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Platelet activation is an important pre-thrombotic event. The elucidation of its pathophysiology could contribute to a reduction in the mortality associated with coronary artery disease-the foremost cause of death in the UK. We examined the platelets of 27 patients with angiographically documented coronary artery disease. All patients had stable angina and were taking their regular medication-including aspirin. We demonstrated significantly increased expression of GP53 and activated GPIIb/IIIa on the platelet surface using a sensitive flow cytometric method of detection. Comparison was made with a control group of 35 patients. Seventeen of the patients had coronary angioplasty carried out. Serial studies of these patients demonstrate an immediate and sustained increase in platelet activation and this has important implications for prevention of restenosis after angioplasty.

227 Background: Non-Hodgkin Lymphoma survival in Ireland has improved significantly over recent years. However, little survivorship research has been conducted in this country. The aim of this study is to assess the quality of life (QOL) in an Irish population of Non-Hodgkin Lymphoma (NHL) survivors. Methods: High–grade NHL survivors treated in 2 University Hospitals participated in this cross–sectional study by completing the validated Lymphoma specific Functional Assessment of Cancer Therapy (FACT–Lym) questionnaire and Symptom Index–18. Scales were measured using a score from 1 (not at all) to 4 (very much). Raw data was transformed to linear scores, with high scores indicating a higher level of functioning. Linear regression analysis was used to compare scores according to time since diagnosis. Results: Of 87 questionnaires, 47 were completed and returned by NHL survivors (54% response rate). QOL scores improved from time of diagnosis, with the exception of 4–5 years where scores decreased before again improving in the following years. After adjusting for age and sex, statistically significant differences were identified 5+ years after diagnosis in emotional, functional wellbeing and global FACT-Lym scores when compared to 1-2 years after diagnosis. Conclusions: QOL improves post diagnosis with a transient decrease at year 4-5 which may represent anxiety prior to being declared ‘cured’ or being discharged from follow–up. Our small, mostly private patient population reported higher QOL than larger government insured American groups (Smith et. al. Health status and quality of life among Non-Hodgkin lymphoma survivors. Cancer. 2009.). Patients reported on–going symptoms after treatment ended. These findings may help to develop a focused cancer survivorship programme in the future. [Table: see text]

SummaryThe stimulated release of von Willebrand factor (vWF) from endothelial cells by secretagogues such as thrombin is associated with the translocation of Weibel-Palade bodies to the cell membrane and the surface expression of P-selectin (also known as GMP 140, PADGEM and CD 62). P-selectin, which is stored in Weibel-Palade bodies, is a neutrophil and monocyte adhesion molecule important in the initiation of inflammation.We have developed a simple assay for the detection of P-selectin on endothelial cells using indirect immunofluorescence and flow cytometry and have confirmed that this is temporally related to vWF release. The assay has been used to demonstrate that IL-1 does not cause Weibel-Palade body degranulation but that trypsin does. This has implications for the use of passaged endothelial cells in the study of vWF release and the assay has numerous possible applications in study of mechanisms of stimulated vWF release.

Background and Objectives Variant Creutzfeldt-Jakob (vCJD) is a fatal transfusion transmissible prion infection. No test for vCJD in the donor population is currently available. Therefore, prion removal by filtration of red cell concentrate (RCC) is an attractive option for prevention. Materials and Methods Twenty patients were recruited with ethical permission, to receive clinically necessary transfusion containing one unit of pfRCC. Follow-up at 24 hours, 6 weeks and 6 months was undertaken. A second pfRCC was administered to 6 patients with similar follow up. pfRCC were prepared using the CE marked P-Capt device by the IBTS. Results In 20 transfused patients undergoing one exposure to a prion filtered unit, no attributable adverse events were noted. A subset of these (n = 6) underwent re-exposure to a further filtered unit without incident. Conclusions This phase 1/11 clinical study provides encouraging data on safety of prion filtration which can be used to plan more extensive studies on the use of filtered blood in adults and children.

1. We have studied the effects of age, sex and the oral contraceptive pill on platelet fibrinogen 'receptor' density (Bmax) and affinity (Kd). 2. [125I]-fibrinogen binding to gel-filtered platelets was assessed after stimulation with adenosine 5-diphosphate (ADP) and thrombin in 60 normal subjects; 37 females and 23 males. 3. For both agonists there was no significant difference in Bmax or Kd between the sexes. A trend towards increasing affinity (reduced Kd) with age was noted in the female group following ADP stimulation. This was not considered to be physiologically relevant. In the group as a whole no significant relationship of Bmax and Kd with age was demonstrated. 4. A further group of eight women taking low dose oestrogen combined oral contraceptive pill were studied on days 7, 14, 21 and 28 of the treatment cycle and compared with eight women with regular ovulatory cycles. No significant variations in Bmax or Kd were detected within or between cycles in these two groups.This study of the platelet membrane fibrinogen binding site, called glycoprotein IIb/IIIa, the final common pathway for platelet aggregation, measured receptor density (Bmax) and affinity (Kd) in men and women of all ages and in cycling women and in those using oral contraceptives. The subjects were 37 women aged 21-91, 23 men aged 20-83, women aged 21-33 using low-dose combined oral contraceptives containing 30-35 mcg estrogen and 150-500 mcg progestin, compared to 8 menstruating women aged 21-43. The assay measured Iodine-125-fibrinogen binding to gel-filtered platelets stimulated with ADP and thrombin. There were no significant differences between the sexes for Bmax or Kd. A trend towards increasing affinity (reduced Kd) with age was seen in women after ADP stimulation, which was within normal limits and judged not of clinical significance. There were also no significant differences in the comparison of cycling and pill using women on cycle days 7, 14, 21 and 28, between groups or phases. Thus glycoprotein II/IIIa, the final common mediator of platelet aggregation, is a stable entity with little variation with age, gender or altered hormonal status.

Aplastic anaemia is a rare complication of systemic lupus erythematosus (SLE). The mechanism is unclear but is thought to be related to an autoantibody to bone marrow precursors of haematopoiesis. We report a case of SLE related aplastic anaemia in which therapy with methylprednisolone and high dose cyclophosphamide followed by prednisolone and azathioprine resulted in complete clinical and haematological remission. Bone marrow cultures showed inhibition of erythropoiesis when incubated with acute and remission serum. Myeloid colony growth was not affected by either serum. The serum inhibitor we demonstrated was only active in vitro, and we postulate that the mechanism for marrow aplasia may have been an autoimmune cellular process.

