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.



























