Academic literature on the topic 'P 25.5 UL 2008 G698'

Abstract Abstract 2638 Poster Board II-614 Background: The importance of cytogenetics in prognosis of AML is now widely recognized and accepted in clinical practice. A recent study found that autosomal chromosomal monosomy predicted for an adverse outcome. The goal of this study is to characterize patients with monosomal karyotype by mutation status and clinical features. Methods: One-hundred forty consecutive AML patients diagnosed at Stanford University Hospital between 2005 and 2008 with adequate material for mutation analysis were studied. Cases were classified using the 2008 WHO criteria. Diagnostic cytogenetic findings were reviewed and patients were stratified into risk groups using Southwest Oncology Group criteria. An abnormality was considered clonal when at least two metaphases had the same aberration, except for clonal monosomy, which required at least three metaphases. The karyotype analysis was based on 20 or more metaphases. All samples were tested for NPM, FLT3 (ITD and D835) and CEBPA mutations. Clinical parameters including hemogram data at time of diagnosis were reviewed. Clinical follow-up including overall survival (OS), progression free survival (PFS) and complete remission (CR) rates were retrospectively determined. Kaplan-Meier methods and univariate Cox proportional hazards regression analysis were used to compare the clinical data. Results: The cases included 77 males and 63 females with a median age of 58 (range 17-83). Cytogenetic risk-group stratification resulted in 14 patients with favorable, 88 with intermediate and 28 with unfavorable risk status. Loss of one or more autosomal chromosomes was present in 18 /130 patients (13.8%) with available cytogenetic studies. A single autosomal monosomy was found in 5 patients while 13 patients had two or more autosomal monosomies. The most common chromosomes lost in these 18 patients included 7 (55% of 18 cases), 5 (50%), 17 (33%), 21 (22%), 20 (22%), 22 (17%) and 18 (11%). Using the 2008 WHO criteria, there were 66 AML with myelodysplasia-related changes (AML-MRC), 55 AML not otherwise specified (AML-NOS), 14 AML with either t(8;21), inv(16) or t(15;17) and 5 therapy related AMLs. Overall, 35 patients (25% of all patients) had a NPM1 mutation (19 of which were FLT3 mutated), 33 had FLT3-ITD mutation (24%), 11 had FLT3-D835 (8%) and 11 had a CEBPA mutation (8%) (4 of which were FLT3 mutated). Patients with monosomal karyotype were significantly older (83 vs. 59 years, p=0.0125) and presented with lower WBC (34 vs. 66 K/uL, p=0.0006), lower platelets (41 vs. 64 K/uL, p=0.0111), and lower blasts (38% vs. 65%, p=0.0030) as compared to the rest of AML patients. In addition, patients with monosomal karyotype were more frequently diagnosed with AML-MRC (16/18 vs. 48/107, p=0.0034) and exhibited a decreased frequency of NPM1 mutation (0/18 vs. 28/107, p=0.0138) and FLT3-ITD mutation (0/18 vs. 29/107, p=0.0117). Clinical outcome data showed that patients with monosomal karyotype had a significantly worse OS, PFS and CR compared to the rest of AML patients (OS p=0.001, PFS p=0.002 and CR p=0.0262). Dividing patients by number of monosomies showed that patients with 2 or more monosomies had a significantly worse OS (p=0.0001) and PFS (p=0.0045) than patients without any monosomies. However, no difference in OS or PFS was seen when comparing patients with 1 monosomy to those with 2 or more monosomies. Within the AML-MRC group, monosomal karyotype correlated with lower WBC (17 vs. 37 K/uL, p=0.0005), lower platelets (21 vs. 35 K/uL, p=0.0095), lower blasts (19% vs. 36%, p=0.0015) and shorter OS (p=0.0322) and PFS (p=0.0084). Conclusion: AML patients with monosomal karyotype exhibit a significantly worse OS, PFS and lower CR as compared to other AML patients. Most of patients fall within the newly defined AML-MRC group and are characterized by significant absence of NPM1 and FLT3-ITD mutations. Disclosures: No relevant conflicts of interest to declare.