SummaryRecent reports have suggested a variation in the density and affinity of fibrinogen binding sites in platelets from patients with myeloproliferative disorders (MPD) which may reflect platelet functional abnormalities in these subjects. We have investigated the binding of 125I-fibrinogen (125I-Fb) to gel-filtered platelets from a large relatively homogeneous group of patients with MPD compared to normal age matched controls. Twenty-two of the patients investigated had polycythaemia vera and four essential thrombocythaemia.The maximal density and affinity (Kd) of 125I-Fb binding was assessed by saturation analysis in gel-filtered platelets (GFP) stimulated with either 10 εM ADP or 150 mU thrombin. In addition the functional significance of the binding sites was studied by evaluating the response of GFP from the two experimental groups by assessing the effects of increasing concentrations of added fibrinogen on the response to 10 εM ADP using standard light transmission aggregometry.In both groups the density of fibrinogen binding sites expressed in response to thrombin stimulation was significantly higher (approximately 2-3 fold) than that found in response to ADP. However, fewer binding sites were detected in the MPD group as compared with the control group in response to both ADP and thrombin. The Kd for 125I-Fb was similar for both agonists in normal controls and was significantly lower than that found in the MPD subjects.Although the 125I-Fb binding study results indicate a significant reduction in both the number and affinity of fibrinogen binding sites in patients with myeloproliferative disorders, the clinical and functional significance of these findings remain uncertain.

Warfarin, the standard oral anticoagulant drug used in Ireland, is a widely prescribed medication, particularly in the elderly. A HSE Mid-Western Area wide audit was undertaken over a 12-month period to examine the prevalence and indications for warfarin use and haemorrhagic complications associated with the drug. Every patient receiving warfarin therapy over a 13-week period was included (2564). The age standardised rate varied from 0.09% of 35-39 year olds to 6.1% of 80-84 year olds. Atrial fibrillation was the most common indication (54%) in patients attending the Mid-Western Regional Hospital anticoagulation clinic. The annual cumulative incidence of adverse haemorrhagic events in patients with a recorded INRor = 5.0 episode was 16.6%. The incidence of major and minor haemorrhagic events per INRor = 5.0 episode was 1.3% and 15.3% respectively. The most common sites of haemorrhage were genitourinary (39%) and gastrointestinal (27%). No fatal or intracranial haemorrhage relating to episodes of over-anticoagulation were reported during the audit period. The most frequent reason for over-anticoagulation was drug interaction (43%). In 74% of patients, the elevated INR was reversed by omitting or reducing warfarin dose. In 17% of cases, vitamin K was administered. Only 3% of incidents were treated with fresh frozen plasma or prothrombin complex concentrates.

e20597 Background: The incidence and cure rates of aggressive NHL are increasing in Ireland. No data is available on QoL in the lymphoma survivor population who are exposed to multiagent chemothera...

It has been suggested that consultants should consider writing directly to patients with a summary of their outpatient consultation. In a controlled trial involving consecutive new referrals to a haematology outpatient clinic, we randomised patients to receive either a personal letter from their consultant summarising their consultation (n = 77) or a brief note thanking them for attending the clinic (n = 73). Patients were assessed for recall of and satisfaction with the consultation by a single independent observer, using standardised methods. At the second visit to outpatients, the patients' median percentage recall of items discussed during the consultation was 67% (IQ range 50–80%) in the intervention group, versus 57% (IQ range 43–76%) in the control group (p = 0.3). Strongly positive views on the personal letter were expressed by patients and referring clinicians. The findings suggest that although personal letters do not substantially improve recall of the clinical encounter, they are feasible, highly valued by patients and acceptable to referring clinicians.

Introduction Acute promyelocytic leukemia (APL) is characterized by gene fusions involving RARα, which disrupt retinoid signaling and lead to the clonal expansion of myeloid precursors halted at the promyelocyte stage of maturation. Treatment with all-trans-retinoic acid (ATRA) can overcome this differentiation block, restore granulocytic differentiation in APL cells and improve APL patient outcome. ATRA treatment of APL cells induces autophagy, a catabolic process whereby redundant proteins and organelles are degraded using lysosomal machinery. ATRA-induced autophagy is important for successful granulocytic differentiation of APL cells through the degradation of fusion oncoproteins and executing the structural protein remodeling necessary for cellular differentiation. The molecular mechanisms linking retinoid signaling and autophagy pathways are poorly understood and are the focus of our study. By integrating available chromatin immunoprecipitation, coupled with next-generation sequencing (ChIPseq) datasets and transcriptomic approaches, we examined the transcriptional effects of ATRA treatment on autophagy-related genes during APL cell differentiation. We identified transcription factor EB (TFEB), a master transcriptional regulator of autophagy, as a retinoid target and have evaluated the consequences of TFEB knockdown on both ATRA-induced autophagy and APL cell differentiation. Methods & Results A list of 557 autophagy-related genes was generated from 3 public autophagy databases. Cluster analysis of expression of these 557 genes in the APL TCGA RNAseq dataset, suggest autophagy is associated with patient survival (Cluster 1 = 26.4 months / Cluster 2 = 60 months). We therefore examined whether the 557 autophagy related genes may be direct ATRA targets. Accessing a public ChipSeq database (GSE18886), increased RARα binding was detected within the TFEB gene in NB4 cells (APL cell line, t15:17) treated with ATRA for 24 hours. Increased RNAPolII binding and transcriptionally active histone markers were also detected, consistent with a direct transcriptionally activating retinoid effect. To test the effects of retinoid therapy on APL gene expression, we treated NB4 cells with ATRA or ethanol control for 72 hours. Isolated RNAs were sequenced using the Illumina HiSeq 2000 platform. Reads were aligned and annotated to the hg19 genome using Tophat and subsequent differential expression analysis performed using Cufflinks/Cuffdiff and Cluster/Treeview. We observed changes in autophagy gene expression upon ATRA treatment and recorded a significant >2 fold increase in expression in >50 autophagy-related genes including TFEB, p62 and DRAM1. We then carried out lentivirally-mediated shRNA knockdown of TFEB in NB4 cells and treated both knockdown and scrambled control cells with ATRA for 72 hours. Transcriptomic analysis demonstrated that TFEB knockdown blocked ATRA-induced TFEB induction, affected the regulation of key autophagy-related genes and impaired CD11b expression. These results were validated by qRT-PCR (n=6)(P We confirmed TFEB upregulation by qRT-PCR in primary human APL samples treated with ATRA ex vivo (n=1) and in primary peripheral blood mononuclear cells isolated from tumour patients treated with ATRA as part of clinical trial NCT00195156 (n=3). We also found that TFEB was only minimally induced by ATRA in the differentiation-resistant NB4R cell line (qRT-PCR n=6), suggesting an important role for TFEB in ATRA-induced APL differentiation. We evaluated the ability of two clinically used differentiating agents - valproic acid (VPA) and arsenic trioxide (ATO), alone and in combination with ATRA, to induce TFEB expression in NB4 cells. While VPA alone induced TFEB (5 fold), combined therapy with ATRA and VPA resulted in a >20 fold induction of TFEB expression, which correlated with enhanced differentiation (n=6)(P Conclusion Retinoid signaling promotes APL differentiation in part through transcriptionally activating autophagy. Novel or existing therapies, which enhance autophagy signaling, may promote retinoid-induced differentiation and circumvent resistance to retinoid therapy in acute myeloid leukemia. Disclosures Orfali: MSD: Unrestricted educational support Other; Amgen: Unrestricted educational support, Unrestricted educational support Other; BMS: Unrestricted educational support, Unrestricted educational support Other; Pfizer: Unrestricted educational support, Unrestricted educational support Other; Novartis: Unrestricted educational support Other.

