ALBERT

Description: Widely used sequence stratigraphic models predict that specific facies assemblages alternate in the stratigraphy of deep-sea fans, depending on the cyclic nature of sea-level variations. Our work tests this assumption through facies reconstruction of submarine fans that are growing in a small basin along the tectonically active Sicilian margin. Connected canyons have heads close to the coastline; they can be river connected or littoral cell–connected, the first receiving sediment from hyperpycnal flows, the latter intercepting shelf sediment dispersal pathways. Hyperpycnal flows directly discharge river-born sediment into the head of the river-connected canyon and originate a large turbidite fan. A drift formed by the longshore redistribution of sediment of a nearby delta introduces sediment to the head of the littoral cell–connected canyon, forming turbidity currents that flow within the canyon to reach the basin plain. However, since sediment failure and landslide processes are common in the slope part of the system, a mixed fan, consisting of both turbidites and mass-transport deposits, is formed. Disconnected canyons, with heads at the shelf edge far from the coastline, are fed by canyon head and levee-wedge failures, resulting in mass-transport or mixed fan deposition, the latter developing when the seafloor gradient or the lithology of the failed sediment allows turbidity current formation. Connected canyons form in areas with high uplift rates, where the shelf is narrow and steep and the shelf edge is at a relatively shallow depth. Disconnected canyons develop where there are lower uplift rates or subsidence, where the shelf is large and relatively gentle with a deeper shelf edge. It is deduced that the relative vertical movements of fault-bound blocks control whether canyons are connected to the coast at the present day. The role of tectonics in controlling the canyon feeding processes and the facies of submarine fan growth during highstand periods is therefore highlighted. A further view that arises from our paper is that in active margins, the slope portion of fan systems, through seafloor instability and variations in channel gradient, is a key factor in determining the final deep-sea fan facies, regardless of the distance between the coast and the canyon. The concomitant growth of turbidites, mass-transport deposits, and mixed fans demonstrates that models that predict changes in submarine fan facies on the basis of sea-level cycles do not necessarily apply to systems developed along tectonically active margins.

Description: Background. In recent years, the number of Hodgkin Lymphoma (HL) patients submitted to reduced intensity haploidentical allogeneic transplant (RIC haplo SCT) consistently increased. [Sureda et al. Curr Treat Options Oncol 2014] However, with a post alloSCT relapse rate so high as 40-60%, disease control after autoSCT relapse remains a clear unmet medical need. In respect of improving transplant outcome identification of factors influencing outcomes are warranted Methods.We reviewed outcomes obtained in 44 consecutive HL patients who received RIC haplo SCT between September 2009 and June 2015 at our institution. The donor was haploidentical relative in all cases. All patients had received at least 3 conventional chemotherapy lines before RIC haplo SCT; most of them (72%) were refractory to front-line chemotherapy and all but one had received an autologous SCT. All patients received the same reduced intensity conditiong regime, and GvHD prophilaxis with post-transplant cyclophosphamide (Raiola et al. BBMT 2008). The median age was 31years (range 18-60). Deauville five-points scale were used to interpretate the results of pre-transplant positron-emission tomography (PET) studies, with a threshold of 4 or above considered positive. Survival curve and GvHD incidence were calculated with the method of Kaplan and Meier. Cox regression model was performed to identify pre-transplant factors influencing outcomes. Results. All patients engrafted but 1 who showed autologous recovery. The median day for 500 neutrophils was 15 days (13-23). Three patients died in remission at 8 (cGvHD), 16 (myocarditis) and 51(pneumonia) months from SCT, respectively. Three years non relapse mortality = 8%. Risk of grade II-IV acute GvHD and 3-year chronic GvHD were 22 and 21%, respectively. With a median follow-up for surviving patients of 38 months (range 13-83), 21 relapsed (47%). All relapsed patients were treated with further therapy, mainly immuno-chemotherapy and donor lymphocyte infusion (DLI). The 3-year overall (OS) and progression free survival (PFS) were 77% and 39%, respectively. Pre-transplant PET status was the only factor influencing outcomes of the procedure (OR 5.4; 95% CI 1.7 - 16.6). In the 41 patients with available pre-transplant PET status, 19 were positive and 22 negative. Outcomes accordingly to pre-transplant PET status are shown in the following table. Conclusions.Pre-transplant PET status is a factor influencing outcomes of relapsed/refractory HL submitted to RIC haplo SCT. Grade II-IV aGvHD was markedly reduced in patients with metabolic remission at time of transplantation. Table Table. Disclosures Angelucci: Novartis oncology, celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees.