Spred1, a member of the Sprouty family of proteins and a negative regulator of RAS-MAPK signaling, is highly expressed in normal hematopoietic stem cells (HSCs) where it negatively regulates self-renewal activity. Lack of Spred1 function has been associated with aberrant hematopoiesis (Tadokoro, 2018). Spred1 knocked-out (KO) mice fed with high-fat diet develop a myeloproliferative phenotype (Tadokoro, 2018), and lower SPRED1 expression in acute myeloid leukemia associates with a poor outcome (Li, 2015; Olsson, 2014; Pasmant, 2015), suggesting a potential role of this gene as a tumor suppressor in myeloid malignancies. In CML, however, the role of Spred1 has not been fully dissected. Thus, we generated Spred1 KO CML (i.e., Spred1-/-SCLtTA/BCR-ABL) mice by crossing Spred1 KO (a gift from Dr. Yoshimura, Japan) with inducible SCLtTA/BCR-ABL CML mice. Spred1 KO mice showed increased cell cycling of BM long-term HSCs (LTHSCs; Lin-Sca-1+c-kit+Flt3-CD150+CD48-; G0: 62% vs 76%), and increased white blood cell (WBC) counts [14 vs 5.9 k/ul at 12 weeks (w) old, n=15 per group, p<0.0001], as compared to wt mice. Upon B/A induction by tetracycline withdrawal, Spred1-/-SCLtTA/BCR-ABL mice had higher WBC (102.5 vs 12 k/ul at 4 w, n=15 per group, p<0.0001), more pronounced splenomegaly (spleen weight: 0.28g vs 0.19g, n=4 per group, p=0.06) and a significantly shorter survival (median: 39 vs 83 days, n=23 per group, p<0.0001) than Spred1 wt CML mice. In Spred1-/-SCLtTA/BCR-ABL mice, we observed a more rapid expansion of circulating mature myeloid cells (CD11b+Gr-1+ cells: 63% vs 25%, n=8 per group, p<0.01) and a deeper decrease of BM LTHSCs (1,385 vs 2,164 per femur, n=5 per group, p<0.01) and increase of spleen LTHSCs (27330 vs 18546, n=5 per group, p<0.01) at 4 w after B/A induction compared with Spred1 wt CML mice. Further, we found a higher fraction of Spred-/-SCLtTA/BCR-ABL mice (33% vs 10%) developed lymph node enlargement, with infiltration with pro-B lymphoblastic cells (B220+CD43+CD19+IgM−) compared with Spred1 wt CML mice. Altogether these features suggested that Spred1 insufficiency accelerates CML development and evolution to more aggressive phases of the disease. Since upregulation of Spred1 reportedly disrupts vascular integrity (Fish, 2008; Wang 2008), a finding that we have also confirmed in the BM niche, in order to evaluate separately the leukemogenic effect of Spred1 expression on different compartments of the BM niche, we generated the following conditional Spred1 KO strains: Spred1flox(f)/fMxl-cre+ (Spred1 KO in HSCs, hereafter called Spred1HSCΔ/Δ), Spred1f/fTie2-cre+ [Spred1 KO in endothelial cells (ECs), hereafter called Spred1ECΔ/Δ], Spred1HSCΔ/ΔSCLtTA/BCR-ABL and Spred1ECΔ/ΔSCLtTA/BCR-ABL by crossing SCLtTA/BCR-ABL with the above Spred1 KO mice. LTHSCs from Spred1HSCΔ/ΔSCLtTA/BCR-ABL mice showed an increase in cell cycling, RAS/MAPK/ERK activity and Bcl-2 levels, and higher engraftment in recipient mice (blood: 9.7% vs 26.5% at 6w, 14.8% vs 42% at 8w, 14.7% vs 48% at 12w, n=10 per group, p<0.01), compared to Spred1 wt CML LTHSCs. Spred1HSCΔ/ΔSCLtTA/BCR-ABL mice (n=15) showed enhanced leukemia progression (WBC: 19 vs 12 k/ul, p=0.004; CD11b+Gr-1+ in blood: 36% vs 25%, p=0.04 at 4 w after B/A induction) and a significantly shorter survival (median: 49.5 vs 83 days, p=0.01) compared to Spred1 wt CML mice (n=20). However, the disease in these mice appeared to be overall less aggressive than global Spred1 KO CML (i.e., Spred1-/-SCLtTA/BCR-ABL) mice (WBC: 19 vs 102 k/ul; CD11b+Gr-1+ in blood: 36 vs 63%; Survival: 49.5 vs 39 days), suggesting that Spred1 depletion in other non-hematopoietic cell compartments may also be important for leukemogenesis. In fact, Spred1ECΔ/ΔSCLtTA/BCR-ABL mice (n=8) showed enhanced leukemia progression (WBC: 26 vs 9.8 k/ul at 4 w after B/A induction, p=0.02), a trend for a reduced survival (median: 56 vs 83 days, p=0.09), and increased arteriolar vascularization, compared to Spred1 wt CML mice (n=20). Mechanistic studies on how endothelial Spred1 insufficiency co-participates in leukemogenesis are ongoing. Altogether our results support a role of Spred1 insufficiency in distinct BM niche compartments to produce a more aggressive CML phenotype, likely through different, but complementary mechanisms. Spred1 may therefore emerge as a novel target for advanced CML. Disclosures No relevant conflicts of interest to declare.

