[2] Reaction of particles with agglutinin is used to indicate present or past host contact with a pathogen.
As a result, the blood of a host applied to a diagnostic kit causes the aggregation of the pathogenic particles due to the antigen-agglutinin interaction.
Conversely, agglutination can also be used to identify new bacteria or cells with a specific antigen by exposing them to serum containing known agglutinins.
A body might produce agglutinins to attack the erythrocytes due to allergies to foods, inhalants, chemicals and infections.
A person suffering from this condition will likely have cooler body parts such as fingers, nose, and ears attacked more often than warmer areas such as armpits.