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The six-minute walk test (6MWT) has been used in patients with sickle cell disease (SCD), in conjunction with tricuspid regurgitant velocity (TRV) and plasma N-terminal pro-brain natriuretic peptide (NT-pro BNP), to assess risk of having pulmonary hypertension. Exercise-induced vital sign changes (VSCs) are predictors of clinical outcomes in other diseases. In this study, we assess the predictors and prognostic value of 6MWT VSC in adult SCD patients. Data from a multinational study of SCD patients (Treatment of Pulmonary Hypertension with Sildenafil: walk-PHaSST) were used to calculate the 6MWT VSC. Predictors of VSC were identified by a multivariable analysis, and a survival analysis was conducted by the Cox proportional hazard method. An increase in heart rate was observed in 90% of the 630 SCD adults, 77% of patients had an increase in systolic blood pressure (SBP), and 50% of patients had a decrease in oxygen saturation. TRV (odds ratio [OR] = 1.82, p = .020), absolute reticulocyte count (OR = 1.03, p

The six-minute walk test (6MWT) is a well-established assessment of the cardiopulmonary function of sickle cell disease (SCD) patients. The test is used for people with SCD who are suspected of having hypoxia or an elevated estimated pulmonary arterial systolic pressure, which increases the risk for early death. Low 6MWT distances are associated with cardiopulmonary compromise. Six-minute walk distance examination has been proposed as a screening test, used in conjunction with plasma levels of brain natriuretic peptide and Doppler-echocardiography, through which to identify high-risk patients. Post-exercise tachycardia or lack of heart rate recovery following a 6MWT has been shown to be a predictor of pulmonary hypertension and mortality in people with pulmonary fibrosis. A rise in blood pressure after exercise is associated with impaired capacity for vasodilation in ischemic heart disease. The prognostic significance of patterns of vital sign change in adult SCD patients completing the 6MWT is currently unknown. In this study, we aimed to assess the distribution and predictors of vital sign change during 6MWT in adult SCD patients and test the association of these changes with patient survival. Data from a multinational observational study of SCD patients (Walk-PhassT), was used to calculate the change in vital signs (heart rate, O2 saturation, systolic blood pressure, diastolic blood pressure, pulse pressure) normalized for walk distance, after a 6MWT. Bivariate and LASSO regression analyses were performed to ascertain the significant predictors of change in each vital sign, in addition to Cox proportional hazard analysis to assess the impact of vital sign change and time to death. The median age of the 630 adult SCD patients was 37 years. 47% were male, 77% had the HbSS phenotype, and 22 (3.7% of 592 with follow-up data) died during a median time of follow up of 29 months. The most frequent changes in vital signs identified were increases in the heart rate (90%) followed by increases in systolic blood pressure (77%, Table 1b). Bivariate analysis revealed significant but weak positive correlations between tricuspid regurgitation velocity (TRV) and increases in both heart rate (r= 0.08; p These findings support links between changes of vital signs during the 6MWT and established markers of hemolysis and cardiovascular dysfunction in SCD patients. Evidence of a protective effect of increased systolic pressure is a novel finding. This might indicate that the ability to increase systolic pressure during submaximal exercise relates to cardiac output and conveys a physiological advantage for SCD patients. These findings could be used as the basis for future mechanistic studies of exercise effects on cardiovascular function in SCD patients. Disclosures Gordeuk: Imara: Research Funding; Global Blood Therapeutics: Consultancy, Research Funding; Novartis: Consultancy; CSL Behring: Consultancy, Research Funding; Ironwood: Research Funding. Gibbs:Pfizer: Consultancy; United Therapeutics: Consultancy; MSD: Consultancy; GSK: Consultancy; Complexa: Consultancy; Bayer: Consultancy; Actelion: Consultancy; Acceleron: Consultancy. Little:BioChip Labs: Patents & Royalties: SCD Biochip (patent, no royalties); GBT: Membership on an entity's Board of Directors or advisory committees; NHLBI: Research Funding; Hemex Health, Inc.: Patents & Royalties: Microfluidic electropheresis (patent, no royalties); Bluebird Bio: Research Funding; GBT: Research Funding.

