bluuebunny/crossref_metadata_2025 huggingface dataset:
Leukemia-Induced Alterations of Bone Marrow Microenvironment Contribute to Leukemogenesis.
Authors: Shim Jae-Seung , Kim Myungshin , Lee Jong Wook , Oh Il-Hoan
Published: October 2019

Abstract 2597

The impact of microenvironment on the regulation of normal hematopoietic process is being unveiled, but their role during leukemogenesis have been poorly understood. In this study, to characterize the leukemic microenvironment, we have analyzed mesenchymal stromal cells (MSC) of bone marrows from 55 cases of acute myelogenous leukemia (AML), and 17 of AML in the remission. When the colonogenic activity of MSCs were compared, 43% of AML-derived BM exhibited defect in colony (CFU-F) formation, where no colony formation or premature growth arrest of colonies were observed, whereas only 11% of normal BM exhibited growth arrest of colonies. In the AML subtypes, M3 type (FAB classification) exhibited most profound loss of CFU-Fs, where none of them (n=9) exhibited normal growth of colonies. In addition, numbers of colony (CFU-F) in AML was significantly lower than normal BM (52 vs. 155 per each ml of BM, respectively for AML and normal, p<0.05). In contrast, BMs of AML in remission did not exhibit significant difference in the number of CFU-F compared to numbers of normal BM (88 vs. 71.4 per 5×106 MNCs, respectively for normal and remission), indicating that the quantitative loss of CFU-F is correlated to disease activity of AML.

We next examined the qualitative changes of MSCs in AML, i.e., 83% of MSCs in AML (5/6) exhibited poor osteogenic differentiation, and all examined AML MSCs (6/6) exhibited lower adipogenic differentiaton compared to normal MSCs. During in-vitro culture, MSCs from AML showed accelerated loss of colonogenic activity during passage cultures compared to normal MSCs and lower intensity levels of CD146 in the cell surface. Moreover, MSCs from AML showed significantly higher levels of senescence-associated beta-galactosidase without changes in telomere length, indicating that the MSC has undergone qualitative change during leukemogenesis. When co-cultured with umbilical cord blood-derived CD34+ cells, AML-derived MSCs inhibited proliferation of CD34+ cells and caused significantly lower levels of hematopoietic cell expansion compared to the levels from co-culture with normal BM-derived MSCs or stroma-free cultures, indicating that leukemic MSCs should contribute to the loss of normal hematopoietic cells in leukemia.

Taken together, our study shows that microenvironment of BM undergoes quantitative and qualitative alteration during leukemogenesis and that such leukemic microenvironment contributes to the pathology of leukemia.

Disclosures:

No relevant conflicts of interest to declare.
The Role of Mel18 Overlaps with BMI1 In the Self-Renewal of Human Hematopoietic Stem Cells.
Authors: Reyal Yasmin , Bonnet Dominique
Published: October 2019

Abstract 2619

Complex mechanisms regulate the ability of hematopoietic stem cells (HSCs) to self-renew, some of which may be exploited by leukemic stem cells. BMI1, a member of the polycomb group (PcG) proteins is known to be a positive regulator of this process, largely by repressing the p16/INK4a locus. However the role of other PcG proteins is unclear. We initially screened HSCs and progenitor populations from umbilical cord blood (CB), for the expression patterns of a number of PcG genes. Levels of expression were heterogeneous, indicating that there may be different roles for different PcG in HSCs versus progenitors. As a starting point we have focused on Mel18 (PCGF2) as it has been suggested in murine hematopoiesis that it acts to counteract BMI1. Lineage negative CB cells were transduced with lentiviral vectors expressing shRNA against Mel18, BMI1 and a control sequence. Specific knockdown by these constructs was confirmed at the RNA level to be at least 80% for both genes and was verified at the protein level by Western blot. Our data indicates that knockdown of Mel18 impairs the proliferation of primitive cord blood cells in both stromal-dependent and -independent culture, in a similar manner to BMI1. Furthermore Mel18 deficiency impedes both primary and secondary colony formation of all myeloid lineages in methylcellulose. These findings have been confirmed in vivo with significant reduction in engraftment of CB lineage negative cells in NOD/SCID mice at twelve weeks. We are investigating whether over expression of Mel18 can rescue BMI1 deficient cells to establish if these homologous genes have redundant functions. The data so far suggests that BMI1 is not unique in its role in HSC self - renewal, and Mel18 may share overlapping functions. This highlights a possible difference between human and murine hematopoiesis. Moreover it is likely that other members of the PcG family are also important in human HSCs. It will be of interest to investigate whether like BMI1, they are also implicated in the maintenance of the leukemic stem cell.

Disclosures:

No relevant conflicts of interest to declare.
Tumor Microenvironment In Pediatric Hodgkin Lymphoma: Clues for Disease Biology
Authors: Henry Meret , Poulik Janet , Buck Steven , Ravindranath Yaddanapudi , Savasan Sureyya
Published: October 2019

