allergy and hypersensitivity
DESCRIPTION
Allergy and Hypersensitivity. Type I hypersensitivity: anaphylactic and atopic (Allergy). Allergens are small Ags, usually inocuous TH2 response intitiated B cells produced IgE IgE binds mast cells, basophils, eosinophils. Genetics factors and Allergies Cytokines and their receptors - PowerPoint PPT PresentationTRANSCRIPT
Allergy and Hypersensitivity
Type I hypersensitivity: anaphylactic and atopic
(Allergy)
•Allergens are small Ags, usually inocuous•TH2 response intitiated•B cells produced IgE•IgE binds mast cells, basophils, eosinophils
• Genetics factors and Allergies– Cytokines and their receptors– MHC II genes– Other polymorphisms
Increase in Atopic Allergy
• Environmental factors– Exposure to pathogens in childhood
• Measles, HepA, tuberculosis exposure beneficial?– Environmental pollution
• Eg. Children in Hale, East Germany– Allergen levels
• No evidence of rise– Dietary changes
• No evidence of effect
Mast Cell mediators
Eosinophil mediators
House Dust Mite Ag
Type II hypersensitivity:cytotoxic
• Cell-reactive antibodies• Cross-reactivity• Cell surface adhesion of foreign antigen…
cell destruction• Complement and phagocytosis activated• Red blood cells and platelets most common
target
Type III hypersensitivity:immune complex
Type IV hypersensitivity:delayed or cell-mediated