antibody (Ab)

An immunoglobulin molecule with a specific amino acid sequence evoked in man or other animals by an antigen, and characterized by reacting specifically with the antigen in some demonstrable way, antibody and antigen each being defined in terms of the other. It is believed that antibodies may also exist naturally, without being present as a result of the stimulus provided by the introduction of an antigen: 1) in the broad sense any body or substance, soluble or cellular, which is evoked by the stimulus provided by the introduction of antigen and which reacts specifically with antigen in some demonstrable way; 2) one of the classes of globulins (immunoglobulins) present in the blood serum or body fluids of an animal as a result of antigenic stimulus or occurring “naturally.” Different genetically inherited determinants, Gm (found on IgG H chains), Am (found on IgA H chains), and Km (found on K-type L chains and formerly called InV), control the antigenicity of the antibody molecule; subclasses are denoted either alphabetically or numerically (e.g., G3mb1 or G3m5). The various classes differ widely in their ability to react in different kinds of serologic tests. See Also: immunoglobulin. Syn: immune protein, protective protein, sensitizer(1).

affinity antibody

agglutinating antibody

anaphylactic antibody

anti-basement membrane antibody

anticardiolipin antibodies

anti-idiotype antibody

antinuclear antibody

antiphospholipid antibodies

avidity antibody

bivalent antibody

blocking antibody

blood group antibodies

catalytic antibody

cell-bound antibody

CF antibody

chimeric antibodies

cold antibody

cold-reactive antibody

complement-fixing antibody

complete antibody

cross-reacting antibody

cytophilic antibody

cytotropic antibody

fluorescent antibody

Forssman antibody

heterocytotropic antibody

heterogenetic antibody

heterophil antibody

heterophile antibody

homocytotropic antibody

idiotype antibody

immobilizing antibody

incomplete antibody

inhibiting antibody

lymphocytotoxic antibodies

monoclonal antibody

natural antibody

neutralizing antibody

nonprecipitable antibody

nonprecipitating antibody

normal antibody

P-K antibodies

polyclonal antibody

Prausnitz-Küstner antibody

precipitating antibody

reaginic antibody

treponema-immobilizing antibody

treponemal antibody

univalent antibody

Vi antibody

Wassermann antibody