Immunoglobulin A


A major class of immunoglobulins (antibodies) found in serum and external body secretions such as saliva, tears, and sweat, as well as in the gastrointestinal, respiratory, and genitourinary tracts. Abbreviated IgA. About 10 percent to 15 percent of the antibodies present in the body are IgA antibodies.

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  • Immunoglobulin D

    A class of immunoglobulins found in small amounts in the body, whose exact function is not clear.

  • Immunoglobulin E

    A class of immunoglobulins that includes the antibodies that are important in an allergic response. Abbreviated IgE. A person who has an allergy often has elevated blood levels of IgE. IgE antibodies attack and engage the invading army of allergens.

  • Immunoglobulin G

    A class of immunoglobulins found in all body fluids. They are the smallest but most common antibodies (75 percent to 80 percent) in the body. Abbreviated IgG. IgG antibodies are very important in fighting bacterial and viral infections. IgG antibodies are the only type of antibody that can cross the placenta in a pregnant woman […]

  • Immunoglobulin M

    A class of immunoglobulins found in blood and lymph fluid that are the first type of antibody made in response to an infection. Abbreviated IgM. IgM antibodies make up about 5 percent to 10 percent of all the antibodies in the body.

  • Immunologist

    A physician or another degreed professional who is knowledgeable about immunology.


Disclaimer: Immunoglobulin A definition / meaning should not be considered complete, up to date, and is not intended to be used in place of a visit, consultation, or advice of a legal, medical, or any other professional. All content on this website is for informational purposes only.