Lecture 16: Chronic Inflammation Flashcards
MDx?
Acute diffuse fibrinous pleuritis
For duration in a morphologic diagnosis what term would you use for
- minutes to hours
- 1-3 days
- 3 days - 1 week
- 1 week and beyond
- Peracute minutes to hours
- Acute 1-3 days
- Subacute 3 days - 1 week
- Chronic 1 week and beyond
What are the 6 Events in the resolution of inflammation
- (1)Return to normal vascular permeability;
- (2) drainage of edema fluid and proteins into lymphatics or
- (3) by pinocytosis into macrophages;
- (4) phagocytosis of apoptotic neutrophils and (5) phagocytosis of necrotic debris; and
- (6) disposal of macrophages. Macrophages also produce growth factors that initiate the subsequent process of repair.
What is the main cell needed to resolve inflammation?
- macrophage!
In an inflammation lesion, there’s a big mess, lot of fluid, lots of excessive proteins that get deposited in area along with a cellular infiltrate
At the end if there’s been successful resolution, it needs to be cleaned up
Macrophages are a big part of that. Leave the vasculature as monocytes, upon maturation will have a phagocytic capability
Neutrophils will already be present and will continue to be recruited as long as there’s debris
During acute inflammation will you see
- hyperemia?
- what type of exudates (think general)
- main WBC seen?
- will see Hyperemia
- Fluid exudates
- Cellular exudates
- Neutrophils
In chronic inflammation will you see
- hyperemia?
- what type of exudates (think general)
- WBCs seen?
- What other types of cells can you see?
- decreased hyperemia
- no longer a need for vessels to be leaky and for that area to be warmer, or to be profused by blood
- decreased fluid exudates
- macrophages, lymphocytes, plasma cells
- fibroblasts and angiogenesis (forming granulation tissue)
Difference between granulation tissue and granuloma?
- There’s the fibrotic, reparative process of granulation tissue
- There’s the inflammatory process composed of macrophages and lymphocytes, called a granuloma
What are 4 general reasons why chronic inflammation happens
- Failure of acute response
- Persistent irritant or Foreign body
- Intracellular pathogens
- Harder to kill, can have complex cell walls (fungi)
- Type IV hypersensitivities
- Prolonged, progressive or insidious course: (like a neoplasia)
- The longer an inflammatory response goes on, the greater chance for neoplasia
What is a beneficial effect of chronic inflammation
Upon inadequate agent neutralization by acute inflammation then you can wall off, entrapment of debris/infectious agent
What are 3 harmful effects of chronic inflammation
- Large, chronic, granulomatous lesions can be tissue-destructive
So get a loss of function- TB is a prime example, Pulmonary TB Takes a huge portion of the lung cavity, Breathing becomes painful and hard to do
- Persistent infections are a drag on the body’s resources. If you’re constantly having to fight something off, that energy and resources you’re not using for normal repair
- Chronic exposure to inflammatory mediators is probably not a good thing. Meant to be a short lived thing
- when chronic inflammation has resolved, what kind of tissue will be left?
- what will that do to its function
- can lead to fibrosis
- will get a loss of function
- As fibrous tissue matures, it’s going to contract. That’s going to put undue pressure on the intact cells and they are going to be damaged as well
What are the 5 types of chronic inflammation exudates?
- Lymphocytic / Plasmacytic
- Granulomatous
- Pyogranulomatous
- Fibrosing
- Proliferative
- Where would you see lymphocytic/ plasmacytic exudates?
- Can you see it grossly?
- What does it imply?
- CNS or interstitium of any organ
- Need to see it histologically
- implies chronicity
- What organ
- What is 1?
- 2?
- What type of exudate?
- brain
- Blood vessel
- lymphocytes, occassional plasma cells and macrophages
- note that they are located aroudn the blood vessel (interstitium)
- lympocytic/ plasmacytic exudate
What are the 3 general agents that cause lymphocytic/ plasmacytic exudate
- parasitic,
- protozoal,
- viral
If you see this in the brain what is the main agent you think of?
rabies!
Can another name for Lymphocytic / Plasmacytic be non-suppurative?
- NO
- Don’t use this term
- Dr. F-W hates this. It doesn’t tell us anything
instead of using this term to describe lymphocytic/ plasmacytic exudate what can you use?
- “Mononuclear infiltrate”
- Some combination of lymphocytes, plasma cells, monocytes and/or macrophages.
- meaning Not neutrophils
- What would granulomatous exudate be composed of and how arranged?
- What is the main WBC you think of with this exudate?
- Specifically arranged, tightly organized structure of macrophages that are then surrounded by lymphocytes and plasma cells, and maybe fibrous tissue
- Macrophage!
What would pyogranulomatous exudate be composed of and how arranged?
- Specifically arranged, tightly organized structure of macrophages that are then surrounded by lymphocytes and plasma cells, and maybe fibrous tissue with the presences of neutrophils in the center
When Dr. F-W sees a pyogranuloma, she looks really carefully for something in the center
When a monocyte leaves the blood stream what can happen to it at a granuloma
- A cell will leave the bloodstream as a monocyte, it will enter this granuloma and mature.
- Drawn there by chemotactic and chemokine factors.
- Matures under the influence of cytokines and chemokines
- can then turn into Epithelioidal cells, have a more epithelial look to them
- Many can merge together and create a Multinucleated giant cells
- would a granuloma be soft or firm?
- what will this imply if it is found in organs
- firm!
- This is solid structure that taking up blood supply, space, and resources.
- can you easily tell this is granulomatous inflammation just by looking at it?
This is an example of mycobacterium avium
Granulomatous enteritis due to macrophages within the submucosa and mucosa
- It’s tough….
- But we can describe it as being thickened, as being abnormally shaped
- And we infer that there’s some infiltrate in a layer that’s causing this expansion
- What is 1 pointing to?
- Hard to tell in this picture but what would this image be an example of?
- enlarged submucosa
- Granulomatous enteritis (will need to zoom in to see)