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An elevated tricuspid regurgitant jet velocity (TRV) is associated with hemolysis and early mortality in sickle cell disease, yet risk factors, clinical parameters, and mortality associated with this biomarker in thalassemia are poorly defined. This report summarizes the prevalence of an elevated TRV in 325 patients screened by Doppler echocardiography in the Thalassemia Clinical Research Network. A documented TRV was reported in 148 of 325 (46%) of patients. Average age was 25.9 years (range, 5-56 years) and 97% were transfusion-dependent. Mean TRV was 2.3 ± 0.4 m/s (range, 0.2-3.5 m/s). An abnormal TRV ≥ 2.5 m/s was identified in 49 of 148 (33%) of patients with a documented TRV, 5% (8/148), with a TRV ≥ 3.0 m/s, suggesting significant PH risk. Older age was strongly associated with a high TRV; however, 16% of children had a TRV ≥ 2.5 m/s. A history of splenectomy, hepatitis C, smoking, or high white blood cell count was associated with TRV elevation. In summary, an elevated TRV is noted in one-third of transfusion-dependent thalassemia patients with a documented value and develops in both children and adults. Age, splenectomy, hepatitis C, and smoking are significant univariate risk factors, with splenectomy surfacing as the dominant risk factor over time. Mortality was low in this cohort. Prospective longitudinal studies are needed. This study is registered at http://www.clinicaltrials.gov as NCT00661804.

Congenital sideroblastic anemias (CSAs) are uncommon inherited diseases resulting from defects in heme biosynthesis, mitochondrial translation or mitochondrial iron-sulfur cluster (ISC) assembly. CSAs are characterized by pathological mitochondrial iron deposits in bone marrow erythroblasts. Recently, mutations in mitochondrialheat shock protein 70 (HSPA9), a critical chaperone involved in mitochondrial ISC assembly, have been reported as a cause of non-syndromic CSA. Human heat shock cognate protein 20 (HSCB), a highly conserved mitochondrial co-chaperone, is the primary binding partner of HSPA9. HSCB allows the transfer of nascent ISC to HSPA9 and stimulates its ATPase activity, promoting ISC transfer to target proteins. To identify novel genes responsible for CSA, we performed whole exome sequencing on more than 75 CSA probands and their family members. In one patient, a young woman, with pancytopenia characterized by a normocytic anemia with numerous bone marrow ringed sideroblasts, we identified two variants in HSCB : a paternally-inherited promoter variant (c.-134C>A) predicted to disrupt a conserved ETS transcription factor binding site, and a maternally-inherited frameshift (c.259dup, p.T87fs*27). A fibroblast cell-line derived from the proband showed a decrease in HSCB expression, but normal HSPA9 expression compared to healthy, unrelated controls. Impairment of ETS1-dependent transcriptional activation of the promoter variant was demonstrated in K562 cells transfected with an HSCB-luciferase reporter construct. K562 cells were also employed to determine if reduced expression of HSCB could result in impaired erythroid metabolism, maturation, or proliferation. K562 cells infected with shRNA directed against HSCB were deficient in multiple mitochondrial respiratory complexes, had abnormal iron metabolism and a defect of protein lipoylation, all consistent with defective ISC metabolism. In addition, both IRP1 and IRP2 expression were decreased and cell surface transferrin receptor 1 (TFR1) expression was enhanced, suggesting disturbed cellular iron metabolism. Nevertheless, cells lacking HSCB partially retained an ability to respond to iron chelation and iron overload. Cells lacking HSCB lose their ability to hemoglobinize in response to sodium butyrate treatment (Figure 1A). This defect was confirmed in vivo using a morpholino strategy in zebrafish, as fish lacking HSCB are also unable to hemoglobize (Fig 1B). We generated an Hscb conditional mouse to better elucidate the underlying pathophysiology of the disease. Heterozygous (Hscb+/-) animals have no discernable phenotype; however, null animals die prior to embryonic day E7.5. Thus, to avoid this lethality, we employed Vav-cre animals (Tg(Vav1-cre)1Graf) to evaluate the loss of HSCB specifically in the hematopoietic compartment. Hscbc/- Vav-cre+ pups are pale and growth retarded compared to control littermates and die at approximately p10 with severe pancytopenia. To assess the loss of HSCB specifically in the erythroid lineage, we bred conditional animals to EpoR-cre (Eportm1(EGFP/cre)Uk) mice. Hscbc/- EpoR-cre+ mice die at approximately E12.5 due to a complete failure of erythropoiesis (Figure 1C). Finally, temporally inducible, hematopoietic-specific deletion animals were generated by transplantation of fetal livers from Mx-Cre (Tg(Mx1-cre)1Cgn) positive Hscbc/- animals. After polyinosinic:polycytidylic acid (pIpC) induction, global defects of hematopoiesis were observed in Mx-Cre+ animals, leading to their death 3-weeks post-induction from profound pancytopenia. A transient siderocytosis was seen in the peripheral blood between days 6-8 post-pIpC. Flow cytometry using FSC-TER119-CD44 gating strategy confirmed the defect in erythropoiesis. Taken together, these data demonstrate that HSCB is essential for hematopoiesis; both whole animal and in vitro cell culture models recapitulate the patient's phenotype, suggesting that the two patient mutations are likely disease-causing. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Thalassemia is one of the most common monogenic diseases of man, prevalent in tropical and subtropical regions of the world. Population migration during the past decades has led to increasing numbers of these patients being encountered in all parts of the world, including in the United States. A

Abstract 340 Transfusions are the primary therapy for thalassemia (thal) but have significant cumulative risks. The Thalassemia Clinical Research Network recently highlighted the increased rate of alloimmunization in this population1. In 2004, the CDC established a national blood safety monitoring program for thal. The goals of the program were to monitor blood safety and strategies for the management of complications. This report focuses on immune and non-immune transfusion reactions. Methods: The CDC Thalassemia Blood Safety Network is a consortium of thal centers that follow patients longitudinally to determine the transfusion-related complications. Serial demographic, physical, and laboratory data are collected along with blood samples analyzed at the CDC. Data collected includes ethnicity, genotype, phenotype, transfusion data, immunizations, type of red cell product, degree of antigen matching, and chelation therapy. Chronically transfused (CT) patients were defined as requiring at least 8 transfusions annually. Intermittently transfused (IT) patients received less than 8 transfusions annually. Statistical analyses included continuous variables, logistic regression, and multivariant analysis. Results: There were 407 patients including 327 CT patients and 80 IT patients. The genotype of chronically transfused patients included: TM (81%), TI (6%), E-Beta-Thal (6%), and Hemoglobin H/CS (4%). The average age of CT patients was 22.3 years ± 13 and 21.4 years ± 17 in IT patients. The average units CT patients received was 149 ± 103. Hemosiderosis occurred in both patient groups and correlated with transfusion history. The average ferritin (m/L) in each group, respectively, was 2261 and 689. 78% of the total population has received chronic chelation therapy. Multiple organ dysfunction was common in the population, including cardiac disease (13%), gonadal failure (17%), growth hormone deficiency (8%), hypothyroidism (8%), hypoparathyroidism (1.2%), diabetes (10%), and thrombotic events (5.4%). 45% of the population was splenectomized. Transfusion reactions occurred in 48% of patients, including allergic (45%), multiple etiologies (32%), febrile (17%), and hemolytic (5%). Transfusion-associated infection included 58 cases of Hepatitis-C and 4 cases of HIV. Two Hepatitis-C cases occurred after specific blood testing was initiated. Recent cases of bacteremia, malaria, and Babesiosis have been documented. 21% of CT patients and 13% of IT patients developed an alloantibody. The most common antigen specificity included E (25%), Kell (13%), C (9%), Jka (5%), Kpa (4%), HLA (4%), V (3%), c (3%), D (2.5%), WA-1 (2.5%), and S (2.5%). 45% of alloimmunized patients had multiple antibodies. Race, transfusion burden, age and splenectomy predicted alloimmunization. Alloimmunization was found in 31% of splenectomized patients vs. 10% of non-splenectomized patients (p Autoantibodies occurred in 6.5% of the population and increased with age and splenectomy. Alloimmunization increased the risk of autoantibodies: 26% of patients with an alloantibody had an autoantibody whereas only 2% of patients without alloantibodies had an autoantibody (p Local institutional policies were the major determinant in the type of units administered. In the last year, 32% of the units were washed and 80% radiated. 40% of patients received standard ABO matching, 47% limited phenotypic matching, and 12% full extended matching. Conclusion: Transfusion-related morbidity is a major problem in thal. Hemosiderosis immunologic and non-immunologic reactions are common. Transfusion-related infections have decreased but new, emerging pathogens have been noted. Disclosures: No relevant conflicts of interest to declare.

