Hemolysis-associated pulmonary hypertension in thalassemia.
Accumulating evidence supports the existence of a condition involving hemolysis-associated pulmonary hypertension (PHT). Hemolysis-induced release of cell-free hemoglobin and red blood cell arginase, resulting in impaired nitric oxide bioavailability, endothelial dysfunction, and PHT, has been reported in sickle cell disease. Since thalassemia is also a condition of chronic hemolysis, these patients are at risk. The data demonstrate that hemolysis-induced dysregulation of arginine metabolism and PHT also occurs in thalassemia. Erythrocyte release of arginase during hemolysis contributes to the development of PHT. Therapies that maximize arginine and nitric oxide bioavailability may benefit patients with thalassemia.
Morris
Claudia R
CR
Department of Emergency Medicine, Children's Hospital & Research Center at Oakland, 747 52nd Street, Oakland, California 94609, USA. claudiamorris@comcast.net
Kuypers
Frans A
FA
Kato
Gregory J
GJ
Lavrisha
Lisa
L
Larkin
Sandra
S
Singer
Titi
T
Vichinsky
Elliott P
EP
D001119:Arginase / Q000097:blood*; D001120:Arginine / Q000097:blood; D004730:Endothelium, Vascular / Q000503:physiopathology; D004912:Erythrocytes / Q000201:enzymology; D006446:Hemoglobin E; D006461:Hemolysis; D006801:Humans; D006976:Hypertension, Pulmonary / Q000097:blood / Q000209:etiology* / Q000503:physiopathology; D009569:Nitric Oxide / Q000097:blood; D009952:Ornithine / Q000097:blood; D013789:Thalassemia / Q000097:blood / Q000150:complications*; D014261:Tricuspid Valve / Q000503:physiopathology; D017085:alpha-Thalassemia / Q000097:blood / Q000150:complications / Q000235:genetics
D009569:Nitric Oxide; D006446:Hemoglobin E; D001120:Arginine; D009952:Ornithine; D001119:Arginase