Author: Glossary
-
Direct antiglobulin test
A laboratory test for the presence of complement or an antibody that is bound to a patient’s red blood cells. The test is used in patients with autoimmune hemolytic anma, hemolytic disease of the newborn, and transfusion reactions. After the patient’s RBCs are washed to remove unbound antibodies, they are mixed with antihuman globulin serum…
-
Antiglobulin test
A test for the presence in human blood of antibodies. The antibodies present in the blood do not, themselves, cause agglutination. It is the addition of an antibody made in animals (antiglobulin) that stimulates red blood cell clumping. The direct antiglobulin test (DAT) is used to diagnose autoimmune hemolytic anemia and hemolytic disease of the…
-
Antiglobulin
An antibody that binds with globulin and makes it precipitate out of solution. Antiglobulins are used in Coomb’s test to detect the presence of a particular antibody or to type blood groups.
-
Antigen unit
The smallest quantity of antigen required to fix one unit of complement.
-
Antigen processing
The mechanism by which foreign antigens are taken into antigen-presenting cells (APCs) and broken up. Part of the antigen is then displayed (presented) on the surface of the APC next to a histocompatibility or “self’ antigen, activating T lymphocytes and cell-mediated immunity. T lymphocytes are unable to recognize or respond to most antigens without APC…
-
Antigenicity
The condition of being able to produce an immune response to an antibody.
-
Epitope antigenic determinant
The simplest form of an antigenic determinant within a complex antigenic marker. The epitope links with a paratope, one area of an antibody combining site.
-
Antigenic determinant
The specific area of an antigen that binds with an antibody combining site and determines the specificity of the antigen-antibody reaction.
-
Antigenemia
The presence of an antigen in the bloodstream.
-
Antigen antibody reaction
The combination of an antigen with its specific antibody. It may result in agglutination, precipitation, neutralization, complement fixation, or increased susceptibility to phagocytosis. The antigen- antibody reaction forms the basis for B-cell mediated immunity. The binding of an antigen to its corresponding antibody.