Summary Background Increased life expectancy in sickle cell disease (SCD) has resulted in greater recognition of the consequences of repeated intravascular vaso-occlusion and chronic haemolysis to multiple organ systems. Aim To report the long-term consequences of liver dysfunction in SCD. Methods A cohort of SCD patients was prospectively evaluated at the National Institutes of Health (NIH) Clinical Center. The association of mortality with liver enzymes, parameters of liver synthetic function and iron overload was evaluated using Cox regression. Results Exactly, 247 SCD patients were followed up for 30 months of whom 22 (9%) died. After controlling for predictors, increased direct bilirubin (DB), ferritin, alkaline phosphatase and decreased albumin were independently associated with mortality. In a multivariable model, only high DB and ferritin remained significant. Ferritin correlated with hepatic iron content and total blood transfusions but not haemolysis markers. Forty patients underwent liver biopsies and 11 (28%) had fibrosis. Twelve of 26 patients (48%) had portal hypertension by hepatic venous pressure gradient (HVPG) measurements. All patients with advanced liver fibrosis had iron overload; however, most patients (69%) with iron overload were without significant hepatic fibrosis. Ferritin did not correlate with left ventricular dysfunction by echocardiography. DB correlated with bile acid levels suggesting liver pathology. Platelet count and soluble CD14 correlated with HVPG indicating portal hypertension. Conclusions Ferritin and direct bilirubin are independently associated with mortality in sickle cell disease. Ferritin likely relates to transfusional iron overload, while direct bilirubin suggests impairment of hepatic function, possibly impairing patients’ ability to tolerate systemic insults.

Background Poor hydroxyurea (HU) adherence limits effective HU use in patients with sickle cell disease (SCD). Electronic directly observed therapy (DOT) may limit costs and achieve high HU adherence in children with SCD. This study aimed to determine if electronic DOT was feasible, acceptable, and could achieve ≥90% HU adherence. Procedure Children with SCD were recruited for this single institution, 6-month pilot study if they had been prescribed HU for ≥6 months and had daily access to a smartphone or computer. Participants submitted HU administration videos daily and received electronic reminder alerts, personalized feedback, and incentives to encourage adherence as part of electronic DOT. Primary outcomes were feasibility, participant satisfaction with electronic DOT, and HU adherence. Secondary outcomes included mean corpuscular volume (MCV), hemoglobin F percentage (HbF), and overall participant satisfaction with HU therapy. Results Of 15 enrolled participants, 14 completed the study. Satisfaction surveys showed electronic DOT reminded participants to take HU and could be completed in fewer than 5 minutes daily. Participants' median medication possession ratio at study entry improved from 0.75 (0.59–0.82) to 0.91 (0.85–1.00) (P = 0.02) at the end of the study. Overall median observed HU adherence with electronic DOT was 93.3%. Median MCV and HbF increased from 96.0 to107.2 (P = 0.009) and 10.5 to 11.4 (P = 0.03), respectively. Conclusions This study demonstrates electronic DOT is feasible, acceptable, and can achieve high HU adherence. Further study is needed to confirm that electronic DOT can improve HU adherence and impact clinical outcomes in children with SCD. Pediatr Blood Cancer 2014;61:1068–1073. © 2014 Wiley Periodicals, Inc.

Platelets are activated in sickle cell disease (SCD), and particularly during vaso-occlusive episodes (VOE). Thrombospondin-1 (TSP1), a major secretory product of activated platelets, is increased in the circulation in VOE and binds to sickle red blood cells (RBC) promoting vascular adhesion. Thus, we hypothesized that TSP1 may represent a plasma biomarker of disease severity in SCD. We tested the plasma collected from patients in steady state (n = 27) and VOE (n = 14), as well as healthy controls (n = 17) at the University of Pittsburgh Medical Center (UPMC), and from patients in steady state enrolled in the walk-PHaSST clinical trial (n = 483). We found that TSP1 levels were increased in VOE in the UPMC cohort. Among steady-state patients at UPMC, TSP1 values correlated positively with lifetime history of acute chest syndrome (r = 0.72, P < 0.0001) and hemoglobin concentration (r = 0.49, P = 0.01), and negatively with markers of hemolysis, such as LDH (r = −0.50, P = 0.009). Analysis of the walk-PHaSST cohort also showed a positive association between TSP1 levels and hydroxyurea use (r = 0.14, P = 0.003), and confirmed the negative associations with the severity of hemolysis. Our results suggest that TSP1 levels are associated with more VOE, hydroxyurea use and lower rates of hemolysis. High TSP1 concentrations may indicate higher risk of the viscosity/vaso-occlusion phenotype of SCD.

Epidemiological studies support a hypothesis that pulmonary hypertension (PH) is a common complication of sickle cell disease (SCD) that is associated with a high risk of death and evolves as a complication of haemolytic anaemia. This fundamental hypothesis has been recently challenged and remains controversial. In order to further test this hypothesis in a large and independent cohort of SCD patients we obtained plasma samples from the Cooperative Study of Sickle Cell Disease (CSSCD) for analysis of a biomarker, N-terminal-pro brain natriuretic peptide (NT-proBNP), which is elevated in the setting of pulmonary arterial and venous hypertension. A NT-pro-BNP value previously identified to predict PH in adults with SCD was used to determine the association between the risk of mortality in 758 CSSCD participants (428 children and 330 adults). An abnormally high NT-proBNP level ≥160ng/l was present in 27·6% of adult SCD patients. High levels were associated with markers of haemolytic anaemia, such as low haemoglobin level (P

Chronic leg ulcers are a debilitating complication of sickle cell disease, associated with increased morbidity and perhaps mortality that affect 8 to 50% of patients. We evaluated the characteristics of SCD patients with a history of leg ulceration, including hemolytic rate, estimated pulmonary artery systolic pressure, and other parameters in a cohort of 505 adults with SCD.

