-
Arthus reaction
A localized skin reaction caused by Type III hypersensitivity, which is antibody-mediated, and distinct from the skin reaction of Type IV hypersensitivity (which is cell mediated)
-
allergen
an antigen that causes a Type I hypersensitivity response
-
allergic rhinitis
A response of the mucous membranes, ultimately begun by IgE, resulting a complex variety of symptoms and molecular responses, most apparent as "runny nose", sneezing, and watery eyes
-
anaphylaxis
A systemic and potentially life-threatening Type I hypersensitivity reaction
-
Cell-mediated immunity
The part of adaptive immunity mediated by T lymphocytes, which either produce cytokines (that affect other cells) or act as cytotoxic cells
-
contact dermatitis
A skin reaction (eczema) that results from direct contact with certain chemicals or metals, and can be associated with Type IV (cell mediated or delayed) hypersensitivity (e.g, poison ivy)
-
delayed hypersensitivity
Type IV hypersensitivity that is mediated by T cells, and usually occurs 24-72 hours after contact with the antigen
-
granuloma or granulomatous tissue
Clusters of actived macrophages, T cells and PMNs that can be associated with the response in Type IV hypersensitivity (and in certain infections), and tend to concentrate in the affected tissue area
-
Hemolytic Disease of the Newborn
An immune response by a mother to her fetus, which results in the production of antibodies against the RBC of the fetus, and a Type II hypersensitivity reaction resulting in lysis of fetal RBC
-
humoral immunity
Immunity that is part of the specific immune response and associated with the production of antibodies, which come from B cells
-
hyperacute graft reaction
A form of Type II hypersensitivity reaction, sometimes the result of antibodies to MHC antigens (such as after tissue transplant in non-MHC-matching donor and recipient)
-
hypersensitivity
An exaggerated or inappropriate immune response by the host which results in disease manifestations (pathology) to that host
-
immediate hypersensitivity
Antibody mediated hypersensitivity (Types I, II or III) that occurs within a short period of time (minutes to a few hours) after contact with an antigen previously encountered
-
intravascular hemolysis
Rupture of RBC within the vascular system, either by mechanical (e.g., fibrin) or immunological (i.e. complement fixation) means, or by means of a toxin (hemolysin) resulting in the liberation of free hemoglobin
-
radioallergosorbent test
An immunoassay that measures IgE levels directed against specific allergens
-
radioimmunosorbent test
An immunoassay that measures total IgE levels, but not those directed against specific antigens
-
serum sickness
A Type III hypersensitivity reaction caused by exposure to foreign proteins contained in animal sera (such as in a vaccine)
-
Type I (anaphylactic) hypersensitivity
The hypersensitivity response that results in production of specific IgE antibodies that sensitize mast cells (tissue basophils) and leads to the production of histamine and other chemical mediators that produce an immediate response, sometimes fatal to the host(anaphylaxis)
-
Type II (antibody dependent) hypersensitivity
A hypersensitivity reaction that is mediated by antibodies directed against cell surface antigens that often results in the distruction of that cell (e.g, transplant rejection)
-
Type III (immune complex mediated) hypersensitivity
A hypersensitivity reaction that begins with the deposition of antigen-antibody complexes and results in activation of complement that can lead to inflammation and tissue damage
-
Type IV (cell mediated or delayed) hypersensitivity
A hypersensitivity response, directed by T cells, that leads to the production of cytokines, and can result in inflammation, granuloma formation, and tissue damage
|
|