Immuno-electronmicroscopic studies of surface antigens of blood elements. I. Autoantibody on erythrocytes in acute hemolytic anemia.

structural localization of various components of complement on sheep erythrocytes previously treated with antibodies and complement.5 In autoimmune hemolytic anemia it has been assumed that an antigen, as yet unidentified, located on the surface of the red cells is responsible for evoking the production of the autoantibody which is then bound to the patient’s own erythrocytes. The purpose of the experiments reported here was to examme the sites of localization of the autoantibody on the red cells of a patient with autoimmune hemolytic anemia, and further to study the sites of localizalion of the patient’s autoantibody on the erythrocytes of other individuals of the same blood group. Ferritin-labeled antibodies to human immunoglobulins and to a fraction of complement were used in an attempt to tag the sites of the red cells where the patient’s autoantibody had been bound.