3. Chronic inflammation Flashcards
Which clinical signs are associated with chronic inflammation?
Pain and swelling
Redness and heat are resolved
Which is the dominant cell type involved in chronic inflammation?
Macrophages
Which 3 ways can chronic inflammation arise?
- Take over from acute inflammation if damage isn’t resolved in a few days
- Without any preceding acute inflammation
- Develops alongside acute inflammation
Give examples of chronic inflammation that doesn’t have preceding acute inflammation.
Autoimmune conditions - RA
Chronic infections
What type of tissue is often present in chronic inflammation?
Granulation tissue
What cells are involved in chronic inflammation?
Macrophages, B and T lymphocytes, Eosinophils, Fibroblasts/myofibroblasts.
Outline some functions of macrophages.
- Phagocytosis
- Processing and presenting antigens
- Cytokine release…
stimulate angiogenesis, fever and acute phase reaction.
Synthesis of cytokines, clotting factors, proteases.
What is the function of fibroblasts/myofibroblasts?
Secrete CT substances - collagen, elastin
Myofibroblasts contract - wound healing
What is a giant cell?
Fusion of macrophages to form one, large cell with lots of nuclei.
How is a giant cell formed?
Frustrated phagocytosis, when macrophages are unable to engulf a foreign body/ microorganism.
What are the 3 types of giant cell?
- Langhans
- Touton
- Foreign- body
What does a langhans cell look like and what disease is it associated with?
Horse-shoe nuclei
TB
When might a touton giant cell be seen?
Lesions with a high lipid content - e.g fat necrosis
Foam cells also present
What are unwanted effects of chronic inflammation?
- Fibrosis - cirrhosis
- Impaired function - excessive fibrous tissue
- Atrophy
- Immune response - e.g RA autoimmunity
What is granulomatous inflammation?
Inflammation with granulomas present
Why does a granuloma form?
Granuloma forms around a particle that is poorly soluble and difficult to eliminate. E.g foreign bodies, bacteria (TB)
Which cell types are present in a granuloma?
Clusters of macrophages and lymphocytes in its centre
Epitheloid cells
What are epitheloid cells?
Macrophages modified to look like epithelial cells, elongated and tightly packed together
What diseases can present with granulomas?
Crohn's, Sarcoidosis, Wegener's granulomatosis BCG granuloma (abnormal reaction)
How can you differentiate between sarcoidosis and TB?
Sarcoidosis has non-casous granulomas
TB has caseous necrosis within granuloma and langhan giant cells
Which inflammatory bowel condition is superficial and affects mucosa only?
Ulcerative colitis
Which symptoms are common to both UC and Crohn’s disease?
Bleeding, diarrhoea, weight loss
Are strictures and fistulae associated with UC or Crohn’s?
Crohn’s disease
What microscopic features would you expect to see in RA?
Inflammatory cells in synovial lining- macrophages, lymphocytes, plasma cells
Fibrosis
Hyperplasia of synovial lining
Rheumatoid nodules - giant cell granuloma’s
What is cirrhosis?
Chronic inflammation with fibrosis
Where is cirrhosis commonly seen?
End stage liver disease - bands of fibrous tissue, impairing liver function
What is chronic cholecystitis?
Gallstones
UC or Crohn’s: Discontinuous distribution
Crohn’s
UC or Crohn’s: Affects any part of gastrointestinal system
Crohn’s
UC or Crohn’s: ‘Cobblestone’ appearance to bowel mucosa.
Crohn’s
UC or Crohn’s: Granulomas often present
Crohn’s
UC or Crohn’s: Significant risk of colon cancer.
UC
UC or Crohn’s: Often most severe in distal colon
UC
UC or Crohn’s: Continous and superficial
UC
UC or Crohn’s: Bowel fistulae more common
Crohn’s
Which patients is sarcoidosis most common?
Young adult women
What tests can be used to differentiate between TB and sarcoidosis?
Acid fast bacilli
What is the definition of an ulcer?
Ulcer = breach in mucosa to level of submucosa or deeper.
How does Helicobacter pylori cause gastritis?
By stimulating production of pro-inflammatory cytokines and by directly injuring epithelial cells and increasing acid secretion.
Which malignancies are associated with h.pylori gastritis?
Gastric adenocarcinoma.
MALT (mucosa associated lymphoid tissue) lymphoma.
TB is acid fast. What does acid fast mean?
Retains stains even on treatment with mixture of acid and alcohol.
What are some clinical examples of chronic inflammation?
Chronic colesystitis Inflammatory bowel diseases Rheumatoid arthritis Chronic gastritis Cirrhosis
