bluuebunny/crossref_metadata_2025 huggingface dataset:
Dasatinib Promotes BIM Dependent Apoptosis Via MEK/ERK without Need for Permanent BCR-ABL Inhibition
Authors: Simara Pavel , Stejskal Stanislav , Martina Peterkova , Koutna Irena , Racil Zdenek , Mayer Jiri
Published: October 2019

Abstract 4472

Chronic myeloid leukaemia (CML) is a clonal disorder of haematopoietic stem cells, characterized by constitutively active BCR-ABL kinase. It was previously shown, that transient inhibition of BCR-ABL by tyrosin kinase inhibitor (TKI) dasatinib induces apoptosis in CML cells (Shah 2008). Dasatinib mediated apoptosis is accompanied by increasing expression level of proapoptotic protein BIM and inhibition of its degradation in proteasome.

Our aim is to find alterations in BCR-ABL downstream pathways and changes in BIM expression after pulse (wash-out after 20min) or continuous treatment with TKI dasatinib alone or in combination with proteasome inhibitor bortezomib in K562 cells.

Higher mRNA levels of BIM were confirmed in both transiently and continuously treated (100nM dasatinib) K562 cells compared to low dose continuous (1nM dasatinib) treatment. Western blot analysis of BCR-ABL induced signalling pathways activity revealed, among others, sustained inhibition of MEK/ERK pathway even in the case of re-activation of BCR-ABL after drug wash-out. MEK/ERK inhibition leads to activation of proapoptotic BIM expression and inhibition of its degradation. We used bortezomib, a reversible inhibitor of proteasome, in order to test the block of BIM degradation in dasatinib treated cells. However, we have not found any difference in cell viability caused by adding of 30nM bortezomib to dasatinib treated cells neither in continuous or transient exposure. These findings suggest that equal increase of BIM in the case of pulse and continuous dasatinib treatment is caused by MEK/ERK inhibition in cells with restored BCR-ABL activity.

This project is supported by grants from the Ministry of Education of Czech Republic NPVII (2B06052) and MSM-0021622430. The substance (dasatinib) for this project was supplied by BMS company.

Disclosures:

Mayer: BMS: Consultancy, Research Funding.
High Adherence to Tyrosine Kinase Inhibitors Seems to Be Related to Best Cytogenetic Responso In the Hasford Lower Risk Graup In Chronic Myeloid Leukemia.
Authors: Almeida Maria Helena , Pagnano Katia B. , Souza Helia , Miranda Eliana C M , Souza Carmino De
Published: October 2019

Abstract 4477

Tyrosine kinases Inhibitors (TKI) of first and second generation are presently the choice of treatment for chronic myeloid leukemia (CML) and adherence to the treatment is an important factor to obtain good therapeutic results. We used the World Health Organization adherence definition that enrolls a global person's behavior including how the medication is used, diet, and/or lifestyle change.

Objective:

To evaluate the adherence to TKI in patients with CML and to identify factors that can affect adherence to TKI treatment.

Methods:

A prospective and observational analysis was performed with 122 patients taking TKI, in a public institution. The median of observation time was 169 days (131-240). We used the Hasford scale to risk assessment of diagnosis. The adherence was calculated using the mean medication possession ratio (MPR), calculated as total days’ dose of TKI divided by the number of the days in the observation time. Statistical analysis began with descriptive analysis and after that we applied Pearson or Spearman's correlation and t-Test, what it is adequate, considering significant p-value £ 0.05.

Results:

A total of 122 patients were evaluated: 92 (75.5%) were taking Imatinib, 16 (13%) Nilotinib, 09 (7.5%) Dasatinib and 5 (4%) Bosutinib. The mean age was 48 (20-82) years. The majority of patients were male (61%) and the median of TKI treatment time was 45 months (7-114). There were 103 (84.5%) patients in first line treatment, 17 (14%) in second line and 2 (1.5%) in third line. Considering all patients, median and mean of adherence was 96% and 90% whereas 23% of patients had 100% of MPR. There was a significant difference between adherence distribution and cytogenetic results, best adherent patients had most complete and major cytogenetic response (p= 0.01) in CML Hasford lower risk group. In all patients, the MPR decreased with longer use of TKI treatment (p= 0.02) and with longer time of diagnosis (P= 0.002). The adherence was superior in patients participating in clinical trials (p= 0.01) and using second generation TKI (p= 0.001).

Conclusion:

The best adherence was correlated to a better cytogenetic response in Hasford lower risk group. Longer time of treatment was related to a poorer adherence, suggesting a continuous approach by health team can make a difference.

Disclosures:

No relevant conflicts of interest to declare.
Comorbidities and Conmedication Use In Patients with Chronic Myelogenous Leukemia.
Authors: Oliveria Susan A , Yood Marianne Ulcickas , Hirji Ishan , Cziraky Mark , Davis Catherine
Published: October 2019

Abstract 4492

Introduction:

Few studies have evaluated the presence of comorbidities and the complexity of conmedication among CML patients in the real-world setting. No studies have used automated claims and medical record review to obtain comprehensive CML diagnosis, treatment, comorbidity, and conmedication information.

Methods:

Medical and pharmacy claims from HealthCore Integrated Research Database™ (8.5 million covered US lives during study time period) were used to identify patients with CML (2001 – 2005). Information on comorbidities and conmedications was obtained using claims data supplemented with medical record review. For the current analysis, conmedication use and the presence of comorbidities were assessed for one year following imatinib initiation.