Abstract 2681

The non-malignant elements in Hodgkin lymphoma (HL) tissue are very prominent and represent a reactive process either directly against or induced by tumor cells. Thus far, only clinical characteristics have been used in the risk assessment of HL. Biologic markers of disease remain largely unidentified. This study examined cellular immunologic features of the tumor microenvironment in pediatric HL patients seen at a single children's hospital since 1997 for whom flow cytometric evaluation at diagnosis was available. Retrospective chart review was conducted to gather other relevant clinical and laboratory data on the cases. Student t-test, nonparametric Mann-Whitney U and Kruskal-Wallis tests, and Pearson's correlation analysis were used for statistical evaluation. Thirty-one patients, 14 male and 17 female, with a median age of 14 years (range 3–17) were included in the study. Twenty-one cases were nodular sclerosis (NS) [71% female, with a median age of 14 years], 6 mixed cellular (MC) [17% female, with a median age of 11 years] and 4 undetermined subtype. While T cells were predominant in nodular sclerosis (NS), the infiltrate was B cell-rich in mixed cellular (MC) subtype. CD4+ T cells were significantly higher in NS (55 vs. 30.5; p=0.01) and, conversely, CD8+ cells in MC (21.3 vs. 11.3; p=0.02). Consistently, CD4/CD8 ratio was significantly higher in NS (9.6 vs. 1.6; p=0.02). All of the MC tumors were in situ EBV-positive, compared to only 24% of NS tumors (p=0.008). The WBC and absolute lymphocyte count were higher in NS compared with MC, 12×109/L vs. 6.1×109/L and 3.9×109/L vs. 1.5×109/L, respectively. Occurrence of primary continuous complete remission (CCR) without recurrence or refractoriness was significantly higher in MC group (p=0.009). Higher hemoglobin, DR+CD38+ lymphocyte percentage and lower CD4/CD8 ratio were also predictive of primary CCR status (p<0.05) in the entire study group. In the NS group, higher DR+CD38+ lymphocyte percentage was again associated with primary CCR (p=0.004). In this group, there was also an association between primary CCR and higher hemoglobin level (p=0.053). While DR+CD38+ lymphocyte percentage negatively correlated with CD4/CD8 ratio, there was positive correlation with WBC. Finally, the immunophenotype characteristics of the EBV-positive NS cases were intermediate to the MC group and EBV-negative NS cases. Albeit a small series, these results point to striking tumor microenvironment differences between NS and MC subtypes and EBV status-associated patterns. Moreover, DR+CD38+ lymphocyte proportion and CD4/CD8 ratio appear to be associated with the risk status of childhood HL, suggesting their potential role as prognostic biologic factors.

Disclosures:

No relevant conflicts of interest to declare.
Comparison of IV Busulfan and Fludarabine Vs Oral Busulfan Plus Cyclophosphamide As Myeloablative Conditioning Regimens for Acute Leukemias and Myelodisplastic Syndromes
Authors: Jaimovich Gregorio , Requejo Alejandro , Milovic Vera , Escobar Nicolas Fernandez , Drelichman Guillermo , Real Juan , Brioschi Sandra , Feldman Leonardo Julio
Published: October 2019

Abstract 4575

Introduction:

The Busulfan Cyclophosphamide (Bu-Cy) combination has been broadly used as a myeloablative conditioning regimen for allogeneic hematopoietic cell transplantation for patients (pts) affected by myeloid malignancies. The Busulfan Fludarabine (Bu-Flu), a newly introduced mieloablative conditioning regimen association showed, in several reports, less regimen related toxicities. We compared in a retrospective study the effectiveness and toxicity of both regimens.

Patients and methods:

From 12/2002 to 12/2010, 59 pts. affected by AML, CML, MDS and ALL were included in the study. Forty two pts. received Bu-Cy (oral Bu 1 mg/kg, every 6 hours × 16doses days -8 to -5 followed by Cy 60 mg/kg per day, days -4 and -3) and 17 pts. received Bu-Flu (Bu IV 3.2 mg/kg, once daily for four days and Flu 40 mg/kg /daily for four days, days – 6 to -3). There were no statistical significant differences between both groups comparing age, diagnosis, disease status and CD34+ cells infused. Regarding the cell source there were more patients in the Bu-Flu group that received peripheral blood stem cells and cord blood and more pts in the Bu-Cy were infused with bone marrow. Another imbalance was the use of more unrelated donors in the Bu-Flu arm. GVHD prophylaxis was with cyclosporine A or tacrolimus and metotrexate. Protective isolation and antibiotic prophylaxis was used in both groups.

Results:

Considering hematopoietic recovery, there were no differences in days to reach 500 granulocytes and 20.000 platelets. Transfusion requirements were without statistical significant differences. The following observations were statistically significant (p<0.001) favoring Bu-Flu: Pts receiving Bu-Flu required less hospital stay days (27,8 vs 35,6) and less days on antibiotics (8,5 vs 16,5). Acute GVHD incidence grade II to IV was 23,5% in the Bu-Flu arm vs 50% in the Bu-Cy group. Early TRM was 5,9% with Bu-Flu vs 16,6% with Bu-Cy. Overall survival and relapse rate at 1 year of follow up was 70.58% vs 50% and 23.5 % vs 30.9% for Bu-Flu and Bu-Cy respectively.

Conclusions:

In our experience Bu-Flu is associated with lower toxicity, neutropenia duration, and severe acute GVHD. The overall survival and relapse rate are also superior. More pts should be included in a prospective study to confirm these observations.

Disclosures:

No relevant conflicts of interest to declare.
Risk Factors of HHV6 Reactivation and Relationship Between Syndrome of Inappropriate Antidiuretic Hormone Secretion After Stem Cell Transplantation in Pediatric Patients
Authors: Kobayashi Ryoji , Toriumi Naohisa , Yoshida Makoto , Iguchi Akihiro , Sarashina Takeo , Suzuki Daisuke , Sano Hirozumi , Ogata Masao
Published: October 2019

Abstract 4580

Many reports were seen about reactivation of human herpes virus 6 (HHV6) after stem cell transplantation (SCT) in adult patients, and this reactivation sometimes induce severe condition of patients. However, few reports were seen about pediatric patients. Therefore, we examined HHV 6 reactivation after stem cell transplantation in patients with children, retrospectively. The cases were 80 patients, 48 male, 32 female, and the median age was 6 years old (range 0–20 years old). Transplantations were 23 related bone marrow transplantations (BMT) or peripheral blood stem cell transplantations (PBSCT), 18 unrelated BMT, one related cord blood transplantation (CBT), 31 unrelated CBT, and seven autologous BMT or PBSCT. We analyzed HHV6 DNA samples of serum with these patients before SCT, 20 days and 40 days after SCT using PCR method. In addition, we analyzed relationship between HHV6 reactivation and syndrome of inappropriate antidiuretic hormone secretion (SIADH).

