Immunoglobulin (Ig) values are usually evaluated together, comparing the differences of the values.
IgG: Immunoglobulin G is the most abundant antibody in the blood. They are produced a few days after infections, providing long-term protection against microorganisms. It helps prevent re-infection with a particular pathogen, so this mechanism is also used by vaccines. When its levels drop significantly, upper respiratory and gastrointestinal infections become much more common.
IgM: in case of infection, the body starts to produce this type of immunoglobulin, which provides short-term protection until IgG production. An increase in its level indicates a recent or existing infection.
IgA: Immunoglobulin A provides primary protection against pathogens on mucosal surfaces (airways and gastrointestinal tract). The amount of IgA in the saliva of patients with recurrent respiratory infections may be lower.