STUDIES ON DESTRUCTION OF RED BLOOD CELLS. II. CHRONIC HEMOLYTIC ANEMIA WITH PAROXYSMAL NOCTURNAL HEMOGLOBINURIA: CERTAIN IMMUNOLOGICAL ASPECTS OF THE HEMOLYTIC MECHANISM WITH SPECIAL REFERENCE TO SERUM COMPLEMENT 1

Abstract

In this chronic hemolytic anemia the fundamental abnormality resides in the erythrocytes, which show increased susceptibility to hemolysis when suspended in acidified (pH 6 to 7) plasma or serum from patients and from normal subjects of compatible blood groups. The sera of patients did not hemolyze normal erythrocytes under the same conditions. Human complement, or a complement-like substance, was required by the hemolytic system. The mechanism of hemolysis may be immunological in nature, but the abnormality of the patient''s red blood cells is not denned. No antigenic difference, when used to immunize rabbits, was observed between the patient''s erythrocytes and those of a normal subject. No hemolytic substance or antibody was removed from the patient''s cells by procedures known to dissociate antigen and antibody. The patient''s erythrocytes showed increased susceptibility to 2 hemolysins of the immunological type, but a normal susceptibility to hemolysis by hypotonic solns. of NaCl, saponin, and Na taurocholate.