In samples of 20 days after SCT, 35.0% of samples were positive for HHV6 DNA. On the other hand, 2.5% and 5.0% were positive before SCT and 40 days after SCT, respectively. From 24 out of 28 samples, over 10E3 of HHV6 DNA were detected in positive samples. Factors associated with HHV6 reactivation were CBT, unrelated donor, malignant diseases, use of total body irradiation as conditioning, cyclosporine and methyl prednisolone as GVHD prophylaxis, acute GVHD (>grade 2), chronic GVHD and use of steroid using univariate analysis. Moreover, CBT was an only risk factor of HHV6 reactivation using multivariate analysis.

In 14 patients with SIADH, 78.6% of patients had HHV6 reactivation. On the other hand, 25.8% of patients had HHV6 reactivation in 66 patients without SIADH. This result was statistically significant (p<0.001).

From this analysis, we can understand HHV6 reactivation was seen in many patients with children. In addition, we thought about the possibility of SIADH is one symptom of the encephalopathy by the HHV6 reactivation.

Disclosures:

No relevant conflicts of interest to declare.
The Biological Role of BAG3 in Human Chronic Lymphatic Leukemia
Authors: Zhu Huayuan , Liu Peng , Li Jianyong
Published: October 2019

Abstract 4589

Objective:

BAG3, a member of BAG family, is shown to sustain cell survival and underlies resistance to chemotherapy in human cancer cells, through down-modulation of apoptosis. It can also enhance cell adhesion and migration to promote tumoral invasion. However, the role of BAG3 in human chronic lymphatic leukemia (CLL) remains unclear. Our study aims to discover the roles of BAG3 in the apoptosis and migration of primary CLL cells.

Method:

In our study, Peripheral blood mononuclear cells were freshly isolated from 18 previously untreated patients. The primary CLL cells were cultured for 6 hours, following, three siRNA (siRNA-1, siRNA-2 and siRNA-3) targeting with different regions of BAG3 mRNA and one non-targeting siRNA were transfected into CLL cells by using Lipofectamine 2000. 6 samples were collected for checking the transfection efficiency by real-time PCR and western blot after 24 or 48 hours. The other 6 samples were exposured with or without fludarabine 12 hours later after tansfection; with another 24 or 48 hours, both cells were harvested, stained with annexin V/PI,and then apoptosis were analyzed using a FACSCalibur flow cytometer.on the other hand, transwell assay were performed in another 6 samples 12 hours after tansfection. to analysis cell migration, the cells were collected and counted 24 hours later.

Result:

By using the siRNA technique, we successfully down-regulated the expression of BAG3 by 3 different siRNAs. BAG3 mRNA was decreased □‘6 folds (p < 0.05). In order to analyze the effect of BAG3 on CLL cell apoptosis, we used flow cytometry to measure cell apoptosis. Here, the apoptosis rates of CLL cells were increased □‘2 folds after 24 hours transfection by siRNA-2 and siRNA-3 (p < 0.05), and □‘2.5 folds after 48 hours transfection by BAG3 siRNA-1, siRNA-2 and siRNA-3 (p < 0.05). These indicate that BAG3 makes an anti-apoptotic, and knocking-down of it increases the cell apoptosis. To assess the role of BAG3 in the migration of CLL, we used transwell assay to measure cell migration. We found that the migration of CLL cells was decreased 28% by BAG3 siRNA-1 treatment (p < 0.05), 47% by siRNA-2 (p < 0.01) and 50% by siRNA-3 (p < 0.01), respectively. These data showed that BAG3 enhances the CLL migration, and down-regulation of it can inhibit cell migration. Furthermore, fludarabine and BAG3 siRNA were co-treated with CLL cells, to check whether knocking-down of BAG3 can reverse the CLL cells’ resistance against fludarabine. However, the apoptosis rates are not different between co-treated cells and fludarabine-treated cells, which indicated knocking-down of BAG3 may not reverse the fludarabine resistance, though it can promote cell apoptosis and inhibit cell migration.

Conclusion: Based on these observations, we conclude that BAG3 may be a potential therapeutic target of human CLL, and inhibition of BAG3 expression can induce cell apoptosis and inhibit cell migration.

Disclosures:

No relevant conflicts of interest to declare.
Inhibition of NOTCH Activity by GLIOTOXIN Induces Apoptosis in CLL Cells and Overcomes the Supportive Effect of Primary Bone Marrow Stromal Cells
Authors: Hubmann Rainer , Hilgarth Martin , Schnabl Susanne , Ponath Elena , Demirtas Dita , Reiter Marlies , Zielinski Christoph , Jäger Ulrich , Shehata Medhat
Published: October 2019

Abstract 4609

Active NOTCH signaling is observed in an increasing number of human neoplasias including chronic lymphocytic leukemia (CLL) and represents a potential therapeutic target. We have recently reported that the γ-secretase inhibitor DAPT may not be effective in all cases of CLL (Hubmann et al; BJH 2010). The aim of this study was to evaluate the therapeutic value of a newly identified NOTCH transactivation inhibitor (gliotoxin) and to compare its efficiency with the highly selective γ-secretase inhibitor (GSI) DAPT in CLL cells.