Abstract Abstract 1720 Background: The myelodysplastic syndromes are commonly divided into lower- and higher-risk subtypes depending on blast percentage and International Prognostic Scoring System (IPSS) score (0–1.0, low or Int-1, median overall survival (OS) 3.5–5.7 years). Because the IPSS is limited in its ability to identify poor prognosis lower-risk patients (pts), a prognostic scoring system specifically for lower-risk MDS pts (LR-PSS) was developed (Garcia-Manero Leukemia 2008) at MD Anderson (MDA), based on unfavorable (non-del(5q), non–diploid) cytogenetics, hemoglobin (hgb) <10g/dl, platelet count (plt) <50 k/uL or 50–200k/uL, bone marrow blast %≥4, and age ≥60 years. The IPSS-R (Greenberg Leuk Res 2011) improves upon the IPSS using novel cytogenetics classifications (Schanz EHA 2010) and a neutrophil cut-off of 800 k/uL. We validated the LR-PSS and the IPSS-R in a separate cohort of lower-risk MDS patients seen at Cleveland Clinic (CC) or at MDA not included in LR-PSS development. Methods: Of 1293 MDS patients identified at CC or MDA from 1991–2010, 664 had lower-risk disease and adequate data for analyses. OS was calculated from first date seen at either institution. The Kaplan–Meier method was used to estimate median OS. Univariable analyses were performed using the log-rank test; multivariable analyses used a Cox proportional hazards model stratified by treatment center. Harrell's c index and the Akaike information criteria (AIC) were used to assess the discriminatory power of the models and relative goodness of fit, respectively. Results: Comparing CC to MDA, baseline values were similar except median age: 70 vs. 67 years (p=.02); time since diagnosis: 2.7 vs. 1.1 months (p<.0001); hgb <10: 51% vs. 43% (p=.05); plt <50k/uL: 30 vs. 24% (p=.06); ANC <1.5 k/uL: 27% vs. 36% (p=.01); blasts <4%: 75% vs. 65% (p=.003); WHO classification RA/RARS/RCMD/CMML: 11/15/26/12% vs. 16/9/45/0% (p<.0001). Cytogenetics were diploid: 61% vs. 66%; del(5q): 9% vs. 2%; del(20q): 3% vs. 5%; -Y: 4% vs. 2%, respectively (p=.5). Median OS was 36.8 months (95% C.I. 33–45) and median follow-up of patients still alive was 13.9 months (range 0.01–155). LR-PSS and IPSS-R classifications for CC and MDA Pts and OS are in Table 1 and Figure 1. In univariable analyses, The IPSS, LR-PSS, and IPSS-R were all predictive of OS (p=.002, <.0001, and <.0001, respectively). Multivariable analyses confirmed the overall predictive abilities of the prognostic tools and of Hgb, plt, age, and IPSS/IPSS-R cytogenetics (all p≤.03). Compared to the IPSS-R, the LR-PSS had the higher (better) Harrell's c value (.64 vs.63) and lower (better) AIC (2518 vs. 2525). The LR-PSS upstaged 156 pts (25%) from IPSS low or Int-1 to LR-PSS Category 3, and downstaged 47 pts (12%) from Int-1 to Category 1. The IPSS-R upstaged 164 pts (27%) from IPSS low or Int-1 to IPSS-R Categories ≥Intermediate, and downstaged 5 pts (1%) from Int-1 to Very Good. Conclusions: The LR-PSS and IPSS-R are valid tools for distinguishing among pts previously thought to have lower-risk disease by the IPSS, and identifying those who have better and worse survival. This latter group of pts may benefit from earlier interventions with disease-modifying therapies, and should be considered in trials targeting higher-risk MDS pts. The LR-PSS appears to provide slightly better prognostic information. Disclosures: Sekeres: Celgene: Consultancy, Honoraria, Speakers Bureau. Maciejewski:Celgene: Membership on an entity's Board of Directors or advisory committees.

Abstract Background: Severe acute pancreatitis (SAP) frequently progresses to pancreatitis-associated multiorgan failure (MOF) with high mortality. Decreased plasma ADAMTS13 activity (ADAMTS13:AC) results in the accumulation of unusually large von Willebrand factor multimers (UL-VWFM) and the formation of platelet thrombi, ultimately leading to MOF. We demonstrated that the imbalance between decreased ADAMTS13:AC and increased UL-VWFM could contribute to SAP pathogenesis through enhanced thrombogenesis, and serve as an early prognostic indicator for SAP patients (Scand J Gastroenterol, 2008, 26:1). Endotoxin has been considered to be the principle activator of the systemic inflammatory response syndrome, which predisposes patients for MOF and/or pancreatic necrosis, ultimately leading to SAP. We investigated the relationship of endotoxin to ADAMTS13:AC and its related parameters, and tried to explore their potential role on the development of MOF in patients with SAP. Methods: We sequentially determined plasma endotoxin concentration, ADAMTS13:AC and its related parameters in 13 SAP patients (APACHE-II score mean 6.6 ± 2.7), who were admitted into intensive care unit of our hospital between 2004 and 2006. Eleven patients were survivors and two were non-survivors whose APACHE II scores were 10 and 12 died of MOF, respectively. The degree of MOF was evaluated according to the SOFA score. Endotoxin concentration was determined by a chromogenic substrate assay (Toxicolor LS –M Set, Seikagaku Kogyo Co.) with kinetic analysis after pretreatment with detergent, Triton X-100, and heating at 70 °C for 10 min. Plasma ADAMTS13:AC was determined by a sensitive chromogenic ELISA (ADAMTS13-act-ELISA: Kainos Inc.). Plasma UL-VWFM was analyzed by a vertical SDS-1.0% agarose gel electrophoresis. Plasma VWF antigen (VWF:AG), interleukin 6 (IL-6), interleukin 8 (IL-8), and tumor necrosis