Chronic Inflammation - SRS Flashcards
What are the principle cell types we should think of when we hear chronic inflammation?
Lymphocytes and Macrophages
Identify the cell on the left
B-cell (plasma cell)
Identify the cell on the right
T Cell (reactive)
What are three causes of chronic inflammation?
- Persistent infections
- Delayed type hypersensitivity
- granulomatous reactions
What disease are we looking at here?
Histoplasmosis
What are the structures surrounding the two eosinophilic centers?
Granulomas
What is the disease? What type of inflammation?
Rheumatoid arthritis - hypersensitivity disease, autoimmune
This tissue sample is taken from a patient with rhuematoid arthritis. What is the circular structure shown here?
Caseous granuloma
Prolonged exposure to toxic agents, exogenous or endogenous can lead to chronic inflammation. Give and example of each.
Silicosis - inhaled silica over a long period of time causes inflammatory lung disease. (Exogenous)
Atherosclerosis - Chronic inflammation induced at least in part by excessive production and tissue deposition of endogenous cholesterol and other lipids. (Endogenous)
Your patient, who is a sand blaster comes in and you obtain the following imaging/samples. Diagnosis? Type of inflammation?
Silicosis - chronic inflammation, exogenous agents
What are the stand out features of each of these four images taken from the brain?
What diagnosis does this indicate?
Top left - Red blobs
Top right - neurons with eosinophilic inclusions
Bottom left - Amyloid plaques
Bottom right - neurofibrillary tangles
Alzheimer’s disease
What is amyloidosis?
Accumulation of misfolded Beta pleated sheets
What are the three morphologic features of chronic inflammation?
- Infiltration with mononuclear cells (macros, lymphos, plasma cells)
- Tissue destruction by persistent offending agent or by inflammatory cells.
- Attempts at healing by CT replacement of damaged tissue, accomplished by angiogenesis and fibrosis
What is the red arrow indicating in this sample from a lung?
What kind of inflammation is this?
What do the black arrows indicate?
Lymphocytes in a germinal center
Chronic inflammation
Interstitial fibrosis (black arrows)
This is lung tissue, what type of inflammation do we see here?
Acute inflammation
Neutrophils present
Macrophages are the dominant cells in most chronic inflammatory reactions. How do they contribute to the reaction? (3)
- By secreting cytokines and growth factors that act on various cells
- By destroying foreing invaders and tissues
- Activating other cells notably T lymphocytes
What are macrophages derived from?
Hematopoietic stem cells in bone marrow
Early Development
progenitors in the embryonic yolk sac
Fetal liver
If you see a mononuclear cell in a peripheral blood smear, what would you call it? When does it’s name change and to what?
Monocyte
Once diapedesed, it is a macrophage.
How are macrophages activated in the classical pathway?
(4)
- Microbial products such as endotoxin binding TLR’s
- T cell derived signals
- IFN-y
- Crystals and particulate matter
What are classically activated macrophages also called?
M1
M1’s produce what substances?
NO
ROS
Upregulate lysosomal enzymes
cytokines
How is alternative macrophage activation accomplished?
Induced by cytokines other than INF-Y such as…
- IL-4
- IL-13
What are alternatively activated macrophages also known as?
M2’s
What is the principle function of M2’s?
What do their secretions do?
Tissue repair and anti-inflammatory effects. They secrete growth factors that promote angiogenesis, activate fibroblasts and stimulate collagen synthesis.
What kind of macrophage reaction produces liver cirrhosis?
Exaggerated M2 reaction
What are these two purple stained cells?
Reactive B-Cells
What is this cell?
Give the classical description you should expect to encounter.
Activated B-Cell - Plasma cell
- Eccentric Clock faced nuclei
- With a perinuclear Hoff body
- and basophilic cytoplasm
Where are Dohle bodies found?
Activated neutrophils
We have a patient with multiple myeloma, who we do a bone marrow biopsy on. We see plasma cells with little eosinophilic globules in them. What are these globules called?
These pink globules are called Russel Bodies. They are immunoglobulin.
In what conditions are you likely to see this cell?
What do the granules contain?
- Immune reactions mediated by IgE
- Parasitic infections
- Peripheral Vascular Diseases
- Cancer
Granules of eosinophils contain major basic protein
What does major basic protein do, and how?
It is a highly cationic protein that is toxic to parasites (and causes lysis of mammalian cells)
What kind of infection would this sample be typical of?
Parasitic - note the presence of eosinophils, plasma cells and multinucleated giant cells.
What type of receptor is expressed on this cell’s surface?
What does this receptor do?
FceRI - binds the Fc portion of the IgE antibody and leads to degranulation of the mast cell, releasing histamine and prostaglandins.
What is chronic bacterial infection of bone called?
Osteomyelitis
What is unique about the cells seen in osteomyelitis?
Neutrophilic exudate can persist for many months
What is this slide showing?
What is the red arrow pointing to?
What is the black arrow pointing to?
Osteomyelitis
Red: Neutrophils
Black: Trabeculated Bone
What are the two types of granulomas?
Foreign body Granuloma
Immune Granuloma
What do you see here?
Immune granuloma
What is this?
Foreign body granuloma
Closer inspection of the granuloma shown at top, taken from lung nodules of a man with HIV revealed the following. What is this most likely?
Tuberculosis
This patient was mid 20’s, found dead in the street with a syringe stuck in his arm. His lungs had multiple white nodules, which we biopsied here. What are the clear spaces with the refractile material?
Talc granuloma - used to cut cocaine… causes a foreign body giant cell reaction
What is this?
Tuberculosis granuloma
If you see a caseating granuloma, what is the first thing to rule out?
TB
What is a non-caseating granuloma with abundant macrophages, particularly in the bowel likely to be?
Sarcoidosis
What would you call acid-fast bacilli in macrophages with noncaseating granuloma?
Leprosy
A rounded, or stellate granuloma containing central granular debris and recognizable neutrophils, with few if any giant cells would point to what?
Cat-scratch disease
What kind of granuloma would you expect to find in Crohn disease (IBD)?
Noncaseating granulomas in wall of intesting with dense chronic inflammatory infiltrate
Chronic inflammation is a prolonged host response to…
Persistent stimuli
Chronic inflammation is caused by…
- Microbes that resist elimination
- immune responses against self and environmental antigens
- toxic substances (Ex/Endogenous)
Chronic inflammation is characterized by what four things?
- Coexisting inflammation
- tissue injury
- attempted repair by scarring
- immune response
The cellular infiltrate in chronic inflammation consists of? (4)
- Macros
- Lymphos
- Plasma Cells
- Other Leukocytes
Immune granulomas are a pattern of chronic inflammation induced by?
T cell and macrophage activation in response to an agent that is resistant to eradication