Design and Validation of Genes Encoding Hyperstable β-Globin mRNAs.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4059-4059
Author(s):  
Osheiza Abdulmalik ◽  
J. Eric Russell
Keyword(s):  
Sickle Cell Disease ◽  
Mrna Stability ◽  
Half Life ◽  
Fold Increase ◽  
Globin Genes ◽  
Wild Type ◽  
Cell Disease ◽  
Globin Mrna ◽  
Stem Loop ◽  
The Stability

Abstract 4059 Poster Board III-994 Transgenic approaches to β thalassemia and sickle cell disease require viral vectors that express high levels of therapeutic β-like globin proteins. We recently proposed that the overall expression of these transgenes would likely be improved by structural modifications that prolong the cytoplasmic half-lives of their encoded mRNAs. Relevant experiments from our laboratory have previously linked the constitutively high stability of β-globin mRNA to a region of its 3'UTR that appears to interact with at least two distinct cytoplasmic mRNA-stabilizing factors, and is predicted to form an imperfect stem-loop (SL) structure. Based upon these findings, we conducted enzymatic secondary-structure mapping studies of the β-globin 3'UTR, unequivocally validating the existence of the predicted functional stem-loop element. We subsequently reasoned that the constitutive half-life of β-globin mRNA might be prolonged by the insertion of multiple SL motifs into its 3'UTR, resulting in increased levels of the mRNA–and its encoded β-globin product–in terminally differentiating erythroid cells. To test this hypothesis, we constructed full-length β-globin genes containing either wild-type 3'UTRs, or variant 3'UTRs that had been modified to contain either two or three tandem SL motifs. Each gene was identically linked to a tetracycline-suppressible promoter, permitting pulse-chase mRNA stability analyses to be conducted in vivo in intact cultured cells. Erythroid-phenotype K562 cells were transiently transfected with SL-variant and control wild-type β-globin genes, exposed to tetracycline, and levels of β-globin mRNA determined by qRT-PCR at defined intervals using tet-indifferent β-actin mRNA as internal control. Relative to wild-type β-globin mRNA, SL-duplicate β-globin mRNAs displayed a position-dependent two-fold increase in cytoplasmic half-life; SL-triplicate β-globin mRNAs did not exhibit any additional stability. These experiments confirm the existence of a defined SL structure within the β-globin 3'UTR, and demonstrate that duplication of this motif can substantially increase the stability of β-globin mRNA. We subsequently designed a series of experiments to elucidate post-transcriptional processes involved in mRNA hyperstability. These studies required the construction of HeLa cells that stably express either wild-type β-globin mRNA (11 subclones) or SL-duplicate β-globin mRNAs (10 subclones). Preliminary analyses indicate an approximate 1.5-fold increase in the median steady-state expression of SL-duplicate genes, consistent with a prolongation in the half-life of its encoded mRNA. While formal mRNA stability studies are not yet complete, early data appear to replicate results from experiments conducted in transiently transfected cells. We have also initiated structural studies to link differences in the stability of SL-variant β-globin mRNA to alterations in its poly(A) tail. Using an RNase H-based strategy, we identified a previously unknown poly(A)-site heterogeneity–of undetermined significance–affecting both wild-type and SL-duplicate β-globin mRNAs. Finally, we recently isolated fifty-four K562 subclones expressing SL-duplicate or control β-globin mRNAs; parallel analyses of these cells will permit the cell-specificity of β-globin SL-directed mRNA stabilization to be investigated in detail. Results from each of these studies will be immediately applicable to the design of high-efficiency therapeutic transgenes for β thalassemia and sickle-cell disease. Disclosures: No relevant conflicts of interest to declare.

Differences in Fetal Hemoglobin Induction in Sickle Cell Disease and beta-Thalassemia.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 555-555 ◽  
Author(s):  
Hassana Fathallah ◽  
Ali Taher ◽  
Ali Bazarbachi ◽  
George F. Atweh
Keyword(s):  
Gene Expression ◽  
Sickle Cell Disease ◽  
Globin Gene ◽  
Fetal Hemoglobin ◽  
Mrna Levels ◽  
Globin Genes ◽  
Thalassemia Intermedia ◽  
Cell Disease ◽  
Globin Mrna ◽  
Globin Gene Expression

