Paul Bunnell antibodies are reactive in all except?

Ans. is 'a' i.e., OX . Paul Bunnell test is the standard diagnostic procedure for IMN in children and adults. . During IMN, heterophile antibodies are produced which agglutinate sheep, horse or cow erythrocytes. . Such heterophile antibodies may also present in normal individuals or after serum therapy (injection of serum). . These antibodies are differentiated by absorption test in which Guinea pig kidney and Ox red cells are used. . IMN heterophile antibodies are absorbed by ox red cells, while heterophile antibodies of normal individuals and after serum therapy are absorbed by guinea pig kidney. Differential absorption test for Paul-Bunnell antibody Result of absorption by Guinea pig kidney Ox red cells Normal serum Absorbed Not absorbed Antibody after serum therapy Absorbed Not absorbed Infectious mononucleosis Not absorbed Absorbed Coming back to the question? . In infectious mononucleosis, Paul Bunnell heterophile antibodies are produced. . These IgM class antibodies have an affinity for sheep, horse and bovine erythrocytes. . Because these heterophile antibodies are adsorbed by ox red cells, they are not reactive in Ox (Ox red cells remove these antibodies).