Gangat, Naseema

Abstract Background The median survival (OS) of patients with primary myelofibrosis (PMF; 6.5y) is significantly shortened compared to reference population (Cervantes et al, JCO 2012; 30:2981). OS is predicted by the four risk categories of IPSS, Dynamic-IPSS and DIPSS-plus score, nevertheless pts heterogeneity persists within these categories, necessitating improved risk stratification. We recently reported that pts harboring mutations in any one of the prognostically relevant ASXL1, EZH2, IDH1/2 and SRSF2 genes constitute a IPSS-and DIPPS-plus independent Molecular High Risk category (MHR+) characterized by significant reduction of OS and leukemia free survival (LFS) (Vannucchi et al, Leukemia 2013). The aim of this work was to analyze the impact of the number of prognostically relevant mutated genes on OS and LFS in PMF. Patients and methods Two independent cohorts are included, a “test cohort” from Europe, analyzed at diagnosis, and a “validation cohort” from Mayo Clinic, analyzed at any time after diagnosis. Mutation analysis was performed in DNA from whole blood or granulocytes using RTQ-PCR, HRM and direct sequencing; all mutations were confirmed at least twice. The prognostic value of the molecular variables with regard to OS and LFS was analyzed by Cox regression. Test cohort It included 490 pts (median age 61y; males = 301) risk stratified by IPSS into high (n=74, 15%), intermediate-2 (n=93, 19% ), intermediate-1 (n=147, 30%) and low (n=176, 36%). The median follow-up was 3.63y (95% CI, 0.06-28.33); 161 pts died (33.0%), of whom 76 (15.6%) had progressed to acute leukemia after a median of 3.4y (0.04-28.3) from diagnosis. One hundred forty-six pts (29.8%) presented at least one of the four aforementioned mutated genes and were classified as MHR+. The OS of MHR+ pts was significantly reduced compared to patients with no mutations (n=344): 80.7 vs 148.9 mo (HR 2.2, CI95% 1.6-3.03). One hundred twelve (22.8%) pts had 1 mutation and 34 (6.9%) had 2 or more mutations. In univariate analysis presence of 2 or more mutated genes was significantly more detrimental for OS (29.5mo; HR 4.12, IC95% 2.6-6.4) than having 1 mutated gene (84.2mo; HR 1.8, IC95% 1.2-2.5) compared with having no mutations (148.9mo). Multivariate analysis results adjusted for IPSS indicated that having two or more mutations was an independent prognostic factor for OS (HR 2.9, 95% CI 1.8-4.5). Notably, the prognostic relevance of harboring two or more mutations involved both lower (low and intermediate-1; HR 1.87, 95% CI 1.3-2.6) and higher (intermediate-2 and high; HR 1.6, 95% CI 1.2-2.1) categories of IPSS. Also LFS resulted significantly shorter (129mo; HR 3.1, 95%CI 1.9-4.8) in MHR+ pts compared with pts with no adverse mutations (323mo). Having 2 or more mutations correlated with greater reduction of LFS (79.6mo; HR 7.02, CI95% 3.9-12.6) than having one mutation only (133.9mo; HR 2.2, IC95% 1.3-3.7) as compared with no mutations (323.2mo). Multivariate analysis showed that IPSS high risk category (HR 4.5; 95% CI 2.3-8.8) and two or more mutated genes (HR 5.3; 95% CI 2.9-9.8) predicted independently for a significant reduction in LFS. The negative impact on LFS of having 2 or more mutated genes compared to one or no mutations was maintained in the lower (HR 6.4, 95% CI 2.6-15.2) and higher (HR 5.5, 95% CI 2.3-12.8) risk categories. Validation cohort Validation cohort included 262 patients (median age 64 years; males = 167) risk stratified by DIPSS-plus into high (n=89, 34%), intermediate-2 (n=92, 35%), intermediate-1 (n=46, 18%) and low (n=34, 13%). One hundred forty-six pts (56%) displayed none of the four aforementioned mutations, 93 (36%) harbored one mutation whereas 23 (9%) harbored two or more mutations. In univariate analysis, having two or more mutations (HR 3.7; 95% CI 2.2-6.1) was significantly more detrimental for OS than having no mutations, which is more favorable than having one mutation (HR 1.9; 95% CI 1.4-2.7). When adjusted for DIPSS-plus, the presence of two or more mutations retained its significance (HR 2.1; 95% CI 1.3-3.6) and outperformed ASXL1 mutation alone in its prognostic relevance Conclusions Overall, these results show that the number of prognostically relevant mutated genes correlate with OS and LFS in pts with PMF, suggesting that screening for these mutations might help to improve risk stratification. Disclosures: No relevant conflicts of interest to declare.

