Chronic inflammation

Question 1

Factors favouring resolution

Answer 1

• Minimal cell death and tissue damage
• Occurrence in an organ or tissue with regenerative capacity eg liver
• Rapid destruction of the casual agent
• Rapid removal of fluid and debris by good local vascular drainage

Question 2

organisation

Answer 2

Replacement of destroyed tissue by granulation tissue

Question 3

Factors favouring organisation

Answer 3

• Large amounts of fibrin
• Substantial necrosis
• Exudate and debris cannot be removed or discharged

Question 4

Signs of organisation

Answer 4

Signs of organisation

• Sprouting capillaries – production of new capillaries
• Proliferation of fibroblasts
• Macrophage infiltration – inflammatory cell
• New capillary beds

Question 5

Organisation - granulation tissue

Answer 5

Orgnisation – granulation tissue

• Much skin is completely destroyed and the underlying tissue is undergoing repair. The underlying tissue is undergoing repair, The damaged area is being replaced by vascular granulation tissue.

Question 6

Inflammatory exudate replaced by

Answer 6

capillaries, macrophages,fibroblasts, collagen

Question 7

what drives organisation ?

Answer 7

TNF, EGF,FGF - growth factors

Question 8

Chronic inflammation

Answer 8

• Primary – occur entirely without a previous episode
• Progression from acute inflammation
• Recurrent episodes of acute inflammation

Examples

1. Resistance of infective agent to phagocytosis and intracellular eg TB, leprosy, viral infections
2. Foreign body reactions to endogenous materials eg gout ( may be acute or chronic )
3. Foreign body reactions to exogenous materials eg asbestos
4. Some autoimmune diseases such as rheumatoid arthritis – primarily in the synovial of the joints
5. Specific diseases of unkown aetiology eg ulcerative colitis
6. Primary granulomatous diseases eg sarcoidosis

Question 9

Factors favouring progression from acute to chronic

Answer 9

1. Indigestible substances eg glass, suture material ( foreign body reaction )
2. Deep seated suppurative inflammation where drainage is delayed or inadequate
   - Thick abcess walls
   - Formation of granulation/fibrous tissue
   - Pus becomes organised
   - Forms fibrous scar

Osteomyelitis – a chronic abcess which is extremely difficult to eradicate

3. Recurrent episodes of acut inflammation and healing may eventually result in the clinicopathological entity of chronic inflammation

Chronic cholecystitis – replacement of wall by fibrous tissue lymphocytes rather than neutrophils predominate

Question 10

What does chronic inflammation look like?

Answer 10

Chronic ulcer

• Mucose breached
• Base lined by granulation tissue
• Fibrous tissue throughout muscle laeyers ( in peptic ulcer)

Chronic abscess cavity eg osteomyelitis, empyema thoracis

Thickening of the wall of a hollow viscus

Granulolmatous inflammation eg tuberculosis

Fibrosis

The cells of chronic inflammation

• On inflammatory process in which lymphocytes plasma cells and macrophages predominate
• Usually accompanied by the formation of granulation tissue resulting in fibrosis

Question 11

Macrophages

Answer 11

• Considerate phagocytic capabilities
• Can ingest a wide range of materials
• Relatively large cells
• Can harbour viable organisms resistant to lyosomal enzymes eg mycobacterium tuberculosis, mycobacterium leprae
• Produce a range of important cytokines
• Activated on migration to an area of inflammation
• Macrophage activation factor ( MAF )
• Migration inhibition factor ( MIF )

Question 12

Sarcoidosis in liver – granuloma of epitheloid histiocyte

Question 13

Granulomatous inflammation

Answer 13

• A granuloma is an aggregate of epitheloid macrophages
• A histriocyte is a a macrophage in connective tissue
• Little phagocytic activity
• Secretory function
• Typical granuloma
• • central giant cells +/- caesation
• Surrounded by epitheliod histiocytes
• Peripheral rim of actvivated lymphocytes

Question 14

Causes of granulomatous disease

Answer 14

• Specific infections
• Foreign bodies – endogenous and exogenous
• Specific chemicals
• Drugs
• Unkown

Question 15

Granulation inflamamtion

Answer 15

May develop – necrotic tissue, giant cells

Mau causative agents are2 ingestible – foreign bodies, specific infections

Question 16

Terms to know relating to inflammation

Answer 16

Granuloma - aggregate of macrophage like cells

Granulation - important healing process with small blood vessels and connective tissues

Fibrin - deposited in acute inflammation

fibrous - typical scar tissue with collagen

Acute vs chronic - distinguished by dynamics and character of process, ie time of onset , resolution and cells involved.

Exudate vs transudate - high protein content from inc vasc perm vs low protein content from normal vasc perm