bluuebunny/crossref_metadata_2025_split huggingface dataset:
PF182 CLINICOBIOLOGIC CHARACTERISTICS AND OUTCOME OF ELDERLY FRAIL PATIENTS WITH ACUTE LYMPHOBLASTIC LEUKEMIA INCLUDED IN A SPECIFIC PROTOCOL (ALL‐07FRAIL)
Authors: Ribera J.M. , García‐Calduch O. , Gil C. , González‐Campos J. , Moreno M.J. , Barba P. , Amigo M.L. , Martínez‐Carballeira D. , Alonso N. , Bergua J.M. , Mercadal S. , Cladera A. , Vall‐Llovera F. , García‐Guiñón A. , López A. , Lavilla E. , Sierra M. , Hernández‐Rivas J.M. 
Published: June 2019

Background:Elderly patients with ALL are frequently excluded from clinical studies, especially if they have criteria of frailty. Treatment of these patients is considered palliative, but here are scarce studies analysing the tolerability and outcome of elderly frail patients included in specific trials.Aims:Here we present the clinicobiologic characteristics and outcome of elderly frail patients with Philadelphia chromosome‐negative (Ph‐neg) ALL included in the ALL‐07FRAIL (NCT01358201) study from the Spanish PETHEMA Group.Methods:Older (55–65 yrs.) and elderly (>65 yrs.) patients with Ph‐neg ALL with Charlson comorbidity index >3 were included in this study. Treatment schedule: pre‐phase (dexamethasone [DXM] for 1 week + triple intrathecal therapy [TIT]). Induction: vincristine (VCR) 1 mg/week x 4 wks and DXM (10 mg/m2/d x 28d) and TIT (d1 and d35). No consolidation. Maintenance: mercaptopurine (MP) (50 mg/m2/d) and methotrexate (MTX) (20 mg/m2/wk) for 2 years from CR, with monthly reinductions with VCR (1 mg), DXM (40 mg/m2, d1,2) and TIT during the 1st year.Results:From 2008 to 2018, 58 patients (pts) were included in the ALL FRAIL07 study. Mean (SD) age 73 (7) yrs., 42 pts (72%) over 70 yrs., 38 males (66%), median WBC count 8.2 x109/L (0.3–475), CNS involvement 5 pts (9%), B‐cell precursor ALL 48/56 (86%)(pro‐B [n = 12], common [n = 23], pre‐B [n = 12], non‐specified [n = 1]), T‐ALL 8/56 (14%)(pro‐T [n = 1], pre‐T [n = 4], mature T [n = 1], non‐specified [n = 2]). Results of induction treatment (n = 57, 1 on treatment): early death 9 (16%), failure 17 (30%), complete remission 31 (54%). The most frequent Grade 3–4 toxicities in induction were: neutropenia 39/51 pts (77%), thrombocytopenia 30/51 (59%), infection 11/51 (22%), neurologic 4/49 (8%) and gastrointestinal 2/49 (4%). Outcome of CR patients: treatment‐related mortality 6 (19%), withdrawn from study 2 (6%), relapse 20 (65%), persistent CR1 3 (10%). The cumulative incidence of relapse at 3‐yrs was 80% (median: 11.1 months [95%CI: 5.2–25.9]). With a median follow‐up of 23.7 months (0.1–53.7), 4 patients are alive, with a median OS of 7.7 months (95% CI, 5.6–9.9)(Figure 1).Summary/Conclusion:Older and elderly frail patients with Ph‐neg ALL can benefit from a structured study using non‐genotoxic drugs, with good tolerability and acceptable CR rate and survival. These results could serve as control for strategies including new drugs in this difficult‐to‐treat population.image
PF185 WT1 OVEREXPRESSION PREDICTED GOOD OUTCOMES IN ADULT B‐CELL ACUTE LYMPHOBLASTIC LEUKEMIA PATIENTS RECEIVING CHEMOTHERAPY
Authors: Wang S. , Wang C. , Li T. , Wang W. , Hao Q. , Xie X. , Wan D. , Jiang Z. , Liu Y. 