Abstract A number of therapeutic agents including hydroxyurea, butyrate and decitabine have shown considerable promise in the treatment of sickle cell disease (SCD). However, the same agents have shown less clinical activity in β-thalassemia. As a first step towards understanding the molecular basis of the different clinical responses to these agents, we have studied the mechanisms of induction of fetal hemoglobin (HbF) by butyrate in BFU-E derived cells from 5 patients with SCD and 9 patients with β-thalassemia intermedia. Exposure to butyrate resulted in a dose-dependent augmentation of γ-globin mRNA levels in erythroid cells from patients with SCD. In contrast, induction of γ-globin expression in erythroid cells from patients with β-thalassemia intermedia was only seen at a high concentration of butyrate. The increase in γ-globin mRNA levels in patients with SCD and β-thalassemia intermedia was associated with opening of the DNA structure as manifested by decreased DNA methylation at the γ-globin promoters. Interestingly, butyrate exposure had markedly different effects on the expression of the β- and α-globin genes in the two categories of patients. Butyrate decreased the level of β-globin mRNA in 4 out of 5 patients with SCD (P = 0.04), while in β-thalassemia the levels of β-globin mRNA did not change in 7 patients and decreased in 2 patients after butyrate exposure (P = 0.12). Thus in patients with SCD, the effects of the induction of the γ-globin gene on the γ/(β+γ) mRNA ratios were further enhanced by the butyrate-mediated decreased expression of the β-globin gene. As a result, γ/(β+γ) mRNA ratios increased in all patients with SCD, with a mean increase of 31% (P = 0.002). In contrast, butyrate increased γ/(β+γ) mRNA ratios only in 4 out of 9 patients with β-thalassemia, with a more modest mean increase of 12% (P = 0.004). Interestingly, the decreased β-globin expression in patients with SCD was associated with closing of the DNA configuration as manifested by hypermethylation of DNA at the promoter of the β-globin gene while methylation of the same promoter did not change following butyrate exposure in patients with β-thalassemia intermedia. More surprisingly, the expression of the α-globin genes increased following butyrate exposure in 4 out of 9 patients with β-thalassemia, while the levels of α-globin mRNA decreased in 4 out of 5 patients with SCD. As a result, the favorable effects of the butyrate-induced increase in γ-globin gene expression on the α: non-α mRNA imbalance in patients with β-thalassemia intermedia were partly neutralized by the corresponding increase in α-globin gene expression. These differences may explain, at least in part, the more favorable effects of inducers of HbF in SCD than in β-thalassemia. Further studies are necessary to fully understand the molecular bases of the different responses to agents that induce HbF in patients with these disorders.

scholarly journals Investigation of the Stability of Yeast rad52 Mutant Proteins Uncovers Post-translational and Transcriptional Regulation of Rad52p

Genetics ◽  
2003 ◽  
Vol 163 (1) ◽  
pp. 91-101 ◽  
Author(s):  
Erin N Asleson ◽  
Dennis M Livingston
Keyword(s):  
Half Life ◽  
Translational Regulation ◽  
Cellular Level ◽  
Missense Mutations ◽  
Wild Type ◽  
Mutant Proteins ◽  
Gal1 Promoter ◽  
Rad52 Protein ◽  
The Stability ◽  
Mutant Forms

Abstract We investigated the stability of the Saccharomyces cerevisiae Rad52 protein to learn how a cell controls its quantity and longevity. We measured the cellular levels of wild-type and mutant forms of Rad52p when expressed from the RAD52 promoter and the half-lives of the various forms of Rad52p when expressed from the GAL1 promoter. The wild-type protein has a half-life of 15 min. rad52 mutations variably affect the cellular levels of the protein products, and these levels correlate with the measured half-lives. While missense mutations in the N terminus of the protein drastically reduce the cellular levels of the mutant proteins, two mutations—one a deletion of amino acids 210-327 and the other a missense mutation of residue 235—increase the cellular level and half-life more than twofold. These results suggest that Rad52p is subject to post-translational regulation. Proteasomal mutations have no effect on Rad52p half-life but increase the amount of RAD52 message. In contrast to Rad52p, the half-life of Rad51p is >2 hr, and RAD51 expression is unaffected by proteasomal mutations. These differences between Rad52p and Rad51p suggest differential regulation of two proteins that interact in recombinational repair.

scholarly journals Engineering, Generation and Preliminary Characterization of a Humanized Porcine Sickle Cell Disease Animal Model

