A New Antibody in Serum of Patients With Acquired Hemolytic Anemia

Abstract

An incomplete or "blocking" antibody was demonstrated in the sera from 3 patients with acquired hemolytic anemia. None showed autoagglutination; one possibly showed autohemolysis No significant titers of cold agglu-tinins were found. Donath-Landsteiner and Ham tests were negative. All had been splenectomized. One died; the other 2 made some clinical and hematological improvement. Serum obtained before splenectomy was studied in one case. Serum from rabbits immunized with human serum was used to demonstrate the incomplete antibodies, on the red cells and free in the sera of the patients. The antibodies were traced by methods which demonstrated some of their im-munological properties. It was possible to test the thermol-ability and species specificity and to study the relative position of the receptor for this new antibody The antibody reacts with red cells irrespective of Rh type. It is also an autoanti-body and a panantibody, but does not react with rhesus cells.