Electrophoretic mobility shift assays (EMSA) showed that gliotoxin completely blocked the formation of DNA-bound NOTCH2 in CLL cells independent of their sensitivity to DAPT. The inhibition of NOTCH2 signaling by gliotoxin was associated with down regulation of its target gene CD23 and induction of apoptosis. The IC50 of Gliotoxin was variable between patients (n=20) and ranged between 50–100 nM irrespective to their sensitivity to GSI. Short term (4 hours) exposure of CLL cells to gliotoxin revealed that gliotoxin modulates the mRNA expression of several NOTCH-related genes including JAG1, PRKCD (PKC-δ), and NR4A1. We (Shehata et al; BLOOD 2010) and others have reported on the supportive effect of primary bone marrow stromal cells (BMSC) for CLL cells. Therefore, we tested whether gliotoxin may overcome this supportive effect. FACS analysis and MTT assays showed that gliotoxin abolished the supportive effect of BMSC under co-culture conditions. The effect of gliotoxin was dose dependent and selectively induced apoptosis in CLL cells accompanied by down regulation of NOTCH2 and CD23 transcription. Western blotting analysis demonstrated that gliotoxin also decreased the phosphorylation of Akt-pSer473 suggesting a link to PI3-K signaling. NOTCH1 has been recently shown to be affected by “gain of function” mutations in a subset of CLL patients. We observed that co-culture of CLL cells with BMSC was associated with increased NOTCH1 mRNA expression which could be decreased upon exposure to gliotoxin. In addition, gliotoxin inhibited DNA-bound NOTCH1 complexes in the T-ALL cell line SupT1 which is known to express high NOTCH1 activity. This indicates that gliotoxin may target both NOTCH1 and NOTCH2 isoforms.

In conclusion, the data show that gliotoxin effectively targets NOTCH activity in CLL cells in a mechanism which is independent of γ-secretase. Thus, gliotoxin might have a beneficial effect in a wider range of CLL patients and warrants further evaluation.

Disclosures:

No relevant conflicts of interest to declare.
β-Arrestin-1 Regulates Epigenetics of Whole Genome in Chronic Myeloid Leukemia Cells
Authors: Zou Lin , Li Kang , Zhou Xiaoyan , Bao Liming
Published: October 2019

Abstract 4636

Chronic myeloid leukemia (CML) is a clonal myeloproliferative expansion of transformed, primitive hematopoietic progenitor cells, which is an incidence of 1 to 2 cases per 100,000 people per year and accounts for 15 percent of adult leukemias. Although the-philadelphia (Ph) chromosome and the BCR-ABL fusion gene are known as the featured molecular characteristic, the pathogenetic mechanism of CML is still not fully clear. In recent years, epigenetics, the heritable changes of gene expression without change in DNA sequence, has rapid development in the area of regulating gene transcription and expression. The epigenetic modification includes the types of DNA methylation, histone acetylation, protein phosphorylation, ubiquitination, chromatin remodeling, and so on. β-arrestin1, one key member of arrestin family that are multifunctional scaffold proteins, was reported to regulate histone acetylation and gene transcription in GPCR signaling. However, little is known about the role of β-arrestin1 in mediating the whole genome epigenetics, especially in CML. Here, we firstly knocked down β-arrestin1 expression in K562 cells, the typical cell lines for CML, and then measured and analyzed the alterations of whole genome epigenetics by combinedly using chromatin immunoprecipitation(ChIP)-on-chip and methylation chip. The data from ChIP-on-chip showed that β-arrestin-1 mediated 7498 genes histone H4 acetylation, mainly afffected the genes of cell part, cell vability and prolieration when β-arrestin1 was knocked down in CML cells. Clustering analysis showed that these affected genes of histone H4 acetylation were involved in MAPK signaling. Moreover, the data from methylation chip indicated that the methylative level of the whole genome were decreased, and genome hypermethylated was more obvious than hypomethylated, when β-arrestin1 knockout. Further analysis found that the differences of CpG island number primarily located in 500–1000bp promoter region. And methylative modifications of influenced CpG island number easily occurred in chromosome 1, 4, 13, 14, 19 and X, compared with other chromosomes. Most interestingly, the distinct changes of acetylation and methylation for some cell part genes (ZNF259, IL23A, COPS6 and COASY) were simultaneously regulated by β-arrestin1 with GO analysis, which could shift the epigenetic alterations by β-arrestin1 in CML cells. These common genes both involved in these two kinds of epigenetics, and function analysis are further study. Taken together, our study shed new light on β-arrestin1 in regulating epigenetics of whole genome in chronic myeloid leukemia cells.

Disclosures:

No relevant conflicts of interest to declare.
Rituximab Has Similar Efficacy in Treatment of Acute Refractory or Chronic Relapsing Idiopathic Thrombotic Thrombocytopenic Purpura (TTP) and Refractory Secondary TTP: A Systematic Review
Authors: Tun Nay Min , Villani Gina M
Published: October 2019

Abstract 4673

Background:

Thrombotic thrombocytopenic purpura (TTP) is a potentially life-threatening disorder. Secondary TTP was known to be more resistant to plasma exchange and have higher mortality. Limited clinical data suggest that rituximab may be effective in the treatment of acute refractory or chronic relapsing nonfamilial idiopathic TTP (ITTP) as well as refractory secondary TTP (STTP). We performed a systematic review to evaluate the comparative efficacy of rituximab in ITTP and STTP.

Method:

An electronic literature search of Medline, CINAHL and the Cochrane library databases using the terms “rituximab” and “thrombotic” yielded 179 articles from March 2002 to June 2011. Studies were included if they met the following criteria: TTP in a first episode or subsequent relapse and TTP refractory to plasma exchange. Exclusion criteria were prophylactic administration of rituximab to patients in remission and familial TTP. Secondary TTP cases were author-defined. Case series without extractable individual data were excluded. Two-Tailed Fisher Exact Test was used to investigate the difference in complete remission rates between ITTP and STTP. Independent-Samples Mann-Whitney U Test was applied to detect the difference in platelet recovery days.