Abstract Abstract 3069 Background: Monosomal karyotype (MK) is defined as the presence of two or more distinct autosomal chromosome monosomies or a single autosomal monosomy associated with at least one structural abnormality (Breems DA et al. J Clin Oncol 2008; 26: 4791). In acute myeloid leukemia (AML), MK has been shown to be prognostically worse than complex or other unfavorable karyotype (Breems DA et al. J Clin Oncol 2008; 26: 4791). In primary myelofibrosis (PMF), complex karyotype or isolated trisomy 8 predicts inferior survival (Hussein K et al. Blood 2010; 115: 496). Objective: To determine if MK in PMF is prognostically distinct from previously defined poor cytogenetic risk categories including complex karyotype and isolated trisomy 8. Methods: The Mayo Clinic database for PMF was used to identify consecutive patients with unfavorable karyotype including complex karyotype and sole trisomy 8. WHO criteria were used for PMF diagnosis and leukemic transformation (Vardiman JW et al. Blood 2009; 114: 937). Results: Among 793 PMF patients with cytogenetic information at the time of their first time referral to the Mayo Clinic, 452 displayed a normal karyotype and 341 (43%) an abnormal karyotype. Of the latter, 41 (12%) displayed complex karyotype and 21 (6%) sole trisomy 8. Among the 41 patients with complex karyotype, 17 (42%) met the criteria for MK and 24 (58%) displayed complex karyotype without monosomies. Overall survival was significantly inferior in patients with MK compared to those with either complex karyotype without monosomies (p=0.02; HR 2.3, 95% CI 1.1–4.8) or trisomy 8 (p=0.02; HR 2.4, 95% CI 1.2–5.1) (Fig. 1). Prognosis among all three groups was significantly worse than patients with normal karyotype (Fig. 1). Leukemia-free survival was also significantly inferior in patients with MK compared to those with either complex karyotype without monosomies (p=0.02; HR 6.9, 95% CI 1.3–37.3) or trisomy 8 (p=0.02; HR 14.8, 95% CI 1.7–130.8) (Fig. 2). LFS in patients with normal karyotype was similar to those with either complex karyotype without monosomies (p=0.31) or trisomy 8 (p=0.86) (Figure 2). Conclusions: Monosomal karyotype in PMF is distinctly associated with extremely poor overall and leukemia-free survivals that are significantly worse than those seen in PMF patients with other unfavorable karyotype including complex karyotype without monosomies and sole trisomy 8 abnormalities. Disclosures: No relevant conflicts of interest to declare.

Abstract Background : Gene mutations are common (~90%) in patients with chronic myelomonocytic leukemia (CMML) and involve epigenetic regulators (TET2 ~ 60%, ASXL1 ~40%), spliceosome components (SRSF2 ~40%) and signal pathways (RAS ~30%). Of these, thus far, only ASXL1 mutations have been shown to adversely impact overall survival (OS). In the current study, we used a 27-gene panel assay to identify additional prognostically-relevant mutations in CMML and to also determine if number of mutations carries prognostic relevance. Methods : 175 patients with WHO-defined CMML were included in the study. All patients had bone marrow (BM) biopsies and cytogenetics performed at diagnosis. Targeted capture assays were carried out on BM DNA specimens obtained at diagnosis for the following genes; TET2, DNMT3A, IDH1, IDH2, ASXL1, EZH2, SUZ12, SRSF2, SF3B1, ZRSR2, U2AF1, PTPN11, Tp53, SH2B3, RUNX1, CBL, NRAS, JAK2, CSF3R, FLT3, KIT, CALR, MPL, NPM1, CEBPA, IKZF, and