Abstract
Erythrocyte membrane proteins from twenty-two patients with hereditary spherocytosis (HS) were analyzed by polyacrylamide gel disc electrophoresis in the presence of 0.1% SDS. Almost complete deficiency was found in a protein component, IVb, in four cases, three of which were siblings. A small but significant decrease in this component was noted in most of the other cases. Such a small decrease in IVb was also found in two cases of autoimmune hemolytic anemia and one case of congenital hemolytic anemia due to pyruvate kinase deficiency.
The IVb component was found to be most susceptible among the erythrocyte membrane proteins to the action of protease of leucocytes. It was unlikely, however, that the abnormalities in IVb were artifacts due to the leucocyte protease as judged from the following evidence. First, the deficiency in IVb was demonstrated even when eucocytes had been completely removed using a column of SE-cellulose before preparation and analysis of erythrocyte membrane. Second, mixing in equal amount the red cells from a normal subject and those from a patient with HS of IVb-deficient type resulted in the appearance of IVb peak of half size in the electrophorogram.
A hypothesis was presented that HS is composed of at least two types, of which IVb-deficient type is caused by membrane dysfunction due to the deficiency in IVb, while in the other type a small decrease in IVb may be secondary to an unknown primary defect. As compared to the other type, the IVb-deficient type showed rather milder clinical features and hematological disorders. Results of family examinations suggested that HS of IVb-deficient type may be inherited as a recessive character.
