Although patients with sickle cell disease (SCD) share a common hemoglobin (Hb) mutation; their clinical presentation is quite variable suggesting a role for extra-erythrocytic genetic and environmental factors in the modulation of the disease process. Chronic pulmonary disease characterized by pulmonary hypertension (PH) and right-sided congestive heart failure (cor pulmonale) is an under-appreciated complication. Although it may be present in up to 40%, it is often asymptomatic. Determination of etiological factors responsible for the development of PH in SCD is important as PH represents an independent risk factor for death in this population. Our laboratory has determined that nitric oxide (NO) metabolism is altered in the acute chest syndrome (ACS) of SCD, with the preferential formation of powerful oxidative metabolites such as peroxynitrite and resultant decreased NO bioavailability. As recurrent episodes of ACS may be a risk factor for the development of PH in SCD patients, similarities in pathogenesis may exist. We hypothesize that extra-erythrocytic genetic polymorphisms are an important pre-disposing risk factor for the development of PH in SCD patients and that these polymorphisms are associated with decreases in NO bioavailability. Reductions in functional NO act within the endothelium to produce a pro-constrictive, pro-adhesive phenotype which likely plays an important role in the development of PH of SCD. To investigate these hypotheses, we will: 1) Determine the prevalence and clinical outcome of PH in a clinic population of SCD patients; 2) Determine the role of altered nitric oxide bioavailability in the development of PH of SCD; and 3) Correlate the presence of single nucleotide polymorphisms in endothelial cell-expressed genes in the NO pathway with the presence of PH of SCD. The goal of this application is to establish a cohort of patients with PH related to SCD so that they may be studied biochemically and genetically to gain great insight into the pathogenesis of pulmonary vascular disease in these patients.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Mentored Patient-Oriented Research Career Development Award (K23)
Project #
5K23HL079003-04
Application #
7342462
Study Section
Special Emphasis Panel (ZHL1-CSR-Q (O1))
Program Officer
Werner, Ellen
Project Start
2005-01-01
Project End
2009-12-31
Budget Start
2008-01-01
Budget End
2008-12-31
Support Year
4
Fiscal Year
2008
Total Cost
$127,359
Indirect Cost
Name
Boston University
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
604483045
City
Boston
State
MA
Country
United States
Zip Code
02118
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Safaya, Surinder; Klings, Elizabeth S; Odhiambo, Adam et al. (2009) Effect of sodium butyrate on lung vascular TNFSF15 (TL1A) expression: differential expression patterns in pulmonary artery and microvascular endothelial cells. Cytokine 46:72-8
Klings, Elizabeth S; Anton Bland, Demedrick; Rosenman, Dara et al. (2008) Pulmonary arterial hypertension and left-sided heart disease in sickle cell disease: clinical characteristics and association with soluble adhesion molecule expression. Am J Hematol 83:547-53
Morris, Claudia R; Suh, Jung H; Hagar, Ward et al. (2008) Erythrocyte glutamine depletion, altered redox environment, and pulmonary hypertension in sickle cell disease. Blood 111:402-10
Odhiambo, Adam; Perlman, David H; Huang, Hua et al. (2007) Identification of oxidative post-translational modification of serum albumin in patients with idiopathic pulmonary arterial hypertension and pulmonary hypertension of sickle cell anemia. Rapid Commun Mass Spectrom 21:2195-203
Klings, Elizabeth S; Wyszynski, Diego F; Nolan, Vikki G et al. (2006) Abnormal pulmonary function in adults with sickle cell anemia. Am J Respir Crit Care Med 173:1264-9