Results:

Two hundred and sixteen CML patients treated with imatinib were included in this analysis. Mean age at imatinib initiation was 51 years and 42.6% were female. The mean number of unique medications for treated patients was 19 (median = 9) in the one-year follow-up. Of all medications prescribed within 1-year of CML treatment initiation, approximately 40% had dosing restrictions (i.e. administration required with/without meals) and dosing of more than once per day. The proportion of patients experiencing 1, 2, 3, and 4+ comorbidities was 22%, 16%, 17%, and 29%, respectively. Analyses were also conducted to explore the complexity (based on dosing guidelines and intake restrictions) of each medication and specific comorbidities. Thirty-four percent % of the conmedications had no intake restrictions while 11% had specific intake restrictions (e.g. take on empty stomach) and 15% had dosing guidelines of more than once per day. Forty-one percent of conmedications had both dosing restrictions and dosing of more than once per day.

Conclusion:

In addition to their CML diagnosis, patients experience a number of other comorbidities, some of which require complex management regimens. This is the first study to use medical record review to validate exposure and CML diagnosis and use claims and medical record review to obtain comprehensive information on comorbidities and conmedications. Additional data are being collected (and will be presented) on this cohort to extend follow-up through 2010, expand the number of CML patients included, and obtain complete information on all CML treatments and comorbidities.

Disclosures:

Hirji: Bristol-Myers Squibb: Employment. Davis:Bristol-Myers Squibb: Employment.
Imatinib Therapy for Chronic Myeloid Leukemia: An Experience From Eastern India.
Authors: Dasgupta Swati , Ray Ujjal , Mukhopadhyay Soma , Bose Chinmoy Kumar , Sarkar Sanjoy , Gharami Firoj , Dey Subhasish , Basak Jayasri , Mukhopadhyay Ashis
Published: October 2019

Abstract 4498

Background:

Chronic Myeloid Leukemia(CML) is an myloproliferative disorder characterized by the expansion of clone of hematopoietic cells that carries the Philadelphia chromosome(Ph).The Ph chromosome results from a reciprocal translocation between the long arms of chromosome 9 and 22,t(9;22) (q34;q11).The molecular consequence of this translocation is a fusion gene. Imatinib inhibits constitutively active BCR-ABL tyrosine kinase of Chronic Myeloid Leukemia (CML).This is a novel molecule, which inhibits the protein product of this fusion gene and hence has been used in the treatment of CML. We are now report 51 months of median follow-up data and focus on 645 number of patients who received Imatinib as a primary treatment from 2002 to 2010.

Materials and Methods:

We included total 645 patients of CML during the period of January 2002 to June 2010.The age range was 02–87 years with median age being 36±11.6 years. Among 645 patient 366 was male and 280 female. A total 645 patients 608was in chronic phase, 31 in accelerated phase and 5 patients had blast crisis at the time of presentation. At present the molecular status of the disease has been detected by RT PCR, Flowcytometry (By Fluorescence Activated Cell sorter, FACS), Karyotyping and FISH.As a runtime protocol we have used Imatinib as 400 mg/day as standard dose at chronic phase, 600 mg/day in accelerated phase and 800 mg/day in blast crisis.We have studied a comparative analysis of Hematological parameter values.

Result:

The best observed average rate of complete hematological response was 97%, complete cytogenetic response was 50%, complete molecular response 35% with partial response in 45% and poor response in 15%.After 1 year levels of BCR-ABL transcripts had fallen in 52% patients and after 4 years levels had fallen in 79%.

Conclusion:

At 51 months of median follow-up in our study, comparative analysis of haematological parameters like haemoglobin, Total Count, Platelet Count between patient and normal population revels that pre-treatment value against normal value is very significant. The post treatment value of the haematological parameters is very close to the normal values and hence it can be proved that Imatinib therapy is effective. We observed that Imatinib drug is tolarence in case of 90% patients and resistance in about 10 % patient. So, we can conclude that Imatinib is an effective and safe drug for CML patient.

Disclosures:

No relevant conflicts of interest to declare.
The Effect of Tacrolimus on Time to Development of Post-Transplant Lymphoproliferative Disorder (PTLD).
Authors: Maitland Hillary S , Stukenborg George , Williams Michael E.
Published: October 2019

Abstract 4500

Background:

Post Transplant Lymphoproliferative Disorder (PTLD) is a rare but potentially fatal complication occurring after solid organ transplant. PTLD is divided pathologically into three subgroups: early lesions, polymorphic PTLD, and monomorphic PTLD. The severity of these complications ranges from reactive lymphoid hyperplasia to aggressive non-Hodgkin lymphoma and Hodgkin-like lymphoma. Most PTLD are of B cell lineage associated with infection or reactivation of Epstein Barr virus (EBV). Post-transplant patients on immunosuppressive therapy may lack sufficient cytotoxic T cells to clear EBV-infected B cells, allowing unchecked polyclonal B cell proliferation and infection of other cells with EBV. Immunosuppression with cyclosporine and tacrolimus has been associated with a higher risk for development of PTLD. This study examines the relationship between tacrolimus and PTLD among solid-organ transplant patients.

Methods:

Differences in time to PTLD between patients with and without exposure to tacrolimus were assessed using a retrospective, case-control design. University of Virginia Health System registry records were searched to identify all patients in the post- solid organ transplant population diagnosed with malignancy in the years 1998–2009. Bone marrow transplant patients were excluded. Following IRB approval, data was collected on the type of transplant, immunosuppressive regimen, time from transplant to development of PTLD, and lymphoma treatment; from electronic charts and pathology reports were reviewed.

Results:

A total of 2841 patients with solid organ transplants were identified, including1486 patients who received tacrolimus for immunosuppression. There were 26 cases of PTLD: 19 with exposure to tacrolimus (1.3%), and 8 without exposure (0.6%). The mean time to PTLD was 2.52 years (SD = 0.65) in the tacrolimus group, and was 6.75 years (SD = 1.80) among those not exposed. This difference in time to event was stat istically significant (Log-Rank = 5.347, p = .0208).

