Chronic Inflammation

Question 1

What is Chronic Inflammation

Answer 1

Secondary stage of inflammatory response
Occurs 24-72 hours after acute inflammation
Occurs if there is not return to steady state conditions following acute inflammation

Question 2

What is the predominant cell in acute inflammation?

Answer 2

Neutrophils

Question 3

What is the predominant cell in chronic inflammation?

Answer 3

Macrophages

Question 4

M1 Macrophages

Answer 4

Converts arginine to nitric oxide
NO is highly toxic to phagocytosed organisms

Question 5

M2 Macrophages

Answer 5

Non-inflammatory
Converts arginine to orthinine
(Orthinine is proline in extracellular fluid)
(Proline is a precursor for collagen synthesis)
Produce additional cytokines (TGF-B) to promote collagen deposition and replace necrotic material

Question 6

Where are pro-inflammatory cytokines produced?

Answer 6

By activated macrophages

Question 7

Examples of pro-inflammatory cytokines

Answer 7

IL-1
IL-6

Question 8

Function of pro-inflammatory cytokines

Answer 8

Interact with damaged tissues leading the brain to:
* Mediate pyrexia
* Induce lethargy
* Weight loss
Also stimulate acute phase proteins

Question 9

What is a granuloma?

Answer 9

Cluster of leucocytes as an inflammatory response to an infection or foreign body
Formed when there is persistent irritant stimulus:
Inert or pathogen

Question 10

How is a granuloma formed?

Answer 10

Irritant material causes formation of a distinct arrangement of inflammatory cells
1. Necrotic centre is made up of foreign material
Macrophages of different stages found in necrotic centre
2. Surrounded by further macrophages to section off necrotic centre from the rest of the body

Question 11

How is a granuloma formed?

Answer 11

Irritant material causes formation of a distinct arrangement of inflammatory cells
1. Necrotic centre is made up of foreign material
Macrophages of different stages found in necrotic centre
2. Surrounded by further macrophages to section off necrotic centre from the rest of the body

Question 11

How is a granuloma formed?

Answer 11

Irritant material causes formation of a distinct arrangement of inflammatory cells
1. Necrotic centre is made up of foreign material
Macrophages of different stages found in necrotic centre
2. Surrounded by further macrophages to section off necrotic centre from the rest of the body
Might contain giant cells or other immune associated cells
3. Infection granulomas have an outer layer of lymphocytes

Question 12

What are the stages of tissue repair?

Answer 12

Inflammation
Proliferation
Maturation

Question 13

Examples of chronic inflammation with a clear pathogen

Answer 13

Parasitic
Fungal
Neoplastic

Question 14

Examples of chronic inflammation without a clear pathogen

Answer 14

Atopic dermatitis
Inflammatory bowel disease (Hypersensitivity)
Toxic agent

Question 15

Pyogranulomatous Lesions

Answer 15

Chronic inflammatory lesion
Characterised by predominance of macrophages and Neutrophils
‘Large granuloma’
Slow growth despite aggressive clinical signs
T-cell interaction with macrophages is more important

Question 16

Pyogranulomatous Lesion Examples

Answer 16

Feline infection peritionitis
Johnes disease in cattle - mycobacterium (paratuberculosis)

Question 17

Caseous granuloma

Answer 17

Affects organ function
Breakdown could lead to excessive bacterial dissemination throughout body

Question 18

Chronic granulomatous disease

Answer 18

Inherited disorder
Occurs when phagocytes don’t function properly
Animal has increased susceptibility to repeated infections

Question 19

Chronic Pyelonephritis

Answer 19

Due to chronic pyogenic infection of kidney
Pyogenic granulomas are small raised red bumps
Often causes hydronephrosis (swollen and stretched due to urine build-up)

Question 20

Actinobacillosis

Answer 20

Bacterial cause - enters wound
Well defined disease of soft tissues in mouth of cattle
Present with increased salivation and difficulty chewing
Proliferative and ulcerative chronic active inflammatory lesions
Contains:
○ Neutrophils
○ Lymphocytes
○ Macrophages
○ Plasma cells
Fibrous tissue replaces muscle in tongue during healing

Question 21

Bacterial causes of chronic inflammation

Answer 21

Chronic mastitis
Tuberculosis

Question 22

Immune mediate arteritis and myocardidtis

Answer 22

Inflammation occurs in blood vessels
Swelling of heart muscle
Often no ‘main’ clinical signs until at a severe stage

Question 23

Chronic hepatitis

Answer 23

• Acute hepatitis is infectious, toxic or idiopathic
• Aetiology of chronic hepatitis is unknown
  ○ Can progress from acute
• Clinical signs:
  ○ Weight loss
  ○ Lethargy
  ○ Depression