The appropriate and timely administration of Anti-D immunoglobulin to Rhesus (D) negative women who have delivered Rhesus (D) positive babies is a vital part of obstetric care. Anti-D has an especially high profile in Ireland because of the tragic inadvertent transmission of Hepatitis C to Irish women in past decades.We have reviewed our policy and procedures pertaining to the administration of Anti-D for sensitising events during pregnancy and postnatally, in the Mid-Western Health Board in 1999/2000. As a result, major changes were made in the storage, issue, recording and administration of Anti-D. New procedures in the transfusion laboratory and in the maternity hospital have been accepted by scientists and midwives and supported by haematology and obstetric medical staff. The pharmacy and haematology laboratory no longer have a role in this programme. IMPLEMENTATION OF MULTI-DISCIPLINARY CHANGE MANAGEMENT: As a result of these changes, the storage, issuing and tracking of Anti-D has become the responsibility of the hospital blood bank. Measurement offoeto-maternal haemorrhage (FMH) is now the responsibility of bio medical scientists in blood bank, utilising both flow cytometry (increasingly recognised as the gold standard method) and the Kleihauer method (Kleihauer-Betke). The programme has moved from a doctor-administered IV Anti-D Ig, to a midwife-administered IM preparation. Prescription remains the responsibility of the doctor. These changes are facilitated by the protocol guided issue of the appropriate dose of Anti-D Ig by bio medical scientists to midwives. The issue of the Anti-D Ig occurs simultaneously with issue of results of mother and baby's serology testing and estimation of volume of FMH. These major changes have been guided by audit and needs assessment and require close liaison between medical, nursing and laboratory scientific staff in haematology, transfusion and obstetrics. CRITICAL INCIDENT AUDIT-CASE REPORT: Before new procedures became official policy, a critical incident audit allowed us to pilot our protocol and to revise it using draft new procedures. In this critical incident we describe successful management of a patient with a large foeto-maternal haemorrhage. This incident supported the need for the procedural enhancements already underway. This critical incident re-emphasised the need for the planned systems improvements to be introduced quickly.

High-dose treatment with autologous stem cell transplantation (ASCT) has become the standard of care for patients with myeloma below the age of 65 years.We report an audit of 60 patients (median age: 52.5 years) who underwent ASCT in the National Bone Marrow Transplant centre in St James's Hospital in Dublin between 1997 and 2003 inclusive.Clinical and laboratory data were retrieved from patient medical records and hospital information management systems.Thirty-six patients had IgG, 11 IgA, 1 IgD, 9 light chain and 3 non-secretory MM. Fifty-seven (95%) patients received anthracycline-corticosteroid combination chemotherapy prior to autografting. There was no transplant-related mortality (TRM). Complete (CR) and Partial Responses (PR) were seen in 16 (29.6%) and 29 (53.7%) of those evaluable (n = 54 (90%)). The actuarial Progression-Free (PFS) and Overall Survival (OS) rates at five years are 13% and 55% respectively.Centre outcome is comparable to published international series and supports the use of ASCT in the treatment of this malignancy.

Alemtuzumab (Campath 1H -MabCampath), initially used for prophylaxis of graft versus host disease in allogenic transplantaion, is now increasingly used for refractory chronic lymphatic leukaemia (CLL). Its efficacy has been well documented in this--the commonest form of leukaemia. Alemtuzumab is associated with severe immunosuppression, allergic reactions and thrombocytopenia. Data sheet and information supplied by the manufacturer confirm the rare occurrence of serious immune thrombocytopenia, recommending discontinuation of therapy when platelet counts fall below 50x10(9)/l. We report a patient with refractory CLL in which relentless progressive cytopenia occurred despite the discontinuation of alemtuzumab therapy while the platelet count was over 97x10(9)/l. Marrow biopsy showed increased megakaryocytes, the patient bleed uncontrollably and died of cerebral haemorrhage with a platelet count10x10(9)/l. Data on the predictive factors underlying this complication are few and deserve further study as this drug is increasingly used the treatment of CLL.

Platelet activation in vivo is important in the pathogenesis of thrombosis. Accurate measurement is difficult due to artefactual in vitro preparation related activation. This can be overcome by using whole blood techniques, such as flow cytometry. However, there is little consensus on methods of platelet preparation, procedures for use of fixation, or the optimal types/amounts of fixative. The use of unfixed platelets has received little attention. We describe a series of experiments comparing platelet activation antigen expression detected by flow cytometry in fixed and unfixed samples. Formaldehyde increased the expression of both CD62 and CD63. We recommend that fixation with formaldehyde should not be used when studying platelet activation.

C/EBPalpha (42 kDa) is commonly dysregulated in acute myeloid leukaemia (AML) by mutation or via the action of AML oncogenes, which can increase the 30 kDa protein oncogenic form of C/EBPalpha (p30). The Trib2 oncogene is associated with dysregulated C/EBPalpha in human AML and leads to the degradation of p42, leaving p30 intact. Indeed there exists a novel paradigm whereby an E2F1-p30-Trib2 positive regulatory loop and an E2F1-p42-Trib2 negative feedback loop plays a key role in Trib2 expression, essential for AML cell proliferation and survival. Thus, it is important to understand the Trib2-C/EBPalpha relationship in the context of p42 degradation and/or C/EBPalpha mutation in AML. Using mouse genetics our data reveals that in the absence of C/EBPalpha (-/-) Trib2 was unable to induce AML whereas in the presence of p42 and mutant p30 (L/+), Trib2 and p30 cooperate to decrease the latency of AML disease. In the situation where p30 is expressed in the absence of p42, which alone can lead to AML (L/L), Trib2 does not lead to a more aggressive disease than that caused by p30 itself. These data show that the modulation of p42 rather than the expression of p30 is a key driver in Trib2 AML. Peptide array analysis showed the site-specific direct interaction between Trib2 and p42, and mutational analysis showed that these site-specific interactions were required for the K48-specific ubiquitin-dependent proteasomal degradation of p42. A C-terminal lysine residue of C/EBPalpha commonly found duplicated in AML patients was critical for Trib2-mediated p42 ubiquitination and proteasomal degradation. Proteasome inhibition using bortezomib induced cell death in Trib2 positive AML cell lines and AML patient samples in vitro and in vivo. Knockdown and overexpression of Trib2 in AML cells followed by transplantation in NSG mice and treated with bortezomib selectively killed Trib2 positive AML. Our data show the mechanism required for oncogene function centres on p42 degradation.

e17627 Background: High-grade non-Hodgkin lymphoma is an aggressive malignancy that requires urgent, intensive management. It is estimated that 60% of patients are cured (Cancer Research UK) so rap...