SETBP1. Paired-end indexed libraries were prepared from individual patient DNA using the NEBNext Ultra Library prep protocol on the Agilent Bravo liquid handler. Capture libraries were assembled according to Nimblegen standard library protocol. Base-calling was performed using Illumina's RTA version 1.17.21.3. Genesifter software was utilized to analyze targeted sequence data. Specific variants were deemed as mutations if they were associated with a hematological malignancy (as identified by COSMIC database), or if they were not associated with a dbSNP Results: Among the 175 study patients, 66% were males and median age was 70 years. 146 (83%) patients were subclassified as CMML-1. At a median follow-up of 23 months, 146 (83%) deaths and 25 (14%) leukemic transformations were documented. Median survivals were 24 months for CMML-1 and 16 months for CMML-2 (p=0.38). Mutational frequencies were; TET2 46%, ASXL1 45%, SRSF2 45%, SETBP1 19%, CBL 14%, RUNX1 14%, NRAS 12%, U2AF1 8%, SF3B1 6%, ZRSR2 6%, Tp53 5%, DNMT3A 5%, IDH2 5%, PTPN11 5%, SH2B3 5%, JAK2 4%, NPM1 3%, CSF3R 2%, IDH1 2%, EZH2 1%, SUZ12 1%, KIT 1%, FLT3 1%, CALR 1%. 172 patients (98%) had at least one mutation, 21 (12%) had 2, 24 (14%) had 3, 20 (11%) had 4, 9 (5%) had 5, while one (1%) patient had 6 concurrent mutations. Risk stratification was based on Mayo prognostic model: 25% high, 32% intermediate and 43 % low risk. In univariate analysis, presence of ASXL1 mutations (p=0.01), absence of TET2 mutations (p=0.005) and presence of DNMT3A mutations (p=0.02) were associated with inferior survival; in multivariable analysis, ASXL1 (p=0.01) and TET2 (p=0.03) mutations remained significant. In order to determine prognostic interaction between these two mutations, patients were stratified into four mutational categories: ASXL1wt/TET2wt (n =56), ASXL1mut/TET2wt (n =31), ASXL1mut/TET2mut (n =50) and ASXL1wt/TET2mut (n =38). Survival data in these four groups showed significant difference in favor of ASXL1wt/TET2mut (median survival 38 months; p=0.016), compared to those with ASXL1wt/TET2wt (19 months), ASXL1mut/TET2wt (31 months)and ASXL1mut/TET2mut (16 months); there was no significant difference in survival among the latter three groups (p=0.3) (Figure). The number of mutations per patient did not affect outcome (p=0.3). In multivariable analysis, presence of ASXL1 mutations (P=0.01) and absence of TET2 mutations (p=0.003) remained significant when risk factors used in the Mayo prognostic model (HB <10 gm/dl, AMC >10 x 10(9)/L, platelets <100 x 10(9)/L, circulating IMC) were added to the model; the same was true for ASXL1wt/TET2mut (p=0.036). In a separate multivariable analysis that included the Mayo prognostic model as a single variable along with presence of ASXL1 and absence of TET2 mutations; or absence of ASXL1wt/TET2mut mutational status, the respective hazard ratios were 1.4 (95% CI 1.07-2.1; p=0.012), 1.5 (95% CI 1.07-2.1; p=0.03) and 1.8 (95% CI 1.2-2.7; p=0.001). Leukemia-free survival was worse in ZRSR2 -mutated cases (p=0.03). Conclusions: Almost 100% of patients with CMML express one or more myeloid neoplasm-relevant mutations. The current study suggests a favorable prognostic impact from TET2 mutations, unless accompanied by ASXL1 mutations. Disclosures No relevant conflicts of interest to declare.

