Immunoglobulins: IgE

Optimal Takeaways

Immunoglobulin E is utilized in the diagnosis of allergies. It is associated with an immune reaction that can be severe and even fatal. It can trigger swelling, itching, rhinitis, asthma, and difficulty breathing. Elevated levels are seen with allergies, asthma, eczema, and infections. Severe IgE reactions can lead to anaphylaxis and death. Low levels aren’t considered clinically relevant.

Standard Range: 0.00 - 114 IU/mL

The ODX Range: 2.00 - 100 IU/mL

Low IgE can be seen with agammaglobulinemia (Pagana 2021).

High IgE levels are seen with allergic reactions, asthma, eczema, and rhinitis, certain infections including parasites or aspergillosis, and use of certain medications including phenytoin, hydralazine, isoniazid, procainamide, tetanus toxoid/antitoxin, and gamma globulin. Levels may be falsely elevated if IgG is also elevated. (Pagana 2021). IgE can facilitate a systemic anaphylactic reaction that can be fatal.

Overview

The IgE immunoglobulin facilitates an allergic response by binding to mast cell and basophil receptors. It is especially effective against parasitic infection and is crucial to host defense (Justiz 2021).

IgE activation of mast cells and basophils results in degranulation and production of cytokines and eicosanoids. While IgE can effectively defend against helminth parasites, it may also mount an allergic response to less harmful environmental antigens and cause the type 1 hypersensitivity reactions seen with allergic rhinitis, asthma, and atopic dermatitis. The IgE-mediated response can also lead to potentially fatal systemic anaphylaxis (Wu 2014).

IgE-mediated food allergies can be life-threatening and require altogether avoiding the offending food. Serum IgE testing for food allergy may yield false positives. It should be evaluated alongside clinical symptoms, which may include erythema, itching, gastrointestinal distress, and respiratory, cardiac, and neurological effects. Intramuscular administration of epinephrine is used in the event of a severe reaction to help constrict blood vessels, maintain blood pressure, dilate airways, and reduce edema (Anvari 2019).

References

Anvari, Sara et al. “IgE-Mediated Food Allergy.” Clinical reviews in allergy & immunology vol. 57,2 (2019): 244-260. doi:10.1007/s12016-018-8710-3

Justiz Vaillant, Angel A., et al. “Immunoglobulin.” StatPearls, StatPearls Publishing, 12 October 2021.

Pagana, Kathleen Deska, et al. Mosby's Diagnostic and Laboratory Test Reference. 15th ed., Mosby, 2021.

Paranjape, Anuya et al. “Oral Immunotherapy and Basophil and Mast Cell Reactivity in Food Allergy.” Frontiers in immunology vol. 11 602660. 14 Dec. 2020, doi:10.3389/fimmu.2020.602660

Wu, Lawren C, and Ali A Zarrin. “The production and regulation of IgE by the immune system.” Nature reviews. Immunology vol. 14,4 (2014): 247-59. doi:10.1038/nri3632