Result:

20 case series and 33 case reports including a small prospective study were eligible. Individual data of 139 patients from Europe, Asia, Australia, South and North America were analyzed. Overall, median age was 40 years (range: 1–72). Male constituted 30% and female 70%. Complete remission rate was 88% (90 out of 102) and 84% (31 out of 37) for ITTP and STTP respectively. There was no statistically significant difference in complete remission rates between the two groups (Two-Tailed Fisher Exact Test p value = 0.569). Median follow-up time was 12 months. Median platelet recovery (more than 150×109/L) from the first dose of rituximab was 8 days (range: 2–74) and 19 days (range: 7–90) for ITTP and STTP respectively. The distribution of platelet recovery days was the same between ITTP and STTP (Independent-Samples Mann-Whitney U Test p value = 0.132).

Conclusion:

Rituximab has the same efficacy in both STTP and ITTP in terms of response rate and platelet recovery days. It appears to be effective and well-tolerated. We recommend the use of rituximab as a salvage therapeutic modality in refractory acute or chronic relapsing nonfamilial idiopathic as well as secondary TTP.

Disclosures:

No relevant conflicts of interest to declare.
Presentation and Outcome of Idiopathic Thrombocytopenic Purpura in Children: A Single Institution Experience
Authors: Bradham Kari , Wilson Felicia L. , Imran Hamayun
Published: October 2019

Abstract 4683

PURPOSE:

To review the presenting features, response to treatment and outcome in children diagnosed with idiopathic thrombocytopenic purpura (ITP) at the University of South Alabama, Children’s and Women’s Hospital and Specialty Clinic.

METHODS:

Using ICD code 287.3, data were collected from the specialty clinic’s medical records and hospital database for children diagnosed with ITP between January 2005 and September 2010. Recurrent and chronic ITP were defined as thrombocytopenia recurring within or more than 6 months of diagnosis, respectively. Univariate and multivariate logistic regression analyses were performed to evaluate variables associated with chronic ITP.

RESULTS:

Eight four patients were identified (M,F 1:1) with an average age of 70 months at diagnosis. Mean platelet count at presentation was 14k. Oral or nasal mucosal bleeding occurred in 19(23%) patients but none experienced a serious hemorrhage. Thirty three (39%) patients had an associated illness prior to diagnosis of ITP. Treatment consisted of intravenous immunoglobulin (IVIG) in 38(45%), WinRho in 11(13%), IVIG or WinRho followed by the other in 20(24%), data not available 8(10%) and no therapy in 7 patients (8%). Average platelet count at discharge and within 2 weeks after IVIG and WinRho was 57k, 337k and 57k, 375 respectively. Forty three (51%) were acute, 17(20%) became recurrent, and 24(29%) became chronic ITP. Bone marrow examination was performed in 26(30%) patients upon subsequent relapse but the diagnosis remained unaltered in all cases. Rituximab therapy was provided to five and splenectomy was performed in 7 patients. Four patients failed both modalities, all of whom currently are IVIG dependant.

Age <5year (OR 0.12, 95%CI 0.22, 0.67, p=0.01) was protective against development of chronic ITP while platelet count >20k at presentation (OR 6.50, 95%CI 1.35, 31.30, p=0.02) and race other than white (OR 36.63, 95%CI 4.61, 291.09, p=0.001) were found to be significantly associated with the development of chronic ITP. Gender, mean platelet volume, total white cell count, and absolute lymphocyte count had no significant association.

CONCLUSION:

Our study supports the published data that patients with an initial platelet count >20k, older age and non-white race have an increased risk of progression to chronic ITP. Other published variables had no significant association in our analyses. Response to IVIG and WinRho was no different in our patients while rituximab or splenectomy did not lead to a complete resolution in refractory cases. Since bone marrow examination did not alter the diagnosis in any patient, we suggest that routine performance of this procedure may be omitted when a diagnosis of ITP is consistent with clinical history, physical examination and laboratory data.

Disclosures:

No relevant conflicts of interest to declare.
Association of Birthdays with Late Relapses of Immune Thrombocytopenia
Authors: Varma Mala
Published: October 2019

Abstract 4685

Adult immune thrombocytopenia (ITP) typically takes a chronic or relapsing course. Etiologies of initial presentations and/or late relapses have not been identified. Emotional stress has been associated with adult ITP, but it is not known if there is a causal relationship.1,2 Birthdays have been described as psychosocial stressors that have been linked with vascular events including stroke and myocardial infarction.3 Based on our observation that a disproportionately high number of late relapses were occurring within 3 weeks of patients’ birthdays, we conducted a retrospective cohort study to determine if birthdays are associated with the onset and/or late relapses of ITP.

Thirty-five consecutive patients with ITP followed between July 1, 2003 through August 11, 2011 were included in the study. Median age at presentation was 48 years (range 22 to 83 yrs). The female:male ratio was 1.9:1. One patient had human immunodeficiency virus. The median duration of follow-up was 28.3 months (range 1.25 to 72 mos). Dates of initial presentation were available for 22 patients. Only 3 (13.6%) presented within 3 weeks of their birthdays. Eleven of 35 patients had a relapse (defined as a platelet count < 30,000/μL or a 50–70% decrease in platelet count from baseline) after an unmaintained remission exceeding 1 year. Four (36%) of these 11 patients had relapses within 3 weeks of their birthdays (binomial test for significance = 0.002). Two of these 4 patients presented 3 weeks following their birthdays, but had noted fatigue 1 week before presenting. Fatigue has been associated with thrombocytopenic exacerbations of ITP;4 these patients therefore were likely relapsing at the onset of fatigue, closer to their birthdays. The other two patients relapsed 3 – 10 days following their birthdays. One was pregnant; pregnancy may have contributed to her relapse. None of the 4 patients had concurrent infections, autoimmune disease, or malignancies.