Abstract Background : Current risk stratification for thrombosis in essential thrombocythemia (ET) utilizes age >60 years, history of thrombosis, JAK2V617F mutation and cardiovascular risk factors (Barbui, Blood 2012;26:5128). Thrombosis history is also predictive of inferior overall survival (OS) in ET (Passamonti, Blood 2012;6:1197). However, whether or not the prognostic impact of thrombosis in ET is contributed by arterial versus venous thrombosis is unclear. Methods: More than 45,000 patient charts with "thrombocytosis" were reviewed to identify those who met either PVSG (older patient cohort) or WHO criteria for diagnosis of ET. Details of type of thrombotic events were obtained by careful review of the medical record. A subset of patients was molecularly annotated for the JAK2, CALR and MPL mutations. OS was calculated from time of initial diagnosis to the time of last follow-up or death. Thrombosis-free survival (TFS) was calculated from the time of diagnosis of ET to the time of development of thrombosis or last follow up or death, in patients censored for thrombosis. Conventional statistics was utilized for all analyses. Results :Patient characteristics: A total of 610 patients met the above-stipulated criteria (median age 57 years; 61% females). 76 patients (12%) had thrombosis documented either prior to or at diagnosis of which 50 patients (66%) experienced arterial events. 302 patients were screened for JAK2/CALR/MPL mutations with a frequency of 53.5%, 31%, and 3% respectively, while12.5% were "triple-negative".Impact of thrombosis history on OS: At a median follow-up of 8.9 years (range: 0-43.6 years), 185 (30%) deaths were documented. Themedian OS for the entire cohort was 20 years. On univariate survival analysis, the predictors of inferior OS included: age ≥60 years (p<0.001), leukocyte count ≥11 x 10(9) (p<0.001), male sex (p=0.0002), thrombosis before or at diagnosis (p=0.01), and presence of the JAK2V617F mutation (p=0.03). All but JAK2 V617F (p=0.64) remained significant on multivariable analysis. When arterial and venous events were considered separately, in univariate analysis, only arterial (p<0.001) but not venous (p=0.387) thrombotic events retained significance. The significant prognostic contribution, to survival, of arterial thrombosis history was sustained (p=0.02) during multivariable analysis, that included age ≥ 60 years (p=<0.001), leukocyte count ≥11 x 10(9) (p=0.001), and male sex (p=0.001) on OS.Impact of thrombosis history on TFS: A total of 84 (14%) patients experienced thrombotic events during follow-up amongst which 60 (71%) experienced arterial thrombosis. On univariate analysis the predictors of inferior TFS included: age ≥ 60 years (p=0.016), leukocyte count ≥11 x 10(9) (p=0.001), thrombosis before or at diagnosis (p<0.001), and presence of the JAK2V617F mutation (p=0.002). On multivariable analysis, thrombosis before or at diagnosis (p<0.001), along with leukocyte count ≥11 x 10(9) (p=0.03), and presence of the JAK2V617F mutation (p=0.01) remained significant; the significance of age ≥60 years became borderline (p=0.07). When arterial and venous thrombosis were analyzed separately, only arterial (p<0.001), but not venous (p=0.48), thrombosis history was significantly associated with inferior TFS. The factors that predicted worse outcome with TFS included arterial thrombosis at or before diagnosis (p<0.001), leukocyte count ≥11 x 10(9) (p=0.03) and presence of the JAK2V617F mutation (p=0.01); the significance of age ≥60 years became borderline (p=0.13). Conclusions : The prognostic impact of thrombosis in ET, in terms of both overall and thrombosis-free survival, might be attributed to only arterial but not venous thrombotic events. The current study also confirms the independent prothrombotic role of JAK2V617F mutation in ET and suggests an additional role for leukocytosis. Disclosures Barbui: Novartis: Speakers Bureau.