The development of cervical cancer and its precursors are linked to persistent infection with oncogenic types of human papillomavirus (HPV). Host immune responses seem to be determinants of risk for this disease. However, little is known about the immunologic determinants of HPV persistence. Here, we examined the association between lymphoproliferative responses to antigens/mitogens and persistent HPV infection in women older than 45 years. Women included in this study were participants in a 10,000-woman population-based cohort study of cervical neoplasia in Costa Rica. Women older than 45 years and HPV DNA positive at a screening visit were selected as cases (n = 283). We selected a comparably sized control group of HPV DNA–negative women, matched to cases on age and time since enrollment (n = 261). At an additional clinical visit, women were cytologically and virologically rescreened, and cervical and blood specimens were collected. Proliferative responses to phytohemagglutinin (PHA), influenza virus (Flu), and HPV16 virus-like particle (VLP) were lower among women with persistent HPV infection [median counts per minute (cpm): 72,849 for PHA, 1,241 for Flu, and 727 for VLP] than for the control group (median cpm: 107,049 for PHA, 2,111 for Flu, and 2,068 for VLP). The decreases were most profound in women with long-term persistence and were only observed for the oldest age group (≥65 years). Our results indicate that an impairment in host immunologic responses is associated to persistent HPV infection. The fact that effects were evident for all studied stimuli is suggestive of a generalized effect. (Cancer Res 2006; 66(22): 11070-6)

Introduction: Acute vaso-occlusive crisis (VOC) is the hallmark clinical complication of sickle cell disease (SCD). VOC involves several mechanisms, including rigid erythrocytes, adhesive blood cells, activated coagulation, activated and dysregulated endothelium, inflammation, and ischemia-reperfusion injury. Surprisingly few data document clinical and laboratory markers that change from steady state to VOC and during the hospital stay, and that predict subsequent rehospitalization. We characterized such markers in this study. Methods: Data were collected as part of a clinical trial of nitric oxide as potential treatment for VOC (DeNOVO). Participants, age ≥ 10 years requiring hospitalization for VOC, were recruited from 11 academic medical centers at the time of VOC. Length of hospital stay (LOS), change in visual analogue scale (VAS) pain score, and hospital readmission within 30 days were study outcomes. Steady state laboratory values were available in a subgroup of patients for comparison. Differences between admission and steady state laboratory measures and changes in clinical and laboratory parameters from hospital admission to discharge were analyzed by Wilcoxon signed-rank test. Multivariate linear and logistic regression analyses were used to identify the independent predictors of LOS and 30-day readmission risk. Results: 150 recruited patients had a median (interquartile range; IQR) age of 24 (17-33) years; 50% were female, and 91% had HbSS genotype. The median VAS score at time of admission was 7.7 cm which subsided to 3.3 cm at time of discharge (P Conclusion: VOC is associated with neutrophilia and increased LDH, consistent with inflammation and hemolysis and/or tissue injury, although of insufficient magnitude to be used as diagnostic criteria. The magnitude of pain and marker of apparent bone involvement predict longer LOS. SCD patients with VOC carry a high burden of readmission risk, which is characterized by higher opioid utilization and earlier discharge from the index hospitalization. These concepts can shape models, especially to reduce readmission rate, to be evaluated in prospective clinical trials. *First two authors contributed equally to this work. Figure Figure. Table Table. Disclosures Lanzkron: NKT: Research Funding; Selexys: Research Funding; Prolong: Research Funding; PCORI: Research Funding; NHLBI: Research Funding; HRSA: Research Funding; GBT: Consultancy; Pfizer: Research Funding.

The role of occupational substances as stomach carcinogens has not been well investigated. In 1979, a population-based case-control study was undertaken in Montreal to explore the possible association between hundreds of occupational circumstances and several cancer sites, including the stomach. In total, 250 male patients with pathologically confirmed stomach cancer, 2,289 male controls with cancers at other sites, and 533 population-based male controls were interviewed to obtain detailed job histories and relevant data on potential confounders. Job histories were evaluated by expert chemists and hygienists and translated into a history of occupational exposures. On the basis of results of preliminary analyses and literature review, we selected 16 occupations and industries and 32 substances for in-depth multivariate analysis using the pooled group of cancer and population controls. We found elevated risks for excavators and pavers, forestry workers, electric and electronic workers, motor transport workers, and food industry employees. The substances that were most plausibly associated with gastric cancer were: crystalline silica, leaded gasoline, grain dust, lead dust, zinc dust, hydraulic fluids, and glycol ethers. The paucity of data documenting the association between most of these occupational circumstances and gastric cancer precludes drawing firm conclusions.

