Alterations in the red blood cell membrane and the effect of vitamin E on osmotic fragility in beta-thalassemia major.

Red blood cell membranes from patients with beta-thalassemia major and intermedia had an average of 25% less sialic acids, and a 50% decrease in titratable SH groups, as compared with normal controls. Membranes from 12 of 13 splenectomized patients were less dense and could be clearly distinguished from normal membranes on a sucrose linear density gradient, indicating a change in lipid-to-protein ratio. The impaired osmotic fragility of thalassemic erythrocytes almost returned to normal following administration of vitamin E, a potent antioxidant, in a daily dose of 750 IU for three to six months. These observations provide more evidence that membrane properties of thalassemic red blood cells differ from those of normal erythrocytes, the difference being due, in part, to increased oxidative stress.