Inflammation

Question 1

What is the role of inflammation?

Answer 1

1. Deliver effector molecules, drugs and cells to site of infection or injury
2. Induce local blood clotting
3. Stimulate adaptive immune response
4. Promote repair of injured tissue

Question 2

What is reddness and heat during inflammation associated with?

Answer 2

Vasodilation: Inc blood to damage site, delivers cells etc

Question 3

What is swelling and pain during inflammation associated with?

Answer 3

Entry of plasma proteins eg antibodies, complement components, clotting components, kinin system to extravascular space

Question 4

Where do inflammatory mediators come from? What is their role?

Answer 4

Mast cells release inflammatory mediators which increase vasodilation
Vasoactive mediators: eg histamine
Lipid mediators: eg prostaglandins

Question 5

What causes fever in inflammation?

Answer 5

Prostoglandins, which are released by activated mast cells

Question 6

Why is pain associated with inflammation?

Answer 6

• Inflammatory mediators affect nocioceptors
• Bradykinin causes pain (acts on pain receptor endings)
• Exudation of plasma increases tissue pressure

Question 7

How is fever initated in inflammation and how is it benefical?

Answer 7

• Stimulated macrophages release IL-1 (IL-6, TNF) stimulating PGE2 synthesis; acts on hypothalamus → ↑ heat production and retention
• Defences work better
• Faster lymphocyte division
• Increases cell migration
• Inhibits microbial replication

Question 8

How do lipotoxins and resolvins help resolve inflammation?

Answer 8

• lipoxins and resolvins are secreted by macrophages, neutrophils and structural cells
  They reduce:
• Diapedesis
• Neutrophil chemotaxis
• Production of pro-inflammatory cytokines
• Vascular permeability

Question 9

What are the stages of accute inflammation?

Answer 9

1) Dilation of small blood vessels
2) Increase vascular permeability
3) Endothelial cell activation and diapedeisis
4) Repair and resolution

Question 10

Why is rheumothoid arthritis a chronic inflammatory disease?

Answer 10

Leukocytes secrete TNF-a and IL-6; which act on fibroblasts in the joints
Cytokines induce fibroblasts to produce MMP and RANK
- MMP attacks soft tissues
- RANK activates bone destroying osetoclasts

Question 11

How is TB an example of partially resolved inflammation?

Answer 11

• Cant completely clear bacteria
• If not killed, infected macrophages are activated by IFN-y released by CD4 T cells
• Forms granuloma: TNF-a is important in maintenance

Question 12

What do steroidal anti-inflammatory drugs do?

Answer 12

• Decrease diapedesis and inflammatory cell activation
• Decrease T-cell activation
• Decrease fibroblast function
• Decrease expression of COX-2 (prostaglandins)
• Decrease release of inflammatory mediators
• Increase release of anti-inflammatory cytokine

Question 13

Why should you not treat rhuematoid arthritis with Infliximab if you have previously been diagnosed with TB?

Answer 13

Because infliximab gets rid of TNF-a, which is what is keeping the granulomas together so it would release a bunch of infected macrophages into your bloodstream and make you sick