2020 ◽  
Author(s):  
Tobias M. Franks ◽  
Sharie J. Haugabook ◽  
Elizabeth A. Ottinger ◽  
Meghan S. Vermillion ◽  
Kevin M. Pawlik ◽  
...  
Keyword(s):  
Animal Model ◽  
Sickle Cell Disease ◽  
Mouse Models ◽  
Sickle Cell ◽  
Cell Model ◽  
Globin Genes ◽  
Cell Disease ◽  
Small Vessels

AbstractMouse models of sickle cell disease (SCD) that faithfully switch from fetal to adult hemoglobin (Hb) have been important research tools that accelerated advancement towards treatments and cures for SCD. Red blood cells (RBCs) in these animals sickled in vivo, occluded small vessels in many organs and resulted in severe anemia like in human patients. SCD mouse models have been valuable in advancing clinical translation of some therapeutics and providing a better understanding of the pathophysiology of SCD. However, mouse models vary greatly from humans in their anatomy and physiology and therefore have limited application for certain translational efforts to transition from the bench to bedside. These differences create the need for a higher order animal model to continue the advancement of efforts in not only understanding relevant underlying pathophysiology, but also the translational aspects necessary for the development of better therapeutics to treat or cure SCD. Here we describe the development of a humanized porcine sickle cell model that like the SCD mice, expresses human ɑ-, β− and γ-globin genes under the control of the respective endogenous porcine locus control regions (LCR). We also describe our initial characterization of the SCD pigs and plans to make this model available to the broader research community.

Abstract P726: Cytochrome B5 Reductase 3 Modifies The Brain-Blood Axis Response To Ischemic Stroke In Mice With Sickle Cell Disease

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Katherine C Wood ◽  
Heidi M Schmidt ◽  
Scott Hahn ◽  
Mehdi Nouraie ◽  
Mara Carreno ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Ischemic Stroke ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
African Ancestry ◽  
Cytochrome B5 ◽  
Heme Iron ◽  
Wild Type ◽  
Cell Disease ◽  
Cytochrome B5 Reductase

Introduction: Stroke and silent infarcts are serious complications of sickle cell disease (SCD), occurring frequently in children. Decreased nitric oxide bioavailability and responsiveness contribute to neurovascular disease. Cytochrome b5 reductase 3 (Cyb5R3) is a heme iron reductase that reduces oxidized soluble guanylate cyclase heme iron (Fe 3+ --> Fe 2+ ) to preserve nitric oxide signaling. A loss-of-function Cyb5R3 missense variant (T117S) occurs with high frequency (0.23 minor allele) in persons of African ancestry. Hypothesis: We hypothesized that impaired reductase function of T117S Cyb5R3 exacerbates brain damage after ischemic stroke in SCD. Methods: Bone marrow transplant was used to create male SCD mice with wild type (SS/WT) or T117S (SS/T117S) Cyb5R3. Blood was sampled before and after middle cerebral artery occlusion (55 minutes occlusion, 48 hours reperfusion). Infarct volume (IV) was determined by 2,3,5-triphenyltetrazolium chloride. Intravascular hemolysis and correlation (Pearson’s R) of hematology changes with IV were determined. Baseline Walk-PHaSST (NCT00492531) data were analyzed for stroke occurrence. Results: Brain IV (63 vs 27 cm 3 , P=0.003) and mortality (3/6 vs 0/8) were greater in SS/T117S vs SS/WT. Red blood cells, hemoglobin and hematocrit declined as IV increased. Plasma oxyhemoglobin increased in parallel with IV (r = 0.74, P=0.09). There were different signatures to hematologic changes that occurred with IV in SCD. Relative to wild type, T117S contracted the erythroid compartment (red blood cell: -13% vs 13%, P=0.003; hematocrit: -20% vs 1%, P=0.008; hemoglobin: -18% vs 2%, P=0.007). Mean platelet volume correlated with IV in SS/T117S (r = 0.87, P=0.06), while the inverse occurred in SS/WT (r = -0.63, P=0.09) Monocytes increased in parallel with IV in SS/T117S (r = 0.73, P=0.16), but followed the opposite trajectory in SS/WT (r = -0.77, P=0.04). WalkPHaSST participants with T117S Cyb5R3 self-reported more ischemic stroke (7.4% vs 5.1%) relative to wild type. Conclusion: Cyb5R3 is an important modifier of the evolution and outcome of ischemic brain injury in SCD and its hematologic consequences. Our findings indicate a bidirectional relationship between stroke and anemia in SCD that may axially turn on Cyb5R3 activity.