Introduction The metabolic syndrome (MS) as a disease entity rarely captures the attention of a clinical haematologist. The prevalence of the MS in the Irish population is estimated at 20% (Villegas et al. Prevalence and lifestyle determinants of the metabolic syndrome. Ir Med J. 2004; 97(10): 300-303). While insulin resistance is implicated, the pathogenesis uniting the components of the syndrome remains unclear. In an additional study from our group (O’Reilly et al. Submitted ASH 2013), we demonstrated an independent association between the MS and clinically significant macrocytosis (mean corpuscular volume≥99fl). In this study we estimated the population attributable fraction for macrocytosis associated with the MS at 13.8%. To our knowledge this link has not been reported previously in the literature. Aims To study the determinants of clinically significant macrocytosis with particular reference to the independent effects of the MS and its individual components in a cohort of 2,047 Irish patients aged 50-69 years sampled from a primary care centre (Mitchelstown Cohort). Methods Details of the methods of the Mitchelstown Cohort study including sampling and recruitment have been described (Kearney et al. Int. J. Epidemiol. (2012) doi: 10.1093/ije/dys131). The study is based in a large primary care centre serving a defined population in Southern Ireland. 66% of eligible patients participated in this study. The metabolic syndrome was defined using the International Diabetes Federation (IDF) 2006 criteria. Systolic and diastolic blood pressures (average of 3 readings), body mass index (BMI) and waist circumferences were measured. A pre-existing diagnosis of hypertension or type II diabetes and use of anti-hypertensive or lipid-lowering agents was recorded. Smoking status and alcohol intake were recorded using a validated questionnaire. Vitamin B12 and folate levels, fasting plasma glucose (FPG), HbA1c and lipid profiles, liver function and full blood counts were measured using standard automated analysers. Statistical analysis was performed using Stata©. Multivariate logistic regression was used to estimate prevalence odds ratios with 95% Confidence Intervals (OR, 95%CI) for macrocytosis and its potential determinants, including the MS and its constituent components. Results The prevalence of clinically significant macrocytosis (MCV≥99fl) in this sample of 2,047 patients was 1.6%. The prevalence of the MS was 31%, B12 deficiency 2.4%, folate deficiency, 1.5%, elevated gamma-glutamyltransferase (GGT), 18%, elevated alanine aminotransferase (ALT), 8%, elevated aspartate aminotransferase (AST), 4.7% and current smoking status, 15%. With respect to the IDF criteria, in univariate analyses, hypertension and elevated triglycerides (TG) were significantly associated with an MCV≥99fl (p=0.04, p=0.03 respectively). Central obesity, BMI, elevated FPG and low HDL did not reach significance. Self-reported alcohol intake was also non-significant. In multivariate logistic regression analysis with adjustment for age and gender the following variables were significantly associated with MCV ≥99fl; elevated TG OR 2.3 (95%CI 1.1-4.7), MS OR 3.4 (95% CI 1.6-6.9), vitamin B12 deficiency OR 6.1 (95% CI: 2.0-18.4), folate deficiency OR 8.2 (95% CI 2.3-29.0), elevated GGT OR 2.3 (95% CI 1.0-4.9), elevated AST OR 8.0 (95% CI 3.5-18.5) and current smoking status OR 6.0 (95% CI 2.8-12.5). In further analyses adjusting for age, gender and all other significant variables, the association between the MS and macrocytosis persisted, OR 3.0 (95%CI 1.3-6.9). Isolated elevated TG was no longer significant. The association between macrocytosis and elevated GGT was attenuated following adjustment for the MS. Conclusions In this study we observed an independent association between macrocytosis and the MS. Non-alcoholic fatty liver disease (NAFLD), with a clinical spectrum ranging from steatosis to steatohepatitis and cirrhosis, is strongly linked to the MS. However we have demonstrated an association independent of abnormal liver indices. As the obesity epidemic escalates worldwide, haematologists should consider its potential impact on red cell mean corpuscular volume. Additional research is needed to determine the effects of this cluster of metabolic disturbances on erythropoiesis. Disclosures: No relevant conflicts of interest to declare.

Introduction High-grade non-Hodgkin lymphoma is an aggressive condition that requires equally aggressive management. Due to the possibility of curative treatment if the disease is effectively managed, rapid diagnosis, precise staging, and swift commencement of treatment are crucial. In Ireland there is little reliable data on how closely guidelines in non-Hodgkin lymphoma treatment are followed. In order to obtain better data, we replicated a recent study carried out in the Netherlands by Wennekes and colleagues (J Clin Oncol 2011 April 10;29(11): 1436-1444). Methods This study was carried out in two hospitals in Cork, Ireland. Ethical approval was obtained from the Cork Research Ethics Committee. We used the National Cancer Registry of Ireland and records of the Citywide Lymphoma Conference to identify high-grade non-Hodgkin lymphoma patients treated at the participating centers. 125 patient records were identified. This was similar to the sample size used by Wennekes. The quality markers used in the Dutch study were chosen as data points. This set was then slightly modified to account for local guideline differences. Data was obtained through a systematic, retrospective chart review. Results When analyzing the data, 90% adherence was set as a target. This was in keeping with previous research. Of our 22 quality markers, 11 reached the target level. Diagnosis and staging markers were generally well adhered to. 93% of non-CNS lymphoma patients received an RCHOP or DA-EPOCH-R regimen, 92.8% of patients were diagnosed with an appropriate biopsy, and 92% received a histological diagnosis before treatment was commenced. Scores regarding treatment were close to the target level. 83.5% of patients began chemotherapy within four weeks of diagnosis, and 74.1% of patients received a histological diagnosis within three weeks of presentation. Lower adherence was noted in areas relating to the communication of results. Use of the Cheson criteria to report radiological response was very limited. 12.8% of PET reports and 5% of CT reports used the Cheson criteria. In addition, the patient’s Ann Arbor staging was rarely included on CT and PET reports – 0% and 2.4% respectively. Conclusion This is the first replication of the Dutch study on non-Hodgkin lymphoma management. Irish hospitals are meeting non-Hodgkin lymphoma management guidelines in 11 of 22 areas. Adherence for the remaining areas ranges from 83.5% to 0%. Further studies in different Irish centers will provide important data to increase the external validity of this study. Disclosures: No relevant conflicts of interest to declare.

