Impaired erythrocyte calcium homeostasis in β-thalassemia

Abstract

Intracellular calcium (Ca) concentration in erythrocytes (RBCs) is controlled by a low passive influx through a relatively impermeable membrane and by active efflux catalyzed by Ca2+,Mg2+-ATPase. Since precipitation of α-globin chains in thalassemic RBCs may interfere with normal membrane function, we studied the RBC intracellular Ca content and the RBC membrane Ca2+,Mg2+-ATpase activity in two groups of patients with nonsplenectomized (n = 9) and splenectomized (n = 9) β-thalassemia intermedia and in two groups of matched controls. The mean ± SD Ca concentration in the nonsplenectomized (n = 12) and splenectomized (n = 6) controls were 6.1 ± 6.0 and 5.8 ± 3.4 μmol Ca per liter of RBCs, respectively, compared with 26.0 ± 7.6 (P