Immunologie-P2

Question 1

What are Type I, II, and III hypersensitivities?

Answer 1

Antibody-mediated hypersensitivities

Question 2

What are Type I, II, and III hypersensitivity responses characterized by?

Answer 2

1. Recall rxn that develops quickly over minutes or hours, but can continue for months if Ab-Ag are available.
2. Demonstrable amts of Ab
3. Can be passively transferred via serum containing the appropriate antibody

Question 3

What is a Type IV reaction and what is it characterized by?

Answer 3

• Cell-mediated reaction
• Characterized by:
  1. Develops over 1 or more days
  2. Can only be transferred adoptively by Ag-specific T cells

Question 4

What is Type I immediate hypersensivity?

Answer 4

• When an antibody response (usually involves IgE antibodies) against usually innocuous antigens results in rhinitis (runny nose), bronchoconstriction (coughing, wheezing, SOB), urticaria (hives).

Question 5

What is atopy?

Answer 5

Presence of specific IgE antibodies in response to common environmental allergens

Question 6

What is anaphylaxis?

Answer 6

severe, body-wide reaction

• results from sudden release of mast-cell and basophil-derived mediators into circulation
• involves post-capillary venules dilating and leaking (leading to edema, hypotension) AND bronchoconstriction (hypoxia, death)

Question 7

What are the target organs involved in hypersensitivity reactions?

Answer 7

GI tract
Respiratory tract
Skin