Abstract Abstract 2910 Poster Board II-886 Background: Polycythemia vera (PV) and primary myelofibrosis (PMF) are stem cell-derived myeloproliferative neoplasms characterized clinically by increased red cell volume and bone marrow fibrosis, respectively. Phlebotomy is the cornerstone of treatment in PV whereas hydroxyurea has been the traditional drug of choice in both PV and PMF. Over the last 20 years, several new treatment approaches have been introduced and promoted (e.g. interferon-alpha, anagrelide, thalidomide, allogeneic stem cell transplantation) but their benefit in terms of survival has not been confirmed in controlled studies. Methods: Study patients were recruited form the Mayo Clinic database for myeloproliferative neoplasms. Diagnosis was based on 2001 WHO criteria. Follow-up information was updated in July, 2009. In order to assess changes in survival over time, patients were stratified into two groups by year-of-diagnosis: 1970-1990 and 1991-2005. Survival analysis was performed by the Kaplan-Meier method and comparisons made by the log-rank test. Cox regression model was used for multivariable analysis. Results: 652 patients were studied, including 314 with PMF (median age 57 years, range 18-88; 193 males) and 338 with PV (median age 63 years, range 18-93; 183 males). Overall median survivals were 6.5 years for PMF and 12.2 years for PV (p<0.0001); ten- and twenty-year survival rates were 37% and 13% in PMF and 60% and 18% in PV (Figure). Both the International Prognostic Scoring System for PMF (IPSS; Cervantes et al. Blood 2009;113:2895) and the age/leukocyte count-based PSS for PV (Gangat et al. BJH 2007;138:354) were validated in the current series of patients. Considering all patients, there was no significant difference in survival when either PMF (p=0.91) or PV (p=0.73) patients were stratified according to year-of-diagnosis (Figure); median survivals were 4.7 and 6.6 years in PMF patients diagnosed 1970-1990 (n=54) and 1991-2005 (n=260), respectively; the corresponding median survival figures for PV were 11.8 (n=170) and 12.2 (n=168) years. These results did not change when adjusted for age and sex and, in PV, for age/leukocyte count-based PSS. In PMF, however, borderline significance (p=0.05) was noted when IPSS scores were introduced into the Cox model with further analysis showing improved survival in Int-2/high risk patients with PMF diagnosed after 1990 (p=0.01). Conclusion: The current study provides mature survival data in PMF and PV using large cohorts of consecutive patients seen at a single institution. Although median survival is significantly better in PV compared to PMF, their survival curves converge after 20 years of follow-up, underscoring the poor long-term prognosis in PV patients. The study also suggests improved survival for high/intermediate-2 risk PMF in recent years. Disclosures: Off Label Use: hydroxyurea use in myelofibrosis.

Abstract Abstract 2785 Poster Board II-761 Background: Cytogenetic abnormalities are common in the myelodysplastic syndromes (MDS) and carry considerable prognostic weight. One of the most common cytogenetic abnormalities in MDS is isolated trisomy 8 (∼20%). However, the impact of this abnormality on prognosis in MDS is unclear. In the following, we report on all MDS cases with isolated trisomy 8 seen at our institution and describe the natural history of this abnormality. Methods: After approval from the Institutional Review Board, the cytogenetics laboratory database at Mayo Clinic was searched for all cases of isolated trisomy 8. All patients had given written informed consent to enable use of their medical record for research. The medical records were reviewed and relevant demographic, clinical, and laboratory characteristics were abstracted. Survival was determined from diagnosis until death or last contact with the patient and measured using the Kaplan-Meier method. Univariate and multivariate analysis for survival were performed using the Cox proportional hazard method. Results: Out of a total of 23, 375 unique patient specimens evaluated over a twenty year period (January 1988 – December 2008), we identified a cohort of 106 patients (0.45%) with trisomy 8 as the sole cytogenetic abnormality (males with –Y were included). Of these patients, 89 had a classical MDS and 66 patients were males. The median age at diagnosis of MDS was 70.0 years (range: 31 – 91) for the whole cohort (females: 67 yr, males: 71.5 yr, p=0.22). All patients presented with at least one cytopenia, median Hb: 9.8g/dl (3.9 – 15.4); WBC: 4.6×103/ml (1.0 – 102.6); PLT: 119×103/ml (3.0 – 740), bone marrow blasts: 5% (0 – 22.5), LDH: 221 (62 – 1342). Considering trisomy 8 as an intermediate risk abnormality (score = 0.5), the median IPSS for the cohort was 1.0 (0.5 – 2.5) (Intermediate-1). The distribution of cases included: MDS with <5% blasts (55%), RAEB-1 (16%), RAEB-2 (18%), and CMML (11%). 85% of patients required transfusion sometime after diagnosis and 40% were treated with some form of chemotherapy. Transformation to acute myeloid leukemia (AML) occurred in 25 patients (28.1%) and of these, 22 have died. The median time from diagnosis to transformation to AML was 33 months. The median overall survival from diagnosis was 36 months, similar to what is expected for Int-1 patients (Blood 89:2079, 1997). On univariate analysis, age at diagnosis (p=0.05), LDH (p=0.017) and time to transformation (p<0.0001) were prognostic. On multivariate analysis, LDH (p=0.007) and time to transformation (p=0.009) remained independent prognostic factors. Conclusions: Isolated trisomy 8 in MDS is associated with intermediate risk disease. The risk of transformation to acute leukemia is 28% and the median survival from diagnosis of MDS is approximately 3 years. A significant fraction of patients die due to causes unrelated to their hematopoietic disorder. Disclosures: No relevant conflicts of interest to declare.

