S3 Chronic Inflammation Flashcards
What are the features of chronic inflammation?
Prolonged inflammation with associated repair
- delayed onset
- variable duration (days to years)
- variable appearances
- limits damage, initiates repair
- can cause debilitating symptoms
How can chronic inflammation arise?
- can take over from acute inflammation (if resolution isn’t possible with acute inflammation)
- develops alongside acute inflammation (severe/persistent irritation)
- arises ‘de novo’ (no acute inflammation before e.g. in autoimmune conditions)
What cell types are involved in chronic inflammation?
- macrophages
- lymphocytes
- plasma cells
- eosinophils
- basophils
- giant cells
- fibroblasts/myofibroblasts
What is the name for a macrophage in circulation?
Monocyte
What is another name for macrophages?
Histiocyte
What is the shape/structure of macrophages like?
Shape is inconsistent based on what they are engulfing
- nuclei look a bit like ‘slippers’
- large cells
- have an abundant foamy cytoplasm (phagolysosomes)
What is the function of macrophages?
- phagocytosis - removal of pathogen/necrosis/debris and antigen presentation to immune system
- synthesise and release inflammatory mediators which control and regulate the inflammatory response
What is the shape/structure of lymphocytes?
- small cells (slightly larger than RBCs)
- have a spherical nucleus
- have a thing rim of cytoplasm around the nucleus
What is the function of lymphocytes?
- T cells - helper (assist other inflammatory cells) and killer (destroy pathogens)
- B cells - mature into plasma cells, produce antibodies, neutralise pathogens
What is the structure/shape of plasma cells?
- eccentric nucleus - ‘clock face’ chromatin
* have a peri-nuclear clearing - a paler area around the nucleus (where Golgi bodies are present)
What is the function of plasma cells?
They are fully differentiated B lymphocytes that produce antibodies
What is the structure of an eosinophil?
- bilobed nucleus
* granular cytoplasm that stains red
What is the function of eosinophils?
- release mediators (that result in an allergic reaction)
* involved in hypersensitivity reactions and parasitic infections
What is the role of fibroblasts and myofibroblasts?
Involved in regeneration and repair
What is the structure of giant cells?
- multinucleate cells
* result from the fusion of many macrophages
What are the 3 types of giant cells? How are their nuclei arranged?
- Foreign body giant cell - random
- Langhans giant cell - ‘horse shoe’ shape
- Touton giant cell - arranged in circle towards centre
In what disease are langhans giant cells most commonly seen in?
Tuberculosis
In what type of necrosis are touton giant cells most commonly seen in?
Fat necrosis
Give an example of conditions that you see more 1. Plasma cells 2. Lymphocytes 3. Macrophages In
- Rheumatoid arthritis
- Chronic gastritis
- Leishmaniasis (protozoan infection)
What does chronic inflammation result in?
- fibrosis
- impaired function
- atrophy
- stimulation of immune response
How do gall stones result in gall bladder fibrosis?
- Repeated obstruction of bile duct by gall stones
- Repeated bouts of acute inflammation which leads to chronic inflammation
- Fibrosis of the gall bladder walls occurs (looks thickened and pale)
Compare Crohn’s disease and ulcerative colitis.
Crohn’s - affects all of GI tract, has discontinuous patches of inflammation (skin lesions), inflammation affects full thickness of the bowel wall (trasnmural), granulamata can be present, less likely to have rectal bleeding
Colitis - affects only the large bowel, has continuous inflammation, inflammation affects only the superficial bowel wall (mucosa and submucosa), no granulomata present, more likely to have rectal bleeding
What can cause liver damage?
- alcohol
- hepatitis
- drugs and toxins
- fatty liver disease
What is granulomatous infection?
Type of chronic inflammation that involves formations of granulomas
