“…In aggregate, these data suggest that circulating mononuclear cells participate in a compensatory response to the repetitive vascular injury characteristic of sickle cell disease. 43,44,63,64 For example, despite having reduced nitric oxide bioavailability and endothelial dysfunction, 27,28 patients with sickle cell disease do not develop atherosclerotic coronary disease, [65][66][67] which may be due to the vascular protective functions of the HO-1 and p21 systems. Other antioxidant genes such as glutathione peroxidase, thioredoxin, and thioredoxin peroxidase are up-regulated in sickle cell patients, demonstrating a compensatory response to chronic ischemiareperfusion-induced oxidant injury.…”