Conclusion:

In our population of post solid organ transplant patients with PTLD, exposure to tacrolimus was associated with significantly shorter time to development. Prospective studies are needed to better elucidate the relationship between type of immunosuppression and development of PTLD. These results suggest that immunosuppressive regimens using tacrolimus may be associated with increased risk of developing PTLD.

Disclosures:

No relevant conflicts of interest to declare.
The Impact of ABO Major Incompatibility In Hematopoietic Stem Cell Transplantation Using Reduced Intensity Conditioning.
Authors: Nakamura Kazuhiro , Kamata Aya , Miki Mizuka , Kajiume Teruyuki , Sera Yasuhiko , Sato Takashi , Kobayashi Masao
Published: October 2019

Abstract 4520

The impact of ABO major incompatibility in hematopoietic stem cell transplantation (SCT) using conventional myeloablative conditioning has been reported to be negligible in clinical settings. To date, there are scant studies about its clinical significance using reduced-intensity nonmyeloablative SCT (RISCT). In this study we analyzed 32 cases performed HSCT using fludarabine-based RISCT (median age was 15 years old ranged from 7 months to 35 years old, 10 cases with and 22 cases without ABO major incompatibility) and 19 cases using conventional myeloablative SCT (median age was 8 years old ranged from 1 to 16 years old, 6 cases with and 13 cases without ABO major incompatibility) in our institution from January, 2005 to April, 2010. All patients using RISCT were non-malignant disorders including 13 patients with chronic granulomatous disease, 11 with aplastic anemia, and 5 with severe congenital neutropenia. On the other hand, all patients with conventional myeloablative SCT were pediatric malignant disorders including 8 patients with acute lymphoblastic leukemia, and 7 with acute myelogenic leukemia. As shown in Table, in RISCT, the number of red blood cell (RBC) transfusion after SCT was significantly higher and the last day of RBC transfusion was also significantly longer in patients with ABO major incompatibility than those in patients with ABO compatibility. Notably, two patients with ABO major incompatibility had prolonged delay of RBC engraftment and pure red cell aplasia due to the presence of high titer of anti-A antibody. Furthermore, the prolonged recovery of platelet and neutrophil were also observed in patients with ABO major incompatibility (Table). On the other hand, in HSCT using conventional myeloablative conditioning, no differences in the recovery of RBC and platelet were noted irrespective of ABO incompatibility. These data suggest that RISCT with ABO major incompatibility affects the engraftment and recovery of multi-lineage blood cells. Thus, the alternatives of donors may be an important role in transplant-related morbidity of RISCT with ABO incompatibility.TablePatients using RISCTABO major incompatibilityCompatibleIncompatibleP valuesPatients NumbersN=22N=10The number of RBC transfusion* (time)2.1 ± 3.113.6 ± 26.7<0.01The last day of RBC transfusion* (day)16.4 ± 14.7117.9 ± 203.8<0.01The number of Platelet transfusion* (time)14.0 ± 10.717.6 ± 13.2NSThe last day of Platelet transfusion* (day)29.1 ± 15.451.8 ± 42.10.05The day of ANC recovery above 500/ml* (day)18.2 ± 3.723.8 ± 8.8<0.05*After hematopoietic stem cell transplantationRBC: red blood cell ANC: absolute neutrophil count NS: not significant

Disclosures:

No relevant conflicts of interest to declare.
Is Antifungal Prophylaxis Useful In Stem Cell Transplantation (SCT) During Hospitalization?.
Authors: Irrera Giuseppe , Giuseppe Messina , Console Giuseppe , Martino Massimo , Maria Cuzzola , Meliadò Antonella , Iacopino Pasquale
Published: October 2019

Abstract 4541

Introduction:

Limited data demonstrate to what extent preventing fungal exposures is effective in preventing infection and disease. Further studies are needed to determine the optimal duration of fluconazole prophylaxis in allogeneic recipients to prevent invasive disease with fluconazole-susceptible Candida species during neutropenia. Oral, nonabsorbable antifungal drugs might reduce superficial colonization and control local mucosal candidiasis, but have not been demonstrated to reduce invasive candidiasis. Anti-fungal prophylaxis is recommended in a subpopulation of autologous recipients with underlying hematologic malignancies with prolonged neutropenia and mucosal damage.

Methods:

This is a retrospective study of 1007 SCT performed in our center between 1992 and 2009 in 809 consecutive patients, irrespective of diagnosis. HEPA filter and environmental monitoring (air, water, surfaces) are attributes of our transplant center.

Results:

The main characteristics of the patients are reported in Table 1. Systemic prophylaxis was used according to the guidelines (Table 2): fluconazole in the nineties, then itraconazole and from 2004 was either abolished or substituted with non-adsorbable prophylaxis in transplants with standard risk. Secondary prophylaxis was prescribed for high risk patients (with infectious fungal history, suggestive iconography, positive fungal biomarker). In 17 years our Center has never been colonized by mould. Only 3 probable aspergillosis infections and 4 proven fungal infections (fusarium, mucor and 2 aspergillosis) were diagnosed, all in allogeneic patients (2 haplotipical, 1 singenic, 1 sibiling, 1 MUD and 2 mismatched), resulting in death in all cases. No infection was documented in autologous setting, while the infection rate in allogenic setting was 3.6% with an incidence rate of 1.1 infection per 10000 transplants/year. These results are significantly lower than published reports.

Conclusion:

Systemic antifungal prophylaxis should not be performed in autologous SCT patients. The abuse of systemic prophylaxis targeting yeasts has influenced the change of epidemiology in the transplant setting with prevalence of mould infections. The identification of high risk patients is useful to select patients for systemic antifungal or secondary prophylaxis to reducing overtreatment, incidence of resistant strains and costs.

