E2 Hypersensitivity

Question 1

define allergy

Answer 1

disease following a response by the immune system to an otherwise innocuous antigens

Question 2

Type 1 mediated hypersensitivity

Answer 2

immediate: IgE
induced by allergens
mast cells, basophil, vasoactive amine lipids mediators, cytokines
- anaphylaxis
(antigens that evoke Th2 & Ige = allergens & induce type I response)

Question 3

Type II & III hypersensitivity

Answer 3

2-6 hours: IgG
induced: IgM, IgG
neutrophils, monocytes, complement
- haemolytic newborn: T.II
- Serum sickness T.III

Question 4

Type IV hypersensitivity

Answer 4

proteins - T cell activation
(24-72hrs)
CD4+ macrophages, cytokines: IFNy, TNF

Question 5

IgE binding to mast cells stimulates

Answer 5

IgE binds FCeRI on mast cells, basophils & eosinophils. Triggers degranulation releases mediators&cytokines

Question 6

Features of allergens that promote induction of allergy

Answer 6

Protein, Enzymatically active, Low dose, Low molecular weight, Highly soluble, Stable, MHC class II binding peptides

Question 7

Best treatment for allergens

Answer 7

desensitisation