Published: June 2019

Background:B‐cell acute lymphoblastic leukemia (B‐ALL) is a clinically and biologically heterogeneous disease that is characterized by the clonal expansion of developmentally arrested B‐cell precursors. Despite significant improvements in the management of this disease in children, the prognosis of adult patients remains poor. Identifying new prognostic markers is necessary to help select the best therapeutic schedules. Wilms’ tumor gene 1 (WT1) is a transcription factor that is overexpressed in diverse neoplasms, including acute leukemia. The prognostic role of WT1 in ALL is still controversial. No study has focused on the prognostic role of WT1 expression in adult B‐ALL patients receiving chemotherapy only.Aims:To investigate the prognostic value of WT1 expression in adult patients with B‐ALL.Methods:The WT1 transcript levels of 162 de‐novo adult B‐ALL patients were determined by TaqMan‐based real time quantitative PCR (RQ‐PCR) at the time of diagnosis. Eighty‐eight patients received allogeneic hematopoietic stem cell transplantation (allo‐HSCT). Survival functions were estimated by the Kaplan‐Meier method and compared by the log‐rank test. Cumulative incidences were estimated for relapse to accommodate competing risks. A Cox proportional hazard regression model was used to determine the associations between WT1 transcript levels and CIR, RFS and OS.Results:WT1 overexpression was defined as a transcript level higher than 0.50%, which is the upper limit in normal bone marrow. WT1 overexpression was identified in 66.0% of the patients. WT1 overexpression was an independent positive prognostic factor for the cumulative incidence of relapse (CIR), relapse‐free survival (RFS) and overall survival (OS) in patients who received chemotherapy only (CIR: HR = 0.236 [95% confidence interval 0.094–0.592]; P = 0.002; RFS: HR = 0.223 [0.092–0.543]; P = 0.001; OS: HR = 0.409 [0.214–0.783]; P = 0.007) and in patients who did not have BCR‐ABL fusion or KMT2A rearrangements (CIR: HR = 0.431 [0.201–0.921]; P = 0.030; RFS: HR = 0.449 [0.224–0.899]; P = 0.024; OS: HR = 0.521 [0.278–0.977]; P = 0.042). However, WT1 overexpression had no prognostic value in patients who received allogenic hematopoietic stem cell transplantation (allo‐HSCT). Furthermore, allo‐HSCT could improve the prognosis of patients with low WT1 expression.Summary/Conclusion:Therefore, testing for WT1 expression at the time of diagnosis may predict outcomes in adult B‐ALL patients who receive only chemotherapy and who do not have the BCR‐ABL fusion gene or KMT2A rearrangements. Allo‐HSCT may improve the prognosis of patients with low WT1 transcript levels.
PF186 INTENSIVE CARE OF THE LIFE –THREATING COMPLICATION DE NOVO ACUTE LYMPHOBLASTIC LEUKEMIA (ALL) PATIENTS (PTS)
Authors: Bazhenov A. , Galstyan G. , Parovichnikova E. , Troitskaya V. 
Published: June 2019

Background:Treatment of ALL pts can be associated with the life‐threating complications requiring intensive care unit (ICU) admission. The long‐term outcomes of ALL pts after discharge from ICU is unknown.Aims:To compare the overall survival (OS) of de novo ALL pts who required and not required ICU admission during induction remission chemotherapy.Methods:All de novo ALL pts (median age 28 yo, 17–60 yo), treated from 2013 to 2017, were enrolled into the study. Pts were divided into 2 groups: pts required ICU admission (ICU group), and pts not required ICU admission (non‐ICU group). Landmark OS was assessed by the Kaplan – Meier method, log rank value p < 0.05 was considered as significant. Landmark was the date of discharge from ICU, and median time of discharge from ICU. Univariate analysis was performed with χ 2 tests or Fisher's exact tests for categorical variables to find an independent ICU mortality predictor.Results:In total, 87 ALL pts were enrolled into the study, 18 (20.6%) of them pts required ICU admission and 69 pts were treated without ICU. Reasons for ICU admissions were: acute respiratory failure (44%), acute neurological events (28%), tumor lysis syndrome (17%), septic shock (SS) (11%). Mechanical ventilation (MV) was required in 28% of pts, vasopressor support ‐ in 28% of pts, and renal replacement therapy ‐ in 22% of pts. ICU survival rate was 89% (2 pts died in ICU due to the SS). Needs for MV and for vasopressors were independent predictors of ICU mortality (p < 0.05). No one pts died in non‐ICU group during induction chemotherapy. Five year OS was 44% and 76% in ICU and non‐ICU group, respectively, (p < 0.05) (figure 1).Summary/Conclusion:Despite high ICU survival rate (89%), 5– years OS was only 44%. I non‐ICU group OS was 76% (p < 0.05). The long‐term prognosis of ALL pts discharged from ICU worse in comparison AML pts discharged from ICU [1,2]. This phenomenon it could be explained by negative selection of ALL pts in ICU.imageReference1. The influence of ICU admission of the patients with de novo AML on the long‐term survival. Bazhenov A., Galstyan G., Parovichnikova E. et al. Intensive care medicine experimental. 2018 (6) supplement 2. P.4422. Prognostic factors for intensive care unit admission, intensive care outcome, and post‐intensive care survival in patients with de novo acute myeloid leukemia: a single center experience. Schellongowski P. Haematologica. 2011. № 2 (96).