Disclosures:

No relevant conflicts of interest to declare.
Refractory NK/T Cell Lymphoma Treated with Bortezomib+Chemotherapy and APBSCT.
Authors: Fu Chengcheng , Wang Juan , He Xuefeng , Xu Ting , Zhang Ri , Depei Wu
Published: October 2019

Abstract 4602

Backgrouds:

NK/T cell lymphoma is a rare disease, but usually shows a highly aggressive clinical course and its prognosis is poor due to the stumbling block in early diagnosis and effective management. Until present, there are no consensus treatments especially for recurrent patients. Bortezomib, and other new drugs are subject to active investigation, although only limited preliminary information is available. Here, 3 cases of refractory disseminated NK/T cell lymphoma were treated with Bortezomib plus high dose chemotherapy as salvage therapy.

Patients and methods:

From 2008–2010, 3 cases of refractory NK/T cell lymphoma, 2 males, 1 female, aged from 26–35, PS 0–1 were enrolled. Former treatments included at least 2–9 months of chemotherapy (CHOP or CHOP like) and local radiotherapy. The stage of patients was III in 2, IV in 1. IPI scores were all in high risk.

Result:

3 patients received high dose chemotherapy combined with bortezomib as re-induction treatment. 2 patients received hyperCVAD as induction therapy with bortezomib given 1.3mg/m2 on d2, 5, 9 and 12. 1 patient received bortezomib and SMILE protocol, included bortezomib 1.3 mg/m2 on days1, 4, 8, 11, dexamethasone 20 mg twice a day on days 1 through 4, etoposide 100 mg/m2 on days 1 through 3, ifosphamide 1.0 g/m2 on days 1 through 5, methotrexate 30 mg/m2 on days 4, 11, L-asparaginase 6000U/m2 on days 7, 9, 11, 13, 15. All 3 patients had response to the treatment. HyperCVAD, HDAC+MTX and SMILE protocol combined with bortezomib were also given to the patients as consolidation therapy for 1–4 courses. After 2 course of treatment, 1 patient got CR, 2 got PR. Then ASCT was performed. Condition protocol was SEAM+Bz1.3 mg/m2 on days-4, -1. At a median follow-up for 15 months, the median duration of PFS was 12 months. No PN was found in all patients. SAE were neutropenia and thrombocytopenia grade 4, mucositis grade 3, increase AST grade 2 in 3 patients and HZV infection in 1.

Conclusion:

Bortezomib combined with high dose therapy may be effective salvage therapy in some refractory disseminated NK/T cell lymphoma, especially in young adults. More cases need to be carefully investigated to explore the effect and side effect in bortezomib plus high dose therapy in this special disease.

Disclosures:

No relevant conflicts of interest to declare.
Splenic Volume Can Be a Novel Predictive Parameter for the Prognosis of Chronic Lymphocytic Leukemia?
Authors: Song Moo-Kon , Chung Jooseop , Shin Ho-Jin , Seol Young Mi , Choi Young Jin , Lee Ho Sup , Kim Sung Hyun , Cho Goon Jae
Published: October 2019

Abstract 4623

Recently, clinical importance of disease status by computed tomography (CT) before treatment in chronic lymphocytic leukemia (CLL) is increasing. The present study was conducted to evaluate whether splenic volume (SV) by CT would predict the clinical outcome in CLL patients.

SV were measured in 61 Rai II-IV CLL patients who underwent CT scan before chlorambucil therapy. SV was reconstructed and measured from the cross-sectional CT images by using 3 dimensional Voxar analytical volume software.

Median SV was 721.3 cm3 (223.7-3576.6 cm3) is the most significant separated cut-off point on progression-free survival (PFS) and overall survival (OS). Low SV group was associated with longer PFS and OS than high SV group (p<0.001; p<0.001). High SV (SV ≥ 721.3 cm3) was associated with higher Rai stage (SV between Rai II and III, p=0.005; Rai III and IV, p=0.026) and poorer response (SV between CR and PR, p=0.075; PR and SD, p=0.366; SD and PD, p=0.019). Univariate and multivariate analyses revealed that high SV was independent prognostic factor on PFS (HR, 2.924; 95%CI, 1.308–6.538; p=0.009) and OS (HR, 3.024; 95%CI, 1.106–8.270; p=0.031).

SV before therapy reflected the clinical outcome in CLL patients.

Disclosures:

No relevant conflicts of interest to declare.
Preclinical Evaluation of the Proteasome Inhibitor MLN9708 (MLN2238) In Chronic Lymphocytic Leukemia Cells
Authors: Masood Aisha , Miles Kiersten M , Khan Nazmul H , Akhtar Drusilla , Adelaiye Remi , Advani Pooja , Sher Taimur , Chitta Kasyapa , Chanan-Khan Asher A.
Published: October 2019