factor -α (TNF-α) were measured by ELISA. Results: In normal healthy controls (n=20), plasma endotoxin concentration was 7.9±1.7 pg/ml (mean ± SD). The concentration in the SAP patients significantly increased at day 1 (means 65 pg/ml, p<0.001) and at day 2 (88 pg/ml, p<0.001) as compared to healthy controls. The values, thereafter, gradually decreased in 8 survivors (55 pg/ml at day 5, 53 pg/ml at day 7, 27 pg/ml at day 14), while in remaining 3 survivors needing necrosectomy, the concentration further increased (98 pg/ml at day 5, 178 pg/ml at day 7), and decreased to 20 pg/ml at day 14 at the recovery phase. In two non-survivors, the endotoxin levels increased from 37 pg/ml at day 1 to 462 pg/ml at day 2 in one needing necrosectomy, and showed 51 pg/ml at day 1 in another at the age of 91. Within 1 or 2 days after admission, the ADAMTS13:AC was lower in SAP patients (mean 29%, p<0.001) than in healthy controls (99%), and gradually recovered in the 11 survivors but further decreased in the 2 non-survivors. On admission, VWF:Ag was higher (402%, p<0.001) in SAP patients than controls (100%). VWF:Ag gradually decreased in the survivors, except in the 3 survivors needing a necrosectomy, but remained high in the non-survivors. UL-VWFM positive patients showed lower ADAMTS13:AC (25% vs. 42%, p<0.05) and higher VWF:Ag ( 481% vs. 332%, p<0.05), resulting in higher ratio of VWF:Ag to ADAMTS13:AC (25.2 vs. 9.1, p<0.02), as compared to UL-VWFM negative ones. Patients with higher endotoxin concentration more than 50 pg/ml showed lower ADAMTS13:AC than those without (22% vs. 43%, p<0.05). Plasma endotoxin concentration positively correlated with the ratio of VWF:Ag to ADAMTS13:AC (r=0.732, p<0.005). The SOFA score correlated positively with plasma endotoxin concentration (r=0.604, p<0.03), IL-8 (r=0.843, p<0.001), and the ratio of VWF:Ag to ADAMTS13:AC (r=0.700, p<0.01), and inversely with the ADAMTS13:AC (r= − 0.601, p<0.03). Conclusion. The imbalance between decreased ADAMTS13:AC and increased UL-VWFM is closely related to enhanced endotoxemia, which may contribute to the development of SAP and subsequent MOF through enhanced thrombogenesis.

Abstract Background: EBV-positive diffuse large B-cell lymphoma (EBV+ DLBCL) of the elderly is a provisional entity included in the 2008 WHO Classification of Lymphomas. Diagnostic criteria include age >50 years, DLBCL morphology and EBV expression in lymphomatous cells. However, these criteria are evolving as several patients younger than 50 years of age without immunodeficiency have been diagnosed. Also, a specific cut-off for the percentage of EBV expression has not been defined. Lymphopenia, monocytosis, neutrophil-to-lymphocyte ratio (NLR) and the lymphocyte-to-monocyte ratio (LMR) have been reported prognostic in patients with DLBCL and other lymphomas. The goal of this retrospective study is to evaluate these novel prognostic factors in a cohort of EBV+ DLBCL patients. Methods: Between January 2002 and January 2014, all patients meeting criteria for EBV+ DLBCL were included in the analysis. Patients with evidence of immunosuppression were excluded. All cases were positive for the presence of EBV-encoded RNA (EBER) by in situ hybridization, and CD20 and/or PAX-5 expression by immunohistochemistry. Clinical and pathological data were reviewed retrospectively. Lymphopenia was defined as an absolute lymphocyte count <1000/uL, and monocytosis as an absolute monocyte count >600/uL. NLR was defined as the division of the absolute neutrophil count over the absolute lymphocyte count. LMR was defined as the division of the absolute lymphocyte count over the absolute monocyte count. Patient's biopsies were analyzed for the expression of BCL6, CD10, CD30 and MUM-1/IRF4. Overall survival (OS) curves were calculated using the Kaplan-Meier method, and compared using the log-rank test. Results: A total of 45 EBV+ DLBCL patients are included in this study. The median age was 68.9 years (range 25-95 years). Four patients (9%) were younger than 50 years. The male:female ratio was 2.2:1. B symptoms occurred in 60%, ECOG >1 in 55%, advanced stage (III/IV) in 58%, and elevated LDH levels in 44%. The International Prognostic Index (IPI) score was 0-2 in 39% and 3-5 in 61% of the patients. Lymphopenia was seen in 35%, and monocytosis in 69% of patients. Extranodal disease occurred in 23 patients (51%): stomach (n=3), tonsil (n=3), pleura (n=2), palate (n=2), cecum (n=2), bone marrow (n=2), ileum (n=1), bone (n=1), skin (n=1), lung (n=1), meninges (n=1), soft tisue (n=1) and peritoneum (n=1). Based on the Hans classification, 76% had non-germinal center origin. Ki67 expression was >80% in 53% of the patients. Chemotherapy was not received in 25% of the cases due to poor performance status. The Oyama score was: 0 factors (13%), 1 factor (47%), and 2 factors (40%) with 2-year OS of 86%, 49% and 27%, respectively (p=0.016). Lymphopenia was an adverse prognostic factor for OS (HR 3.23, 95% CI 1.24-8.43; p=0.017) in the univariate analysis. The 2-year OS for EBV+ DLBCL patients with lymphopenia was 24%, and 55% for patients without lymphopenia. Monocytosis, NLR and LMR were not significantly associated with OS in our cohort of EBV+ DLBCL patients. Conclusions: Lymphopenia, defined as an absolute lymphocyte count <1000/uL, appears as a prognostic factor for OS in EBV+ DLBCL. Disclosures No relevant conflicts of interest to declare.