Introduction The American Cancer Society anticipates the diagnosis of 80,000 new cases of lymphoma in the US in 2013. Cancer Research UK estimates that more than 80% of Hodgkin Lymphoma (HL) patients and more than 60% of Non-Hodgkin Lymphoma (NHL) patients will be alive 5 or more years after diagnosis. As survival rates improve, focus shifts to ensuring quality of life in survivors and decreasing potential toxicity. Radiological procedures play a prominent role in diagnosis, staging and assessment of treatment response. Exposure to ionizing radiation has been linked to an increased risk of malignancy (Pearce et al 2012, Miglioretti et al 2013, Mathews et al 2013). Cumulative exposure in excess of 75mSv has been estimated to increase cancer mortality by 7.3% (Cardis et al 2007). There is a paucity of data in the literature regarding cumulative radiation exposure in patients with lymphoma. In cancer treatment, the aim is individualized management strategies. This should also be the goal for diagnostic procedures (O' Neill et al 2011, Fletcher et al 2012). Methods A retrospective review of all patients on a prospectively maintained database with biopsy proven HL or NHL between January 2009 and July 2012 was conducted in a University hospital group. The cumulative effective radiation dose (CED) was calculated using standardized procedure-specific radiation dose levels. Results Four hundred and eighty six patients were included in the study. Mean (SD) age at diagnosis was 59 (17) years and 15% were aged < 40. Fifty-nine percent were men. Sixteen percent had HL; 84% had NHL. There were a total of 1127 patient-years of follow-up, with 15% having Ninety-nine per cent of patients had diagnostic imaging. A total of 5748 radiological procedures were performed, equivalent to one procedure every 70 patient days of follow-up. The median estimated total CED ( IQR) per subject was 69mSv (42-118). Forty- six percent had a total CED >75mSv and 14% had a total CED >150mSv – SeeFigure 1. CT contributed 89% of the radiation dose and PET-CT contributed 8%. Patients aged Univariate analysis showed that age (p Discussion This study highlights the considerable ionizing radiation exposure from diagnostic imaging in patients with lymphoma. This is especially relevant in young people who would be considered the most radiosensitive and at highest risk for secondary malignancies. Low grade lymphomas are relapsing and remitting in nature and frequently require re-staging imaging over many years. Longer follow-up will be required here to potentially explain the non-significant trend between histological subtype and different CED. The American College of Radiology stated in 2013 that when used appropriately, the benefits of ionizing radiation far outweigh the risks. However, to minimize risk, institutions should participate in national dose registries. With the widespread use of Picture Archiving and Communication System (PACS), this will be feasible. Low dose CT imaging has emerged as a mechanism for minimizing CED. Dose reduction strategies incorporating patient-specific information would optimize imaging while minimizing the harmful effects (Shah et al 2012). Novel CT reconstruction algorithms allow diagnostic quality imaging to be obtained at reduced radiation doses without the prohibitive noise that would otherwise be present (Prakash et al 2010). Procedures which do not involve ionizing radiation such as MRI and ultrasound are becoming increasingly popular. There is growing interest in PET-MRI for staging of malignancies (Appenzeller 2013) but as yet, PET-CT remains superior. For patients with potentially curable lymphoma, particularly young patients with higher CED, consideration should be given to these strategies. Disclosures: No relevant conflicts of interest to declare.

Introduction The prevalence of macrocytosis in adults is estimated between 1.7% and 8% (Aslinia F et al. Megaloblastic anemia and other causes of macrocytosis. Clin Med Res. 2006; 4: 236-241, McNamee et al. Haematinic deficiency and macrocytosis in middle aged and older adults. 2013 Submitted PLOS ONE). Its diagnosis, depending on the clinical context, may warrant an extensive work-up for a vitamin deficiency or haematological malignancy. Known associations with raised mean corpuscular volume (MCV) include haematinic deficiency, heavy alcohol intake, liver disease, myelodysplasia and myeloma. While it has been suggested that smoking may be a cause of macrocytosis, this hypothesis has not been carefully evaluated. In an earlier study from our group (McNamee et al 2013 PLOS ONE Paper) we observed an independent link between smoking and macrocytosis in a representative sample of Irish adults. In this study we estimated the population attributable fraction for macrocytosis associated with smoking at 24.6%. The degree to which smoking contributes to clinically significant macrocytosis (MCV 99fl) has not been extensively reported in the literature. Aims To study the determinants of clinically significant macrocytosis with particular reference to the independent effects of cigarette smoking in a cohort of 2,047 Irish patients aged 50-69 years sampled from a primary care centre (Mitchelstown Cohort). Methods Details of the methods of the Mitchelstown Cohort study including sampling and recruitment have been described (Kearney et al. Int. J. Epidemiol. (2012) doi: 10.1093/ije/dys131). The study is based in a large primary care centre serving a defined population in Southern Ireland. 66% of eligible patients participated in this study. Vitamin B12 and folate levels, liver function and full blood counts were measured using standard automated analysers. Smoking status and alcohol intake were recorded using a validated questionnaire and the metabolic syndrome was defined using the International Diabetes Federation 2006 criteria. Statistical analysis was performed using Stata©. Multivariate logistic regression was used to estimate prevalence odds ratios with 95% Confidence Intervals (OR, 95%CI) for macrocytosis and its potential determinants, including smoking. Population attributable fractions were estimated using a standard formula for variables that were significantly associated with macrocytosis in multivariate analyses. Results The prevalence of clinically significant macrocytosis (MCV≥99fl) in this sample of 2,047 patients was 1.6%. The prevalence of B12 deficiency was 2.4%, folate deficiency, 1.5%, elevated gamma-glutamyltransferase (GGT), 18%, elevated alanine aminotransferase (ALT), 8%, elevated aspartate aminotransferase (AST), 4.7%, current smoking, 15% and the metabolic syndrome, 31%. In multivariate logistic regression analysis with adjustment for age and gender the following variables were significantly associated with MCV ≥99fl; vitamin B12 deficiency OR 6.1 (95% CI: 2.0-18.4), folate deficiency OR 8.2 (95% CI 2.3-29.0), elevated GGT OR 2.3 (95% CI 1.0-4.9), elevated AST OR 8.0 (95% CI 3.5-18.6), current smoking status OR 6.0 (95% CI 2.8-12.5) and the metabolic syndrome OR 3.4 (95% CI 1.6-6.9). In further analyses adjusted for age, gender and all of the other relevant, significant variables, the association between smoking and macrocytosis was essentially unchanged, OR 5.7 (95%CI 2.6-12.7). By contrast the association with elevated GGT was attenuated following adjustment for the metabolic syndrome. The population attributable fraction for smoking was 38.4% followed by elevated AST, 22.9%, the metabolic syndrome, 13.8%, vitamin B12, 11.7% and folate deficiency, 7.0%. Conclusion Our findings suggest that smoking is an important cause of macrocytosis. Potential mechanisms include the direct toxic effect on erythrocytes of acetaldehyde in tobacco smoke and the response to reduced oxygen-carrying capacity. Macrocytosis frequently prompts a referral to a haematologist. Given the relatively low prevalence of vitamin B12 and folate deficiency in the community setting, considerable thought should be given to the impact of lifestyle factors on mean corpuscular volume. Patients with isolated macrocytosis should potentially be advised regarding smoking cessation. Further studies are required to delineate the effects of smoking on erythropoiesis. Disclosures: No relevant conflicts of interest to declare.