This study is the first to show that birthdays are associated with relapses of ITP after long unmaintained remissions. Birthdays may be accompanied by stress of anticipation, indulgence, and overexertion. Stress is associated with ITP, and may have a causative role in relapsing ITP.

Disclosures:

No relevant conflicts of interest to declare.
Adjuvant Corticosteroid Therapy for Chronic Disseminated Candidiasis in Patients with Acute Leukemia
Authors: Qian Shenxian , Chen Kuang
Published: October 2019

Abstract 4723

Chronic disseminated candidiasis (CDC) is typically observed during neutrophil recovery in patients with acute leukemia and requires protracted antifungal therapy. Our objective was to document the efficacy and tolerance of corticosteroid therapy (CST) in patients with symptomatic CDC, including those who experienced fever and abdominal pain despite ongoing antifungal therapy. We performed a study involving 6 adult patients who experienced ongoing symptomatic CDC despite receipt of appropriate antifungal therapy for whom adjuvant oral CST therapy was initiated. All cases of CDC were proven or probable, as determined on the basis of the European Organization for Research and Treatment of Cancer-Mycosis Study Group definition criteria, and occurred in patients with leukemia.The common manifestations in these six patients were persistent fever, splenohepatomegalia and percussion pain in hepatic region. Meanwhile, 2 of them were accompanied with appearance of painful and diffuse cataneous nodules, expectoration and dyspnoea. The abnormal laboratory test observed of them was increase of alkaline phosphatase. Computed tomography scan showed multiple hypodense lesions in the liver and spleen in all the five patients; one of them showed multiple nodular patchy shadows in bone. Nuclear magnetic resonance imaging showed multiple abnormal signal in liver, spleen and kidneys in one of the patients. Three patients had positive blood candida tropicalis cultures. liver biopsy in one patient was negative for fungal. Two patients received Fluconazole therapy empirically, but it was replaced by Itraconazole later in one because of unresponsiveness to the drug. Three patients received Itraconazole therapy and in one received voriconazole therapy empirically. CDC-attributable clinical symptoms resolved with CST, which was started an average of 31 day since antifungal therapy was initiated. Fever and abdominal pain disappeared a median of 5–6 days, and serum fibrinogen and C-reactive protein levels returned to normal values within 14–30 days. Hepatosplenic microabscesses decreased or disappeared within a mean period of 45 days (range, 27–167 days). All the six patients received further chemotherapy smoothly after the treatment antifungal therapy combined with CST,No relapses of CDC were observed during a median duration of follow-up of 3.2 years (range, 2.6–3.8 years).CONCLUSION: In adults who experience persistently symptomatic CDC despite ongoing receipt of antifungal therapy, CST involving a prednisone equivalent at a dosage of > or =0.25 mg/kg per day for at least 3 weeks is associated with a prompt resolution of symptoms and of inflammatory response. These findings support the pathophysiological hypothesis that CDC belongs to the spectrum of fungus-related immune reconstitution inflammatory syndrome.

Disclosures:

No relevant conflicts of interest to declare.
Location, Location, Location: Reassessing Erythropoiesis Stimulating Agents (ESAs) in the United States (US), Canada, and Europe (2007−2011)
Authors: Norris Leann , Mattison Donald , Qureshi Zaina Parvez , Bennett Charles
Published: October 2019

Abstract 4753

Background:

Erythropoiesis stimulating agents (ESAs) are approved for preventing transfusions (United States (US)) or treating symptomatic anemia (Canada/Europe) among chemotherapy or chronic kidney disease (CKD) patients. Extensive reassessments of safety, efficacy, dosing, and target hemoglobin levels have occurred.

Methods:

Regulatory agencies', ESA manufacturer notifications, clinical guidelines, phase III trials and meta-analyses cited in clinical guidelines were reviewed (2007 to 2011).

Results:

CKD and Cancer: Quality of life benefits are reported in Europe and Canada. In the US, product labels report exercise capacity improvements for CKD patients. CKD: Clinical trials reported cardiovascular, cerebrovascular, and mortality risks with ESAs targeting high versus low hemoglobin levels or cardiovascular and mortality risks with ESAs versus placebo. 2011 US' advisories recommend ESA doses sufficient to prevent transfusions among dialysis patients and caution with ESA administration to non-dialysis patients. Canadian and European recommendations target hemoglobin levels between 10 and 12 g/dl and 11 to 12 g/dl, respectively. Following these recommendations among non-dialysis US patients, ESA use decreased 16%. Most US dialysis CKD patients receive ESAs, with lower achieved hemoglobin levels, and 30% decreased ESA usage since 2008. In Europe and Canada, which initially had substantially lower ESA use, there has been a gradual increase. Cancer: Trials identified mortality, tumor progression, and venous thromboembolism risks with ESAs targeting higher versus lower hemoglobin levels. US labels warn against administering ESAs with potentially curative chemotherapy. European guidelines recommend ESAs for symptomatic patients at hemoglobin levels of 9 to 11 g/dL and consider for asymptomatic patients at levels of 11 to 11.9 g/dL. Canadian advisories report cost-utility ratios exceeding accepted standards. ESA use decreased by 70% in the US. Current ESA utilization rates for cancer are higher in Europe and lower in Canada.

Conclusions:

International differences in interpreting efficacy and safety data and ESA utilization exist. The changes have been most apparent in the US.