Abstract Introduction L-asparaginase therapy results in systemic depletion of antithrombin (AT) and fibrinogen (FG), resulting in thrombotic (TE) and hemorrhagic events (HE). Prophylactic correction of coagulation disturbances have been inconclusive with regard to cost effectiveness, and specifically cost effectiveness of antithrombin concentrate (ATC) replacement has not been evaluated. (Abbott et al, 2009, Mitchell et al, 2003). Currently, AT repletion is recommended for levels less than 60%. (Stock et al, 2012) Several treatment protocols with distinctly different L-asparaginase (LAS) or pegaspargase (PEG) doses complicate the frequency and intensity of ATC replacement. We carried out this study to evaluate the cost effectiveness of ATC replacement, based on our institutional practice. Methods This single center, retrospective, observational study was approved by the Institutional Review Board and conducted at Mayo Clinic, Rochester, MN. Consecutive adult patients with a confirmed diagnosis of ALL receiving LAS or PEG between January 2000 and October 2012 were evaluated. Patients with hereditary or acquired thrombophilias or pre-existing TE or HE, were excluded. Per institutional guidelines, ATC was administered if levels were less than 70%. The Centers for Medicare & Medicaid (CMS) single drug historical pricing guide was utilized for 2000-2004. ATC cost beginning January 1, 2005, was derived from the CMS average sales price, reported quarterly. To adjust for price differences due to regimen utilization trends, each dose was also calculated at the final 2012 cost of 3.05/unit. ATC repletion practices and estimated expenditures were compared between regimens. Results Fifty four patients were treated with LAS or PEG containing regimens. Of these, 47 (87%) received ATC. Twenty-eight patients received LASP, 22 received PEGASP and 4 received both. Distribution across protocols was; CALGB 9111 (n=20, Larson et al, 1998), E2993 (n=13, Goldstone et al, 2008), C10403 (n=9, NLM: NCT00558519), CCG 1941 (n=7, Gaynon et al, 2006) and Augmented HyperCVAD (n=5, Faderl et al, 2005). PEG and LAS dosing schemes are outlined in table 1 . LAS doses were converted to PEG upon specific protocol revision or at discontinuation of LAS availability in 2012. Regimens specified a dose cap with the exception of C10403. A total of 399 LAS and PEG doses resulted in 378 instances of ATC repletion. The reimbursement price of ATC in 2000 was estimated at 1.50/unit U.S. dollars (USD) and 3.04/unit USD by the fourth quarter of 2012. The total estimated average sales price was 2,471,745 USD over the study period. C10403 resulted in the highest median number of PEG doses per patient (n = 5) and a median of 17 ATC doses per dose of PEG. This resulted in C10403 being the most expensive regimen with the median expense for ATC replacement being 118,064 USD (chart 1). This conclusion was also seen after comparing different regimens using the most recent 2012 cost estimates. The overall incidence of TE or HE was 17% and equally distributed between regimens (please see accompanying abstract). Conclusions Repletion of ATC in patients receiving asparaginase containing chemotherapy regimens is very expensive and continues to add to costs at many centers, without clear benefit, especially with regards to TE and HE. A prospective, randomized, multicenter clinical trial looking to answer this question is the need of the hour. Disclosures: No relevant conflicts of interest to declare.