Abstract 4634

The proteasome is an important therapeutic target in multiple hematological malignancies. The proteasome inhibitor bortezomib has demonstrated significant clinical activity in multiple myeloma and mantle cell lymphoma. However, clinically bortezomib has failed to demonstrate efficacy in chronic lymphocytic leukemia (CLL); the exact reason for this remains unknown. MLN9708 (Millennium Pharmaceuticals, Inc., Cambridge, MA) is a proteasome inhibitor which has a shorter proteasome dissociation half life than bortezomib and is currently in Phase I clinical development. Upon exposure to aqueous solutions or plasma, MLN9708 rapidly hydrolyzes to MLN2238, the biologically active form. MLN2238 was used for all of the studies reported here, in which we evaluated the antileukemic effects of MLN2238 in primary CLL cells from 16 patients. MLN 2238 induced a time and dose dependent decrease in CLL cell viability in 12 (75%) patient cells in vitro. Cell death was shown to be due to the induction of apoptosis confirmed by Annexin V staining of CLL cells and cleavage of PARP-1, an indicator of apoptosis. Biochemical analysis showed that caspase 3 and 9 were activated in these cells, indicating that MLN2238 induces cell death through the intrinsic apoptosis pathway. We noted increased mitochondrial outer membrane permeability (MOMP) in the presence of MLN2238, which suggests the engagement of the mitochondria in MLN2238 induced apoptosis in CLL cells. Evaluation of non-responding CLL patient samples demonstrated that increased expression of PSMB5 is associated with lack of sensitivity to MLN2238. Furthermore, incremental addition of autologous serum in responding CLL samples resulted in upregulation of PSMB5 levels, resulting in protection against MLN2238 induced cell death. Our preclinical observations demonstrate for the first time that MLN2238 can induce death in primary CLL cells, and support further investigation in CLL.

Disclosures:

No relevant conflicts of interest to declare.
Expression of C/EBPα and PU.1 Gene In MDS and Their Significance Analysis
Authors: Ji Wencan , Ding Kaiyang , Sun Zimin
Published: October 2019

Abstract 4649

Objective

This study was aimed to investigate the expression levels and significance of CCAAT/enhancer binding protein alpha gene and transcription factor PU.1 gene in myelodysplasyic syndromes (MDS).

Methods

A real time quantitative reverse transcriptase polymerase chain reaction (Real-time PCR) method was used to detect the expression levels of C/EBPα mRNA in bone marrow mononuclear cells (BMMNCs) of 33 patients with MDS and 14 normal controls, Reverse transcription polymerase chain reaction (RT-PCR) was established for detecting PU.1 mRNA expression levels in BMMNCs of above-mentioned samples.

Results

The expression of C/EBPα was significantly lower in low-risk and high-risk MDS than those of normal controls (P<0.01, P<0.001, respectively), moreover, high-risk MDS showed lower C/EBPα expression than those of low-risk MDS (P<0.05). The expression level of PU.1 significantly decreased in low-risk MDS, as compared with normal controls and high-risk MDS (P<0.001), but there was no significant difference in expression level of PU.1 between high-risk MDS and normal controls (P>0.05).

Conclusion

reduced C/EBPα and PU.1 expression level have closely associated with the pathogenesis of MDS, they may be important molecular biological markers of MDS; The degree of down-regulated C/EBPα has closely related to the progression of MDS, the detection of C/EBPα gene expression level may be useful for assessing disease progress and prognostic of patients with MDS.

Disclosures:

Ding: Anhui Provincial Natural Science Foundation (070413257X): Research Funding; Fund of Anhui Provincial “115” Industrial Innovation Program: Research Funding.
The Role of Mir-150 as a Tumor Suppressor In Malignant Lymphoma
Authors: Watanabe, Atsushi , Tagawa Hiroyuki , Teshima Kazuaki , Kameoka Yoshihiro , Takahashi Naoto , Sawada Kenichi
Published: October 2019

Abstract 465

Disease specific genetic alteration or translocation have not been identified in NK/T cell lymphoma. We recently demonstrated that over expressions of miR-21 and/or miR-155 are frequently occurring in natural killer (NK) cell lymphoma/leukemia and deeply associated with their lymphomagenesis by deregulation of AKT signaling. In this study, we tried to identify tumor suppressor miRNA(s) in malignant lymphomas including B-cell, NK-cell and CD4+T-cell lymphoma, by using quantitative PCR and/or Northern blot analysis. We found that miR-150 in both cell lines and primary samples of NK and T-cell lymphoma showed significantly lower expression than those of normal natural killer cells and CD4+T cells. To examine the role for lymphomagenesis, we stably transduced miR-150 into lymphoma cell lines. Enforced expression of miR-150 in NK/T cell lymphoma cell lines showed increased levels of susceptibility of apoptosis, and showed senescence with reduced levels of telomerase activity and telomere DNA shortening. We further demonstrated that miR-150 directly down regulate AKT2, leading to reduced expression of phosphorylated AKTser473/474 with upregulation of tumor suppressors, Bim, p27 and p53. Since it has been proven that AKT kinase phosphorylate hTERT (human telomerase reverse transcript), downregulation of miR-150 in lymphomas lead to activate telomerase activity, resulting immortalization of the cancer cells. These results suggest that miR-150 play as a role of tumor suppressor in NK/T-cell lymphoma. Our recent and previous report demonstrate that downregulation of miR-150 and upregulation of miR-21/miR-155 collaborately contribute to NK/T-cell lymphomagenesis by deregulating AKT signaling. These findings will give a new insight into the pathogenesis of NK/T cell lymphoma and the miR-150 itself and/or AKT targeting therapy can be a useful against aggressive lymphoma.

Disclosures:

No relevant conflicts of interest to declare.
Sequential Infusion of rFVIIa and Plasma-Derived Activated Prothrombin Complex Concentrate In Haemophilia A Paediatric Patient with Inhibitors
Authors: Lassandro Giuseppe , Scaraggi Francesco Antonio , Scaraggi Rosanna , Capriati Teresa , De Mattia Domenico , Giordano Paola
Published: October 2019

