A defence protein, usually a globulin. A substance prepared in the body for the purpose of withstanding infection by viruses, bacteria and other organisms. Produced by reaction of the body’s immune system to an antigen. See: ANTIGENS.
A protein that is made by certain lymphocytes (white blood cells) to neutralize an antigen (foreign protein) in the body. Bacteria, viruses, and other microorganisms contain many antigens; antibodies that are formed against these antigens help the body to neutralize or destroy the invading microorganisms. Antibodies may be formed in response to vaccines, thereby giving immunity. Antibodies are also known as immunoglobulins.
Inappropriate or excessive formation of antibodies may lead to illness, as in an allergy.
Antibodies against antigens in organ transplants may result in rejection of the transplanted organ.
In some disorders, antibodies are formed against the body’s own tissues, resulting in an autoimmune disorder.
A protein belonging to the class of proteins called immunoglobulins. Antibodies are produced by plasma cells to counteract specific antigens or foreign proteins (including infectious agents like viruses, bacteria, etc... or venom). The antibodies then combine with the antigen they are made to fight and often cause the death of that infectious agent. Their presence helps prevent symptoms or disease processes on further exposures to the same antigen.
Immunologic proteins, usually made from immunoglobulins, that are capable of binding to, and rendering inactive, foreign substances that have entered the skin envelope and have been deemed dangerous. They may be synthesized anew in the presence of a previously encountered substance (antigen); they may be present in small amounts at all times in the bloodstream; or they may be present in the tissues in a more primitive form designed to react to a broad spectrum of potential antigens. The latter may be responsible for some allergies.
n. a special kind of blood protein that is synthesized in lymphoid tissue in response to the presence of a particular *antigen and circulates in the plasma to attack the antigen and render it harmless. The production of specific antibodies against antigens as diverse as invading bacteria, inhaled pollen grains, and foreign red blood cells is the basis of both *immunity and *allergy. Chemically, antibodies are proteins of the globulin type; they are classified according to their structure and function (see immunoglobulin).
As used by immunologists, this term refers to IgE antibodies. As used by microbiologists, it refers to antibodies produced in syphilis – probably in response to the tissue damage caused by Treponema pallidum. Production of these antibodies in patients with syphilis has been utilised in the development of the non-treponemal serological tests for syphilis such as the VDRL Test, the RPR Test and the now superceded Wasserman Complement Fixation Test. These tests are useful in that they are only positive in active syphilis but they have many biological false positive reactions, including pregnancy.... reaginic antibody
(APS, Hughes syndrome) an autoimmune disease in which the presence of antibodies against phospholipid (see anticardiolipin antibodies; lupus anticoagulant) is associated with a tendency to arterial or venous thrombosis and, in women of childbearing age, to recurrent miscarriage. APS may be primary or occur in association with systemic lupus erythematosus (SLE) or other connective-tissue diseases. Treatment is by low-dose aspirin or heparin.... antiphospholipid antibody syndrome
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