Question

Relate the use of kidney cells, beef erythrocytes and horse/sheep erythrocytes to IM testing

Answer 1

#. Differential Test for Infectious Mononucleosis

To determine if the patient has heterophile antibodies associated with IM

Reagents used in IM

Guinea pig antigen- specific for the detection of Forssman antibodies

Horse RBCs- will react with all three heterophile antibodies

Principle of IM

Guinea pig antigens will absorb both forssman and serum sickness antibodies from the serum when added to the inactivated serum, but it does not absorb IM antibodies. Thus, when horse cells are added only IM antibodies will be present to agglutinate the Horse RBCs if they are present

#. Reactions in differential test for IM

- Beef (bovine) cell antigen BCA added in Forssman antibody

No absorption

- Beef (bovine) cell antigen BCA added in Serum Sickness

Absorption

- Beef (bovine) cell antigen BCA added in IM

Absorption

- term-13Guinea pig kidney antigen GPKA in Serum Sickness

Absorption

- Then add Sheep or Horse cell in Serum Sickness

No agglutination

- Guinea pig kidney antigen GPKA in Infectious Mono

No Absorption

- Then add Sheep or Horse cell in Forssman

Agglutination

- Guinea pig kidney antigen GPKA in Forssman (natural) Antibody

Absorption

- Sheep or horse RBC are added in Forssman (natural) Antibody

No agglutination

- Sheep or horse RBC are added in Infectious mono

Agglutination

- Then add Sheep or Horse cell in IM

No agglutination

- Sheep or horse RBC are added in Serum Sickness

No agglutination