Abstract 4660

One of the serious complication in hemophilia therapy is the development of high titre inhibitors to FVIII and less often to others coagulation factors. It makes treatment of bleeds very challenging. We report a case of hemarthrosis in hemophilia A pediatric patient with inhibitors, treated with sequential infuson of rFVIIa (rFVIIa, NOVOSEVEN; Novo Nordisk A/S, Bagsvaerd, Denmark) and plasma activated prothrombin complex concentrate (pd- aPCC, FEIBA; Baxter AG Vienna Austria). rFVIIa and plasma activated prothrombin complex concentrate are, indeed, used as haemostatic bypassing agents to prevent eaemorrages, with the goal of limiting sequelae as arthropathy, or to control quickly heamostasis as intensive on–demand treatment. A 3 years old male patient affected by haemophilia A with inhibitors came to our observation for a traumatic hemarthrosis of the left knee. Clinic examination showed swelling and pain. His inhibitor titre was 29 Bethesda Units. First we infused rFVIIa for seven consecutive days at the dose of 90 ug/kg every 3 hours. This therapy didn't determinate any clinical improvement. Then we infused plasma activated prothrombin complex concentrate for the next consecutive seven days at the dose of 60 UI/kg every 12 hours. At the end of treatment we noticed pain disappearance and reducing swelling. Medical literature recently describes similar paediatric cases treated with sequential infusion of rFVIIa and plasma activated prothrombin complex concentrate. Our positive experience could stimulate to use haemostatic bypassing agents because apparently safe. We encourage to use this therapeutic scheme because it seem to reduce healing times of acute events.

Disclosures:

No relevant conflicts of interest to declare.
Pregnancy-associated Thrombotic Thrombocytopenic Purpura: A Single Institution's Experience
Authors: Boro Jordana , Pavenski Katerina , Freedman John J. , Garvey Marie B. , Hicks Lisa K
Published: October 2019

Abstract 4675

Thrombotic thrombocytopenic purpura (TTP) is a rare, life-threatening form of microangiopathic hemolysis that can be associated with pregnancy. Although the association between TTP and pregnancy is well recognized, the presentation, natural history, and ideal treatment of TTP in this population remain poorly understood. St. Michael's Hospital is a regional referral centre for TTP in Ontario, Canada. We conducted a retrospective review of all cases of TTP referred to our pheresis unit between July 1993 and May 2010. Ninety-four cases were identified, of these, ten patients were pregnant or up to one week post-partum at the time of TTP diagnosis. Median age at presentation was 34 (29-36). Only one patient had been previously diagnosed with TTP and then developed a TTP relapse while pregnant. At presentation, all patients had thrombocytopenia (platelets: < 3 to 124 × 106/ml), anemia (hemoglobin: 60 to 99 mg/L), elevated LDH (1.3 to 12.5 × ULN), and fragmentation on blood film. ADAMTS13 was assessed in six of ten patients. It was normal in four patients, and deficient in two patients. Seven patients had neurological symptoms at presentation, one of whom suffered permanent right sided paralysis. Six patients had depressed glomerular filtration ratio (GFR) at presentation, four of these six recovered normal GFR. Hypertension was present in only one patient, and no patients had abnormal coagulation parameters at presentation. ALT was normal in six patients, mildly elevated in two patients, and unavailable in two patients. There were no patient deaths in this series. Patients were treated with a median of 17 plasma exchanges (range: 9 to 55) using either fresh frozen plasma or cryosupernatant. Eight patients achieved complete remission with plasma exchange. Two patients had refractory disease which ultimately responded to splenectomy and rituximab respectively. There were two fetal deaths, one a first trimester miscarriage, and the second an intrauterine death in the second trimester. In conclusion, in our series of pregnancy associated-TTP, there were no maternal deaths and most women responded to a short course of plasma exchange. ADAMTS13 deficiency was uncommon in our series. Nonetheless, in our series, TTP was not difficult to distinguish from preeclampsia and/or disseminated intravascular coagulation using routine laboratory parameters.

Disclosures:

No relevant conflicts of interest to declare.
A Three Year Experience at An Inner City Safety-Net Hospital with Immune Thrombocytopenic Purpura (ITP)
Authors: Poola Harsha V , Gaddh Manila , Ofori Samuel N. , Shah Moushmi , Kassem Mohammed A. , Haidau Augustin , Catchatourian Rosalind , Telfer Margaret
Published: October 2019

Abstract 4684

Immune Thrombocytopenic Purpura or ITP remains a clinical diagnosis of exclusion. There are numerous treatments, attesting to the fallibility of each. A 3 year experience at an Inner City safety net hospital was analyzed. For inclusion in the study, the hematology service had to have excluded consumption disorders, prior chemotherapy, medication known to cause thrombocytopenia and Viral Infection- HIV and/Hepatitis. 93 patients met these criteria and had platelet counts below 50,000. The median age of the whole group was 49 yrs, with a range of 21 to 78 years. A few were ANA positive. The female preponderance reflects the literature.

All Patients were started on Prednisone at 1mg/kg. Three Patients also received IV IGG to hasten the response. There were no intracranial hemorrhages or bleeding described as major.

Patients from the Far East had to be excluded for Hepatitis Virus exposure.

Results

All who did not respond to steroids fully were treated with a second line Rx. i.e, Rituximab, Azathioprine, IV IGG or WIN Rho. One patient received high dose Dexamethasone and responded.

Conclusion:

Pending the use of TPO agonists, treatment of ITP in adults remains a chronic problem challenging the Hematologist to use as little corticosteroid as possible.