Abstract Abstract 2919 Poster Board II-895 Background: Flow cytometry (FCM) assessment of cerebrospinal fluid (CSF) has recently been known to increase the rate of positivity of occult leptomeningeal disease (LD) in comparison to conventional cytologic examination (CC). However it's still unknown its prognostic value. Patients and methods: The aim of this study was to compare CC vs FCM in a large cohort of patients with newly diagnosed aggressive NHL at high risk for LD (diffuse large B-cell lymphoma (DLBCL) IPI 2-3 and elevated LDH with at least two extranodal sites or with bone marrow, testis, paranasal sinuses, orbit or paravertebral involvement; Burkitt lymphoma (BL); blastoid variant of mantle cell lymphoma (B-MCL); B-cell precursor lymphoblastic lymphoma (B-LL); HIV+ aggressive lymphoma patients). All patients were required to have no evidence or signs of neurological disease. All patients received intrathecal standard prophylactic therapy with 12 mg of methothrexate except for BL that were given prophylaxis with 50 mg of liposomial aracytin for a total of 4 doses. CFS samples were analysed both with CC and FCM. The incidence of positive test for occult LD with FCM and CC was compared using the McNemar test for paired data. Results: Between August 2004 and June 2008, a total of 159 consecutive patients were enrolled in 11 Italian centres and underwent evaluation of CSF. Out of these, 128 patients (80%) were considered at high risk of occult LD. Clinical characteristics were: median age 53 years (IQR:43-62); DLBCL 96 patients (75%); BL 21 pts (16%); B-MCL 6 pts (5%); B-LL 5 pts (4%); 26 pts (20%) were HIV positive. FCM was able to detect a clonal population in 17 out of 128 patients (13%) whereas CC detected abnormal cells only among 7 pts (5%)(p= 0.0002). Therefore, 10 patients (8%) were discordant: FCM+/CC-. Among the 128 patients, there was no association between the CFS total protein, glucose level and the presence of positive analysis of FCM, whereas the difference between the number of WBC cells in CSF was significantly higher in patients with positive versus negative FCM with a median value of 12 cells/ul (IQR: 3.5;40) versus 1.0 cells/ul (IQR: 0.0;3.0) (p=0.0120). Univariate and multivariate analyses, using logistic models, showed that abnormal LDH (OR 3.98, 95%CI: 1-15.92)(p=0.05) and number of WBC cells in CSF ≥5 (OR 4.57, 95%CI:1.37-15.33)(p=0.014) were the only predictive factors of a positive test performed by FCM. From date of diagnosis, overall median follow up of survivors was 14 months (IQR:8-22). We observed 39 (30%) systemic progressions, 6 (5%) CNS progressions (in 5 cases an isolated CNS progression whereas 1 pts experienced a CNS along with systemic progression). Thirty-two (25%) patients died and causes of deaths were as follows: 27 progressive disease, 1 infection, 1 treatment related toxicity, 1 hepatitis, 2 unknown. PFS at 1 year was 71% (95%CI:62-78) in the whole group of patients. The progression risk was significantly higher in patients both FCM+/CC+ compared with patients both FCM-/CC- (1-yr PFS 43% vs 74%) (HR 3.8 95%CI:1.6-9.0) (p=0.003). An higher but not significant risk of progression was found in pts discordant (FCM+/CC-) with respect to patients both FCM-/CC- (1-yr PFS 65% vs 74%) (HR 1.61, 95%CI:0.63-4.11) (p=0.315). In the univariate and multivariate analyses performed with Cox models, we found that the presence of ECOG PS≥2 (HR 2.14, 95%CI: 1.14-4)(p=0.018) and level of protein in CSF >40/ul (HR 1.83 95%CI: 1.01-3.29)(p=0.045) were prognostic factor of PFS. Conclusion: FCM assessment of CSF increase the rate of positivity of occult LD compare with CC but it's clinical relevance is still to be clearly defined. Our preliminary data suggest that patients both FCM+/CC+ have an higher risk of progression compared with those both negative, whereas discordant cases may have an intermediate prognosis. Disclosures: No relevant conflicts of interest to declare.

