MoD 3 (Chronic Inflammation) Flashcards
Which cells are associated with chronic inflammation?
- Macrophages
- Lymphocytes
- Eosinophils
- Fibroblasts/Myofibroblasts
Which type of interferon activates macrophages?
Gamma Interferon
Name the functions of macrophages in chronic inflammation:
- Phagocytosis
- Secretion of cytokines, complement, blood clotting factors and proteases
- Antigen presentation (initiation of immune response)
- Stimulation of angiogenesis
- Induce fibrosis
Induce fever, cachexia and acute phase response
What are the functions of lymphocytes in chronic inflammation?
- Process antigens
- Secrete antibodies
- Secrete cytokines
- Kill cells
What type of lymphocytes kill cells?
T lymphocytes
What type of lymphocytes secrete antibodies?
B lymphocytes that have become plasma cells
Describe the appearance of eosinophils:
- Pink, granular cytoplasm
- Bi-lobed nucleus
(Sun-burnt cell wearing sunglasses)
What kind of immune reactions cause the production of large amounts of eosinophils?
- Allergic reactions ie Asthma
- Parasitic infections
- Some neoplasms (Hodgkin’s lymphoma)
What kind of connective tissue fibres can be secreted from fibroblasts?
- Collagen
- Elastic
- Reticulin
- Glycosaminoglycans
What name is given to fibroblasts that can contract?
Myofibroblasts
What cell type recruits fibroblasts in chronic inflammation?
Macrophages
Neutrophils are the main cell type in what kind of inflammation?
Acute inflammation
Macrophages, Lymphocytes, Eosinophils and Fibroblasts are all cell types of what kind of inflammation?
Chronic inflammation
Define ‘giant cell’:
Multinucleate cells made by the fusion of macrophages, due to ‘frustrated phagocytosis’
When does frustrated phagocytosis occur?
When a phagocyte is unable to engulf its target because the target is physically too large to encompass
Giant cells form due to the fusion of which cell type?
Macrophage fusion
Name the 3 types of giant cells:
1) Langhans’
2) Foreign body
3) Touton
Langhan’s giant cells are made by the fusion of what type of cell?
Epithelioid histocytes (activated macrophages resembling epithelial cells)
What is an epithelioid histocyte?
An activated macrophage resembling an epithelial cell
What type of giant cell is formed by the fusion of epithelial histocytes?
Langhans’ giant cells
Describe the miscroscopic appearance of Langhans’ giant cells:
> 15 peripherally placed nuclei arranged in horseshoe formation
eosinophilic cytoplasm
Langhans’ giant cells are seen in chronic inflammation caused by what?
- Tuberculosis
- Crohn’s disease
- Sarcoidosis
- Late stage syphilis
What type of giant cells are seen in a tuberculosis infection?
Langhans’ giant cells
What type of giant cell is associated with granulomatous conditions?
Langhans’ giant cells
Describe the microscopic appearance of foreign body giant cells:
- Multiple nuclei scattered throughout cell
- May contain Ca2+, bone/plastic fragments etc
Describe the microscopic appearance of Touton giant cells:
Central ring of nuclei
Foamy cytosol
Why do Touton giant cells have a foamy cytosol?
Due to engulfed lipid
When are Touton giant cells seen?
- Fat necrosis
- Xanthoma
Which type of giant cell has a central ring of nuclei?
Touton giant cells
Which type of giant cell has a peripheral horseshoe formation of nuclei?
Langhans’ giant cells
Which type of giant cell has nuclei randomly scattered throughout the cytoplasm?
Foreign body giant cells
In which situations does chronic inflammation typically occur?
- After acute inflammation
- Autoimmune conditions
- Chronic persistent infections
- Prolonged exposure to toxic agents
Name some possible complications of chronic inflammation:
- Fibrosis
- Atrophy
- Stimulation of immune response
How does Rheumatoid Arthritis cause joints to become unstable and deformed?
Causes inflammation and proliferation of synovial membrane, which stretches the joint capsule
Which type of arthritis causes symmetrical pain and stiffness of joints?
Rheumatoid arthritis
Ulnar deviation of fingers is a sign of which type of arthritis?
Rheumatoid arthritis
Describe the distribution of ulcerative colitis:
Continuously proximal inflammation of colon from the rectum
What layers of the bowel wall are affected in ulcerative colitis?
Mucosa
Submucosa
Describe the microscopic appearance of ulcerative colitis:
Thinning of bowel wall
Loss of crypt architecture
Ulcer formation
Inflammation limited to mucosa and submucosa
What are the symptoms of ulcerative colitis?
- Bloody diarrhoea
- Abdominal pain
- Malaise/lethargy
- Anorexia
What is pancolitis?
When the entire colon is affected by ulcerative colitis
What are the 2 main types of non-specific inflammatory bowel disease?
1) Ulcerative colitis
2) Crohn’s disease
List some of the complications of ulcerative colitis:
- Increased risk of colon cancer
- Liver disease
- Anaemia
- Bowel perforation
- Osteoporosis (due to treatment)