title: Novel approach to reactive oxygen species in nontransfusion-dependent thalassemia.
abstract: The term Nontransfusion dependent thalassaemia (NTDT) was suggested to describe patients who had clinical manifestations that are too severe to be termed minor yet too mild to be termed major. Those patients are not entirely dependent on transfusions for survival. If left untreated, three main factors are responsible for the clinical sequelae of NTDT: ineffective erythropoiesis, chronic hemolytic anemia, and iron overload. Reactive oxygen species (ROS) generation in NTDT patients is caused by 2 major mechanisms. The first one is chronic hypoxia resulting from chronic anemia and ineffective erythropoiesis leading to mitochondrial damage and the second is iron overload also due to chronic anemia and tissue hypoxia leading to increase intestinal iron absorption in thalassemic patients. Oxidative damage by reactive oxygen species (generated by free globin chains and labile plasma iron) is believed to be one of the main contributors to cell injury, tissue damage, and hypercoagulability in patients with thalassemia. Independently increased ROS has been linked to a myriad of pathological outcomes such as leg ulcers, decreased wound healing, pulmonary hypertension, silent brain infarcts, and increased thrombosis to count a few. Interestingly many of those complications overlap with those found in NTDT patients.
authors.affiliation: Department of Physiology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon.
authors.forename: Paul I
authors.initials: PI
authors.lastname: Tyan
authors.affiliation: Department of Internal Medicine, American University of Beirut Medical Center, P.O. Box 11-0236, Beirut, Lebanon.
authors.forename: Amr H
authors.initials: AH
authors.lastname: Radwan
authors.affiliation: Department of Physiology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon.
authors.forename: Assaad
authors.initials: A
authors.lastname: Eid
authors.affiliation: Department of Internal Medicine, American University of Beirut Medical Center, P.O. Box 11-0236, Beirut, Lebanon.
authors.forename: Anthony G
authors.initials: AG
authors.lastname: Haddad
authors.affiliation: Department of Internal Medicine, American University of Beirut Medical Center, P.O. Box 11-0236, Beirut, Lebanon.
authors.forename: David
authors.initials: D
authors.lastname: Wehbe
authors.affiliation: Department of Internal Medicine, American University of Beirut Medical Center, P.O. Box 11-0236, Beirut, Lebanon.
authors.forename: Ali T
authors.initials: AT
authors.lastname: Taher
mesh_terms: D001803:Blood Transfusion; D006801:Humans; D000860:Hypoxia / Q000473:pathology; D019190:Iron Overload / Q000378:metabolism / Q000628:therapy; D019255:NADPH Oxidases / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013789:Thalassemia / Q000378:metabolism* / Q000628:therapy*
chemical_list: D017382:Reactive Oxygen Species; D019255:NADPH Oxidases