Abstract Abstract 1588 Background: EBV-positive diffuse large B-cell lymphoma (EBV+ DLBCL) of the elderly is a provisional entity included in the 2008 WHO Classification of Lymphomas. Diagnostic criteria include age >50 years, DLBCL morphology and EBV expression in lymphomatous cells. However, these criteria are evolving as several patients are <50 years and a specific cut-off for the percentage of EBV expression has not been defined. The goal of this retrospective study is to evaluate clinical and pathological characteristics of EBV+ DLBCL from Peruvian patients. Methods: Between January 2002 and January 2012, all patients meeting criteria for EBV+ DLBCL were included in the analysis. Patients with evidence of immunosuppression were excluded. All cases re positive for the presence of EBV-encoded RNA (EBER) by in situ hybridization, and CD20 and/or PAX-5 expression by immuno-histochemistry. Clinical data were reviewed retrospectively and patient's biopsies were analyzed for the expression of BCL6, CD10, CD30 and MUM-1/IRF4 using a tissue microarray (TMA) technique. The overall survival (OS) curves were calculated using the Kaplan-Meier method, and compared using the log-rank test. Results: A total of 43 EBV+ DLBCL patients are included in this study. The median age was 73 years (range 25–95 years). Four patients (9% ) were <50 years. The male:female ratio was 2.2:1. B symptoms occurred in 59%, ECOG >21 in 60%, advanced stage (III/IV) in 58%, elevated LDH levels in 44%, and lymphocyte count <1000/uL in 35%. The International Prognostic Index (IPI) score was 0–2 in 39% and 3–5 in 61% of the patients. Extranodal disease occurred in 20 patients (46%): stomach (n=3), tonsil (n=3), pleura (n=2), palate (n=2), cecum (n=2), bone marrow (n=2), ileum (n=1), bone (n=1), skin (n=1), lung (n=1), meninges (n=1), breast (n=1) and peritoneum (n=1). Three patients had central nervous system involvement (7%), one at presentation and two at relapse. Based on the Hans classification, 76% had non-germinal center profile. Ki67 expression was >80% in 53% of the patients. Eleven evaluated patients had a c-myc-negative status. Chemotherapy was received in 75% of the cases due to poor performance status. The overall response rate with conventional chemotherapy was 46%, with complete response in 39%, partial response in 7%, and no response in 54%. The median survival was 7.5 months. The Oyama score was: 0 factors (13%), 1 factor (47%), and 2 factors (40%) with median OS of 41, 11 and 1.5 months respectively (p=0.07). A lymphocyte count <1000/uL was a prognostic factor for OS (p=0.001). Conclusions: Based on our study, which is the largest cohort in Latin-America, EBV+ DLBCL is an aggressive entity with frequent extranodal disease and poor response to conventional chemotherapy. The overall survival remains poor. Lymphopenia, as defined as lymphocyte count <1000/uL, appears as a prognostic factor for OS. Disclosures: No relevant conflicts of interest to declare.

Abstract Abstract 3681 Background: Pediatric Immune Thrombocytopenia (ITP) has an incidence of 4–6/100,000 with 1/3 of cases becoming chronic. Treatment choice is arbitrary, because few studies are powered to identify predictors of therapy response. Increasingly, rituximab is becoming a treatment of choice in those refractory to other therapies (Neunert CE, et al. Pediatr Blood Cancer 2008; 51(4):513). Previous studies in ITP have not examined predictors of response to rituximab or whether response to prior treatments predicts response. Objective: To evaluate univariate and multivariable predictors of platelet count response to rituximab. Methods: After local IRB approval, 550 patients with chronic ITP enrolled in the longitudinal, North American Chronic ITP Registry (NACIR) between January 2004 and June 2010. Eligibility included: ages 6 months-18 years at ITP diagnosis, clinical diagnosis of ITP, and ITP duration >6 months. Primary ITP was defined as isolated thrombocytopenia without associated conditions. Secondary ITP included those patients with immune thrombocytopenia associated with other immune-mediated medical conditions, including Evans Syndrome. Treatment response was defined as a post-treatment platelet count ≥50,000/uL within 16 weeks of rituximab and within 14 days of steroids. Steroids were prescribed as 1–4 mg/kg prednisone or adult equivalent over 4–14 days with or without taper. The NACIR captured treatment responses both retrospectively prior to enrollment and then prospectively, and both periods were included in this analysis. The multivariable logistic regression modeling process utilized SAS 9.1 using binary variables which were either significant in the univariate analysis or clinically important. A backwards elimination procedure was used to select the final model. Results: Seventy-six (13.8%) patients were treated with rituximab. Demographics of the patients treated with rituximab include: 42% male; 81% Caucasian, 17% Black, and 2% Asian. The mean age at diagnosis of ITP was 8.4 ± SD 5.1 years. The median platelet count at diagnosis of acute ITP was 10,000/uL (IQR 5,000-20,000/uL). 19 (25%) patients had secondary ITP or Evans syndrome. Treatment with rituximab had an overall response rate of 63.2% (48/76). Univariate predictors of response to rituximab are shown in Table I. The strongest univariate predictor of response to rituximab was response to steroids. Gender, ethnicity, and race were not predictive of response to rituximab. Furthermore, other variables which did not predict rituximab response include: history of a bleeding score ≥3 (Buchanan and Adix, J Pediatr 2002; 141: 683), symptoms ≥1 month prior to ITP diagnosis, older age (age >5 years), platelets ≥20,000/uL at acute ITP diagnosis, and a positive ANA. In multivariable analysis, response to steroids remained a strong predictor of response to rituximab with an OR 6.2 (95% CI 1.8–21.3, p=0.004). Secondary ITP also remained a strong a predictor of a positive response to rituximab with an OR 5.9 (95% CI 1.2–33.3, p=0.03). Conclusion: In the NACIR, response to steroids and secondary ITP were strong predictors of response to rituximab, a finding not previously reported in children or adults. Although this finding requires further validation, this result may provide evidence that rituximab should be most considered in patients previously responsive to steroids. Disclosures: Off Label Use: Rituximab for chronic ITP. Lambert:Cangene: Membership on an entity's Board of Directors or advisory committees. Klaassen:Novartis: Research Funding; Cangene: Research Funding. Neufeld:Novartis, Inc: Research Funding.

