Heterophil agglutination tests

Alternative names:

Forssman antibody test; Paul-Bunnell test

Normal values:

The Paul-Bunnell, and Forssman antibodies react with sheep and horse red blood cells, causing clumping.

No clumping (agglutination) with a titer lower than 1:56 is the normal result.

What abnormal results mean:

If the titer rises to around 1:220 in the 3rd or 4th week of infection, then gradually decreases in the following 4 weeks infectious mononucleosis may be diagnosed.