Immunopathology - Week 5 - Chronic Inflammation

Question 1

Describe the different patterns of chronic inflammation.

Answer 1

There are 2 main patterns:
1. Non-specific proliferative chronic inflammation
* Characterised by granulation tissue
* Infiltration by fibroblasts which lay
down fibrin and new blood vessels.

2. Granulomatous inflammation
   * Characterised by distinct nodules
   called granulomas.
   * Have a centre of macrophages,
   epithelioid cells and giant cells

Question 2

Describe the histological features that typify chronic inflammation.

Answer 2

• Infiltration of the affected tissue by
  inflammatory cells.
• Predominantly mononuclear cells: lymphocytes, plasma cells
  and macrophages
• Tissue damage
• caused by inflammatory cytokines, growth factors, enzymes.
• Ingrowth of granulation tissue
• Young, highly vascular connective tissue which contains
  fibroblasts, which eventually causes fibrosis and possibly granuloma formation.

Question 3

Explain the possible consequences of chronic inflammation.

Answer 3

• Significant scarring
• Ulcers
• Strictures and subsequent obstructions
• Fistulas
• Deformations
• Pain
• Impaired function of the structures affected (joints)

Question 4

Describe the causes of chronic inflammation.

Answer 4

1. Inability to resolve an episode of acute inflammation
   - Delayed healing
   - Persistence of injury
   - Interruption of healing process.
2. Persistent low-grade infection
3. Recurrent episodes of acute inflammation
4. Prolonged exposure to toxic agents
   - Asbestos induce a chronic inflammatory response in the lungs
5. Autoimmune diseases
   - rheumatoid arthritis

Question 5

Define chronic inflammation.

Answer 5

Chronic inflammation is a long-term, persistent inflammatory response that can last for months or even years. Unlike acute inflammation, chronic inflammation happens when the immune system continues to send inflammatory cells even when there is no clear threat.