Immunology Flashcards
What are tolerance mechanisms?
The processes by which autoreactive B/T cells are killed/inactivated.
Which gender is more susceptible to autoimmune disease?
Females (due to hormonal influences).
How quickly does type 1 hypersensitivity occur?
Within seconds - hence often called immediate hypersensitivity.
Which type of hypersensitivity reaction is IgE-mediated?
Type 1(immediate) hypersensitivity.
What are examples of type 1 (immediate) hypersensitivity conditions?
Anaphylaxis
Asthma
Eczema
Allergic rhinitis
How quickly does type 2 hypersensitivity occur?
Within seconds/hours.
What occurs in type 2 hypersensitivity reactions?
IgM or IgG antibodies bind to antigens on cell surfaces, resulting in a complement cascade, or antibody-dependent cell-mediated cytotoxicity.
What conditions are examples of type 2 hypersensitivity reactions?
Goodpasture’s syndrome
Grave’s disease
How quickly does type 3 hypersensitivity occur?
Within hours.
What occurs in a type 3 hypersensitivity reaction?
Antibodies bind to excess antigens, producing immune complexes. These clog up capillaries, joints and glomeruli.
This blockage activates the complement system, thus causing an immune response to occur.
What conditions are examples of type 3 hypersensitivity reactions?
Hypersensitivity pneumonitis
SLE
How quickly does type 4 hypersensitivity occur?
Within days.
What occurs in a type 4 hypersensitivity reaction?
This process is T cell-mediated, with the release of inflammatory cytokines, resulting in cell-mediated toxicity.
What conditions are examples of type 4 hypersensitivity reactions?
Tuberculosis
Sarcoidosis
Rheumatoid arthritis