Poor hydroxyurea (HU) adherence limits effective HU use in patients with sickle cell disease (SCD). Electronic directly observed therapy (DOT) may limit costs and achieve high HU adherence in children with SCD. This study aimed to determine if electronic DOT was feasible, acceptable, and could achieve ≥ 90% HU adherence.Children with SCD were recruited for this single institution, 6-month pilot study if they had been prescribed HU for ≥ 6 months and had daily access to a smartphone or computer. Participants submitted HU administration videos daily and received electronic reminder alerts, personalized feedback, and incentives to encourage adherence as part of electronic DOT. Primary outcomes were feasibility, participant satisfaction with electronic DOT, and HU adherence. Secondary outcomes included mean corpuscular volume (MCV), hemoglobin F percentage (HbF), and overall participant satisfaction with HU therapy.Of 15 enrolled participants, 14 completed the study. Satisfaction surveys showed electronic DOT reminded participants to take HU and could be completed in fewer than 5 minutes daily. Participants' median medication possession ratio at study entry improved from 0.75 (0.59-0.82) to 0.91 (0.85-1.00) (P = 0.02) at the end of the study. Overall median observed HU adherence with electronic DOT was 93.3%. Median MCV and HbF increased from 96.0 to 107.2 (P = 0.009) and 10.5 to 11.4 (P = 0.03), respectively.This study demonstrates electronic DOT is feasible, acceptable, and can achieve high HU adherence. Further study is needed to confirm that electronic DOT can improve HU adherence and impact clinical outcomes in children with SCD.

Sickle cell disease (SCD) is characterized by increased cellular adhesiveness, hemolytic anemia, hemostatic activation, vaso-occlusion and thrombosis. We found that patients with SCD in steady state have elevated plasma levels of the platelet protein thrombospondin-1 (TSP1) and that these levels are

The intensity of hemolytic anemia has been proposed as an independent risk factor for the development of certain clinical complications of sickle cell disease, such as pulmonary hypertension, hypoxemia and cutaneous leg ulceration. A composite variable derived from several individual markers of hemolysis could facilitate studies of the underlying mechanisms of hemolysis. In this study, we assessed the association of hemolysis with outcomes in sickle cell anemia. A hemolytic component was calculated by principal component analysis from reticulocyte count, serum lactate dehydrogenase, aspartate aminotransferase and total bilirubin concentrations in 415 hemoglobin SS patients. Association of this component with direct markers of hemolysis and clinical outcomes was assessed. As primary validation, both plasma red blood cell microparticles and cell-free hemoglobin concentration were higher in the highest hemolytic component quartile compared to the lowest quartile (P≤0.0001 for both analyses). The hemolytic component was lower with hydroxyurea therapy, higher hemoglobin F, and alpha-thalassemia (P≤0.0005); it was higher with higher systemic pulse pressure, lower oxygen saturation, and greater values for tricuspid regurgitation velocity, left ventricular diastolic dimension and left ventricular mass (all P

Background: Frequent painful vaso-occlusive crises (VOCs) were associated with mortality in the Cooperative Study of Sickle Cell Disease (CSSCD) over twenty years ago. Modern therapies for sickle cell anemia (SCA) like hydroxyurea are believed to have improved overall patient survival. The current study sought to determine the relevance of the association between more frequent VOCs and death and its relative impact upon overall mortality compared to other known risk factors in a contemporary adult SCA cohort. Methods: Two hundred sixty four SCA adults were assigned into two groups based on patient reported outcomes for emergency department (ED) visits or hospitalizations for painful VOC treatment during the 12 months prior to evaluation. Results: Higher baseline hematocrit (p = 0.0008), ferritin (p = 0.005), and HDL cholesterol (p = 0.01) were independently associated with 1 or more painful VOCs requiring an ED visit or hospitalization for acute pain. During a median follow-up of 5 years, mortality was higher in the ED visit/hospitalization group (relative risk [RR] 2.68, 95% CI 1.1-6.5, p = 0.03). Higher tricuspid regurgitatant jet velocity (TRV) (RR 2.41, 95% CI 1.5-3.9, p < 0.0001), elevated ferritin (RR 4.00, 95% CI 1.8-9.0, p = 0.001) and lower glomerular filtration rate (RR=2.73, 95% CI 1.6-4.6, p < 0.0001) were also independent risk factors for mortality. Conclusions: Severe painful VOCs remain a marker for SCA disease severity and premature mortality in a modern cohort along with other known risk factors for death including high TRV, high ferritin and lower renal function. The number of patient reported pain crises requiring healthcare utilization is an easily obtained outcome that could help to identify high risk patients for disease modifying therapies. Trial Registration: ClinicalTrials.gov NCT00011648 http://clinicaltrials.gov/

