Increased erythrocyte Ca2+ content in hereditary spherocytosis.

The Ca2+ content of red blood cells (RBC) appears to correlate inversely with the Ca2+-ATPase activity of the red cell membrane (Fig. 1). When hereditary spherocytosis (HS) cells and normal control erythrocytes are compared, the dependence of Ca2+ content upon ATPase activity is similar. The Ca2+ content of HS red cells is increased compared with appropriate control erythrocytes matched for cell age (Fig. 2). Splenectomy has a different effect upon HS cells than upon normal cells (Fig. 2). Erythrocytes of splenectomized patients with HS seem to contain less Ca2+ than do those of presplenectomy patients with HS, whereas the reverse appears to pertain in normal subjects.