Role of spleen in hereditary spherocytosis: evidence for increased in vitro proteolysis of red cell membrane.

In vitro proteolysis of red cell membranes has been studied by means of electrophoretic separation on SDS-polyacrylamide gel of solubilized ghost proteins and subsequent densitometry of separated, stained bands; the amounts of major membrane proteins were measured in ghosts either with inhibited or with allowed proteolysis in the following cases: 15 patients suffering from hereditary spherocytosis (HS) with variable degree of spleen enlargement, eight cirrhotic patients with spleen enlargement and 12 healthy blood donors as control group. Proteolysis was present to a greater extent in HS patients with larger splenomegaly, lesser in HS with smaller splenomegaly, and was comparable to healthy controls both in splenectomized HS and in patients with spleen enlargement due to liver cirrhosis. The results suggest the involvement of splenomegaly in the enhancement of in vitro proteolysis in HS red cell membrane; it is probably attributable to joint effects of the damage induced in red cells by prolonged retention within haemolysing spleen together with the abnormalities genetically affecting the structure of HS red cell membrane.