Aims: Hemoglobin-based oxygen carriers (HBOC) provide a potential alternative to red blood cell (RBC) transfusion. Their clinical application has been limited by adverse effects, in large part thought to be mediated by the intravascular scavenging of the vasodilator nitric oxide (NO) by cell-free plasma oxy-hemoglobin. Free hemoglobin may also cause endothelial dysfunction and platelet activation in hemolytic diseases and after transfusion of aged stored RBCs. The new soluble guanylate cyclase (sGC) stimulator Bay 41-8543 and sGC activator Bay 60-2770 directly modulate sGC, independent of NO bioavailability, providing a potential therapeutic mechanism to bypass hemoglobin-mediated NO inactivation. Results: Infusions of human hemoglobin solutions and the HBOC Oxyglobin into rats produced a severe hypertensive response, even at low plasma heme concentrations approaching 10 μM. These reactions were only observed for ferrous oxy-hemoglobin and not analogs that do not rapidly scavenge NO. Infusions of L-NG-Nitroarginine methyl ester (L-NAME), a competitive NO synthase inhibitor, after hemoglobin infusion did not produce additive vasoconstriction, suggesting that vasoconstriction is related to scavenging of vascular NO. Open-chest hemodynamic studies confirmed that hypertension occurred secondary to direct effects on increasing vascular resistance, with limited negative cardiac inotropic effects. Intravascular hemoglobin reduced the vasodilatory potency of sodium nitroprusside (SNP) and sildenafil, but had no effect on vasodilatation by direct NO-independent activation of sGC by BAY 41-8543 and BAY 60-2770. Innovation and Conclusion: These data suggest that both sGC stimulators and sGC activators could be used to restore cyclic guanosine monophosphate-dependent vasodilation in conditions where cell-free plasma hemoglobin is sufficient to inhibit endogenous NO signaling. Antioxid. Redox Signal. 19, 2232–2243.

Doppler-defined pulmonary hypertension (PH) in sickle cell disease (SCD) is associated with 40% mortality at 40 months. To assess the effect of bosentan in SCD-PH, two randomized, double-blind, placebo-controlled, 16-week studies were initiated. Safety concerns are particularly relevant in SCD due to comorbid conditions. ASSET-1 and -2 enrolled patients with pulmonary arterial hypertension (PAH) and pulmonary venous hypertension (PH), respectively. Haemodynamics and 6-min walk distance (6MWD) were obtained at baseline and week 16. The studies were terminated due to slow site initiation and patient enrolment (n = 26). Bosentan appeared to be well tolerated. Although sample sizes were limited, in ASSET-1 at baseline, 6MWD correlated with cardiac output (CO; P = 0.006) with non-significant inverse correlations between 6MWD and pulmonary vascular resistance (PVR; P = 0.07) and between 6MWD and right atrial pressure (P = 0.08). In ASSET-2 at baseline, there was a non-significant correlation between 6MWD and CO (P = 0.06). Due to limited sample sizes, efficacy endpoints were not analysed. However, in both studies, non-significant increases in CO were observed with bosentan compared to placebo. Similarly, non-significant decreases in PVR were observed with bosentan. Limited data in SCD-PH suggest that a low 6MWD predicts a low CO. Standard-dose bosentan appears to be well tolerated. Further investigation is warranted. Clinicaltrials.gov registration numbers NCT00310830, NCT00313196, NCT00360087.

Background The role of pulmonary hypertension as a cause of mortality in sickle cell disease (SCD) is controversial. Methods and Results We evaluated the relationship between an elevated estimated pulmonary artery systolic pressure and mortality in patients with SCD. We followed patients from the walk-PHaSST screening cohort for a median of 29 months. A tricuspid regurgitation velocity (TRV)≥3.0 m/s cuttof, which has a 67–75% positive predictive value for mean pulmonary artery pressure ≥25 mm Hg was used. Among 572 subjects, 11.2% had TRV≥3.0 m/sec. Among 582 with a measured NT-proBNP, 24.1% had values ≥160 pg/mL. Of 22 deaths during follow-up, 50% had a TRV≥3.0 m/sec. At 24 months the cumulative survival was 83% with TRV≥3.0 m/sec and 98% with TRV47 years, male gender, chronic transfusions, WHO class III–IV, increased hemolytic markers, ferritin and creatinine were also associated with increased risk of death. Conclusions A TRV≥3.0 m/sec occurs in approximately 10% of individuals and has the highest risk for death of any measured variable. The study is registered in ClinicalTrials.gov with identifier NCT00492531