Haemoglobinopathies

2013 ◽  
pp. 1466-1470
Author(s):  
David Rees
Keyword(s):  
Bone Marrow ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Lupus Erythematosus ◽  
Single Gene ◽  
Globin Genes ◽  
Globin Chain ◽  
Cell Disease ◽  
Chain Synthesis ◽  
Marrow Expansion

Inherited abnormalities of the globin genes are the commonest single-gene disorders in the world and fall into two main groups: thalassaemias and sickle cell disease. Thalassaemias are due to quantitative defects in globin chain synthesis which cause variable anaemia and ineffective erythropoiesis. Thalassaemia was initially thought to be a disease of the bones due to uncontrolled bone marrow expansion causing bony distortion, although this is now unusual with appropriate blood transfusions. Osteopenia, often severe, is a feature of most patients with thalassaemia major and intermedia, caused by bone marrow expansion, iron overload, endocrinopathy, and iron chelation. Treatment with bisphosphonates is generally recommended. Other rheumatological manifestations include arthropathy associated with the use of the iron chelator deferiprone. Sickle cell disease involves a group of conditions caused by polymerization of the abnormal -globin chain, resulting in abnormal erythrocytes which cause vaso-occlusion, vasculopathy, and ischaemic tissue damage. The characteristic symptom is acute bone pain caused by vaso-occlusion; typical episodes require treatment with opiate analgesia and resolve spontaneously by 5 days with no lasting bone damage. The frequency of acute episodes varies widely between patients. The incidence of osteomyelitis is increased, particularly with salmonella, although it is much rarer than acute vaso-occlusion. Avascular necrosis can affect the hips, and less commonly the shoulders and knees. Coincidental rheumatological disease sometimes complicates the condition, particularly systemic lupus erythematosus (SLE) which is more prevalent in populations at increased risk of sickle cell disease.

Haemoglobinopathies

2013 ◽  
Author(s):  
David Rees
Keyword(s):  
Bone Marrow ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Lupus Erythematosus ◽  
Single Gene ◽  
Globin Genes ◽  
Globin Chain ◽  
Cell Disease ◽  
Increased Risk ◽  
Marrow Expansion

Inherited abnormalities of the globin genes are the commonest single-gene disorders in the world and fall into two main groups: thalassaemias and sickle cell disease. Thalassaemias are due to quantitative defects in globin chain synthesis which cause variable anaemia and ineffective erythropoiesis. Thalassaemia was initially thought to be a disease of the bones due to uncontrolled bone marrow expansion causing bony distortion, although this is now unusual with appropriate blood transfusions. Osteopenia, often severe, is a feature of most patients with thalassaemia major and intermedia, caused by bone marrow expansion, iron overload, endocrinopathy, and iron chelation. Treatment with bisphosphonates is generally recommended. Other rheumatological manifestations include arthropathy associated with the use of the iron chelator deferiprone. Sickle cell disease involves a group of conditions caused by polymerization of the abnormal -globin chain, resulting in abnormal erythrocytes which cause vaso-occlusion, vasculopathy, and ischaemic tissue damage. The characteristic symptom is acute bone pain caused by vaso-occlusion; typical episodes require treatment with opiate analgesia and resolve spontaneously by 5 days with no lasting bone damage. The frequency of acute episodes varies widely between patients. The incidence of osteomyelitis is increased, particularly with salmonella, although it is much rarer than acute vaso-occlusion. Avascular necrosis can affect the hips, and less commonly the shoulders and knees. Coincidental rheumatological disease sometimes complicates the condition, particularly systemic lupus erythematosus (SLE) which is more prevalent in populations at increased risk of sickle cell disease.

The Bβ-sheet in the PAI-1 Molecule Plays an Important Role for Its Stability

2000 ◽  
Vol 83 (06) ◽  
pp. 896-901 ◽  
Author(s):  
Guang-Chao Sui ◽  
Björn Wiman
Keyword(s):  
Amino Acids ◽  
Half Life ◽  
Ph Dependence ◽  
The Other ◽  
Wild Type ◽  
E Coli ◽  
Reactive Center ◽  
The Stability ◽  
Β Sheet ◽  
Pai 1