Abstract 257 Background. Advances in treatment of thalassemia have led to increased life expectancy for patients making outcomes such as health related quality of life (HRQOL) an important consideration of therapy. Little has been published about the HRQOL of pediatric patients with thalassemia. There are limited reports on how this illness impacts the family. Because the familial situation is the starting point for how patients learn to live with their condition, it is important to document this effect and how it changes over time. This report looks at changes in parental reported HRQOL from baseline (BL) to year 1 (Y1) in the Thalassemia Clinical Research Networks (TCRN) Thalassemia Longitudinal Cohort (TLC) study. Patients and Methods. The TCRN is a NIH-sponsored network of 16 major thalassemia centers in the US, Canada and London. We report here on the results from 77 patients under the age of 14 who completed BL and assessments at Y1. Overall the patients were 47% male with a mean age of 9 years (range 5–13). 94% were chronically transfused, and 69% had β-thalassemia, and 12% were E-β thalassemia patients. 57% used an oral chelator, while 29% were on desferoxamine (DFO). HRQOL was measured by self-report with the Children Health Questionnaire (CHQ), 28-item Parental Form (PF28). The 28 items derive 12 subscales that assess physical and psychosocial health. 2 summary scales assess overall physical health and psychosocial health. We defined a clinically significant change as a difference of at least 2 points on any subscale. Results. Clinical Changes: 45% saw a reduced number of transfusions from BL to year 1 (32% showed no change). 73% did not change chelator, while 18% changed from DFO to oral (2.6% other way). 5% began a chelation regimen. Only one percent of patients developed new secondary complications. 63% showed no change in their general adherence rate; 25% showed a decrease. HRQOL changes: As a population, mean HRQOL remained stable over the 1 year study period. Age appears to be significant for CHQ assessment of child's self esteem and behavior (and overall psychosocial assessment), but gender, country and ethnicity do not appear to be significant. The average number of scales with significant changes was eight. Only one CHQ assessment does not show any significant changes on any CHQ scale, while three reports showed changes on all 14 scales. The psychosocial scales showed more significant changes than physical health assessments. Figure 1 illustrates the reported changes by scale. Measures of overall general health, parental emotions and child behavior showed the most changes. Assessment of the child's physical and psychosocial roles and family cohesion showed the least change. The physical health assessments of function and pain showed lower significant changes than the psychosocial health assessments. More psychological health measures show a significant drop than familial assessments. When we examine scale changes by age groups, the youngest age group (5-7) showed modestly better physical and psychosocial scale changes. The 8–10 age group saw more than twice the number of parents seeing a decline in a physical or psychosocial health scale. The oldest age group (11-14) showed the fewest changes, with mainly higher physical health scale changes, but lower scores on the psychosocial scales. Clinical Associations: Changes in number of transfusions and adherence do not appear to impact CHQ assessment. However, changes in chelator appear to be significant for parental time (P=0.048) and the psychosocial summary scale (p=0.04). Changes in secondary complication appear to be associated with changes in the CHQ assessment of the child's behavior (p=.04). Conclusions. The dearth of clinical changes suggests that patients enrolled in TCRN are receiving optimized health care. The lack of changes on the CHQ's physical health scales is to be expected given the low number of clinical changes, and the reported changes in CHQ do not appear to be related to clinical changes. At this stage of data analysis, CHQ assessment in thalassemia appears to be associated with the normal effects a growing child has on the family. This would be the desired result of effective clinical intervention in thalassemia. Further analyses of changes are needed to understand the relationship between changes in HRQOL and specific changes in clinical measures. Disclosures: Neufeld: Novartis, Inc: Research Funding; Ferrokin, Inc: Research Funding.