Disclosures:

No relevant conflicts of interest to declare.
Genome-Wide Analysis Reveals Frequent Inactivating Mutations of Acetyltransferase Genes In B-Cell Lymphoma
Authors: Pasqualucci Laura , Dominguez-Sola David , Chiarenza Annalisa , Fabbri Giulia , Grunn Adina , Trifonov Vladimir , Kasper Lawryn H. , Lerach Stephanie , Jing Ma , Rossi Davide , Mullighan Charles , Gaidano Gianluca , Rabadan Raul , Brindle Paul K. , Dalla-Favera Riccardo
Published: October 2019

Abstract 474

B cell non-Hodgkin lymphoma (B-NHL) comprises a variety of biologically and clinically distinct diseases whose pathogenesis is associated with largely unique genetic lesions affecting oncogenes and tumor suppressor genes. The identification of the complete set of genes and cellular pathways that are altered in the lymphoma cell is critical for a full understanding of the genesis and maintenance of these malignancies. Using genome-wide copy number analysis and high throughput whole exome sequencing, we have recently found that the two most common types of B-NHL, follicular lymphoma (FL) and diffuse large B cell lymphoma (DLBCL), are associated with frequent structural alterations inactivating the genes that encode CREBBP and, in a smaller fraction of cases, EP300, two highly related histone and non-histone acetyltranferases (HAT) that act as transcriptional coactivators in multiple signaling pathways. Overall, ~29% (n=39/134) of DLBCL and 32% (n=15/47) of FL samples display genomic deletions and/or somatic point mutations that remove or inactivate the HAT domain of CREBBP. In 19 additional cases (15 DLBCL and 4 FL), mutations and deletions were found in the EP300 gene, also predicting its functional loss. With few exceptions, structural alterations of CREBBP and EP300 were mutually exclusive, suggesting that inactivation of these loci is at least in part functionally equivalent. Thus, in total ~36% of all DLBCL (n=49/134) and at least 40% of FL cases (n=19/47) display genetic aberrations targeting acetyltransferase genes. Interestingly, while these lesions were observed in both DLBCL phenotypic subtypes, their frequency appears to be significantly higher in germinal center B cell type DLBCL, where they account for ~46% of the cases (n=30/65) as compared to 27% in activated B cell type DLBCL (n=11/69; p<0.01). CREBBP and EP300 structural alterations commonly affect a single allele, suggesting that reduction in HAT dosage is important for lymphomagenesis. While the functional consequences of these lesions are likely to be broad on gene transcription, we demonstrate specific defects in the acetylation-mediated inactivation of the BCL6 onco-protein and activation of the p53 tumor suppressor, both of which contribute to transformation. These results identify CREBBP/EP300 alterations as a major pathogenetic mechanism shared by common forms of B-NHL, and have direct implications for the development of therapeutic regimens targeted to acetylation/deacetylation mechanisms.

Disclosures:

No relevant conflicts of interest to declare.
Cognitive Impairment In Adult De Novo Acute Leukemia Patients
Authors: Verleden Stijn , Audenaert Kurt , Noens Lucien
Published: October 2019

Abstract 4746

Introduction:

A significant percentage of cancer patients develop or have chemotherapy-induced cognitive impairment, during and even long after completion of aggressive treatment. Cognitive deficits are usually subtle and mild, and can occur in various cognitive domains. In AML/MDS patients, impaired cognitive functions, even prior to initiation of chemotherapy, have been described.

Objective:

To assess baseline cognitive functions and short-term cognitive evolution in de novo acute leukemia patients during induction treatment, and to compare our data with previous research.

Methods:

Current longitudinal-prospective study of adult de novo AML/ALL patients, treated with induction chemotherapy at the Hematology Department, UZ Ghent, Belgium. Eligible patients are enrolled and investigated with a comprehensive cognitive test battery, within on average five days after admission (pre-induction) and after completion of induction chemotherapy, on average after two months (pre-consolidation). Cognitive functions are assessed across various domains, including attention, executive functions, motor dexterity, and verbal/visual memory. Patients’ psychological functions and quality of life are assessed simultaneously.

Results:

Twenty adult patients were enrolled between 01/2009 and 06/2010. The median age was 43 years, 50% were male, 80% had AML (20% ALL), and median years of education was 12 years. Baseline hematological values were assessed, with WBC count (mean: 10,4 10E3/uL), RBC count (mean: 3,1 10E6/uL), and HgB (mean: 9,8 g/dL). Adult patients had normal cognitive functions (range: 1,0 SD below normative mean) in different cognitive domains, and mainly in attention and executive functions (COWA letter fluency & semantic fluency, and SCWT mental flexibility), except for mild cognitive deficits in verbal learning (AVLT A1-5), but especially in motor dexterity (PPT left and right hand). These functions were heterogeneous at baseline, ranging from severely impaired to good within a cognitive domain. At follow-up, attention, executive functions, motor dexterity, and verbal learning had all improved significantly (p<0.02).

Conclusion:

Adult de novo AML/ALL patients exhibit at baseline normal cognitive functions, except for verbal learning and motor dexterity. Cognitive deficits in attention, executive functions, and verbal learning were found similar to previous reported research in AML/MDS. However, our data showed less impaired motor dexterity. Moreover, cognitive functions improved at follow-up.

Disclosures:

No relevant conflicts of interest to declare.
Development of A Clinical Prediction Rule for Risk Stratification of Recurrent Venous Thromboembolism In Patients with Cancer-Associated Venous Thromboembolism
Authors: Louzada Martha L , Lazo-Langner Alejandro , Dao Vi , Zhang Jerry , Kovacs Michael J. , Carrier Marc , Rodger Marc , Wells Phil
Published: October 2019

Abstract 475

Background:

Current guidelines suggest that all cancer patients with venous thromboembolism be treated with long-term low molecular weight heparin (LMWH). However, whether treatment strategies should vary according to patient and malignancy characteristics, in particular whether patients with low risk of VTE recurrence can be identified, remains unknown.

Methods:

We performed a single centre retrospective cohort study conducted at the Thrombosis Unit of the Ottawa Hospital. The charts of patients with cancer and VTE followed from 2002 to 2004 and from 2007 to 2008 were reviewed to assess the feasibility of derivation of a clinical prediction rule that stratifies VTE recurrence risk in patients with cancer—associated venous thrombosis through identification and evaluation of characteristics of malignancy and other clinical characteristics. We analysed only the patients who had a recurrent VTE within the first 6 months of anticoagulation. A univariate analysis determined the strength of association between each potential predictor and VTE recurrence. All potential predictor variables (p<0.25) were evaluated in a logistic regression model.