Description: Background and aims Myelodisplastic syndromes (MDS) are a group of hemopoietic disorder characterized by an impaired blood cell production, morphologic dysplasia and peripheral cytopenias; they are the most common hematologic neoplastic disorder and its diagnosis relays on morphologic evaluation, associated to a karyotypic assay. In order to predict the outcome of patients affected from these disorders, knowing that the order of survival can be extremely variable, several prognostic index were developed such as International Prognostic Score Sistem (IPSS) or the most usefull WHO-Prognostic Score Sistem (WPSS). On the contrary of acute leukemia, these disorders have not a biomolecular profile evalutation of intrinsic markers able to stratify patients in different prognostic risk groups. The aim of our study is to assess the risk of leukemic evolution, in MDS patients, on the basis of the levels expression of WT1 and BAALC at disease diagnosis, and to evaluate the leukemia free survival (LFS) at 6-12-24-36 months of follow up, among the different risk category according to IPSS and irrespectively of treatment. Materials and method In five years we analized 102 patients with a diagnosis of MDS divided according to the WHO classification such as follows: 38 AR, 1 AR with del(q5), 21 aREB-1, 23 AREB-2, 3 chronic myelomonocitic leukemia, 1 RARS, 1 MDS, 11 RCMD, 1 5q- syndrome, 2 suspected MDS. According to IPSS 58 belonged to the low risk category, 21 to the intermediate-1, 23 to the intermediate-2/high risk. Cytogenetic assay showed 20 people with an abnormal karyotype, 8 of them fallen into the high risk class and 12 into the intemediate risk. Low risk and intermediate-1 patients were treated only with supportive care; high risk patients were treated with hypomethylating agents. Iron chelation were used when necessary. Lenalidomide was used in the only case of 5 q- syndrome Samples of bone marrow were analized with Real-Time quantitave PCR and levels of WT1 and BAALC expression were determinated. Molecular datas were analized with X-square Test and a significant association was recorded between overexpression of the genes evaluated (WT1 higher than 100 copy numbers and BAALC higher than 1000 copy numbers) and the probability of develop acute myeloid leukemia ( AML ). Results Nine out of 102 patients showed an isolated WT1 hyperexpression (3 of them developed an AML ), in 15 cases we reported an isolated BAALC overexpression (3 of them developed an AML ), while 13 out 18 patients ( 72% ) with combined WT1 and BAALC overexpression developed AML within an average time of 6 months; instead only 5% of patients, which expressed low levels of WT1 and BAALC, developed AML within the interval of observation. In particulary a combined high expression of WT1 and BAALC were strongly associated with an high risk to develop leukemia and a short LFS, especially in INT-1 subset. After that we calculated the LFS, divided for the risk category at 6-12-24-36 months of follow up. Patients with combined overexpression of WT1 and BAALC showed a LFS of 40% at 6 months of follow up and 0% at 24 months. Conclusion MDS have a great variable survival, and the current approach to these diseases relays on morphological evaluation, karyotypic assay and need of transfusional support; gene expression could be a promising system to predict the prognosis in these patients. Analysis of gene expression, which belong to AML evaluation, allows to divide patients in several risk groups; furthermore is not the single gene evaluation that is more predictable but a combined assay. With this method, which seems to be more realiable than IPSS, we could find that a great percentage of patients with levels of WT1〉100 and BAALC 〉1000, indipendently from karyotypic status and treatment, developed AML and have a shorter LFS than the population with WT1