Abstract 2126 Introduction: Serum ferritin (SF), the most convenient marker of iron burden in sickle cell anemia (SCA), is potentially confounded by effects of inflammation in SCA. Serum transferrin (STF) has been described as one of the independent predictors of elevated tricuspid regurgitant velocity (TRV) in SCA. Therefore in this report we investigate the potential predictive role of STF in morbidity and mortality of individuals with SCA. Methods: Patients with sickle cell disease documented by high-pressure liquid chromatography were eligible for the study. Four hundred and sixty SCA patients were recruited in this study from the community through multimedia advertisements, community outreach, and regional clinics. All evaluated patients were screened by history taking, physical examination, laboratory studies, and transthoracic echocardiography. All patients provided written informed consent. The advertisements and protocol were approved by the institutional review boards of the National Heart, Lung, and Blood Institute and Howard University. Only outpatients in stable condition were included; patients who had had a vaso-occlusive crisis within the previous two weeks or an episode of acute chest syndrome within the previous four weeks were excluded. Results: Two hundred and sixty two participants with HbSS were included in the data analysis. Forty-seven percent were male. Median age was 32 years old. Median TRV in this cohort was 2.4 m/s. Forty nine percent of participants had TRV≥2.5 m/s and 19% had TRV≥3 m/s. Patients with lower STF (0.05), but all-cause death rate was higher (22% vs. 6%, p=0.0001). Hemoglobin, CRP, alkaline phosphatase, uric acid, placenta growth factor ( Among age, gender, BNP, TRV,GFR,WBC, STF, systolic blood pressure and fetal hemoglobin, the Cox proportional analysis of mortality found TRV, GFR and STF the independent significant predictors of mortality in this cohort. Kaplan-Meier survival curve showed that patients with transferrin Conclusion: In this cohort of adults with sickle cells anemia, STF is found to be an independent predictor of endothelial dysfunction, high TRV and mortality. It may be a more sensitive predictor than serum ferritin. We propose that iron overload may induce a state of endothelial dysfunction that is a risk factor for clinical vasculopathy and death. Disclosures: No relevant conflicts of interest to declare.

Context Inhaled nitric oxide has shown evidence of efficacy in mouse models of sickle cell disease (SCD), case series of patients with acute chest syndrome, and 2 small placebo-controlled trials for treatment of vaso-occlusive pain crisis (VOC). Objective To determine whether inhaled nitric oxide gas reduces the duration of painful crisis in patients with SCD who present to the emergency department or hospital for care. Design, Setting, and Participants Prospective, multicenter, double-blind, randomized, placebo-controlled clinical trial for up to 72 hours of inhaled nitric oxide gas vs inhaled nitrogen placebo in 150 participants presenting with VOC of SCD at 11 centers between October 5, 2004, and December 22, 2008. Intervention Inhaled nitric oxide gas vs inhaled nitrogen placebo. Main Outcome Measures The primary end point was the time to resolution of painful crisis, defined by (1) freedom from parenteral opioid use for 5 hours; (2) pain relief as assessed by visual analog pain scale scores of 6 cm or lower (on 0-10 scale); (3) ability to walk; and (4) patient's and family's decision, with physician consensus, that the remaining pain could be managed at home. Results There was no significant change in the primary end point between the nitric oxide and placebo groups, with a median time to resolution of crisis of 73.0 hours (95% confidence interval [CI], 46.0-91.0) and 65.5 hours (95% CI, 48.1-84.0), respectively (P = .87). There were no significant differences in secondary outcome measures, including length of hospitalization, visual analog pain scale scores, cumulative opioid usage, and rate of acute chest syndrome. Inhaled nitric oxide was well tolerated, with no increase in serious adverse events. Increases in venous methemoglobin concentration confirmed adherence and randomization but did not exceed 5% in any study participant. Significant increases in plasma nitrate occurred in the treatment group, but there were no observed increases in plasma or whole blood nitrite. Conclusion Among patients with SCD hospitalized with VOC, the use of inhaled nitric oxide compared with placebo did not improve time to crisis resolution. Trial Registration clinicaltrials.gov Identifier: NCT00094887

