Definition: An antibody is a protein produced by the body’s immune system when it detects harmful substances, called antigens. Examples of antigens include microorganisms (bacteria, fungi, parasites, and viruses) and chemicals.
Antibodies may be produced when the immune system mistakenly considers healthy tissue a harmful substance. This is called an autoimmune disorder.
Each type of antibody is unique and defends the body against one specific type of antigen.
Abbas AK, Lichtman AH, Pillai S. Antibodies and antigens. In: Abbas AK, Lichtman AH, Pillai S, eds. Cellular and Molecular Immunology. 9th ed. Philadelphia, PA: Elsevier; 2018:chap 5.
The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of any other sites. Content provided by A.D.A.M and is prepared for the United States of America. Recommended treatments may not be applicable, available, or permissible in Canada or other jurisdictions. A.D.A.M. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC’s accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health on the Net Foundation (www.hon.ch