Abstract Abstract 1701 Patients with features of MDS and MDS/MPN who do not fulfill diagnostic criteria for a specific subtype of MDS and MDS/MPN are categorized by the WHO 2008 diagnostic criteria as MDS-U and MDS/MPN-U. MDS includes RCUD, RCMD, RARS, RAEB-1, RAEB-2, MDS-U and 5q- syndrome while MDS/MPN includes CMML, JMML, atypical CML and MDS/MPN-U. The natural history of patients who belong to these disease subtypes are hetergeneous. Although included in currently accepted prognostic scoring schemes like the International Prognostic Scoring System (IPSS) in MDS, Revised IPSS, and MD Anderson prognostic scoring schemes, they represent a minority of patients in the cohort. Within MDS/MPN cases, the clinical heterogeneity of diseases that belong to this group has been recognized and has led to the development of the MD Anderson prognostic Scoring System for CMML. Similarly, a prognostic scoring system for JMML has also been devised to help in risk stratification and treatment decisions. However, there are no prognostic scoring systems for unclassified cases of MDS and MDS/MPN. Clinically, we observe stark differences in treatment responses and clinical outcomes between MDS/MPN-U and other MDS/MPN-subtypes, and MDS-U with other subtypes of MDS. In total, we studied 92 patients with unclassifiable cases seen at the Cleveland Clinic, including MDS/MPN-U (n=52 [57%]) and MDS-U (n=40 [43%]). Hematologic, bone marrow (BM), cytogenetic (metaphase cytogenetic [MC]/SNP-A) and survival data were collected. Survival comparisons were made by Kaplan-Meier analyses. Cox-proportional hazard ratio was used to determine factors predictive of outcomes. A p-value of ≤0.05 was considered statistically significant. In this cohort, median age at diagnosis was 69 years (20–88), 65% (60/92) were male, and 35% (32/92) were female. Median follow-up was 21 months. Median absolute neutrophil count (ANC) was 2.69k/uL (0–87), peripheral blood (PB) blasts 0% (0–70%), hemoglobin 9.6g/dL (5–15), and LDH 260 U/L (105–2113). SNP-A karyotyping was completed for 65 patients, and new cytogenetic mutations were detected in 72% (47/65): (gains [64%], losses [57%], UPDs [25%]). In 52% (49/92) of patients, we sequenced molecular mutations that typically confer poor prognosis in myeloid neoplasms, such as ASXL1, IDH1/2, EZH2, K/NRAS, CBL and TP53. This sequencing revealed a mutational frequency of 18% (9/49) in TET2, 14% (7/49) in ASXL1, 6% (3/49) in EZH2 exons 18–19, 2% (1/49) in CBL, 2% (1/49) in NRAS, and 4% (2/49) in TP53. No mutations were found in IDH1/2 and KRAS. In univariate analysis of clinciopathologic factors, the following factors were found to be associated with overall survival: ANC (≥8.5 vs <8.5k/uL) (p<.0001), presence of PB blasts (p<.0001), presence of immature myeloid cells (p<.0001), presence of BM blasts (>3% v. ≤3%) (p<.0001), age (≥65 vs <65) (p<.0003), LDH (≥550 vs <550U/L) (p<.0004), albumin (≤3.6 vs >3.6g/dL) (p<.0008), IPSS Risk Group (Int-2/high vs int-1 vs low) (p<.01), IPSS-R Risk Group (High/very high vs low vs very low) (p<.001), WBC (≥15 vs <15k/uL) (p<.001), Hgb (≤11.5 vs >11.5g/dL) (p<.003), % BM cellularity (>85 vs ≤85%) (p<.009), and number of cytopenias (3 vs 2 vs 1 vs 0) (p<.04). In multivariate analysis, age (HR=3.47 CI 1.85–6.51, p=.001), ANC (HR=2.27 CI 1.15–4.49, p=.02), Hgb (HR=2.11 CI 1.07–4.14, p.03), peripheral blasts (HR=2.27 CI 1.19–4.36,p=.01) and LDH (HR=2.40 CI 1.11–5.16, p=.03) were independent predictors of OS in unclassifiable cases of MDS and MDS/MPN. Consequently, a prognostic scoring system was developed to include these factors. A simple scoring assigned 2 points each to an ANC of ≥8.5k/uL, the presence of peripheral blood blasts, hemoglobin ≤ 11.5g/dL, LDH ≥ 550U/L; and 3 points for age ≥65. This results in three well-separated prognostic groups: (favorable [score:0–3], median OS=67.4 months; intermediate [score:4–6],median OS=28.9 months; and poor [score: ≥ 7], median OS=13.1 months, p<.0001). 34, 21, and 24 patients were placed in these three groups, respectively. In conclusion, clinic-pathologic factors like age, LDH levels, ANC count, Hgb levels and peripheral blood blasts are helpful in predicting survival outcomes in patients with unclassifiable cases of MDS and MDS/MPN disorders. This is the first scoring system devised specifically for patients with this disease subtype. Disclosures: No relevant conflicts of interest to declare.