PF187 LEUKEMIA AND DEPLETED URANIUM IN KOSOVO
Authors: Latifi‐Pupovci H. , Selmonaj M. , Ahmetaj‐Shala B. , Dushi M. , Grajqevci V. 
Published: June 2019

Background:Prolonged exposure and overexposure to depleted uranium (DU) is leukemogenic and genotoxic due to its radiological (alpha particle) and chemical (metal) components. The use of DU in the 1999 Kosovo War raised concern about the increase of new cases of leukemia.Aims:The aim of this study was twofold: 1) to analyze the incidence rates of leukemia in Kosovo in the pre‐war (1995–1998) and two post‐ war periods (2000–2003 and 2012–2015); and 2) to examine if there is any association between the use of DU rounds and incidence rates of leukemia in different regions of Kosovo.Methods:Patients diagnosed with leukemia in the University Clinical Centre of Kosovo for the period 1995–2015 were subject of this study. Annual incidence crude rates per 100,000 persons/year were calculated for seven regions of Kosova in three periods (1995–1998, 2000–2003 and 2012–2015). The number of DU rounds by region was determined from accurate NATO records containing geographic coordinates. Regional distribution, difference in incidence between pre‐war period and first and last post‐war period were calculated. In addition, to examine possible links between the presence of DU ordnance and incidence rates of leukemia, we analyzed the correlation between rounds/km2 and average annual incidence rates in the 27 municipalities.Results:Difference of incidence rates between the pre‐war (1995–1998) and the first post‐war period (2000–2003) for the entire territory of Kosovo shows that leukemia increased by 12.63% whereas between pre‐war and last post war period by 68.95% (Table 1). Region of Gjakova and Peja, the first and third most exposed regions to DU ordnance (7.73 rounds/km2 and 4.78 rounds/km2 respectively) ranked first and second in difference in leukemia incidence whereas Prishtina, Gjilan and Ferizaj, regions with the least number of rounds/km2, were characterized by declining in incidence rates of leukemia. After 15 years, still the difference in leukemia between pre‐war period and the last post‐war period remains larger in Gjakova and Peja.In the first post‐war period (2000–2003), significant moderate Spearman correlation was found between the DU rounds/km2 and cases of leukemia (Figure 1).imageFigure 1. Correlation between rounds/km2 and annual average incidence rates by municipalities for leukemia in the period 2000–2003. Data was analysed using the Spearman correlation test and significance accepted when p < 0.05.Summary/Conclusion:The rise in incidence of leukemia in Kosovo may be partially induced by the use of DU during the war, but further studies are needed to explore this.image
PF215 THE ROLE OF GROWTH FACTOR INDEPENDENCE 1 (GFI1) IN GENOME STABILITY, DNA REPAIR AND LEUKEMIA GENOMIC EVOLUTION
Authors: Frank D. , Al‐Matary Y. , Khandanpour C. 