The pseudokinase TRIB2 is a potent acute myeloid leukaemia (AML) oncogene, capable of inducing transplantable AML with a relatively short latency in murine models. Functionally, the oncogencity of TRIB2 has been linked to its degradation of CCAAT/enhancer binding-protein-alpha (C/EBPα), a transcription factor necessary for regulation of haematopoietic stem cells (HSC) and myeloid differentiation and is mutated in ∼10-15% of cytogenetically normal AMLs. Previously, we have demonstrated that elevated TRIB2 mRNA expression is associated with a small subset of C/EBPα dysregulated AML patients. However in our analysis of primary AML patient samples we reveal detectably high TRIB2 protein expression in a greater number of samples than predicted from mRNA studies compared to normal peripheral blood mononuclear cells. Here, using in vivo ubiquitination assays we determined that TRIB2 exerts its effect through K48 specific ubiquitin-dependent proteasomal degradation of C/EBPα. Peptide array analysis identified the specific amino acids involved in the direct binding of these two proteins. Site-directed mutagenesis of these amino acids demonstrated that the direct binding of TRIB2 and C/EBPα was required for TRIB2-mediated C/EBPα degradation. In order to determine if posttranslational modification of C/EBPα was a trigger for TRIB2-mediated binding and degradation, we assessed the phosphorylation of C/EBPα, often a modification involved in target substrate ubiquitination. We found that TRIB2 decreased the levels of phosphorylated Serine 21 (S21) C/EBPα through preferential binding to the phosphorylated form of S21 C/EBPα and mediating its K48 specific ubiquitin-dependent proteasomal degradation. While TRIB2 retains the canonical amino acid motifs of a kinase and the ability to bind ATP, indicative of kinase activity, the absence of phosphorylated S21 C/EBPα in the presence of TRIB2 suggests that it does not have sufficient kinase activity to enable efficient phosphotransfer. The presence of TRIB2 further blocked the ability of mitogenic stimuli to phosphorylate S21 of C/EBPα. TRIB2 thus acts to perturb the regulation and function of C/EBPα phosphorylation ultimately leading to its degradation. We propose this contributes to the leukaemic phenotype of AML cells which include increased self-renewal and proliferation. Using clinically available inhibitors of the proteasomal degradation pathway we have investigated the targeted inhibition of the TRIB2 degradation function to induce cell death in AML cells. In TRIB2 overexpressing AML cell lines, and in AML patient samples identified to have elevated levels of TRIB2, we have demonstrated that elevated TRIB2 expressing samples are more sensitive than low TRIB2 expressing samples to cell death induced by proteasomal inhibition. Our data shows that in the presence of TRIB2 phosphorylated S21 C/EBPα is a trigger for its ubiquitin dependent degradation. We propose TRIB2 mediates is leukaemogenic effects in AML through direct protein-protein interaction, perturbation of phosphorylation signalling, resulting ultimately in proteasomal mediated degradation of its target C/EBPα. As C/EBPα plays a key role in both stem cell function and myeloid differentiation in AML, the targeted inhibition of TRIB2-mediated C/EBPα degradation may provide therapeutic avenues in AML. Disclosures: No relevant conflicts of interest to declare.

OBJECTIVE: To assess the prevalence and determinants of haematinic deficiency (lack of B12 folate or iron) and macrocytosis in blood from a national population-based study of middle-aged and older adults. METHODS: A cross-sectional study involving 1,207 adults aged ≥45 years, recruited from a sub-study of the Irish National Survey of Lifestyle Attitudes and Nutrition (SLÁN 2007). Participants completed a health and lifestyle questionnaire and a standard food frequency questionnaire. Non-fasting blood samples were obtained for measurement of full blood count and expert morphological assessment, serum ferritin, soluble transferrin receptor assay (sTfR), B12, folate and coeliac antibodies. Blood samples were also assayed for thyroid function (T4, TSH), liver function, aminotransferase (AST) and gamma-glutamyl transferase (GGT). RESULTS: The overall prevalence (95% C.I.) of anaemia (Hb 21 nmol/ml) only 2.3% were iron-deficient. 3.0% and 2.7% were found to have low levels of serum folate (99fl) was detected in 8.4% of subjects. Strong, significant and independent associations with macrocytosis were observed for lower social status, current smoking status, moderate to heavy alcohol intake, elevated GGT levels, deficiency of folate and vitamin B12, hypothyroidism and coeliac disease. The population attributable fraction (PAF) for macrocytosis associated with elevated GGT (25.0%) and smoking (24.6%) was higher than for excess alcohol intake (6.3%), folate deficiency (10.5%) or vitamin B12 (3.4%). CONCLUSIONS: Haematinic deficiency and macrocytosis are common in middle-aged/older adults in Ireland. Macrocytosis is more likely to be attributable to an elevated GGT and smoking than vitamin B12 or folate deficiency.

Platelet transfusions are undoubtedly effective in securing hemostasis in bleeding children with absent or nonfunctioning platelets. They are, however, abused in some circumstances and are not without risk. The use of platelet transfusions to prevent rather than to treat bleeding in children with malignant disease has increased several times over the last two decades. When joining in this widespread practice, physicians should be aware that there is a relatively unimpressive evidence base supporting it and also that for patients with uncomplicated myelo-suppression the most persuasive studies suggest that a threshold platelet count of 10 x 10(9)/L is no less effective than the more customary 20 x 10(9)/L is. Still lower thresholds await evaluation. For children with nonmalignant conditions the use of platelet transfusions should be carefully evaluated on a case-by-case basis, but they should normally be avoided in the absence of clinically important bleeding. Neonates with thrombocytopenia, particularly those with immune disease due to a maternal alloantibody, are considered an exception to this generalization. The serious hazards of platelet transfusions include alloimmunization and the induction of refractoriness, graft-versus-host (GVH) disease, and the transmission of infection, all of which can be life threatening. Less risky alternative therapeutic approaches may become more widely available in the future, including recombinant thrombopoietin and lyophilized heat-treated platelet membrane preparations.

Cellular adhesion molecules (CAMs) are critical components in the processes of embryogenesis, tissue repair and organization, lymphocyte function, lymphocyte homing and tumor metastasis, as well as being central to the interactions between hemopoietic progenitors and bone marrow microenvironment, and between leukocytes and platelets with vascular endothelium. Expression of CAMs regulates normal hemopoiesis and migration and function of mature hemopoietic cells. CAMs are an important part of the inflammatory response and may regulate cytokine synthesis. In addition, CAM expression may be critical for tumorigenesis. Monoclonal antibodies to CAMs have been developed for clinical use; initial results suggest that these agents have great potential in the prevention and treatment of inflammation, thrombosis, reperfusion injury, and graft rejection.