Description: Sickle cell disease (SCD) is characterized by chronic hemolytic anemia and vaso-occlusion. Hypocholesterolemia has been long recognized in SCD patients, and while it has been postulated that it is secondary to increased erythropoiesis, these mechanisms are not fully understood. Despite their name, angiopoietin-like proteins (ANGPTLs) are family of regulators of angiogenesis unable to bind to receptors classically targeted by angiopoetins. ANGPTL3 and ANGPTL4 are also inhibitors of lipoprotein lipase (LPL), and have become pharmacological targets in the treatment of dyslipidemia. We hypothesized that ANGPTL levels would be abnormal in SCD and could contribute to the understanding of lipid dysregulation. We aimed to determine, compare and correlate the circulating concentrations of ANGPTL3 and ANGPTL4 with hemolysis, lipid metabolism and endothelial dysfunction biomarkers in patients with sickle cell anemia (HbSS), hemoglobin SC disease (HbSC), and healthy individuals (HbAA). Thirty-six HbSS patients (age range 18-55, 21 men), 19 HbSC patients (HbSC) (age range 29-68, 8 men), and 31 HbAA controls (age range 18-66, 23 men) were enrolled in this study. Exclusion criteria were pregnancy, history of blood transfusion or sickle cell pain crisis in the past 3 months. Peripheral blood samples were collected for complete blood counts, biochemistry tests (lactate dehydrogenase [LDH], bilirubin, cholesterol and low and high density fractions, oxidized LDL [oxLDL], hemopexin), and determination of ANGPTL3, ANGPTL4, and soluble vascular cell adhesion molecule-1 (sVCAM-1) levels as marker of endothelial dysfunction. Differences in the intensity of hemolytic anemia between the two groups of SCD were confirmed, as well as decrease in total cholesterol (AA 176±32, SC 141±28 and SS 124±33mg/dL, p

Description: Background Natural Killer (NK) cells have been widely studied due to their non-major histocompatibility complex (MHC)-restricted cytotoxicity towards transformed or virally infected target cells. In the setting of hematopoietic stem cell transplantation (HSCT), donor NK cells may be "alloreactive" as their killer immunoglobuline-like receptors (KIRs) do not recognize their ligands on recipient human leukocyte antigen (HLA) class I molecules (i.e. KIR-ligands), leading to NK activation. NK alloreactivity can often occur in haploidentical HSCT (Haplo-HSCT), by means of KIR/KIR-L mismatch in graft versus host (GvH) direction, contributing to graft-versus leukemia (GvL) effect, clearing residual leukemic blasts. In the last decade, several studies have shown that NK cells alloreactivity plays a role in T-depleted Haplo-HSCT leading to higher disease free survival rates for patients transplanted from NK-alloreactive donors; recent studies have also shown that donors having KIR B haplotypes (characterized by the presence of more activating KIR) or expressing KIR2DS1 correlated with a better clinical outcome of transplantation. Thus, these NK cell features might be positively considered in the donor selection strategy. Materials and Methods: We analyzed NK-alloreactivity in the setting of unmanipulated Haplo-HSCT with post-transplant cyclophosphamide for patients affected by acute myeloid leukemia or myelodisplastic syndromes. 101 consecutive patients transplanted from September, 2010 to October, 2014 were enrolled, with the big majority of donors and patients studied for HLA-genotype and KIR. Results: Disease status at HSCT was the most relevant factor affecting outcome (p =2) or who had KIR2DS1 was not associated with better outcome (p 0.67 and p 0.89, respectively). We observed an high expression of CD56 and inhibitory receptors such as NKG2A on surface of NK cells in post-HSCT samples, suggesting that NK-cell function could be inhibited in unmanipulated haploidentical setting. Conclusions NK alloreactivity seems not to play a role in preventing leukemia relapse in unmanipulated haploidentical transplantation with post-transplantation. The different immunosuppressive approach of this Haplo-HSCT setting compared to T-depleted Haplo-HSCT, with concomitant use of cyclosporine from early transplant days, which has been shown to interact and possibly inhibit NK cells in vivo, and post transplant cyclophosphamide effects, selectively killing activated T-cell and inducing long-term tolerance, could affect NK efficacy. Further studies are needed to better understand the complexity of this intriguing issue, leading to a more complete definition of NK cell functions in this Haplo-HSCT setting. Disclosures No relevant conflicts of interest to declare.

