Allergy and hypersensitivity

Question 1

what is an allergy and what is it mediated by

Answer 1

An abnormal immune response to an unfamiliar antigen and itis mediated by antibodies,t cells, and immune complexes

Question 2

Define atopy

Answer 2

Genetic tendency to develop allergic diseases and is associated with heightened immune response

Question 3

Causes of allergy/hypersensitivity

Answer 3

• Loss of T cell tolerance
• B/T cells are autoreactive or react to antigens that are allowed to persist

Loss of tolerance may be peripheral/central

Question 4

Discuss the Gell and Coombs classification of hypersensitivity/allergy

Answer 4

Type (in roman numerals )

1. Immediate hypersensitivity mediated by IgE
2. Cytolytic immune response usually mediated by IgM /IgG
3. Immune complex deposition
4. cell-mediated ( delayed hypersensitivity )