Deregulation of the transcription factor E2F1 occurs in AML, and it has been shown to induce both cell cycle progression and apoptosis. In normal granulopoiesis, proliferation arrest and differentiation mediated by C/EBPalpha involves repression of E2F1 target genes. Elevated Trib2 expression has been linked with a subset of human AML and dysregulated C/EBPalpha. Using promoter assays, mutational analyses and chromatin immunoprecipitation experiments, we show that E2F1 (and E2F2, E2F3, but not E2F4 or E2F5) are bound directly to the DNA on site-specific regions on the Trib2 promoter in leukaemic cells. Trib2 expression is decreased following siRNA-mediated knockdown of E2F1, and in E2F1 knockout cells as compared to wild type cells. The reintroduction of E2F1 rescued Trib2 expression showing that E2F1 is regulating the expression of endogenous Trib2. Further analyses revealed that this activation of Trib2 by E2F1 is repressed by wild type C/EBPalpha consistent with C/EBPalpha having a negative regulatory role on E2F1, and in normal GMP cells we detect C/EBPalpha bound to the Trib2 promoter. Conversely there was synergistic activation upon coexpression of the oncogenic C/EBPalpha truncated mutant, and Trib2 expression levels were elevated in GMPs from preleukaemic mutant C/EBPalpha mice compared to wild type GMPs. Indeed a positive correlation between Trib2 and E2F1 expression in AML datasets support these findings. Finally, inhibition of the cell cycle pathway in leukaemia cells expressing high endogenous levels of Trib2 protein resulted in G1 arrest with a reduction in E2F1 levels and Trib2 protein levels. Our work indicates that the cell cycle regulator E2F1 plays a key role in the control of Trib2 expression important for the control of cell proliferation and may have important implications for normal and malignant haematopoiesis.

Platelet degranulation occurs when platelets are activated. Alpha degranulation releases P-selectin whereas lysosomal degranulation releases GP53. A correlation between these two markers might therefore be expected. We studied the correlation between P-selectin and GP53 in 50 patients with myeloproliferative disorders (MPD), 35 normal controls and 105 disease controls (patients with inflammatory bowel disease [IBD, n = 52], rheumatoid arthritis [RA, n = 26] and coronary artery disease [CAD, n = 27]) by flow cytometry before and after stimulation with thrombin ex vivo. There was no significant correlation between percentage expression of P-selectin and GP53 in unstimulated samples in normal individuals; r = 0.13, P = 0.3, n = 34. Mild thrombin stimulation (10 mU/ml) led to both alpha and lysosomal degranulation with a strong correlation (r = 0.62, P < 0.001, n = 35). Disease controls (IBD, RA and CAD) showed similar trends. In patients with MPD, in contrast, a strong correlation between the expression of these platelet activation markers was demonstrable in unstimulated samples (r = 0.37, P = 0.007, n = 50). P-selection and GP53 expression in stimulated samples also correlated well. The data support the existence of different control pathways for the steady state expression of P-selection and GP53. Heterogeneous steady state responses of P-selectin and GP53 may be physiological and loss of this heterogeneity may be a hitherto unreported and pathologically important feature of MPD. This lack of correlation appears to be specific to MPD and is not simply a function of increased in vivo platelet activation.

Abstract 1791 Six courses of FCR is considered standard therapy for fit, non-(17p) deleted patients with Chronic Lymphocytic Leukaemia (CLL), however the optimal dose of Rituximab in combined chemotherapy for CLL or the number of FCR courses required has never been formally assessed. Minimal residual disease (MRD) eradication (assessed by 6 colour flow-cytometry(FC) is associated with an increased disease free interval and is a logical endpoint in determining length/efficacy of treatment. Serial MRD testing following therapy provides an objective test of disease re-emergence. A multi-centre prospective phase II study in treatment-naïve CLL patients with modified FCR (Rituximab 375mg/m2) using MRD to determine treatment length/efficacy and identify disease emergence recruited from 2009–2012. Standard pre-treatment assessment plus C-T scan, FISH and Ig somatic hypermutation (SHM) analyses were performed. Patient in radiological and MRD-ve remission after 4 courses of FCR stopped therapy and the remainder received 6 courses. All were followed by 6 monthly MRD assessment. Fifty-two patients were included (35M/17F), mean age 52 years (range 37–72), mean WCC 51 × 109/L (range 8–386), elevated LDH 23 of 45 (51%), lymphadenopathy 43 (83%) and hepatosplenomegaly in 37 (71%). Abnormal FISH results were, del(11q) in 15, +12 in 5, del(13q) in 18; SHM 15(29%) mutated and 37(71%) unmutated or with V3–21 gene usage. Post-treatment MRD is available in 43 patients; 36 (70%) were MRD –ve including 18 (42%) after 4 courses. Nine patients did not complete treatment (toxicity −7, progression-1, non-compliance-1). With a mean follow-up of 20.7 months (range 4.5–38), 6 patients have reverted to MRD +ve at a mean of 13 months (range 10–19) from therapy; only the patient with primary treatment failure has required further chemotherapy. Myelotoxoicty resulted in 23 NCI grade 3 episodes and 7 treatment delays of a mean duration of 25 days (range15–32). One further grade 3 toxicity of pneumonia was identified. Modified FCR was effective in this patient cohort with high risk features (38% unfavourable FISH, 71% unfavourable SHM), with 70% patients achieving MRD-ve status on completion of therapy. 42% of patients became MRD-ve after 4 courses of FCR, suggesting that some patients may not require 6 courses of therapy. Myelotoxicity remains an issue with 7 patients not completing therapy. Longer follow-up will clarify whether shortened therapy will have an impact on MRD+ve reversion, time to re-treatment and survival. Disclosures: No relevant conflicts of interest to declare.

Abstract 3171 Autoimmune haemolytic anaemia (AIHA) is characterised by severe haemolysis due to development of auto antibodies directed against patient's own red cells. Rituximab is a chimeric monoclonal antibody that specifically depletes B cells by targeting CD20 on both immature and mature B lymphocytes We evaluated the use of Rituximab in patients with AIHA who are refractory to conventional Immunosupression in 5 centres in ireland. Methods: 24 cases of AIHA from five centres in the Republic of Ireland were identified who were treated with Rituximab at the standard dose of 375mg/m2 weekly for four weeks. All patients had received prior therapy with steroids and 50% of patients received two or more courses of Immunosupression. One patient had splenectomy prior to Rituximab. Five patients had an underlying lymphoproliferative disorder and two had a myeloproliferative neoplasm. Response was assessed at 1,3,6,12,36, 48 and 60 months. Medium duration of follow up was 34 months. Response was defined as normalisation of Haemoglobin concentration and haemolytic parameters reticulocyte count, bilirubin and lactate dehydrogenase (LDH). Overall response to Rituximab was 83.3% at 28 days post treatment. Four patients responded to Rituximab in combination with other Immunosupression such as Azathioprine or low dose steroids. Medium response duration was 11.5 months. Sustained response at 1 year, 2 years and 4 years post treatment were 60%, 55% and 30% respectively. Rituximab was well tolerated without significant complications in the majority of patients. One patient developed neutropenic sepsis. One patient received second course of Rituximab after relapse within a year and had sustained response of over two years after the second course. Conclusion: Rituximab is a safe and effective treatment for patients with AIHA who are resistant to steroids.The majority of patients will initially respond but a significant number will gradually relapse over time. Re-treatment with rituximab maybe considered on relapse. Disclosures: No relevant conflicts of interest to declare.