Abstract Background In routine myelodysplastic syndromes (MDS) practice, physicians do not submit bone marrow (BM) slides for central review. Instead, they rely on available BM reports to assess prognosis and make therapeutic decisions. Such practice is likely to introduce inaccuracies, especially in the diagnosis of MDS-unclassifiable (MDS-U). The objectives of the current study were to describe the natural history of MDS-U that is diagnosed based on routine BM and peripheral blood (PB) smear reports and compare its prognosis to refractory anemia (RA) or refractory cytopenia with multi-lineage dysplasia (RCMD), which were diagnosed in the same manner. Methods Mayo Clinic databases were reviewed to identify consecutive patients who meet current WHO criteria for MDS-U, RA and RCMD (Swerdlow et al. WHO classification of Tumors, Lyon 2008). No central review was required and diagnosis was based on routine Mayo Clinic pathology reports. Included in the current WHO-defined MDS-U are patients with findings of i) refractory cytopenia with unlineage dysplasia (RCUD) or RCMD with 1% blasts in the PB, 2) MDS with unilineage dysplasia and pancytopenia and 3) persistent cytopenia with ≤1% PB blasts, <5% BM blasts, <10% BM myeloid cell dysplasia and cytogenetic abnormalities considered presumptive evidence of MDS. Patients who had exposure to chemotherapy and/or radiotherapy were excluded. Results A total of 382 patients met WHO diagnostic criteria for MDS-U (n=146; 38%), RA (n=26; 7%), and RCMD (n=210; 55%). Presenting clinical characteristics for patients belonging to each one of these three categories are listed and compared in table 1. There was no difference between the three subgroups in age or gender distribution. Similarly, with the exception of thrombocytopenia that was more prevalent in RCMD, complete blood count and transfusion need at diagnosis were not significantly different between the groups. Risk distribution using conventional prognostic models for survival did not reveal significant differences between MDS-U, RCMD and RA. At the time of this analysis, 265 deaths and 25 leukemic transformations were documented. Overall and leukemia-free survival was similar between the three groups (Figure 1). IPSS and IPSS-R karyotypes (Figure 2&3), however delineate patients into distinct category (P=0.001 and P= 0.01) Conclusions Distinguishing between MDS-U, RCMD and RA, in daily practice, has limited clinical relevance. It might be simpler and more practical to consider MDS without excess blasts under one common morphologic category and utilize instead cytogenetic and molecular information for further prognostic stratification and identify patient subgroups with specific therapeutic needs. Myelodysplastic syndrome-unclassifiable (MDS-U) (n=146) compared with refractory anemia (RA) (n=26) and refractory cytopenia with multilineage dysplasia (RCMD) (n=210) Disclosures: No relevant conflicts of interest to declare.

Abstract Background It is widely recognized that advanced age and prior thrombosis predict recurrent thrombosis in essential thrombocythemia (ET) and are used to risk-stratify patients. However, the paucity of large sample size and long-term follow-up has limited the development of similar prognostic models for survival and leukemic transformation (LT). Methods Data was abstracted from the medical records of a consecutive cohort of patients with WHO-defined ET seen at the Mayo Clinic. Cox proportional hazards was used to determine the impact of clinical and laboratory variables on survival and LT. Overall survival and leukemia-free survival was estimated by Kaplan-Meier plots. Results i. Patient characteristics and outcome The study cohort included 605 patients of which 399 (66%) were females (median age, 57 years; range 5–91). Median follow-up was 84 months (range; 0–424). During this period, 155 patients (26%) have died and LT was documented in 20 patients (3.3%) occurring at a median of 138 months (range; 23–422) from ET diagnosis. ii. Prognostic variables for overall survival Univariate analysis of parameters at diagnosis identified age ≥ 60 years, hemoglobin less than normal (defined as < 12 g/dL in females and < 13.5 g/dL in males), leukocyte count ≥ 15 x 109/L, tobacco use, diabetes mellitus, thrombosis, male sex, and the absence of microvascular symptoms as independent predictors of inferior survival. All of the above except the last two (i.e. male sex and the absence of microvascular symptoms) sustained their prognostic significance on multivariate analysis. Based on the first three prognostic variables: age, hemoglobin level, and leukocyte count, we constructed a prognostic model for survival: low-risk (none of the risk factors), intermediate-risk (1of 3 risk factors), and high-risk (≥ 2 risk factors). The respective median survivals were 278, 200, and 111 months (p<0.0001; Figure 1) iii. Prognostic variables for leukemic transformation On univariate analysis of parameters at ET diagnosis, LT was significantly associated with platelet count ≥ 1000 x 109/L, hemoglobin less than normal, and exposure to P-32. However, on multivariate analysis, only hemoglobin less than normal and platelet count ≥ 1000 x 109/L maintained independent prognostic value. Accordingly, we utilized these two variables, to construct a prognostic model for LT: low-risk (none of the risk factors), intermediate-risk (1 risk factor), and high-risk (both risk factors). Only 1 of the 239 patients (0.4%) in the low-risk group vs. 14 of the 289 (4.8%) in the intermediate-risk and 5 of the 77 (6.5%) in the high-risk group underwent LT (p=0.0009; Figure 2). Conclusion The current study provides clinician-friendly prognostic models for both survival and LT in ET. Figure 1 Figure 1. Figure 2 Figure 2.