Abstract Background: Myelodysplastic syndrome (MDS) therapeutic decisions have been traditionally based on the IPSS; however, this score system does not allow the identification of patients with low risk disease (low or intermediate-1 IPSS) but a poor prognosis, who could benefit from an early intervention. Garcia-Manero et al (Leukemia 2008) described a specific prognostic scoring system for this subgroup of patients (LR-PSS) based on age ≥60 years, hemoglobin <10g/dl, platelet count <50k/uL or 50-200k/uL, bone marrow blasts ≥4% and unfavorable cytogenetics (non-del(5q), non-diploid). This LR-PSS score system enables the stratification of low risk MDS patients into 3 different risk categories; interestingly, the third category identifies a subgroup of patients with a median overall survival (OS) similar to that of patients classified as intermediate-2 and high risk IPSS. Besides, the IPSS-R described by Greenberg et al (Blood 2012) has demonstrated a strong prognostic value for OS and LFS as compared to the IPSS when applied to different independent series of MDS patients. The prognostic impact of the LR-PSS has not been analyzed in MDS patients with very low-, low- and intermediate IPSS-R scores. Aim: To analyze the prognostic impact according to OS and leukemia free survival of the LR-PSS when applied to a population MDS patients with very low, low and intermediate IPSS-R. Methods: A total of 789 consecutive patients diagnosed with MDS (01/1992-12/2014) at the Catalan Institute of Oncology of Barcelona were included in the study. 413 (52%) had available cytogenetics and therefore, IPSS-R was calculated. Overall, 371 (89%) patients were classified as very low, low and intermediate IPSS-R and included in the study. Results: 123 (30%) patients were classified as very low, 182 (44%) low and 66 (16%) intermediated IPSS-R risk MDS; median age 72 years (range 32-101) and 258 (69%) male. 1.4 % CRDU, 7.6 % RA, 41.6 % RCMD, 16.2 % RAEB‐1, 4.1 % RAEB‐2, 25.9 % CMML and 3.2 % MDS‐U with isolated 5q deletion according to the 2008 WHO classification. At diagnosis, median hemoglobin, platelet and bone marrow blast were 11.8 g/dL (5.5-17.1), 152 x109/L (1-1492) and 3 % (0-17), respectively and fifty-three (14.3 %) patients had unfavorable LR-PSS cytogenetics. For the whole population, median follow up was 6.6 years (range 6-7.7). At the time of last follow up, 48.2 % (179) had died and only 49 (13%) had progressed to acute myeloid leukemia. When the LR-PSS was applied to the very low, low and intermediate IPSS-R subgroups three well-differentiated prognostic categories could be identified: 58 patients (15.6%) category 1, scores 0-2; 277 (74.6%) patients category 2, scores 3-4 and 36 (9.8%) patients category 3, scores 5-7 with significantly different overall survival and leukemia free survival. Median OS for categories 1 (9.4 years; 95% CI 6.7-12), 2 (6 years; 95% CI 5-7.1) and 3 (2.6 years; 95% CI 2.1-3) were significantly different (p<0.001; Figure 1). Moreover, the rate of progression to acute myeloid leukemia was 5% (3/58), 13% (37/277) and 25% (9/36) for categories 1, 2 and 3, respectively. Summary/Conclusion: When applied to a low risk (very low, low and intermediate) IPSS-R cohort of MDS population, the LR-PSS identifies a subgroup of patients with a significantly worse prognosis who could benefit from an early intervention. Further studies are warranted. Fig 1. Kaplan-Meier survival for patients with very low-, low- and intermediate IPSS-R risk assigned to categories 1 to 3 by LR-PSS. Fig 1. Kaplan-Meier survival for patients with very low-, low- and intermediate IPSS-R risk assigned to categories 1 to 3 by LR-PSS. Disclosures Sureda: Takeda: Consultancy, Speakers Bureau.