Result:

Of 543 patients 55 (10.1%) presented with a VTE recurrence during the first 6 months of anticoagulation. At VTE recurrence 19 (9.5%) patients were using VKA and 36 (10.5%) patients were using LMWH. The relative risk for VTE recurrence was not significantly different between patients who used VKA or LMWH [RR= 1. 13 (95%CI, 0.743 – 1.711; p= 0.565)]. A multivariate analysis suggested that gender, primary tumour site, tumour stage and history of prior VTE were significant variables to include in the clinical prediction rule. The final model included female gender, lung cancer and prior history of VTE as increasing risk and breast cancer and stage I disease as lowering risk. Patients with a score equal or less than 0 have low risk (4.5%) for VTE recurrence and this represented 48% of our patients. Patients with a score equal or above 1 have high risk (> 19%) for VTE recurrence (Tables 1 and 2).

Conclusion:

We were able to derive a simple and easy scoring system that stratifies patients with cancer-associated thrombosis into low or high risk of recurrent VTE. Future prospective validation of the model is warranted and may be very relevant to better tailor anticoagulation treatment in this heterogeneous population.

Disclosure:

No relevant conflicts of interest to declare.
Polyploidization of Megakaryocyte Is Associated with the Proliferation Rate of Precursor Cell
Authors: Wang Jianhui , Nardi Michael A. , Li Zongdong
Published: October 2019

Abstract 4802

Endomitosis, the uncoupling of DNA replication with cytokinesis, occurs during the maturation of megakaryocytes (MK) and leads to the MK polyploidization (4N to 128N DNA content). The mechanism that controls the ploidy in MKs is not well understood. We investigated the correlation of cell proliferation rate with MK ploidy in several differentiating megakaryoblastic cell lines. Meg-01, CHRF-288, and K562 cells were treated with a Src kinase inhibitor (3 μm Su6656) for 4 days and the ploidy was assessed by propidium iodide. Proliferation rate was determined by the doubling time of synchronized cells cultured in 10% serum. We found a significant correlation between ploidy and proliferation rate in these cell lines, with the K562 line having both the highest proliferation rate and the percentage of ploidy cells. We then differentiated the megakaryocyte cell line L8057 cells by thrombopoietin using various concentrations of serum (5%, 10%, and 20%) to control proliferation. The proliferation rate of L8057 cells varied with serum concentration and was also highly correlated the percentage of ploidy cells (23%, 32.8%, and 40.9% respectively). Thus, our data suggest that factors control the cell proliferation rate may contribute to the polyploidization of megakaryocyte.

Disclosures:

No relevant conflicts of interest to declare.
The Value of Procalcitonin and Lipopolysaccharide Binding Protein to Differentiate the Fever In the Patients with Sickle Cell Anemia
Authors: Unal Selma , Arslankoylu Ali Ertug , Kuyucu Necdet , Aslan Gönül , Erdogan Semra
Published: October 2019

Abstract 4818

Objective:

Differentional diagnosis of fever is very important in patients with sickle cell anemia (SCA) in order to prevent inappropriate antibiotic use, drug resistance and to shorten the hospitalization period. A reliable marker to be used in the differentional diagnosis of fever in these patients has not been defined yet. We aimed to evaluate the values of C Rective Protein (CRP), procalcitonin (PCT), and lipopolysaccharide binding protein (LBP) levels in the differentional diagnosis of fever in patients with SCA.

Material and Methods:

86 children with SCA (40 males and 36 females, mean age of 9.6 ± 3.84, range: 1–18 years), (Group 1) and 49 healthy children as a control group (mean age: 8.8 ± 3.91, range: 1–18 years) (Group 2) were included in this study. Patients who had admitted to the emergency department for concurrently vasoocclusive crisis and fever (axillary temperature ≥38C°) were classified as Group 1A and who had vasoocclusive crisis but no fever were classified as Group 1B and the patients without fever and vasoocclusive crisis were classified as Group 1C. A detailed history was taken from every child, and a full physical examination was performed. The patients who had taken antibiotics in last one week were excluded. The type of vasoocclusive crisis were recorded in Group 1A and 1B patients. In Group 1A patients, the fever was evaluated with appropriate laboratory tests (WBC count, periferic blood smear, serum CRP level, urinary test, chest radiography, blood and urinary culture). No infection focus was identified in patient and conrol groups. The WBC count, serum CRP, PCT and LBP levels were evaluated in all the patient and control groups.

Results:

The median CRP level of all patient groups was significantly higher than the control group (0.78 mg/L; range 0.21–70.0) (p<0.0001). The median CRP level in Group 1A (7.42 mg/L) and Group 1B (6.94 mg/L) were significantly higher than group 1C patients (2.24 mg/L). There were no significant difference between the SCA groups considering median serum PCT levels (Group 1A: 0.18 ng/ml, Group 1B: 0.11 ng/ml, Group 1C: 0.13 ng/ml, p>0.05). These values were significantly higher than control group (0.08 ng/ml) (p<0.0001). LBP level in Group 1A (median:11.5 μg/ml) was significantly higher than Group 1B (median: 8.9μg/ml), Group 1C (median: 7.7μg/ml) and control group (median:5.9μg/ml) (p<0.0001). Also serum LBP in both Group 1B and Group 1C were higher than control group (p<0.0001).

Conclusion:

PCT level is not affected from the acute inflamation originates from the vasoocclusive crisis. Thus, serum PCT level can be considered a good marker in the differentional diagnosis of fever in patients with SCA.

Disclosures:

No relevant conflicts of interest to declare.