Abstract Background : Celiac disease (gluten sensitive enteropathy) is a systemic disease with hematological manifestations including; iron deficiency anemia, vitamin B12 and folate deficiency, leukopenia/neutropenia, hyposplenism, venous thromboembolism, and the enteropathy associated T cell lymphoma (E-TCL). Leukopenia/neutropenia is rare, and can result from folate or copper deficiency, but in many cases remains idiopathic. The consequences of neutropenia and neutrophil responses to a gluten free diet are not well described. We carried out this study to assess the incidence and outcomes of neutropenia in patients with celiac disease. Methods : The Mayo clinic celiac disease database (n=1729) was retrospectively analyzed for all patients with a confirmed diagnosis of celiac disease that had leukopenia (<3.5 x10(9)/L) and/or neutropenia (<1.5 x 10(9)/L). The diagnosis of celiac disease was established by positive tissue transglutaminase antibodies (TTG) and confirmatory small bowel biopsy findings. Additional causes of neutropenia such as copper and folate deficiency, drugs, benign ethnic and cyclic neutropenia, chemotherapy, hematological malignancies, combined variable immunodeficiency (CVID), and autoimmune diseases were meticulously excluded. Data abstracted included demographics, temporal association with diagnosis, nadir counts, associated hematological findings, relationship with infections, the use and effect of G-CSF, response to gluten free diet and survival outcomes. Results: 21(1.2%) of 1729 cases screened had idiopathic-celiac related neutropenia; 17 (81%) Caucasian, 15 (48%) females. In 12(57%) patients the neutropenia preceded or occurred near the time of the diagnosis of celiac disease, while in 7 (33.3%) it occurred subsequently. In 2 cases the temporal association could not be established. The median age at diagnosis of celiac disease was 46 years (10-67) and the median follow up for this group was 41.7 months (0-207.3). At last follow up 1 (4.8%) death has been documented; 0 from infectious complications, with no cases of E-TCL. The median laboratory values at diagnosis of celiac disease were available in 11 (52%) patients and included; hemoglobin 12.9 g/dL (10.5-16.8), MCV 91.5 fl (79.6-102.8), WBC 3.2 x109/L (2.3-5.2), ANC 1.29x109/L (0.33-3.24), ALC 1.34x109/L (0.75-2.17), AMC 0.39x109/L (0.15-0.71), and platelet counts 225x109/L (168-711). Anti-granulocyte antibodies were assessed in 7 patients and were negative in all cases. None of these patients had coexistent hyposplenism and three cases of neutropenia that occurred in the setting of celiac disease and CVID were excluded. In 15 (71%) patients the neutropenia was incidentally detected during routine laboratory work and in 4 (19%) it came to light secondary to infections. Ten (48%) patients had recurrent infections (≥1) as documented by their providers, including 7 with sinopulmonary infections, 1 with urinary tract infections, and 1 with skin and soft tissue infections. Additional immunological assessments were not available in these patients. Three (14%) patients had an ANC <500 (significant neutropenia); of which 2 had recurrent sinopulmonary infections. The third patient remained largely asymptomatic. Two of the 3 patients received G-CSF support during infections and responded adequately (ANC improvement > 1 x 10(9)/L). The ANC in patients in this cohort did not correlate with severity of infections. Five (23%) of 21 patients had improvement in neutrophil counts after adopting a gluten free diet, while there was no response in 10 and data was unavailable in 6. The median time to ANC response was 14.5 months (10-15.3) and the median increment in ANC was 0.67 x 10(9)/L (0.48-0.98). Conclusions: Celiac disease associated neutropenia, especially significant neutropenia (ANC <500) is a rare occurrence (~1%). It can often pre-date the diagnosis of celiac disease or occur subsequently. It is potentially associated with an increased incidence of infections, with-out good correlation with the severity of neutropenia. Less than half the patients do seem to respond to a gluten free diet. G-CSF responses seem to be adequate and G-CSF can be used in the setting of severe infections. Disclosures No relevant conflicts of interest to declare.