstract
Several clinical observations illustrate the link between iron and erythropoietin (EPO)-mediated signaling in committed erythroid progenitor cells. In iron deficiency anemia (IDA), erythropoiesis is blocked despite increased serum EPO concentrations. Intravenous iron improves the effectiveness of exogenous EPO in patients with EPO-refractory anemia of chronic disease. These clinical observations suggest that iron dominantly regulates EPO-receptor signaling. However, the mechanism of this iron-mediated signaling remains unclear. We recently demonstrated that 1) the aconitases, multifunctional iron-sulfur cluster proteins that convert citrate into isocitrate are essential in the iron- EPO-signaling pathway in erythroid progenitor cells, and that 2) isocitrate, the product of aconitase, can enhance the effectiveness of EPO during iron deficiency in vitro and in mice with IDA and in rats with the anemia of chronic inflammation. These observations suggest that isocitrate, or its derivatives that synergize with erythropoiesis stimulating agents, have important therapeutic application in the treatment of anemia. New data shows that cellular iron restriction regulates mitochondrial oxygen consumption rates (OCR) differentially over time during erythropoiesis, suggesting a novel link between mitochondrial function and erythropoeisis. It is unknown how iron deficiency induced inhibition of mitochondrial aconitase (ACO2) regulates mitochondrial metabolism during RBC production. Pilot data show that ACO2 inhibition by cellular iron deprivation or pharmacological inhibition of ACO2 decreases mitochondrial respiratory rates (RRs) and alters reactive oxygen species (ROS) production. Further, isocitrate normalizes mitochondrial RRs and ROS and restores RBC production. Importantly, disruption of mitochondrial ROS generation with a mitochondrial-specific anti-oxidant blocks RBC production and a subset of oxidant generators promote erythropoiesis. Targeted reduction of ACO2 protein expression and enzyme activity in iron replete stably transduced K562 cells decreases OCRs. This confirms the link between ACO2 and mitochondrial metabolism in human erythroid cells. These data inform our overarching hypothesis that iron-restriction inhibits ACO2, thereby inhibiting mitochondrial metabolism, resulting in the loss of a mitochondrial ROS signal that is required for erythropoiesis. The loss of this critical mitochondrial ROS signal inhibits the EPO signaling that is required for RBC production. These data also suggest that ACO2 is an iron-sensing regulator of mitochondrial metabolism and ROS signaling.

Disclosures
No relevant conflicts of interest to declare.
Decrease in the Severity of Painful Sickle Cell Crises with Oral Pglg
Authors: Niihara Yutaka , Tran Lan , Razon Rafael , Stark Charles , Macan Henry 
Published: October 2019

Abstract
Background: Our earlier work suggested an enhancement of nicotinamide adenine dinucleotide (NAD) in sickled Red Blood Cells (sRBC) by administering a precursor of NAD, L-glutamine. We hypothesized that L-glutamine would decrease the incidence of painful sickle cell crises (PSCC). Small proof of concept studies led to the development of a multi-center Phase 2 placebo-controlled trial where oral pharmaceutical grade L-glutamine (PGLG) suggested benefit when measuring PSCC incidence at 24 weeks. A large multi-center Phase 3 trial further demonstrated that there was a reduction in the incidence of PSCC by administering PGLG compared to placebo. Additional analyses on the data from this trial were conducted and we are reporting our evaluation on the severity of crises between treatment arms.
Methods: A randomized (2:1), double-blind, placebo-controlled, parallel-group Phase 3 study was conducted at 31 sites in the United States. Subjects were stratified by hydroxyurea usage. This study included subjects 5 years of age and older that had at least 2 PSCC during the year prior to enrollment. The primary endpoint for the Phase 3 trial was the number of PSCC between treatment arms. Since PSCC events were adjudicated by a blinded third party committee and data were collected as an adverse event ranked as "None"(0), "Mild" (1), "Moderate" (2) and "Severe" (3), the difference in "Severity" of PSCC between treatment arms using Cochran Mantel Haenszel (CMH) Ranked Scores statistics was evaluated post-hoc. Each patient was counted only once at the highest level of severity.
Results; A total of 230 patients were enrolled; ages 5-58; 53.9 % female; 152 were assigned to PGLG and 78 to placebo; and the groups were well balanced for baseline clinical characteristics. The comparison of Severity for PGLG vs. Placebo indicated that at (0) was 24% vs. 10% respectively; at (1) was 6% vs. 8%; at (2) was 36% vs. 35%; and at (3) was 34% vs. 47%. Summary statistics for the cohort taken as a whole indicated a treatment difference benefit for the PGLG treatment (p = 0.0167). Other adverse events in the PGLG arm were similar to those observed in the placebo arm.
Conclusion: PGLG therapy may be providing clinical benefit over placebo in adult and pediatric patients with a history of two or more crises per year by reducing the "Severity" of painful crises. Difference appeared to be driven by (0) or "None" PSCC events and by a decrease in (3) "Severe" PSCC events. PGLG was administered without difficulty and did not require special monitoring.