Abstract 2016 Poster Board I-1038 BACKGROUND: Pulmonary hypertension (PH) contributes to heart disease, the leading cause of death in thalassemia. PH in thalassemia is multifactorial, including oxidative stress, hemolysis, thrombosis, splenectomy, abnormal arginine-nitric oxide bioavailability, and iron overload. Despite the high mortality rate associated with PH, no intervention studies in thalassemia have been completed. This report summarizes the prevalence of elevated tricuspid regurgitant jet velocity (TRV) as a proxy for PH in patients clinically screened by Doppler echocardiography (echo) in the Thalassemia Clinical Research Network (TCRN). PATIENTS AND METHODS: The TCRN is an NIH-sponsored network of major thalassemia centers in the US, Canada and London, UK. This analysis is part of the Thalassemia Longitudinal Cohort (TLC), which collects longitudinal data from 428 patients at 16 centers. We report results from 303 patients (71%) who were assessed by echo at least once. Predictors considered for analysis were age, gender, splenectomy, hepatitis C, WBC, ferritin, hemoglobin, liver function, creatinine, chronic transfusion status, number of transfusions, chelation status, and hydroxyurea use. Multivariate effects of predictors significant in univariate analysis were modeled using logistic regression for elevated TRV. RESULTS: Measurable TRV jet was detectable in 144/303 (48%) of patients. Average age of the cohort with a detectable TRV was 25.8 years (range 5-56 years); half were female.. 97% of the patients studied were transfusion dependent. Mean TRV was 2.3±0.4 m/s (range 0.2-3.5 m/s). An abnormal TRV ≥ 2.5 m/s was identified in 45/144 (31%) of patients screened, 18% (8/45) of whom had a TRV ≥ 3.0 m/s suggesting significant PH. Older age was strongly associated with PH (r = 0.38, p CONCLUSIONS: Elevated TRV is noted in at least 1/3 of transfusion-dependent thalassemia patients with measurable TR jets. We observed elevated TRV in both children and adults. Less than half of patients screened by echo had a measurable TRV, suggesting that technical diligence is needed to increase the fraction of echos with a measured TRV to better identify patients at risk of PH. Age, splenectomy and history of hepatitis C are significant univariate risk factors in this population, with age remaining an independent risk factor in multiple regression analysis. Ongoing assessment in the TLC and specific prospective longitudinal studies of PH in thalassemia are needed to understand the natural history and pathophysiology in thalassemia in order to determine optimal therapy. Interventional trials for PH in thalassemia are needed. Disclosures: No relevant conflicts of interest to declare.

Abstract 1371 Poster Board I-393 The study examines the quality of life (QOL) of pediatric thalassemia patients and their families enrolled in the Thalassemia Longitudinal Cohort (TLC) study of the NHLBI-sponsored Thalassemia Clinical Research Network, which comprises 17 centers in the US, Canada, and London, UK. The study evaluates 99 baseline responses to the Children's Health Questionnaire (CHQ) PF28, a self-administered survey filled out by the parent or guardian of patients age 5 y and older. The CHQ utilizes 12 scales that can be grouped into parental assessments of the child's physical well-being; mental, emotional and behavioral health; and the familial context. We previously showed that compared to the US population, the thalassemia population is significantly different on 7 of the 12 scales. Here we evaluate these data by patient gender, race, age, and chelator type. The mean age of the population was 9.7 y (range 5.0-13.8 y), with 48% male, and 65% non-white. While parents assessed males to have a lower QOL than females, the only significant difference was in their assessment of the child's emotional role/behavior (school or friends). When comparing white to non-white (predominantly Asian) patients, with the exception of bodily pain, non-white thalassemia patients reported poorer PF28 scores. However, only the reported impact on parental time and emotion are significant. These variances appear to mirror the US population. Figure 1 shows PF28 summary scores by age in thalassemia compared to the general US population. Parents evaluate their child with thalassemia with lower physical health than US norms (p Finally, when CHQ PF28 assessments are compared by chelator type (subcutaneous deferoxamine vs. oral deferasirox), parents report that children receiving deferoxamine have generally lower QOL than the rating for those receiving Deferasirox. However, the only significant differences are with perceived physical function, impact on family activities, and the overall physical summary scale. The CHQ PF28 data provides important insight into the impact the child with thalassemia has on the family. Although psychosocial QOL is similar, children, and especially adolescents, with thalassemia have lower physical QOL, especially those on chelation with Deferoxamine. Because PF28 takes the parents' point of view, it can't be determined from these data alone whether the reported difference between parenteral and oral chelator would hold true for direct patient assessments. The gender of the child also appears to affect parental expectation of the child's QOL. These data validate the observational evidence that a child with thalassemia has a significant impact on the family. Figure 1 TLC CHQ PF28 Summary Scales compared to US norms Figure 1. TLC CHQ PF28 Summary Scales compared to US norms Disclosures: Odame: Novartis: Consultancy, Speakers Bureau. Thompson: Novartis: Research Funding. Neufeld: Novartis: Research Funding.