Description: Induction of fetal hemoglobin (HbF) production is an effective therapeutic strategy in the management of patients with beta hemoglobinopathies. Hydroxyurea is the only drug with this mechanism approved for clinical use, and 20% or more of patients do not respond or tolerate it, which has led to the search for new HbF inducers. Benserazide (BEN) is a DOPA decarboxylase inhibitor used in combination with levodopa in the treatment of parkinsonism, but it was also noticed to induce increased gamma globin production in preclinical models. The mechanisms by which BEN acts include downregulation of BCL11A, LSD1 and HDAC3 on the promoter region of the gamma globin gene, making it an interesting candidate for clinical studies in hemoglobinopathies. We hypothesized that patients undergoing treatment for parkinsonism with chronic use of BEN-containing medication may develop increase in HbF production and in circulating F-cells. Material and Methods: Peripheral blood samples were collected from patients with parkinsonism during their follow-up at the Neurology Clinic, who had been using BEN for at least 30 days (BEN group), from healthy controls (group AA), and from patients known to have increased of HbF due to sickle cell anemia (group SS), for comparison purposes. Exclusion criteria for BEN and AA groups were: any hemoglobinopathy, transfusion in the last 90 days, and use of HU or any chemotherapeutic agent. Automated complete blood counts with reticulocyte count were performed on a XN-3000 equipment (Sysmex, Japan), HbF levels were determined by HPLC (BioRad, USA), and F-cell percentage was determined by flow cytometry (BD FACSCalibur, USA). Results: Thirty-five patients on BEN, 10 negative controls (AA group) and five positive controls (SS group) were included. One patient taking BEN was excluded due to HPLC compatible with beta thalassemia trait. Patients taking BEN had blood counts within the normal range. There was no statistically significant difference between BEN and AA groups, and the SS group was significantly anemic as expected. We found a strongly positive correlation between HbF and circulating F-cells (p

Description: Abstract 4959 Introduction Notwithstanding recent findings, multiple myeloma (MM) remains an incurable disease and almost all treated patients invariably relapse. The clinical presentation of recurrent MM is heterogeneous. Extramedullary relapses (EMRs) are rare, but recently an increased frequence has been reported, probably favoured by the new diagnostic imaging techniques, and maybe caused by the induction chemotherapeutic regimens. Patients We report 6 cases of EMRs, occurring after a median time of 3 years (yrs) from stem cell transplantation (SCT). Five (A,B,C,D,E) male and one (F) female patients (pts), median age 50 yrs (39-63), were affected by IgGk (5 pts) and IgAk (1 pt) MM, all in stage IIIA. At diagnosis one pt (E) had an EM sternal extrapleural plasmocytoma, which was successfully irradiated. Three pts were treated with total therapy II (B,D,E), 2 pts with VAD and autologous-SCT (ASCT) (A,F) or ASCT followed by mini allogeneic-SCT (AlloSCT) (C). The patient F showed an orbital localization after VAD, before ASCT. After SCT all 5 patients resulted in complete remission (CR). Results A systemic relapse occurred after 3 yrs in pt A, who was treated according to EDAP chemotherapy (etoposide-dexamethasone-cytarabine-carboplatin); after 2 yrs in pt B, treated with combination of bortezomib-thalidomide-dexamethasone (VTD). Both pts reached a second CR and a maintenance with thalidomide was started. However, after one yr, pt A had a lumbar paravertebral EMR, and pt B lumbosacral extradural and dorsal endocanalar EMRs, besides a tumour mass in the pelvic bone, jutting in abdominal cavity. As regarding the other 4 pts, C had a pulmonary embolism 4 yrs after first CR and an EMR was demonstrated, looking as a 6 cm long lumbar mass, infiltrating the inferior vena cava and determining thrombosis of it. In pt D the EMRs occurred 2 yrs after ASCT: one lumbar 3 cm long mass and another of 9 cm of diameter in the pelvic bone. Finally patient E and F had a dorsal 7 × 5 cm paravertebral and a femoral mass, respectively, 1 and 4 yrs after ASCT. Only in pt B elevated lactate dehydrogenase levels were present when EMR was diagnosed. Therapeutic approaches to EMRs were represented by radiotherapy; in addition pts B,C,E,F were treated with EDAP, without response; AlloSCT was performed in pt A; PAD plus lenalidomide in pt D. The latter (D) reached a third CR, so an AlloSCT was performed, but unfortunately the patient died because of hepatic acute GVHD. The other patient firstly treated with AlloSCT (pt A) was refractory and was treated with VTD chemotherapy, but he recently showed nodular lesions in the liver, showing hypercaptation at PET. Chemotherapy with lenalidomide, dexamethasone and cyclophosphamide (LDC) was started, but after 2 cycles a progressive hepatic EM disease (lesion of 7 cm) is now present. As we mentioned 4 patients (B,C,E,F) has been treated with EDAP, which