NH4Cl-HCO3(-)-mediated hemolytic reaction in the erythrocytes of hereditary spherocytosis.

A NH4Cl-HCO3(-)-mediated, acetazolamide modulated hemolysis test was carried out in seven patients with hereditary spherocytosis (HS), and the amount of enzyme antigen as well as activities of carbonic anhydrase (CA) were determined. Except for a decrease in CA-B activity (p less than 0.05), the amount of enzyme antigen, total and specific activities of both isozymes of CA and dependent activity of CA-C were within the normal range. Fifty percent and 95% hemolysis times were significantly shorter than the normal range, and they remained abnormal even in the presence of acetazolamide. This hemolysis test, especially H50 valuse, was therefore shown to have diagnostic value in HS.