HEMOLYTIC ANTIBODIES FOR SHEEP AND OX ERYTHROCYTES IN INFECTIOUS MONONUCLEOSIS 1

Abstract

Absorption tests showed that the hemolytic and hemagglutinative antibodies for sheep red cells found in the sera of cases of infectious mononucleosis are not of the heterophil or Forssman type, as reported by previous investigators; they have no affinity for a large variety of thermostable heterophil tissues and bacteria tested. They have the power not only to hemolyze and agglutinate sheep erythrocytes, but also to a greater extent to hemolyze and to some degree agglutinate ox corpuscles. They are not isophil, however, since they are absorbed from the serum by boiled ox or sheep corpuscles. The isophil antigen in these cells is thermolabile and is destroyed by boiling. Ox erythrocytes appear to have a broader antigenic relationship to the antibodies of infectious mononucleosis than sheep corpuscles. The immune substances are probably not found in normal human serum, but are rather a specific response to an antigen associated with infectious mononucleosis only, this antigen having a factor in common with a thermostable component of sheep and ox red cells, a certain strain of B[acillus] xvelchii, and possibly horse kidney, as shown by absorption tests. These immune agents were not absorbed by any of the bacteria isolated from the upper respiratory tract of cases of the disease. The hemolysins and hemagglutinins in infectious mononucleosis and the thermostable antigen in ox and sheep red cells which combine with and neutralize them have unique and previously undescribed properties of specificity. The primary titration of a serum with fresh sheep erythrocytes, followed by absorption with boiled ox red cells and then retitration of the absorbed serum with fresh sheep corpuscles, provides a specific diagnostic method for this disease.