Immunopathology - Week 7 - Hypersensitivity Tut Questions Flashcards
(10 cards)
What are the three types of Graft rejection?
Hyperacute rejection
Acute rejection
Chronic rejection
What type of hypersensitivity reaction is in Hyperacute rejection?
Type 2 reaction
What type of hypersensitivity reaction is in Acute rejection?
Type 2 and 4 reaction.
What type of hypersensitivity reaction is in Chronic rejection?
Type 4 reaction
Name the 4 types of hypersensitivity reactions.
Type 1: Anaphylactic reactions
Type 2: Tissue specific reactions
Type 3: Immune complex reactions
Type 4: Delayed Hypersensitivity reactions
What are examples of local reactions and systemic reactions in Type 1 reaction?
Local: Hay fever and Asthma
Systemic: bee venom, drugs and some foods
What are examples of primary and secondary mediators that are released in type 1 reaction?
Primary:
Histamine
Chemotactic factors
Secondary:
Lipid mediators
Cytokines
Prostaglandins
Name the 5 mechanisms involved in Type 2 hypersensitivity.
For all mechanisms:
Antibody attaches to either a tissue specific antigen or to an antigen which attaches to the tissue.
Mechanism 1: Complement enzymes attach to this combination and destroy the cells.
Mechanism 2:
- Complement C3b attaches targeted cell.
- Phagocytosis of the targeted cell occurs.
Mechanism 3:
- Complement C3b attaches targeted cell
- Neutrophils are attracted and attempt to phagocytose, but cannot always do so due to size of the tissue.
Mechanism 4:
- The antibody is recognised by receptors on
Natural Killer cells,
which then releases toxic substances which cause damage to the tissue.
Mechanism 5:
The effect of the antibody binding with the target cells causes an alteration in function, rather than destroying the
tissue.
Briefly describe what happens in Type III reaction.
The antigen and antibody join and form a complex prior to depositing on
innocent tissue.
What are some examples of Type 3 reaction?
Rheumatoid arthritis
Systemic lupus erythematosus