resulted ineffective. Patient C, after EDAP, started bortezomib-dexamethasone therapy (VD), with initial clinical and radiological response (PET negative); however shortly after, he showed other scapular and axillary PET positive EMRs; radiotherapy, thalidomide-dexamethasone (TD) and then donor lymphocyte infusions (DLI) from the allogeneic donor were performed; as results the previous hypercaptant scapular regions resulted negative at PET, but various new lesions appeared, so a salvage therapy with LDC has been recently started. Femoral and humeral radiotherapy has been simultaneously started. Patient F died soon after EDAP because of renal failure. The other 2 pts, refractory to EDAP chemotherapy, showed successive EMRs. The patient B died after progressive cranial, orbital, encephalic EMRs, complicated by CD56 negative plasma cell leukaemic meningitis. Patient E developed maxillary, cranial, orbital, zygomatic MM masses, pelvic, humeral and radial fracture and died. Discussion From the initial diagnosis of MM one pt died after 3 and three patients died after 4.5 yrs respectively; 2 patients are still long survivors after 7 and 9 yrs. EMRs could be the consequence of a clonal selection after high dose chemotherapy, with the persistence of a plasmacellular clone after induction therapy before ASCT. In spite of the small number of patients, our experience shows that EMRs appear refractory to radiotherapy and to conventional and even high dose chemotherapy. Instead it seems that regimens including new drugs (thalidomide, bortezomib, lenalidomide) could be useful, prolonging survival, as demonstrated for patient A and C, still surviving, and for patient D, who died in CR for acute GVHD. Disclosures No relevant conflicts of interest to declare.

Description: Introduction Allogeneic hematoopoietic stem cell transplantation (HSCT) is the only today available curative treatment for Myelodysplastic Syndrome (MDS) patients. Wide approach to transplant has been hampered by HLA compatible donors availability, advanced diseases, donor and patients advanced age. In the recent years improvement of haploidentical HSCT has offered to many patients the opportunity to undergo this curative approach. The Genova transplant team included haplo HSCT for MDS in his standard operative procedure since 2011. Therefore this unselected consecutive patients cohort offers the possibility to verify feasibility of haplo HSCT in MDS patients. Patients and Methods. Form August 2011 since March 2016 thirty (30) consecutive patients were transplanted from an haploidentical donor in our center. All of them were lacking an HLA identical family donor and an 8/8 matched unrelated donor. Table 1 reports patients and disease characteristics. All donors were haploidentical family member. Conditioning regimen was myeloablative for 10 patients and reduced intensity for 20 patients as previously reports (Raiola et al Biol Blood Marrow Transplant. 2013; 1:117-22). Patients received a median of 3.1 x10e8 /kg (range 1.1 -6) un-manipulated marrow derived nucleated cells. Graft versus host disease (GvHD) prophylaxis consisted in post transplant cyclophosphamide 50 mg/kg , on day+3 and +5 , cyclosporine (from day 0) , and micophenolate (from day +1). Data are expressed and median with a range unless indicated. Disease free survival and GvHD rate are calculated with the methods of Kaplan and Meier. Results Hematologic recovery was complete in 28 (93%) patients. The median times to neutrophil (〉500/μL) and platelet recovery (〉20,000/μL) was 18 days (range, 14-24 days) and 25 days (range, 12 - 51 days), respectively. Two patients had autologous recovery and were successfully re-transplanted with the same protocol. The incidence of acute GVHD grade II-IV was 15%. No early death was registered. Two patients died, in complete remission of MDS, at 389 (chronic GVHD + sepsis) and 1123 (interstitial pneumonitis) days after transplant, respectively. Seven patients relapsed at median time from transplant of 188 days (range 139 - 560 days). All relapsed patients subsequently died by disease progression. The incidence of chronic GVHD was 20% (6 patients, severe in 5). At the time of this report of the 21 surviving patients (all in remission by MDS) two are under chronic GvHD treatment. With a median follow up of 20.5 months (range 4 - 54) the 3 years probability disease free survival is 69% (95%, CI 51-87). Discussion Haploidentical transplant, together with conventional donor approach, offers the majority of patients the possibility to undergo HSCT. The data here presented demonstrated feasibility of the procedure in advanced disease patients even by an haploidentical donor. In our knowledge no similar results are achievable by today available or experimental medical therapy. HSCT transplantation, even from haploidentical donor, should be offered to all MDS patients presenting with this indication. Disease relapse is the most important cause of transplant failure. Disclosures Angelucci: Novartis oncology, celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees.