Disclosures:

No relevant conflicts of interest to declare.
Translating Research Into Policy: A Review of Pharmacovigilance Efforts From the Southern Network On Adverse Reactions (SONAR) Group
Authors: Bennett Charles , Norris Leann , Qureshi Zaina Parvez , Miller April , Bookstaver Brandon , Mattison Donald
Published: October 2019

Abstract 4756

Introduction:

SONAR, the only state-funded (South Carolina) pharmacovigilance initiative in the nation, focuses on identifying near fatal side effects of hematology and oncology therapeutics. Most safety findings are like “trees falling in the forest” – with no one hearing the noise. Our objective was to describe the outcomes from the findings of the pharmacovigilance efforts from the SONAR group.

Methods:

SONAR investigators reviewed practice and policy outcomes to our identification of adverse drug reactions with hematologic implications. Data sources used were PubMed, the Food and Drud Administration (FDA) files, and the Approved Drug Products with Therapeutic Equivalence Evaluations (Orange Book).

Results:

Conclusions:

Most SONAR findings have been followed by FDA notifications and market responses. Identifying and reporting sADRs can have marked beneficial effects on medical care.

Disclosures:

No relevant conflicts of interest to declare.
Bone-Marrow Derived Cells Can Reconstitute GCLM Function in the Sickle Lung
Authors: Adisa Olufolake , Ghosh Samit , Tan Fang , Chappa Prasanthi , Archer David R. , Ofori-Acquah Solomon F
Published: October 2019

Abstract 4836

Sickle cell disease (SCD) is a chronic hemolytic and inflammatory disorder characterized by repeated episodes of vaso-occlusion and hemolysis, resulting in oxidative stress and endothelial dysfunction. We have recently demonstrated that the heme scavenging capacity in SCD is severely impaired, highlighting the danger posed by excess heme in this disorder. Paradoxically, heme induces expression of several cyto-protective enzymes including the modifier subunit of glutamate cysteine ligase (GCLM), the rate-limiting enzyme in glutathione (GSH) synthesis, which is a crucial antioxidant in the lung. While the induction of cytoprotective enzymes is thought to attenuate the deleterious effects of heme in SCD the somatic origin of this protection has not previously been defined. Using transgenic mouse models we show for the first time that the level of GCLM in the sickle lung is markedly up-regulated due primarily to enhanced expression of the enzyme in the epithelium and blood mononuclear cells, but not in the endothelium. Based on these findings, we tested the hypothesis that leukocyte-derived GCLM was sufficient to protect the sickle lung from oxidative stress. Thus, bone marrow chimeric SCD mice with GCLM deficiency were generated by transplanting bone marrow from Berkeley SCD transgenic mice into GCLM null mice recipients. We confirmed that the chimeric GCLM-null-SCD mice had a SCD phenotype as determined by >95% engraftment of donor white blood cells, reticulocyte counts, urine osmolality and hemoglobin gel electrophoresis. Whole lung GCLM and total GSH levels in the chimeric mice were identical to the levels in the wild-type SCD mice. Moreover, lung function, as determined by oxygen saturation and breath rate, were identical in the two mouse strains. These results show that loss of GCLM expression in resident lung cells does not compromise production of GSH or the function of the lung in SCD.

Disclosures:

Ofori-Acquah: Emory University: Patents & Royalties.
Identification of Chondroitin Sulfate Proteoglycan-4 In Acute Myeloid Leukemia Using Monoclonal Antibody 225.28
Authors: Fenton Moon , Gasparetto Maura , Hong Chang-Sook , Wang XinHui , Smith Clay , Whiteside Theresa , Ferrone Soldano , Boyiadzis Michael
Published: October 2019

Abstract 4885

Chondroitin sulfate proteoglycan-4 (CSPG4) is a membrane-bound proteoglycan that is expressed on the surface of differentiated malignant cells, progenitor cells, and cancer initiating cells in various types of solid tumors. CSPG4 is highly conserved through evolution; its structure, amino acid sequence and functional properties show a high degree of homology with its rat counterpart, named neuron-glial antigen 2 (NG2). CSPG4 has been shown to be involved in the activation of several signaling pathways that play an important role in tumor progression. Because of its high levels of expression on malignant cells and its restricted distribution in normal tissues, CSPG4 is potential candidate tumor marker and target for immune- and targeted therapy. CSPG4 has been shown previously to be expressed on AML cells using an antibody raised against the rat counterpart and levels of expression were correlated with the clinical course of the disease. In this report we extend these findings by identifying a monoclonal antibody (mAb) directed at a human CSPG4 epitope and then used this antibody to examine co-expression with other common markers in AML as well as important molecular/cytogenetic abnormalities. Initially we screened a panel of 15 CSPG4-specific mAb which recognize 7 distinct epitopes for reactivity with leukemic blasts. mAb 225.28 was shown to have the highest reactivity and was selected for further studies. CSPG4 expression using mb225.28 was detected in 18/18 peripheral blood samples containing AML blasts at levels ranging from 0.2% to 98%. 7 samples showed less than 10% CSPG4 positive cells, 2 showed 10 – 20% positivity, 4 showed 20 – 30% positivity, and 5 showed greater than 30% positivity. CSPG-4 expression was not confined to any single blast sub-population defined by co-staining with CD34, CD117 and CD33. The expression of CSPG4 was shown on leukemic cells with mixed lineage leukemia (MLL) gene rearrangements, FTL3 mutation, NPM1 mutation, and complex cytogenetic abnormalities. These results indicate that the expression of CSPG4 is not restricted to any sub-type of AML or confined to one developmental compartment and using the mAb 225.28 CSPG4 may constitute a potential marker for AML.

