4- Inflammation Flashcards
Compare acute and chronic inflammation
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
Define inflammation
Reaction of living vascularised tissue to sub-lethal cellular injury.
What are the local clinical features of acute inflammation
RUBOR – redness TUMOUR – swelling (oedema) CALOR – heat DOLOR – pain Loss of function
Gives examples of targeting inflammatory regulators
Histamine –Antihistamine •Prostaglandins –Aspirin •IL-1 and TNF –Anti-TNF antibodies
What are exudates?
“What comes out of leaky vessels due to inflammation – fluids, cells, proteins (fibrin, antibodies, small molecules involved in cell signaling) Purulent Serous Haemorrhagic Fibrinous
What is the cause of chronic inflammation?
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))
What are the components ofinflammation?
Cells, vessels, ecm, soluable factors
What is histamine?
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)
What are some inflammatory mediators?
Histamines, prostaglandins, chemokines, cytokines, complements
What is transudate?
TRANSUDATE - caused by disturbances in hydrostatic and colloid osmotic pressure, NOT CAUSED BY INFLAMMATION Low protein Cell poor Low Specific Gravity
How does wbc move from vessel to tissue?
Margination, Rolling, Adhesion, Transmigration, Chemotaxis, Phagocytosis
Define chronic inflammation
Inflammation of prolonged duration in which active inflammation, tissue destruction and attempts at repair occur simultaneously
What is granulomatous inflammation ?
Particular form of chronic inflammation showing granuloma formation
–Cluster of macrophages
–Involves specific immune reaction T cells
What causes granulomatous inflammation?
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)
What are the long term sequelae of inflammation?
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
What are “the sequential changes in wound healing?
Parenchymal cell regeneration and RESOLUTION
•REPAIR by connective tissue and SCAR TISSUE FORMATION
What are the components of fibrous scar tissue?
Fibroblasts – produce collagen
•Collagen – strong “scar” type collagen
•Remodelling – reorientation of collagen fibres for maximal tensile strength
What can hinder repair?
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.
What are complications of repair?
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
What is amyloidosis?
“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). ”
What are the cells of chronic inflammation?
Macrophages and lymphocytes
What is the function of exudate
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
What are the types of exudate
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
What is suppuration
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.