Abstract 4056 Poster Board III-991 BACKGROUND Survival in thalassemia is strongly influenced by iron burden and adherence to chelation therapy. Deferoxamine (DFO) is an effective chelator, in use since the 1970s, but the parenteral mode of administration hinders adherence. Deferasirox (DFX), taken orally, became commercially available in the US in Jan. 2006, and deferiprone (DFP) is only available in North America (N.A.) through research or compassionate use. The impact of expanded chelation options on iron burden in thalassemia patients has not been studied. The goals of this study were to assess the chelator choices among patients with thalassemia and to compare efficacy and treatment adherence among chelators. METHODS The TCRN is a NHLBI-sponsored clinical trial network of Thalassemia Centers in N. A. and London, U.K. The Thalassemia Longitudinal Cohort (TLC) study of the TCRN was launched in 2006. Baseline data collection included a five-year retrospective component, with clinical, radiographic, and laboratory data from 2002 onward. This is followed by annual prospective data collection thereafter. The current analyses include data from the retrospective portion through baseline assessment. The dates of data collection span the initiation of DFX, first in clinical trials and then in routine clinical use. RESULTS Of the 404 enrolled subjects, 317 had ever received chelation therapy. Mean age was 21.2 ± 12.1y, and 46.4% were male. Genotype distribution included beta-thal major (79.2%), beta-thal intermedia (6.6%), chronically transfused HbE-beta-thal (9.5%), Hb E-beta-thal, not chronically transfused (1.6%), chronically transfused alpha-thal syndromes (2.3%), and other (1%). The median ferritin level was 1431 ng/mL (range, 122-23712 ng/mL) and mean liver iron content (LIC) was 10.8 mg/g dw (0.3-43.3 mg/g dw). Current choices are: DFO (27%), DFX (58%), DFP (1%), combination DFO+DFP (5%), DFO+DFX (3%), and no chelation (7%). Among chelated patients, 65 (21%, mean age 19.1y) chose to continue DFO and never used DFX, while 192 (61%, mean age 21.9y) have taken DFX (p=0.1). The mean current doses of DFO and DFX were 39 mg/kg/day and 25 mg/kg/day, respectively. Compared to those who switched to DFX, patients who continued DFO had lower initial ferritin levels (1499 DFO v. 2144 ng/mL DFX, p=0.02), but similar LICs (14.1 v 13.9 mg/g dw, p=0.9). Reasons for switching to DFX included: participation in clinical trials before 2006 (26%), commercial availability of drug (27%), patient/family preference (22%), high iron burden (15%), and other (10%). Conversely, 32 subjects who tried DFX switched back to DFO for the following reasons: patient/family preference (38%), high iron burden on DFX (16%), renal dysfunction (6%), elevated alanine aminotransferase (3%), and other (37%). Over the 5-year period, patients currently receiving DFX had a significant reduction in LIC (13.3 to 10.9 mg/g dw, p=0.02) and a trend towards reduction in ferritin level (2198 to 2027 ng/mL, p=0.06), while those receiving DFO had no significant change in LIC (12.2 to 10.4 mg/g dw. P=0.17) but had a significant decrease in ferritin levels (1881 to 1516 ng/mL, p=0.04). Self-reported treatment adherence was higher in the DFX group than in the DFO group, with 89% compared with 76.5% reporting adherence at least 75% of the time (p=0.02). Twenty-seven percent of patients on DFO at study entry and 30% of patients on DFX have ferritin >2500 ng/mL and/or LIC >15 mg/g d.w., indices of inadequate chelation. CONCLUSIONS DFX is currently the predominant chelator choice among patients with thalassemia in the TCRN. LIC appeared to improve among patients who have switched to DFX between 2002 and baseline TLC studies in 2007-2009, although ferritin remained stable. In the same time period, for DFO treated patients, ferritin significantly decreased but the LIC did not change. Nevertheless, the final LIC was similar between DFO and DFX treated groups. Inadequate control of iron burden was observed in a significant subset of patients receiving either chelator; thus, close monitoring of iron burden and encouragement and support of adherence are essential. Disclosures: Thompson: Novartis: Consultancy, Honoraria. Mueller:Novartis: Site principal investigator. Odame:Novartis: Consultancy, Speakers Bureau. Giardina:Novartis: Research Funding. Vichinsky:Novartis: Consultancy, Research Funding. Porter:Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Vifor International: Membership on an entity's Board of Directors or advisory committees. Coates:Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau. Neufeld:Novartis: Research Funding.