SummaryWe have investigated the B β-sheet in PAI-1 regarding its role for the stability of the molecule. The residues from His219 to Tyr241 (except for Gly230 and Pro240), covering the s2B and s3B strands, and in addition His185 and His190 were substituted by amino acids with opposite properties. The 23 generated single-site changed mutants and also wild type PAI-1 (wtPAI-1) were expressed in E. coli. Subsequently they were purified by heparin-Sepharose and anhydrotrypsin agarose affinity chromatographies. The stability of the purified PAI-1 variants was analyzed at 37° C and at different pHs (5.5, 6.5 or 7.5). At pH 7.5 and 37° C, single substitutions of the residues in the central portions of both strands 2 and 3 in the B β-sheet (Ile223 to Leu226 on s2B and Met235 to Ile237 on s3B), caused a significant decrease in stability, yielding half-lives of about 10–25% as compared to wtPAI-1. On the other hand, mutations at both sides of the central portion of the B β-sheet (Tyr221, Asp222, Tyr228 and Thr232) frequently resulted in an increased PAI-1 stability (up to 7-fold). While wtPAI-1 exhibited prolonged half-lives at pH 6.5 and 5.5, the PAI-1 variant Y228S was more stable at neutral pH (half-life of 9.6 h at pH 7.5) as compared to its half-life at pH 5.5 (1.1 h). One of the 4 modified histidine residues (His229) resulted in a variant with a clearly affected stability as a function of pH, suggesting that it may, at least in part, be of importance for the pH dependence of the PAI-1 stability. Thus, our data demonstrate that the B β-sheet is of great importance for the stability of the molecule. Modifications in this part causes decreased or increased stability in a certain pattern, suggesting effects on the insertion rate of the reactive center loop into the A β-sheet of the molecule.

Nitrated Lipids in a Murine Model of Sickle Cell Disease at Baseline.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3758-3758
Author(s):  
Jeffrey Schwartz ◽  
Paul R.S. Baker ◽  
Francisco J. Schopfer ◽  
Bruce A. Freeman
Keyword(s):  
Linoleic Acid ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Ion Trap ◽  
Internal Standard ◽  
Wild Type ◽  
Cell Disease ◽  
Inflammatory Signaling ◽  
No Bioavailability ◽  
Anti Inflammatory

Abstract Introduction Sickle cell disease (SCD) is increasingly recognized as a disorder of inflammatory homeostasis. One major focus in recent years has been understanding the role of Nitric Oxide (NO) in the pathophysiology of SCD. NO is a critical mediator of inflammatory pathways and current evidence supports the precept that NO bioavailability is decreased in SCD, resulting in normal concentrations of NO at baseline but an inability to increase NO during stress. Nitrated fatty acids, such as Nitrolinoleate (LNO2), have recently been reported as potent and abundant anti-inflammatory signaling mediators with the ability to cause vasorelaxation and inhibition of platelet and neutrophil activation. Evidence supports their anti-inflammatory signaling is mediated through the release of NO and NO-related products. LNO2 has not previously been described in patients with SCD and our objective was to quantify LNO2 in a murine model of SCD at baseline. Methods Whole blood was obtained from transgenic sickle cell and wild type mice (n = 5 and 6, respectively). Blood was centrifuged and separated into plasma and packed red blood cells (RBCs). These biological samples were prepared for lipid analysis by the method of Bligh and Dyer; care was taken so that the pH of the extraction milieu was consistently maintained at 7 so as to avoid artifactual nitration. Samples were analyzed for free LNO2 content by electrospray ionization tandem mass spectrometry. Using a hybrid triple quadrupole ion trap mass spectrometer, MRM transitions were monitored that specifically identified nitrated linoleic acid species; these species were concomitantly confirmed by the qualitative analytical abilities of the ion trap. The presence of nitrated linoleic acid was confirmed by HPLC chromatographic retention times, MS/MS “fingerprints” and was quantitated by the inclusion of a known quantity of 13C-labeled LNO2. Results LNO2 concentration was calculated as a function of the ratio of analyte to internal standard peak areas by using an internal standard curve linear over five orders of magnitude. Free LNO2 in the RBCs and plasma of 5 transgenic sickle cell mice were 3.97 ± 2.56 nM and 12.37 ± 9.83 nM, respectively. Free LNO2 in the RBCs and plasma of 6 wild type mice were 9.49 ± 8.32 nM and 14.91 ± 10.08 nM, respectively. There were no significant differences in LNO2 concentration between any of the groups. Conclusions LNO2 is present in both transgenic sickle cell mice and wild type mice in comparable concentrations at baseline. As a mediator of NO anti-inflammatory signaling, this is consistent with human studies showing comparable concentrations of NO metabolites at baseline between sickle cell patients and healthy controls. Further study of LNO2 in sickle cell disease is warranted to better understand its role in the inflammatory process associated with acute stress, such as vaso-occlusive pain crisis and acute chest syndrome, when NO bioavailability is decreased.

