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)
What would this be called
- Granulomatous enteritis
- We see macrophages mixed with lymphocytes
- What type of exudate?
- What type of stain is the bottom picture used?
- purple lines near the middle of the bottom picture?
- granulomatous exudate
- acid fast stain
- acid-fast bacteria (mycobacteria in this case)
This is a set of lungs that you would have taken out of the dog, placed out of table, and it won’t collapse. Air won’t be released out of there.
This dog had blastomycosis
Would feel firm
Diffusely mottled with dark red to pink color
You might even feel some subtle nodularity within the lung fields
- What type of exudate/ inflammation are you thinking of?
Granulomatous inflammation
This is an image of lung tissue
- 1?
- 2?
- 3?
- 4?
- What type of inflammation is this?
- multinucleated giant cell
- fibroblast
- neutrophils
- blastomyocosis organism
- Pyogranulomatous inflammation
- Here, it’s not forming a discrete granuloma
Why were fibroblasts (2) seen in this pyogranulomatous inflammation image of lungs
- This has been an extremely damaging lesion. Unbridled growth of a fungal agent, a dimorphic yeast
- Has wiped out a large degrees of parenchyma
- In order to recover, the body is bringing in a large amount of fibroblasts with the idea of stabilizing that area with more fibrous tissue
- It won’t fix the problem, but that’s the next best thing, better than having excessive fluid in your lungs
1
2
3
4
5
1- cornea
2- lens
3- optic nerve
4- retina, being pushed up by exudate
5- inflammatory exudate exudate
- If you zoomed in and saw mostly macrophages and neutrophils what would you call this (also include the structure)
- What main cardinal sign is being affected here
- What has caused this
- Pyogranulomatous endophthalmitis
- loss of function cardinal sign because dog was blind
- Blastomycosis
What kind of necrosis can you see in a granuloma (not always)
+/- Caseation necrosis
What is fibrosing exudates
Exudates in the sense that cells are entering an area that they normally would not
What is happening in an proliferative exudate
- Starts reparative, ends up contributing to a loss of function
- can be Epithelial- example= Proliferative Ileitis
- can be Mesenchymal - example= Chronic proliferative laminitis
- What is seen at 1
- What would this image be called
- P3 is rotated
- Triangular area here, if you were to look microscopically would be a combination of epithelial and mesenchymal proliferation
- That tissue is desperately trying to reestablish a connection between the primary lamella of the hoof wall and the ridges of P3
- Not an effective process. Just making extra tissue in an area that doesn’t have lots of extra space
- Chronic proliferative laminitis
look at this chart
- What is circled?
- is this weak or strong
- What can this cause?
- Fibrotic adhesion
- strong
- Twisting, Impaction
- Especially if there’s a concurrent adhesion to the body wall
what is circled
Fibrotic adhesion
