A hypothesis of target cell formation in sickle cell disease

An explanation of the reversal of erythrocyte echinocytosis by incubation and storage by serum albumin

It is proposed that the specific reversal by serum albumin of the erythrocyte echinocytosis in an inorganic phosphate buffer saline or in a saline, either after 24 h in blood or after a storage of 6-7 weeks in SGAM or PAGGSM media, is due to a cell dehydration by a decrease of the total NaCl and KCl concentrations favoring the stomatocytogenic slow outward transport of inorganic phosphate with a hydrogen ion by band 3 anion exchanger, which was previously proposed to control the erythrocyte shape. This proposal would indicate that the opposition of the erythrocyte echinocytosis by serum albumin is not limited to binding to echinocytogenic amphiphiles, supported by the ability of the band 3-based mechanism of control of the erythrocyte shape to explain a variety of observations on the erythrocyte shape. It would also imply that this mechanism is a determinant of the erythrocyte rheological properties since influenced by cell shape and volume. It is shown that the above process of stomatocytosis can explain stomatocytoses by different agents as well as a knizocytosis induced in vitro and occurring in acquired and inherited disorders and other situations. Lastly, it can also explain the opposition of hemolysis by mannitol in SGAM and PAGGSM media.