Disclosures
Niihara: Emmaus Medical, Inc: Employment, Equity Ownership. Tran:Emmaus Medical, Inc: Employment, Equity Ownership. Razon:Emmaus Medical, Inc: Employment. Stark:Emmaus Medical, Inc: Employment, Equity Ownership. Macan:Emmaus Medical, Inc: Employment.
Thymic-Derived Tolerizing Dendritic Cells Are up-Regulated upon Treatment with Intravenous Immunoglobulin or Splenectomy in a Murine Model of Immune Thrombocytopenia
Authors: Kapur Rick , Aslam Rukhsana , Speck Edwin R. , Kim Michael , Zufferey Anne , Guo Li , Segel George B. , Ni Heyu , Semple John W. 
Published: October 2019

Abstract
Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder characterized by low platelet counts. ITP has a complex pathogenesis, in which both anti-platelet antibodies as well as T cells have been shown to be important. Initial management of newly diagnosed ITP may be either watchful waiting or pharmacologic intervention, such as glucocorticoids or Intravenous Immunoglobulin (IVIg), a blood product consisting of polyclonal immunoglobulin G (IgG) derived from thousands of donors. Second-line therapy may include dexamethasone, high-dose methylprednisolone, rituximab, thrombopoietin (TPO)-receptor agonists, or splenectomy. The working mechanism of IVIg is actively under investigation and is still a matter of debate, as various different working mechanisms have been suggested. One of them is that IVIg may shift the balance from a pro- to anti-inflammatory state through immunomodulating the activity of dendritic cells (DCs). To gain more insights into the role of DCs in ITP, upon IVIg treatment or splenectomy, we analyzed DC subsets in a murine model of ITP, which features both the antibody and T cell mediated thrombocytopenia. Severe combined immunodeficient (SCID) mice were administrated 4x104 splenocytes from CD61 (GPIIIa) knockout mice immunized against CD61 (or naïve control splenocytes) and the mice were treated with or without 1 g/kg IVIg twice a week. Also the same type of splenocytes were transferred into splenectomized SCID mice. Weekly platelet counts were assessed and after 4 weeks the mice were sacrificed and spleen and thymuses were harvested. Splenocytes and thymocytes were isolated and examined by flow cytometry for cross-presenting (XCR1+) and non-presenting tolerizing (SIRP alpha+) DCs. Without IVIg or splenectomy, both splenic DC subset numbers correlated positively with platelet counts and both the thymic DC subset numbers correlated negatively with platelet counts, indicating thymic retention of DC in a setting of thrombocytopenia. Interestingly, splenectomized SCID mice, apart from increased platelet counts, demonstrated a complete reversal of the DC pattern in the thymus, as thymic DC subsets correlated positively with platelet counts in splenectomized mice. Upon IVIg treatment, apart from a general increase in platelet counts, the splenic tolerizing DCs significantly increased in numbers. Moreover, the thymic retention of tolerizing DCs and thus the negative correlation with platelet counts (R2: 0.46, p<0.05) was fully abrogated upon IVIg treatment (R2: 0.02, NS). Overall, our results indicate that both splenectomy as well as IVIg treatment can immunomodulate thymic tolerizing DCs significantly, in a murine model of ITP.

Disclosures
No relevant conflicts of interest to declare.
Survival in Essential Thrombocythemia and Prefibrotic Primary Myelofibrosis - Correlation of Clinical Phenotype with Histomorphological Diagnosis
Authors: Jeryczynski Georg , Woelfler Albert , Gisslinger Bettina , Schalling Martin , Burgstaller Sonja , Buxhofer-Ausch Veronika , Krauth Maria Theresa , Geissler Klaus , Schlögl Ernst , Sliwa Thamer , Schiefer Ana-Iris , Muellauer Leonhard , Simonitsch-Klupp Ingrid , Beham-Schmid Christine , Thiele Jürgen , Gisslinger Heinz 
Published: October 2019

Abstract
Introduction
The correct diagnosis of myeloproliferative neoplasm (MPN), especially the correct classification of early or prodromal stages, remains a matter of debate. While the 2008 WHOcriteriarecognize the existence of an early, prefibrotic primary myelofibrosis, other diagnostic systems make no such distinction between ET and prePMF. According to WHO criteria the accurate diagnosis is based mainly onhistomorphologicassessment of bone marrow (BM) biopsy samples. However, there is an ongoing debate if ET, prePMF, PV and overt PMF are, dependent from their molecular genetic phenotype, a continuum or rather independent entities.
Methods
From a multicenter database, we selected 251 patients with ET and 185 patients with prePMF, in which the diagnosis had been established by BM biopsy and in which clinical data at time of diagnosis and for follow up were available.
We compared overall survival in patients from both entities in which common clinical features of prePMF were present at time of bone marrow biopsy. These were anemia (male <13 g/dL, female <12 g/dL),leukocyte counts ³ 11 G/L, elevated lactate dehydrogenase levels (LDH) as well as splenomegaly.
Results
Survival was substantially impaired in WHO-defined prePMF patients when compared to the ET cohort (Fig. 1). Median overall survival was significantly worse in patients with leukocytosis (9.3 vs. 14.9 years, 95% CI 6.9-11.6 vs. 9.1-20.7, p<0.001), elevated LDH levels (10.6 vs. 21.7 years, 95% CI 7.7-13.4 vs. 11.5-31.9, p<0.001) and splenomegaly (6.8 years vs. median not reached, 95% CI 6.8-10.8 vs.n.a.,p<0.001). Significance was narrowly missed in anemic patients (7.2 vs. 13.1 years, 95% CI 4.7-9.8 vs. 9.2-16.9, p=0.089).
Discussion
Our data illustrate, that the distinction of prePMF and ET patients based onhistomorphologicalcriteria by the WHO 2008 diagnostic criteria translates into different overall survival patterns in patients that may share some similar clinical features at diagnosis. This suggests that the underlying diseases are two different entities, with different underlying biology, that can both present with the same adverse clinical parameters. Further, these two entities can only be accurately differentiated by bone marrow histology.
Therefore the concept that ET, WHO-defined prePMF and overt PMF form a continuum of the same disease, with prePMF just being an advanced stage of ET, may need revision in face of this study.
Figure 1 Figure 1.

Disclosures
Burgstaller: Novartis: Consultancy, Honoraria. Geissler:Novartis: Honoraria. Gisslinger:AOP Orphan: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Baxalta: Consultancy, Honoraria.