Abstract 946 Platelets are activated in patients with sickle cell disease (SCD), particularly in those with pulmonary hypertension (PH), high levels of intravascular hemolysis and during vaso-occlusive crisis [Villagra et al. Blood 2007 110:2166; Hu et al. Blood 2010 doi 10.1182/blood-2010-01-267112]. One of the major factors released by activated platelets is the platelet glycoprotein thrombospondin 1 (TSP1). Our group has discovered that TSP1 inhibits nitric oxide (NO) signaling through interaction with its ubiquitous receptor CD47 [Isenberg et al. J Biol Chem 2006; 281:26069] and has been implicated in atherogenesis, intimal hyperplasia, hypertension and PH in pre-clinical animal models [Moura R et al.; Circ Res 2008; 103:1181]. We therefore hypothesized that elevated TSP1 levels in SCD patients with activated platelets could inhibit NO-signaling via a novel TSP1-dependent mechanism and impair vascular function, predisposing patients to chronic vascular disease. We have tested the plasma collected from patients (n=96) and self-reported African American control subjects (n=19) enrolled in the NIH-pulmonary hypertension screening trial for levels of TSP1. This is one of the most comprehensively phenotyped cohorts of plasma samples from patients with SCD in steady state. Plasma from healthy controls and patients was assessed in parallel for levels of TSP1 by ELISA. We found a signficant difference in TSP1 levels between patients with SCD in steady state (median (IQ range) = 888.4 ng/ml (574.0-1161.0) and healthy controls (median (IQ range) = 515.5 ng/ml (398.6-701.9)) (Wilcoxon two-sample p=0.008). Unexpectedly, TSP1 levels positively correlated with LDL cholesterol (r=0.25, p=0.03), while the correlation with total cholesterol (r=0.20, p=0.07), and apolipoprotein B (r=0.20, p=0.07) did not reach statistical significance. Interestingly, we also observed a trend between systolic blood pressure and TSP values (p=0.07). TSP1 positively correlated with white blood cell count (r=0.28, p=0.01). As expected based on TSP1 localization in platelet alpha granules, TSP1 levels strongly correlated with platelet count (r=0.56, p=0.0001). LDL remained a significant predictor of elevated TSP levels in a logistic regression model (p=0.03). We next validated these results in prospectively collected plasma samples from patients with SCD at the University of Pittsburgh Medical Center presenting in steady state (n=13) and vaso-occlusive crisis (n=7), as well as healthy controls (n=8). To minimize the confounding effect of platelet activation and degranulation ex vivo, possibly leading to spurious elevation of TSP1 levels, we immediately processed these samples in laboratory facilities adjacent to the collection sites with a double centrifugation step to obtain platelet-poor plasma. Patients with SCD in crisis had significantly elevated TSP1 levels (median (IQ range) = 544.5 ng/ml (446.4-616.9) as compared to controls (median (IQ range) = 226.6 ng/ml (30.1-287.6). In this smaller cohort, patients in steady state SCD did not have significantly elevated TSP1 values as compared to healthy controls. The association of elevated TSP1 with dysregulated lipoprotein levels may indicate a role in SCD vascular pathobiology and is the subject of current studies. Interestingly, the trend between elevated blood pressure and TSP levels is consistent with our recent report that soluble TSP1 inhibits endothelial based NO formation and endothelial dependent vasodilation [Bauer et al, Cardiovasc Res 2010 doi10.1093/cvr/cvq218]. This association suggests a possible role for TSP1 in limiting vascular NO signaling in SCD. Ongoing prospective analysis will determine the strength of these preliminary associations. We are also conducting experiments to explore whether blockade of TSP1-CD47 in the BERK murine model of SCD restores endothelial function and modulates vasculopathy. Disclosures: Ragni: Novo Nordisk, Inc.: . Isenberg:Vasculox: Equity Ownership; Radiation Control Technology: Equity Ownership.

