Studies on Paul-Bunnell (P-B) antigen-antibody system. V. Immunoglobulin classes of P-B antibodies.

By means of enzyme immunoassay (EIA) with purified Paul-Bunnell (P-B) antigen of bovine erythrocytes and sera of infectious mononucleosis, P-B antibodies of IgG (92%), IgM (94%), IgA (77%), and IgE (64%) classes were demonstrated. Absorption and inhibition studies ascertained the P-B specificity of the antibodies of all four classes. Absorption of selected IM sera with sheep erythrocytes revealed the presence of both BS and B antibodies of P-B specificity in these sera. In three IM patients whose sequential serum samples were studied, P-B antibodies of all four classes appeared and reached their peaks within a few weeks after the onset of the disease, persisted for a month, and sharply declined thereafter.