4- Inflammation

Question 1

Compare acute and chronic inflammation

Answer 1

Acute Inflammation
Neutrophils
Histamine
Prominent necrosis
Immediate onset
Lasts a few days
Outcomes include:
Complete resolution
Progression to chronic inflammation

Chronic Inflammation
Monocytes/Macrophages
Cytokines
Prominent scar tissue
Delayed onset
Lasts weeks/months/years
Outcomes include

Question 2

Define inflammation

Answer 2

Reaction of living vascularised tissue to sub-lethal cellular injury.

Question 3

What are the local clinical features of acute inflammation

Answer 3

RUBOR – redness
	TUMOUR – swelling (oedema)
	CALOR – heat
	DOLOR – pain
Loss of function

Question 4

Gives examples of targeting inflammatory regulators

Answer 4

Histamine
–Antihistamine
•Prostaglandins
–Aspirin
•IL-1 and TNF
–Anti-TNF antibodies

Question 5

What are exudates?

Answer 5

“What comes out of leaky vessels due to inflammation – fluids, cells, proteins (fibrin, antibodies, small molecules involved in cell signaling)
Purulent
Serous
Haemorrhagic
Fibrinous

Question 6

What is the cause of chronic inflammation?

Answer 6

Usually due to persistence of injury causing agents
(Persistent damage
•Persistent infection (HCV, TB)
•Prolonged exposure to toxic agent (uric acid)
•Autoimmunity (RA, SLE)
•Foreign body (splinter, silica))

Question 7

What are the components ofinflammation?

Answer 7

Cells, vessels, ecm, soluable factors

Question 8

What is histamine?

Answer 8

A vasoactive amine
•Produced by mast cells
•Preformed and released cell degranulates
–Degranulation triggered by cell surface IgE antibody interaction with antigen
•Leads to..
–Vasodilation
–Increased vascular permeability
•Dysregulation
–allergy (Type 1 hypersensitivity)

Question 9

What are some inflammatory mediators?

Answer 9

Histamines, prostaglandins, chemokines, cytokines, complements

Question 10

What is transudate?

Answer 10

TRANSUDATE - caused by disturbances in hydrostatic and colloid osmotic
pressure, NOT CAUSED BY INFLAMMATION
Low protein
Cell poor
Low Specific Gravity

Question 11

How does wbc move from vessel to tissue?

Answer 11

Margination, Rolling, Adhesion, Transmigration, Chemotaxis, Phagocytosis

Question 12

Define chronic inflammation

Answer 12

Inflammation of prolonged duration in which active inflammation, tissue destruction and attempts at repair occur simultaneously

Question 13

What is granulomatous inflammation ?

Answer 13

Particular form of chronic inflammation showing granuloma formation
–Cluster of macrophages
–Involves specific immune reaction T cells

Question 14

What causes granulomatous inflammation?

Answer 14

FORM OF CHRONIC INFLAMMATION - shows granuloma formation
• Clusters of macrophages
• Involves specific immune reaction T cells

Infection – TB, fungi
–Foreign material
–Reaction to tumours
–Immune diseases (sarcoid, Crohn’s)

Question 15

What are the long term sequelae of inflammation?

Answer 15

Good: Removal of causative agent
 Cessation of the inflammatory reaction
 Healing of tissue damage to preserve integrity and function (resolution)
Bad:
LOCAL
•Can cause excess local tissue damage and scarring
•Secondary effects on nearby tissue
–E.g. Bronchoconstriction in asthma

SYSTEMIC
•Can evolve into systemic inflammatory reaction and secondary multi-organ failure
–E.g. Septic shock
–Amyloid

Question 16

What are “the sequential changes in wound healing?

Answer 16

Parenchymal cell regeneration and RESOLUTION

•REPAIR by connective tissue and SCAR TISSUE FORMATION

Question 17

What are the components of fibrous scar tissue?

Answer 17

Fibroblasts – produce collagen
•Collagen – strong “scar” type collagen
•Remodelling – reorientation of collagen fibres for maximal tensile strength

Question 18

What can hinder repair?

Answer 18

General
–POOR NUTRITION - Require protein for collagen production, and energy for cell function.
–VITAMIN DEFICIENCY
Vitamin C – needed by fibroblasts to make collagen
Vitamin A - required for epithelial regeneration
–MINERAL DEFICIENCY eg. Zinc
–SUPPRESSED INFLAMMATION by steroids, old age, diabetes
•Local
–POOR BLOOD SUPPLY eg. ischaemic leg ulcers
–PERSISTENT FOREIGN BODY eg. splinter
–MOVEMENT e.g across a fracture site -> need for a cast.

Question 19

What are complications of repair?

Answer 19

Keloid Formation
• Excess collagen deposition
• You can get scar tissue formation other than at the site of original injury
Contractures
• Fibrous scar tissue contracts as part of its maturing process
• If this happens across a joint, you can get reduced joint mobility
Impaired Organ Function
• Fibrous scars forming in organs will cause loss of functional tissue
• This affects organ function

Question 20

What is amyloidosis?

Answer 20

“In response to chronic inflammation anywhere in body, liver produces and releases increased amounts of serum amyloid A protein into the blood.

In some cases this is deposited in tissue as dense protein (amyloid). ”

Question 21

What are the cells of chronic inflammation?

Answer 21

Macrophages and lymphocytes

Question 22

What is the function of exudate

Answer 22

Exudate consist of: fluid, cells, proteins including fibrin, antibodies etc.
• Fluid - dilutes pathogen and allows soluble mediators to spread
• Fibrin - walls off pathogen to stop it spreading. Gives inflammatory cells
substrate to hold on to/migrate through

Question 23

What are the types of exudate

Answer 23

Serous = fluid filled
EXAMPLE: Blister
Lower protein content of all the exudates
• Fibrinous = High fibrin content
More due to traumatic injury
EXAMPLE: Viral Pericarditis
• Purulent = pus filled
Combination of fibrin, inflammatory cells, debris and fluid EXAMPLE: peritonitis following bowel perforation

Question 24

What is suppuration

Answer 24

The formation of pus, neutrophils, bacteria and cellular debris Suppuration is an example of exudate formation that commonly occurs as part of the body’s immune response.