| antiphospholipid antibody syndrome | <syndrome> An immune disorder characterised by the presence of abnormal antibodies in the blood associated with certain medical conditions including abnormal blood clotting, migraine headaches, premature miscarriage, and low blood platelet counts (thrombocytopenia). (12 Dec 1998) |
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| antithyroglobulin antibody | <endocrinology, immunology> A serologic blood test which measures the antithyroglobulin antibodies in the blood. Thyroglobulin is a protein found in thyroid tissue. It is the source of thyroid hormones in the body. The presence of antibodies to this protein can result in decreased thyroid gland function. A negative assay is considered normal. Conditions where the assay may be positive include: lupus, rheumatoid arthritis, Hashimoto's thyroiditis, thyrotoxicosis, hypothyroidism, thyroid cancer, myxoedema, Sjogren's syndrome and autoimmune haemolytic anaemia. (13 Jan 1998) |
| avidity antibody | The sum total of the functional binding strength between a polyvariant and its antibody. The total binding strength represents the sum strength of all the affinity bonds. (05 Mar 2000) |
| binding sites, antibody | Local surface sites on antibodies which react with antigen determinant sites on antigens. They are formed from parts of the variable regions of the fab fragment of the immunoglobulin. (12 Dec 1998) |
| bivalent antibody | Antibody that causes a visible reaction with specific antigen as in agglutination, precipitation, and so on; so-called because according to the "lattice theory" aggregation occurs when the antibody molecule has two or more binding sites that can crosslink one antigen particle to another; probably a characteristic of the class of immunoglobulin. (05 Mar 2000) |
| blocking antibody | An antibody used in a reaction to prevent some other reaction taking place, for example one antibody competing with another for a cell surface receptor. See: desensitisation. (18 Nov 1997) |
| reaginic antibody | <immunology> A type of antibody which is able to attach itself to the surfaces of cells without needing specific combining sites. A homocytotropic antibody will only bind to cells which are from the same species as itself. (09 Oct 1997) |
| maternal antibody | Any antibody transferred from a mammalian mother transplacentally into the foetus. See under immunoglobulin for details of the classes of Ig that are transferred to the foetus. (18 Nov 1997) |
| catalytic antibody | <chemistry> Antibody raised against a transition state analogue (e.g. A phosphate analogue of a carboxylic acid ester transition state) that can then catalyse the analogous chemical reaction, though not as effectively as a true enzyme. (16 Mar 1998) |
| Vi antibody | A form of antibody that agglutinates highly virulent strains of Salmonella typhi, i.e., cells with Vi antigen; such bacteria are not agglutinable with O antiserum until the Vi antigen is destroyed. See: Vi antigen. (05 Mar 2000) |
| cell-bound antibody | A term used for antibody on the surface of cells that may be bound either through antigen combining sites or other sites such as the Fc region. (05 Mar 2000) |
| CF antibody | Antibody that combines with and sensitises antigen leading to the activation of complement, which may result in cell lysis. Synonym: CF antibody, sensitizing substance. (05 Mar 2000) |
| chimeric antibody | <immunology> An antibody that contains polypeptides from different species. (05 Jan 1998) |
| chimeric/humanised antibody | <immunology> Genetically engineered combination of a human and mouse antibody. Because a monoclonal antibody is always made with mice cells, it causes an immune response when injected into humans. By replacing the constant regions of a mouse antibody with those of a human antibody, an antibody that binds to an antigen like the original monoclonal antibody, but which is recognised by the human immune system like a human protein, can be manufactured. Alternatively, only those amino acids directly involved in antigen binding are transferred from the mouse antibody into the framework of the human antibody, with a similar result. (05 Jan 1998) |
| microsomal antibody | This special serologic test is used to measure thyroid anti-microsomal antibody in the bloodstream. This test can be performed from a simple venipuncture specimen. The anti-microsomal antibody or microsomal antibody test is used to diagnose conditions such as Hashimoto's thyroiditis and other autoimmune disorders. (27 Sep 1997) |