Published: June 2019

Background:Growth factor independence 1 (GFI1) is a transcriptional repressor, which regulates the proliferation and differentiation of hematopoietic stem cells. We have previously shown that lower expression of GFI1 promotes the development of myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) in patients and murine models of leukemiua. Additionally, a germline single nucleotide polymorphism variant of GFI1, called GFI1–36N (Ser36 replaced by Asn36) contributes to the development of MDS and AML. Both lower expression of GFI1 and presence of GFI1–36N leads to expression of a number key AML associated oncogenes and signaling cascades promoting AML development, as low level of GFI1 or GFI1–36N are not able to repress these patways. Aorund 30% of all AML patients have either low expression levels of GFI1 or are carrier of GFI1–36N. This patient cohort has a particular poor prognosis. However, we also have preliminary data that GFI1 might be involved in DNA repair.Aims:We analyzed whether GFI1 plays a role in DNA repair.Methods:We analyzed genome wide mutational analysis from AML patient cohorts and gene wide expression data.Results:We reanalyzed available genomic data of MDS/AML patients with expression of GFI1–36N or low expression of GFI1. These patients showed significantly more cytogenetic aberrations than patients with normal level of GFI1–36S. We have established two different mouse strains, which express either low level of GFI1 or express GFI1–36N. In murine models of human AML, low level of GFI1 or expression of GFI1–36N led to a significantly higher rate of genomic alterations such as mutations, deletions and insertions than GFI1 wildtype (wt) expressing murine leukemic cells. These findings indicate that low expression of GFI1 or expression of GFI1–36N is associated with genomic instability. To understand the molecular pathways GFI1 is involved with regad to DNA repair, we irradiated GFI1 wt, GFI1 low expressing and GFI1–36N expressing thymocytes. Using comet and γH2AX assay we showed that presence of Gfi1–36N or reduced level of GFI1 is associated with diminished DNA repair. Furthermore we found that presence of GFI136N or reduced level of GFI1 is associated with low level of MGMT. Other groups have shown that patients with low expression of MGMT respond well to treatment with Temozolomide (alkylating agent). Due to this fact we treated leukemic cells differently expressing GFI1 with Temozolomide. We found that the leukemic cells with low level of GFI1 or GFI1–36N are highly susceptible to Temozolomide compared to the leukemic control cells.Summary/Conclusion:In summary, low expression of GFI1 or expression of GFI1–36N leads to a clonal genetic evolution by impeding DNA repair. Therefore GFI1 could be a new target in leukemia therapy by using Temozolomide for these patients.
PF240 COMBINED INHIBITION OF SHP1 AND SHP2 WITH PHORBOL ESTERS AS A DIFFERENTIATION THERAPY AGAINST ACUTE MYELOID LEUKEMIA
Authors: Pérez‐Fernández A. , López‐Ruano G. , Prieto‐Bermejo R. , Ijurko C. , Díez‐Campelo M. , Sánchez‐Guijo F. , Hernández‐Hernández Á. 
Published: June 2019

Background:The differentiation‐based therapy for acute promyelocytic leukemia (APL) is an inspiring example for the search of novel strategies aimed at treatment of other subtypes of acute myeloid leukemia (AML). Thus, the discovery of new molecular players in cell differentiation becomes a paramount research area to achieve this goal.Aims:To assess the involvement of the protein tyrosine phosphatases SHP1 and SHP2 on leukemic cells differentiation along with the therapeutic possibilities of their targeting to enhance the differentiation induction effect of phorbol esters.Methods:The oxidation status and enzymatic activity of SHP1 and SHP2 during PMA‐induced differentiation of HEL cells was evaluated. Additionally, the effects of RNAi‐mediated downregulation of these phosphatases on cell differentiation was studied. Afterwards, the impact of chemical inhibition of SHP1 and SHP2 on differentiation both in the presence and absence of phorbol esters was tested. Finally, the anti‐leukemic potential of phorbol esters and chemical inhibitors of SHP1 and SHP2 was addressed in several AML model cell lines, a xenograft mouse model and AML primary cells in vitro.
Results:An increase of oxidation with a concomitant decrease of activity was observed for both phosphatases at the onset of PMA‐induced differentiation. Consistently, silencing of these proteins favored the process, with an enhanced effect upon their simultaneous downregulation. Moreover, the proteins SRC and β‐catenin were identified as downstream targets of SHP1 and SHP2 in this context. In agreement with these findings, chemical inhibition of the phosphatases promoted cell differentiation itself and enhanced the effect of phorbol esters. Interestingly, treatment with the phorbol ester prostratin and the dual inhibitor of SHP1 and SHP2 NSC87877 synergistically hampered the proliferation of AML cell lines, prolonged the survival of xenografted mice and reduced the clonogenic potential of AML primary cells.Summary/Conclusion:SHP1 and SHP2 are relevant mediators of differentiation in AML cells and their inhibition either alone or in combination with prostratin seems a promising differentiation‐based therapeutic strategy against different subtypes of AML beyond APL.
PF243 AN MLL‐AF9 ZEBRAFISH LEUKEMIA MODEL
Authors: Saberi M. , Delfi O. , Browett P.J. , Kakadiya P.M. , Bohlander S. 
