Module 7: Type III

Question 1

Type III also called

Answer 1

Immune Complex mediated hypersensitivity

Question 2

Antigen/antibodies involved in Type III are

Answer 2

Soluble
Floating around in plasma
Not attached to cells or tissue

If Ag and Ab persist, they may precipitate or deposit in tissues as an immune complex

Question 3

Disposition of Ag-Ab complexes depend on (2)

Answer 3

an increase in vascular permeability

Increased blood pressure and turbulence

Question 4

Complete set of steps for Type III

Answer 4

1. Soluble antigen and Ab combine
2. Bind complement and stimulate PLT aggregation
3. Amines released from PLT aggregation cause endothelial cell retraction
4. Immune complex is deposited into blood vessel wall (where it is retracted)
5. PLT aggregation and complement activation
6. Microthrombi form on basement membrane
7. Neutrophils attracted to the site cannot ingest the complexes
8. Neutrophils release their enzymes leading to tissue damage

Question 5

6 examples of Immune complex disorders

Answer 5

Glomerulonephritis
Vasculitis
Hemolysis
Serum Sickness 
Complications in Renal transplants
Arthur Reaction (vasculitis at injection site of injection of an antigen)