Abstract 2583 Poster Board II-560 Background: Leg ulceration is a common, debilitating complication of sickle cell disease (SCD), affecting 8 to 50% of patients, and recently found to be associated with the hemolytic phenotype. We evaluated the relationship of leg ulceration history with estimated pulmonary artery systolic pressure, hemolytic rate and other clinical characteristics in a cohort of 396 adults with SCD. Materials and methods: All SCD patients were enrolled in a NHLBI-approved protocol and were screened for pulmonary hypertension with echocardiography at steady state. We collected a detailed past medical history, as well as a comprehensive set of laboratory tests. Comparisons between patients with and without a history of leg ulcers were made using Wilcoxon rank sum tests to compare medians of continuous variables. Associations between categorical variables and leg ulcer history in two groups were tested using the chi-square test of independence. Results: Eighteen % of all subjects had a history of leg ulceration. Patients affected were older, predominantly had homozygous SCD, and had markers of significantly more severe hemolysis, including low hemoglobin and high reticulocyte counts, LDH and AST. They also had a significantly higher prevalence of elevated tricuspid regurgitation velocities (TRV≥2.5 m/sec, 56% vs. 40%, p=0.02; TRV≥3 m/sec, 22% vs. 12%, p=0.006). High serum uric acid and lower serum albumin were significantly associated with a history of leg ulcers. A self-reported history of hepatitis also was associated with leg ulceration. None of the other parameters evaluated were significantly associated with leg ulceration, including history of pain, acute chest syndrome, stroke or priapism. Significantly, patients with a history of leg ulcers were more likely to have died by the time of data analysis (21% vs. 9%, P=0.02). Discussion: These data in SCD patients with a history of leg ulcers provide the first demonstration of an association with elevated serum uric acid and confirmation of published associations with elevated pulmonary pressures and markers of hemolytic severity. The uric acid association is more significant than that for serum creatinine or urea nitrogen, suggesting that uric acid is more than simply a marker of renal dysfunction. In patients without SCD, there is a growing literature implicating uric acid as a possible cause of hypertension and a marker of risk for cardiovascular disease, pulmonary hypertension, and early mortality. This is particularly interesting, in view of the epidemiological relationship between leg ulcers and pulmonary hypertension demonstrated here and previously by others. The results continue to support linkage of leg ulcers and pulmonary hypertension to a hyperhemolytic -vasculopathy subphenotype of SCD. Disclosures: No relevant conflicts of interest to declare.

Background Sleep disturbance and depression are commonly encountered in primary care. In sickle cell disease, depression is associated with pain, poor treatment compliance, and lower quality of life. The prevalence of sleep disturbance and its effect upon quality of life in adults with sickle cell disease is unknown. The goal of this study was to determine the prevalence of sleep disturbance and if it is associated with pain and depression in sickle cell disease. Methods Three hundred twenty eight adults with sickle cell disease enrolled on the Bethesda Sickle Cell Cohort Study were assessed using the Pittsburgh Sleep Quality Index and Beck Depression Inventory II screening measures as a cross-sectional survey. Scores greater than 5 (Pittsburgh Sleep Quality Index) and 16 (Beck Depression Inventory II) defined sleep disturbance and depression, respectively. Clinical and laboratory parameters were also assessed. Results The mean Pittsburgh Sleep Quality Index score was 8.4 (SD ± 4.2) indicating a 71.2% prevalence of sleep disturbance. The mean Beck Depression Inventory II score was 8.0 (SD ± 8.9). Sixty five (20.6%) participants had a score indicating depression, and half of these (10.0%) had thoughts of suicide. Both Pittsburgh Sleep Quality Index and Beck Depression Inventory II scores were significantly correlated (p

Abstract 90 The Walk-Phasst Study of sickle cell disease (SCD) affords a unique opportunity to examine renal function in a large number of adults with SCD. Extensive clinical and laboratory data were obtained on 463 adults with HbSS and 127 adults with HbSC. Where possible, correlates for estimated glomerular filtration rate (eGFR, calculated by the 4-value MDRD equation) and albuminuria/proteinuria were also evaluated in historical data, from SS adults in the CSCCD cohort and the Multicenter Study of Hydroxyurea (MSH) in sickle cell disease. Adjusted decline in eGFR was more rapid in SS compared with SC, at −2.6 and −0.92 ml/min/1.73 m2/year, respectively (p Albuminuria (≥30 mg albumin/gm creatinine) was detectable in 66 and 41 % of adults with HbSS and HbSC in Walk-Phasst (185/287 evaluable SS and 25/61 evaluable SC, p=0.001). In Walk-Phasst, albuminuria in SS was associated with evidence of increased red cell destruction (lower total hemoglobin (P=0.07), higher LDH (P Subjects with SS in Walk-Phasst had depressed serum bicarbonate levels, of 23.8±3.4 compared with 24.7±3.2mEq/dL in SC (p In conclusion, renal function is perturbed in sickle cell syndromes in several ways, including more rapid decrement in eGFR, highly prevalent albuminuria, and, in SS, marked abnormalities in acid-base balance. Albuminuria is associated with anemia in two large cohorts of sickle cell disease patients and, in Walk-Phasst, with evidence for enhanced red cell destruction. Importantly, albuminuria correlated with an increased risk for mortality in sickle cell disease. (We acknowledge the many contributions made by the Walk-PHASST Investigators: Badesch DB, Barst RJ, Castro OL, Girgis RE, Gibbs JS, Goldsmith JC, Hannoush H, Hassell KL, Kato GJ, Krishnamurti L, Lanzkron S, Machado RF, Morris CR, Novelli EM, Rosenzweig EB, Sachdev V, Schraufnagel DE, Taylor JG 6th.) Disclosures: No relevant conflicts of interest to declare.