This test measures the amount of IgE anti-alpha-gal antibodies in the blood. Anti-alpha-gal IgG antibodies are present in all people and are not associated with any form of illness. IgE anti-apha-gal antbodies are much less common and are associated with allergy to red meat in the form of delayed (4-8 hours) systemic allergic reactions including anaphylaxis after eating red meat. The primary cause of this allergy is a reaction to be being bitten by a tick. In Australia the common paralysis tick Ixodes holocyclus is the cause. In the US and Europe different types of ticks can cause this disease.

The anti-alpha-gal test is used to diagnose red meat allergy in people suspected of having this condition. IgE antibodies to red meats such as beef, lamb and pork may also be ordered at the same time.

The test is usually requested when people develop symptoms after eating red meat.

When significant amounts of IgE anti-alpha-gal are present in the blood, then allergy to red meat can be diagnosed. 

People with red meat allergy are also likely to be allergic to the cancer drug Cetuximab.