Meridian Valley Lab measures food-specific IgG4 antibodies using the ELISA method for the assessment of delayed food allergies.
Immunoglobulin G (IgG) is the most abundant antibody class representing approximately 75% of the total antibody pool present in the blood. There are 4 subclasses of the IgG antibody family named in order of their abundance in the blood (IgG1 being the most abundant). IgG4 is the least represented IgG subclass in blood, at less than 5% of total IgG under ‘normal’ physiologic conditions. However, under chronic allergen exposure, IgG4 levels increase dramatically creating a strong IgG4 response. IgG4 has a very high affinity or attraction to allergens, unlike the other subclasses. This makes IgG4, rather than total IgG, ideal for assessing chronic food sensitivities.