Disclosures:

No relevant conflicts of interest to declare.
Mast Cell Leukemia?—Malignant Mastocytosis with Leukemia-like Manifestations
Authors: EFRATI P. , KLAJMAN A. , SPITZ H.
Published: October 2019

A case of probable leukemia in an adult female is described which is classified as tissue mast cell leukemia. Clinical course and autopsy findings are analyzed and a detailed morphologic description is given of the different stages of maturation of T.M.C. as found in the peripheral blood and in bone marrow aspirates.

The patient succumbed to massive gastrointestinal hemorrhage following cortisone treatment.

Histologic examination of spleen and loose areolar tissue suggested origin of T.M.C. from both reticulum cells and fibroblasts.

Focal osteosclerosis in the vertebrae probably represents a lesion related to the basic disorder.
Unique Sequence of Pernicious Anemia, Polycythemia, and Acute Leukemia
Authors: ZARAFONETIS CHRIS J. D. , OVERMAN ROBERT L. , MOLTHAN LYNDALL
Published: October 2019

The development of three primary blood dyscrasias, namely, pernicious anemia, polycythemia vera, and acute myeloblastic leukemia, in one patient has been reported.
Leukocyte Antibodies in Human Sera and in Immune Rabbit Sera
Authors: WALFORD ROY L. , PETERSON E. TAYLOR , DOYLE PATRICIA
Published: October 2019

A study of leukocyte antibodies is presented using (1) the sera of rabbits immunized with human leukocytes, and (2) the sera of three patients screened for the presence of such antibodies from among 36 patients with hematologic disease, 31 of whom (including the 3 studied in detail) had received multiple transfusions. The following technics are described and were employed: Leukoagglutination, leukoprecipitation including tube and agar-plate methods, agglutination of antigen-coated tanned and untanned sheep erythrocytes, the effect of antisera upon phagocytosis of heat-killed staphylococci by leukocytes, and upon ameboid motility of leukocytes.

The leukoagglutinin test gives reliable clearcut results providing that appropriate controls are included and certain criteria adhered to, in order to facilitate the recognition of clumping due to other factors than true antigen-antibody union.

No leukoprecipitins were detected in human sera with the technics used in this study. Immune rabbit sera, on the other hand, gave two reaction-lines in agar media, when set up against leukocyte extract.

Immune rabbit sera reacted strongly with antigen-coated tanned sheep red blood cells. Human sera did not so react. One of the three selected human sera reacted with antigen-coated untanned erythrocytes, suggesting the presence of a polysaccharide antigen extractable from human leukocytes and capable of stimulating antibody formation in the human. Immune rabbit sera, and other human sera, did not react in this test.

A suggestive but perhaps not a conclusive effect upon phagocytosis of bacteria by leukocytes exposed to human leukocyte antibody for 1 hour could be demonstrated.

By means of ameboid motility studies, a cytotoxic effect of the human antisera upon human leukocytes could be demonstrated after 18 hours of incubation, but not after 3 hours. This was interpreted as evidence of a delayed reaction.

Certain cardinal points from a clinical and theoretical standpoint with regard to the genesis of leukocyte antibodies in man are briefly reviewed. A possible analogy between leukocyte antibody formation and the homograft reaction is discussed. It is suggested that the rarity of leukocyte iso-antibody formation following transfusion is related to the fact that the intravenous pathway may be a poor route of immunization for these antigens.
Erythroblastopenia with Giant Pro-Erythroblasts in Kwashiorkor
Authors: LIEN-KENG KHO
Published: October 2019

Description of seven cases of kwashiorkor in children of one and a half to eight years of age, in which at one time or other an aplastic crisis (erythroblastopenia) occurred with the appearance of giant proerythroblasts or their precursors in the bone marrow. This condition independent of the treatment—reversed to normal in four cases and was followed by a reticulocytic crisis. Three of the children died during or shortly after the aplastic crisis. The author considers erythroblastopenia in these cases as due to insufficiency of the bone-marrow (lability) caused by chronic protein deficiency superimposed by frequent infections. The giant pro-erythroblasts are pathologic forms of erythropoiesis and are not identical with Ehrlich’s megaloblasts.
A Modified Urinary Excretion Test for Measuring Oral Cobalt60 Labeled Vitamin B12 Absorption and its Application in Certain Disease States
Authors: MILLER AARON , CORBUS HOWARD F. , SULLIVAN JOHN F.
Published: October 2019

1. Factors relating to the urinary excretion test for oral vitamin B12 absorption were studied. A modified procedure is presented giving a high percentage of urinary recovery of radioactivity in the normal.

2. Values in the pernicious anemia range were found in the presence of acute infection and severe renal insufficiency. Other limitations in the interpretation of the test are discussed.
The Dead Leukocyte Content of the Blood in Normal and Leukemic Patients
Authors: PETRAKIS NICHOLAS L. , LIEBERMAN ESTELLE , FULLERTON JEAN
Published: October 2019

The dead leukocyte content of the blood of normal and leukemic subjects was determined by the technic of the unstained-cell counts of Schrek. A small and constant number of dead leukocytes was found in the normal blood, averaging 46 per cu. mm. In patients with chronic lymphocytic leukemia and acute leukemia, higher numbers of dead leukocytes were commonly found, ranging from normal values to as high as 4,600 per cu. mm. No correlation was found between the numbers of smudge forms on blood smears from these patients and the number of dead leukocytes. The smudge forms on blood smears appear to result from the mechanical trauma produced in making the smears. The leukocytes from chronic lymphocytic leukemia and acute leukemia appear to be much more susceptible to the mechanical forces produced in the preparation of blood smears than are leukocytes from normals and patients with chronic granulocytic leukemia.