Description: Abstract 2535 Background and aims. Detection of minimal residual disease (MRD) has a relevant prognostic value in Acute Myeloid Leukemia (AML). MRD, when used as early treatment response assessment, allows identification of true low-risk and high-risk patients, who may profit alternative chemotherapy approach. In the present retrospective study, we evaluated the impact of MRD assessed by 4-color flow cytometry and WT1 RQ-PCR gene expression in a cohort of AML patients treated at our institution. Methods. Bone marrow samples of 50 adult AML patients (45 de novo and 5 secondary) with available karyotype (K), FLT3-ITD and NPM-A genes mutational status were assessed for MRD after induction. All included patients had a baseline WT1 expression greater than 1000 copies/Ablx104 (range 1060–346060; lab references for normal values 0–500). Fludarabine-based regimen was used as induction; one course of intermediate dose Ara-C 2g/sqm plus idarubicin, followed by 3 courses of intermediate dose Ara-C (2g/sqm) as further consolidation therapy. WT1 log reduction (DWT1) was used to assess the WT1 clearance (DWT1 = logWT1diagnosis – logWT1 post induction). A positive flow MRD was defined by the presence of no less than 25 clustered leukemic cells/105 total events - threshold of 2.5 × 10−4 residual leukemic cells. In patients submitted to bone marrow transplantation (BMT) only the first consolidation course was administered and disease free survival (DFS) was censored at the date of BMT. Results. Two (4%) patients had favorable, 40 (80%) intermediate, and 5 (10%) poor risk K (3 had no metaphases); 14 (28/%) carried FLT3-ITD mutation: among them 8 carried NPM-A mutation too, while 6 were wild type. After the first induction regimen 42 of 50 (84%) patients achieved a complete remission (CR). Patients with a negative flow MRD (32%) had 3 years DFS of 69.5%, whereas those with a positive flow MRD (68%) had a DFS of 27.3% (p = 0.032). Patients with a DWT1 〉 1.5 log (65%) had a 3-years DFS of 58.3%, whereas those with a DWT1 ≤ 1.5 log (35%) had a DFS at 1 and 2-years of 13,5% and 0%, respectively (p 〈 0.001). All patients with a negative flow MRD had also a DWT1 〉 1.5 log, whereas 12 (52%) of those who achieved a DWT1 〉 1.5 log were still positive by flow MRD. Fourteen (28%) patients with a high risk (HR) profile at diagnosis (poor risk K, intermediate K with FLT3-ITDpos/NPM-Aneg, AML secondary to therapy or previous haematological disorder), 6 were no responder to induction, whereas no one of 8 patients in CR reached a negative MRD status in both test with a very poor outcome (projected DFS 4.8 months). MRD assessment using both flow and DWT1 allow to discriminate no-HR profile patients in three prognostic group: good (flow MRD neg) intermediate (flow MRD pos and DWT1 〉 1.5 log) and adverse prognosis (flow MRD pos and DWT1 ≤ 1.5 log) with a projected DFS of 70.5 months, 38.2 months and 4.2 months, respectively (p 〈 0.001). Conclusions. DWT1 identified patients who would relapse better than flow, whereas a negative flow MRD was the best predictor of long DFS. Using both test in combination with baseline biologic parameters enabled the definition of discrete prognostic categories (Fig 1). Outcome of patients with DWT1 ≤ 1.5 log was very poor and comparable with that of patients with HR profile at diagnosis. In these patients forecast a cure is very difficult with the current treatment option and clinical trials with new drugs should be used already in up-front setting. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 4675 The prognostic value of WT1 expression at diagnosis is still controversial. It has been retrospectively evaluated in 99 consecutive non pretreated non M3 AML patients who had undergone a complete prognostic work up at diagnosis and had received intensive chemotherapy. Biological markers were evaluated on fresh marrow samples collected at diagnosis. WT1 expression was evaluated using TaqMan Gene Expression Assays as described. All patients received induction therapy with combination of fludarabine, Ara-C and anthracycline ± low dose gemtuzumab ozogamicin (n. 59) or with a conventional combination of Ara-C and anthracycline (n. 40) A conventional post-induction chemotherapy including intermediate dosage Ara-C was administered to all responding patients. Univariate comparisons between patients in CR vs non CR were performed using chi-square analysis or Fisher's exact test for categorical variables and t-test for continuous variables. P values 〈 0.05 were considered statistically significant. Analyses were performed using SPSS. The prognostic impact of WT1 expression was evaluated using quartiles as cut off point and selecting the one with the lowest p value. The event free survival and OS were calculated using the Kaplan Meier method. Non CR after the first induction course, relapse and death due to any cause were considered events. OS and EFS duration were calculated from start of treatment. The impact of multiple predictor variables was assessed by multivariate analyses according to the Cox regression model for OS and EFS while for the evaluation of RC was used the Logistic regression model. Median age of patients was 59 years (range 17-81). Cytogenetic alterations were prognostically favorable in 3 patients and belonged to the intermediate prognostic group in 77 patients (normal karyotype in 75 patients and +8 in two). Nineteen patients had a poor prognosis cytogenetics. For statistical analyses we considered two karyotipic groups: unfavorable (19 patients) and not unfavorable (80 patients). CRs were 60/99 (60%), of which 40 in 51 patients aged 60 or less (78%) and 20 in 48 older than 60 years (41%). Twenty-six patients relapsed, 54 are alive, 45 have died, with a median follow up of 360 days (range 20-2300). In Table 1 are reported clinical indicators of outcome being patients grouped according to the percentile of WT1 expression with the lowest p value (75th). Statystical analysis showed that all WT1 quartiles were balanced for other prognostic factors, such as cytogenetics, BAALC expression, FLT3 and NPMA and B mutations, age, blast count and therapy. The lack of consense on the role of WT1 level at diagnosis in the prognostic stratification indicate that further clinical studies are required. The clear correlation between the level of WT1 transcript and the tumor burden explains why WT1 is used in the follow up of leukemic patients as universal marker of residual disease, also in patients with specific chimeric products. On the contrary, the biological explanation of the prognostic impact of WT1 transcript level at diagnosis remains uncertain. Over the years WT1 gene has been considered as an oncogene or a tumor suppressor gene. In our experience the protective influence of high WT1 expression cannot be explained with an association with good prognosis biological features (such as mut NPM and / or low BAALC). The positive prognostic value of high WT1 expression might be implicated either with WT1 antioncogenic function, or with the stimulating effect of WT1 oncogene on leukemic cellular cycle, possibly associated with an enhanced response to chemotherapy.Table 1WT1 2400 N./N.pts (%)p univ,p multiv.*RR (95% CI)CR (all karyotypes)41/ 75 (54)19/24 (82)0,0260.063.364 (0.927-12.202)CR (int/good karyot.)36/59 (61)19/210.010,0276.649 (1.240-35.645)CR (denovo AML int kar)31/45 (69)14/15 (98)0.020,03412.557 (1.218-129.446)CR (denovo, N.K.)26/40 (65)15/16 (94)0.0250.0413.430 (1.111-162.318)EFS at 24 months (all karyotypes)8%6%0.0020.050.486 (0.235-1.007)EFS at 24 months (int / good karyot.)9%64%0.0010.0230.360 (0.150-0.866)EFS at 24 months (de novo, N.K.)5%70%0.0010.0070.227 (0.077-0.671)OS (all karyot)15%55%0,110,660.837 (0.371-1.890)OS (int/good kar.)18%63%0,050,180.507 (0.186-1.381)Table 1 legend: * for multivariate analysis age, karyotype, FLT3, NPM mutation, BAALC expression, denovo/secondary disease were considered. Disclosures: No relevant conflicts of interest to declare.