Abstract 2087 Poster Board II-64 Acute myeloid leukemia (AML) most frequently affects the elderly, many of whom are unable to tolerate intensive chemotherapy. Therefore, improvements in clinical outcomes for patients with AML largely depend upon the development of novel targeted therapies. Aurora A is a serine/threonine kinase that plays a key role in mitosis by regulating the G2-M transition, centrosome separation, spindle assembly and chromosome segregation. It is overexpressed in AML and has been implicated in genetic instability, disease progression and drug resistance. MLN8237 is a novel orally available Aurora A inhibitor that has entered Phase I and Phase II trials for cancer therapy. Based on the critical role of Aurora A in cell cycle regulation and its intrinsic overexpression in AML cells, we hypothesized that MLN8237 would possess significant antileukemic activity. We tested our hypothesis in established human AML cell lines, primary AML patient specimens, and a mouse model of AML. MLN8237 potently inhibited the in vitro growth and survival of all AML cell lines and primary human AML cells from patients with newly diagnosed AML and patients with relapsed, chemotherapy resistant disease. Mechanistic studies showed that MLN8237 reduced the activity of Aurora A kinase as evidenced by reduced phosphorylation of Aurora A at Thr288. MLN8237 treatment also disrupted normal cell cycle kinetics and induced apoptosis in a dose- and time-dependant manner characterized by the accumulation of G2/M and aneuploid cells prior to the onset of apoptosis. Exposure to MLN8237 led to activation of FOXO3a followed by a dose-dependent increase in the expression of its transcriptional target Bim. These events appear to be important mediators of the pro-apoptotic effects of this agent. We next investigated the ability of MLN8237 to increase the efficacy of cytarabine in AML. Treatment with the combination of MLN8237 and cytarabine resulted in significantly greater apoptosis and more effective inhibition of survival than treatment with either agent alone in AML cell lines and primary patient specimens. MLN8237 and cytarabine cooperated to enhance mitochondrial-mediated apoptosis as evidenced by increased processing of caspases-9 and -3 to active forms. Daily oral administration of MLN8237 to immunodeficient mice bearing AML xenografts was well tolerated, effectively reduced tumor growth and led to the disruption of mitotic spindles and centrosome amplification. Moreover, MLN8237 significantly enhanced the activity of cytarabine to achieve tumor regression. Our data demonstrates that MLN8237 has a multifaceted mechanism of action comprised of pro-apoptotic and growth inhibitory effects. Our collective findings indicate that the combination of MLN8237 and cytarabine represents a novel, very promising therapeutic strategy for AML. A clinical study investigating the safety and efficacy of this combination in patients with refractory AML is planned. Disclosures: Ecsedy: Millennium Pharmaceuticals: Employment.

Background; Transmission of vCJD by blood transfusion from pre-symptomatic blood donors has occurred in 4 reported cases to date. Screening blood donors for infectivity is unlikely to be feasible for several years. Removing infectivity from blood using selective filtration may provide a useful degree of protection from transfusion transmission of the disease. A filter that may remove infectivity from red cell concentrates has been developed and trialed in volunteers receiving autologous blood. No studies have been carried out to date of pfRCC in allogeneic transfusions in the clinical setting. Aims; To establish safety and tolerability of transfusion of prion filtered red cell concentrates. Methods; Twenty patients scheduled to receive transfusion were recruited following ethical approval and with informed consent. Prion filtered units were prepared by the Irish Blood Transfusion Service. A mean loss of 9 gm of haemoglobin per unit of RCC occurred during the filtration process. Each patient received one unit of pfRCC, and a median of 2 units overall (range 1 to 4 units) per transfusion episode. A cross-match sample, full blood count (FBC), renal and liver profile was taken from each patient prior to transfusion. Patients were observed for adverse reactions. After 24 hours, FBC, renal and liver profile were repeated. Six weeks after the transfusion a further sample was tested for red cell antibodies. Six of these patients have consented to undergo re-transfusion with pfRCC. Two re-infusions have taken place uneventfully six months after the first exposure to pfRCC and 4 more are planned. Results No serious adverse events were encountered during the study, or at 24 hour and 6 week follow up after the initial transfusion episode. Mean haemoglobin increment per unit transfused was 0.68g (SD 0.45g; range −0.5 to 1.35g ). Recruitment and follow-up is ongoing in patients exposed to repeat transfusion challenge. Summary The first clinical transfusions of pfRCC were well tolerated. Two patients were rechallenged with transfusions of pfRCC without adverse effect. Further studies with transfusions of prion filtered red cells are now warranted to extend the safety data and to determine whether efficacy is comparable to standard transfusions in adult and paediatric populations.

Insertion and/or deletion mutations of the CALR gene have recently been demonstrated to be the second most common driver mutations in the myeloproliferative neoplasms (MPNs) of essential thrombocythemia (ET) and primary myelofibrosis (PMF). Given the diagnostic and emerging prognostic significance of these mutations, in addition to the geographical heterogeneity reported, the incidence of CALR mutations was determined in an Irish cohort of patients with MPNs with a view to incorporate this analysis into a prospective screening program. A series of 202 patients with known or suspected ET and PMF were screened for the presence of CALR mutations. CALR mutations were detected in 58 patients. Type 1 and Type 1-like deletion mutations were the most common (n = 40) followed by Type 2 and Type 2-like insertion mutations (n = 17). The CALR mutation profile in Irish ET and PMF patients appears similar to that in other European populations. Establishment of this mutational profile allows the introduction of a rational, molecular diagnostic algorithm in cases of suspected ET and PMF that will improve clinical management. Keywords: CALR, Essential thrombocythemia, JAK2, Myeloproliferative neoplasm, Primary myelofibrosis

Survival rates among patients with lymphoma continue to improve. Strategies aimed at reducing potential treatment-related toxicity are increasingly prioritized. While radiological procedures play an important role, ionizing radiation exposure has been linked to an increased risk of malignancy, particularly among individuals whose cumulative radiation exposure exceeds a specific threshold (75 millisieverts). Within this retrospective study, the cumulative radiation exposure dose was quantified for 486 consecutive patients with lymphoma. The median estimated total cumulative effective dose (CED) of ionizing radiation per subject was 69 mSv (42–118). However, younger patients (under 40 years) had a median CED of 89 mSv (55–124). This study highlights the considerable radiation exposure occurring among patients with lymphoma as a result of diagnostic imaging. To limit the risk of secondary carcinogenesis, consideration should be given to monitoring cumulative radiation exposure in individual patients as well as considering imaging modalities, which do not impart an ionizing radiation dose.