S3) Chronic Inflammation Flashcards
What is the definition of chronic inflammation?
Chronic response to injury with associated fibrosis
3 ways chronic inflammation can arise
Acute inflammation where quick resolution isn’t possible
De novo
Alongside acute inflammation
Give 3 examples of de novo chronic inflammation
Autoimmune reactions (RA)
Chronic infections (viral hepatitis)
Chronic low level irritation
4 functions of macrophages
Phagocytosis
Antigen presentation
Synthesis of cytokines, complement proteins, clotting factors and proteases
Control of other cells by cytokine release
Which cells are present in chronic inflammation? (6)
Macrophages
Lymphocytes
Plasma cells
Eosinophils
Fibroblasts/ myofibroblasts
Giant cells
In what situations are eosinophils recruited? (3)
Allergic reactions
Parasite infections
Some tumours
How are giant cells made?
Uni/ multinucleate?
Name three types of giant cells and the conditions which they are seen in
Fusion of macrophages
Multinucleate
Langhans - tuberculosis
Touton - fat necrosis
Foreign body type
Which cells are most prevalent in RA?
Plasma cells
Which cells are most prevalant in gastritis?
Lymphocytes
5 effects of chronic inflammation:
Fibrosis eg gall bladder, cirrhosis
Impaired function
Sometimes increased function eg thyrotoxicosis
Atrophy - gastric mucosa and adrenal glands
Stimulation of the immune response
What causes chronic cholecystitis?
What changes does this causes to the organ involved?
Repeated obstruction by gall stones leads to repeated acute inflammation, which leads to chronic inflammation
Fibrosis of gall bladder wall
Which parts of the bowl does inflammatory bowel disease affect?
What two conditions cause IBD?
What is the primary difference between these two conditions?
Small and large bowel
Ulcerative colitis and Crohn’s disease
Ulcerative colitis is superficial, Crohn’s disease affects the whole organ
What main symptoms are seen in Ulcerative Colitis?
Diarrhoea, rectal bleeding
What main symptoms are seen in Crohn’s disease?
Strictures - narrowing
Fistulae - abnormal connections between epithelium lined organs
Causes of cirrhosis (5)
Alcohol
Infection with HBV or HCV
Immunological
Fatty liver disease
Drugs and toxins
What is a granuloma?
Why does it form?
A collection of histiocytes (modified macrophages)
The immune system attempts to wall off substances which it can’t eliminate
Causes of granulomatous inflammation (3)
Irritant foreign material
Infections eg mycobacteria or fungi
Unknown causes
What effect does TB have?
Mycobacterial infection which causes persistent cell-mediated immunity
How does chronic inflammation present?
4 clinical signs are resolved but pain persists
Generally, which cells are most dominant in chronic inflammation?
Macrophages
What are the functions of lymphocytes?
Process antigens
B - secrete antibodies
T - secrete cytokines
NK - kill tumour/ virus infected cells
How do Langhan cells appear microscopically?
Peripheral nuclei
How do foreign body giant cells appear microscopically?
Randomly arranged nuclei
Seen when indigestible foreign bodies are found
Large foreign bodies stick to the cell surface
How do Touton cells appear microscopically?
Nuclei arranged in a ring towards the centre of the giant cell
Formed in lesions where there is a high lipid content eg fat necrosis or xanothomas