Risk Factors for Echocardiography-Determined Cardiopulmonary Abnormalities In Sickle Cell Anemia In the Walk-PHaSST Study

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 260-260 ◽  
Author(s):  
Gregory J. Kato
Keyword(s):  
Sickle Cell Disease ◽  
Diastolic Dysfunction ◽  
Sickle Cell ◽  
Sickle Cell Anemia ◽  
Fold Increase ◽  
Lateral Wall ◽  
Left Ventricular Diastolic Dysfunction ◽  
Left Ventricular ◽  
Cell Disease ◽  
Ventricular Diastolic Dysfunction

Abstract 260 Background: Elevated right ventricular pressure [1] and left ventricular diastolic dysfunction [2] as assessed by echocardiography are each independently associated with increased mortality in adults with sickle cell anemia. To determine independent risk factors for these echocardiographic findings, we examined a large, prospective, multi-center international cohort in a cross-sectional manner. In a previous study of adults with sickle cell disease, we identified histories of cardiac and renal disease, higher values for serum lactate dehydrogenase (LDH), alkaline phosphatase, and systolic blood pressure, and lower values for transferrin to have independent associations with elevated right ventricular systolic pressure as estimated by echocardiography [1]. Methods: Walk-PHaSST (treatment of Pulmonary Hypertension and Sickle cell disease with Sildenafil Therapy) includes an on-going observational study of sickle cell disease patients at nine United States Centers and one United Kingdom Center. In the screening phase of the study, clinical evaluation and echocardiography were performed on 720 subjects. For this analysis, we determined among 483 patients with hemoglobin SS baseline clinical associations with the echocardiographic measurements of tricuspid regurgitation velocity (TRV), which reflects right ventricular systolic pressure, and left ventricular lateral wall E/Ea ratio, which reflects left ventricular filling pressure as a measure of diastolic dysfunction. The study prospectively defined moderately elevated TRV as 2.7–2.9 m/sec and markedly elevated TRV as ≥3.0 m/sec. A hemolytic component was derived by principal component analysis from four markers of hemolysis: reticulocyte percent, serum LDH, aspartate aminotransferase and bilirubin. Results: Of 483 hemoglobin SS patients, the median age was 35 years (range of 12 to 69 years) and the gender distribution was 250 females and 233 males. TRV was measured in 453 patients, lateral wall E/Ea was measured in 436 and hemolytic component was calculated in 406. TRV was 2.7–2.9 m/sec in 22% and ≥3.0 m/sec in 17%. By ordinal logistic regression, an increase of age of 10 years was independently associated with a 1.5-fold increase in the odds of progressively higher TRV categories (95% CI of 1.2–1.8; P <0.0005), an increase in the hemolytic component of 2 SD with a 2.4-fold increase in the odds of progressively higher categories (95% CI of 1.5–3.8; P <0.0005), a log increase in the lateral wall E/Ea ratio with a 3.2-fold increase in the odds (95% CI of 1.6–6.6; P=0.001), and a serum creatinine >1.4 mg/dL with a 2.1-fold increase in the odds (95% CI of 1.0–4.3; P=0.047). By linear regression, older age was independently associated with a higher log lateral wall E/Ea ratio (beta=0.005; P <0.0005) as were serum creatinine >1.4 mg/dL (beta=0.23; P <0.0005) and lower hemoglobin concentration (beta=-0.002; P=0.022). Conclusions: The findings of this large prospective, multicenter, international study of patients with sickle cell anemia emphasizes the association of older age, severe hemolytic anemia, renal dysfunction, and left ventricular diastolic dysfunction with high TRV, a previously confirmed marker of early mortality. Clinical trials are indicated to test whether strategies to correct hemolytic anemia and to prevent renal dysfunction in adults and adolescents with sickle cell anemia may prevent or delay the development of left ventricular diastolic dysfunction and/or pulmonary hypertension. References: 1. Gladwin, M.T., et al., Pulmonary hypertension as a risk factor for death in patients with sickle cell disease. N Engl J Med, 2004. 350(9): p.886-95. 2. Sachdev, V., et al., Diastolic dysfunction is an independent risk factor for death in patients with sickle cell disease. J Am Coll Cardiol, 2007. 49(4): p.472-9. Disclosures: No relevant conflicts of interest to declare.

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