Published: June 2019

Background:Acute Leukaemia (AL) is a genetically heterogeneous disease caused by somatic mutations and chromosomal translocations. Translocations can lead to the formation of fusion genes such as the MLL‐AF9 fusion, which results from the t (9;11)(p22;q23). MLL‐AF9 is one of the most common fusions involving the MLL (KMT2A) gene. MLLAF9 leukemias have an intermediate to poor prognosis. The MLL‐AF9 fusion is frequently used to establish murine leukemia models. However, to date, no MLL‐AF9 leukemia model in zebrafish has been reported.Aims:Our aim was to establish a transgenic zebrafish leukemia model using the MLL/AF9fusion gene.Methods:We cloned two transgenic constructs (pTol2‐Runx1+23_MLL‐AF9_IRES‐EGFP and pTol2‐Runx1+23_MLL‐AF9_IRES‐mCherry). The Runx1+23 murine promoter was used to target MLL‐AF9 expression to zebrafish hematopoietic stem cells, while EGFP or mCherry were used as fluorescent markers. The final transgenic constructs were co‐injected with Tol2 transposase mRNA into fertilized embryos at the one cell stage. The embryos were sorted 24 hours post fertilization based on the expression of the heart marker.Results:About 40% of the transgenic embryos died in the first week after injection but the remaining 60% reached adulthood. After 6 to 12 months, 30% (30 out of 100) fish showed signs of disease. They became less active, sat at the bottom of the tank and, in some cases, they had splayed eyes. When this happened, the fish were euthanized and dissected. The autopsies showed enlarged kidneys, splenomegaly and in some cases a pale spleen. Histological sections revealed increased cellularity of the kidney and liver with massive infiltration of hematopoietic cells in these organs. In flow cytometry, kidney marrow cells from the transgenic fish showed a different forward scatter (FSC) and side scatter (SSC) profile compared to that of the normal zebrafish kidney marrow cells. The FSC/SSC profile in the transgenic F0 zebrafish showed an expansion of the hematopoietic progenitor cell population. These findings strongly suggest that the fish had developed a leukemia‐like disease. We performed whole mount in situ hybridization (WISH) with early hematopoietic markers in 24 hpf embryos and detected reduced expression of gata1, myb and tal1as well as increased expression of lyz in transgenic embryos. Currently, transplantation experiments are being performed to determine whether the disease is transplantable which is a sign of leukemia.Summary/Conclusion:Although our flow cytometry, histology and WISH data strongly suggest that we have established an MLL/AF9‐driven leukemia model in zebrafish, additional experiments are needed to further characterize our model and confirm the malignant nature of the observed disease.Our MLL/AF9 zebrafish leukemia model will be a helpful tool to study leukemia biology and test new therapeutic strategies.
PF246 PERSONALIZED FOLLOW‐UP OF ACUTE MYELOID LEUKEMIA THROUGH MULTIPARAMETER FLOW CYTOMETRY: A PROOF OF CONCEPT
Authors: Jacqmin H. , Louveaux Q. , Chatelain B. , Jacqmin P. , Chatelain C. , Dogné J.‐M. , Graux C. , Mullier F. 
Published: June 2019

Background:Standardization, machine learning techniques and comparison to normality are concepts that are changing the landscape of multiparameter flow cytometry data analysis in clinical hematology. We applied these concepts to the follow‐up of acute myeloid leukemia (AML), which remains challenging due to the heterogeneity of the disease.Aims:To evaluate a new flow cytometry data analysis approach for the follow‐up of measurable residual disease in AML.Methods:Based on retrospective flow cytometry data, we developed a strategy for personalized monitoring of AML. This strategy is an evolution of the “leukemia associated immunophenotype” or “LAIP”‐approach that has been used the last decades in specialized flow cytometry laboratories. It relies on new concepts, comparing simultaneously the patient's follow‐up and diagnosis results to control group samples. We named these concepts the “leukemic cloud” and the “abnormality ratio”. To evaluate this approach, flow cytometry data of 6 AML patients and 20 control patients was used. All samples were analyzed with the same 10‐parameter (FSC‐A, SSC‐A, CD45, CD34, CD117, CD13, CD33, CD19, CD3, HLA‐DR) FACS Canto II flow cytometry assay. The “abnormality ratio” results over time were compared with morphology and molecular biology results.Results:The “Abnormality Ratio” results over time were in line with the clinical evolution of the patients (see example on image below) and were overall more sensitive for detecting residual disease than morphology and molecular biology, excepted for NPM1‐mutated AML. The “Abnormality Ratio” did not consider phenotypic switches of the malignant cell population identified at diagnosis. However, the discrepancy between the “abnormality ratio” results and morphology or molecular biology results could be used to objectify these phenotypic switches.Summary/Conclusion:We developed a quasi‐fully automatable flow cytometry data analysis algorithm. It could be used as a basis for the development of “next generation” flow cytometry assays for monitoring of hematological malignancies such as AML. Prospective studies are needed to confirm the applicability and limitations of our concepts.image