Chronic Inflammation Flashcards
What is the definition of chronic inflammation?
Inflammation lasting over 2 weeks
True or false: inflammation, tissue destruction, and attempts at repair coexist are separate events in inflammation
False, all at once
What are the three reasons for chronic inflammation?
- Persistent microbial infection
- Immune-related inflammatory diseases
- Prolonged exposure to potentially toxic agents
What are the characteristics of the microbes that cause chronic inflammation?
Low pathogenicity
What are the three morphological characteristics of chronic inflammation?
- Infiltration with monocytes
- Tissue destruction
- Attempts at healing
What do the attempts at healing look like histologically in chronic inflammation?
Deposition of CT (heavy eosinophilia); angiogenesis or fibrosis (pink collagen deposition)
Histological sample where there are Ducts + islets = where?
Pancreas
What happens in chronic inflammation of lung tissue? (3)
Enlarged alveolar cells
Deposition of collagen
Mononuclear cell infiltration
Plasma cells in tissue = ?
Chronic inflammation
How do plasma cells appear in tissues? (3)
Clock face nucleus
Clear areas around the nucleus representing Golgi
Nucleus pushed to one side
What is the key cells in chronic and granulomatous inflammation?
Macrophages
What happens to monocytes when they enter tissues?
Name change:
turn into macrophages (Kupffer cells for liver or pulmonary macrophages)
Macrophages is in bone =?
Osteoclasts
Macrophages is in brain =?
Microglia
How do activated macrophages appear relative to unactivated macrophages?
Much larger, like a squamous cell
What are the four features of a mature macrophages (activated monocyte)?
- Increased size
- Increase in lysosomes
- Increased lysosomal enzymes
- Increased ability to kill organisms
What are the maturation steps of monocytes to macrophages?
- Stem cell
- Monoblasts
- monocytes
- macrophages
How long do macrophages take to enter site of inflammation?
48 hours
What is the main activation signal of macrophage activation?
interferon gamma
Where does gamma interferon mainly come from? (2)
Activated T cells (Th1 cells and NK cells)
What causes the tissue destruction seen in chronic inflammation?
The injury factors or the inflammatory mediators are constantly there
How do macrophages appear in tissue?
Relatively clear staining nucleus
What are macrophages that are in the liver?
Kupffer cells
Macrophages in the lungs = ?
Pulmonary macrophages
What are the morphological characteristics of activated macrophages?
Large cells with relatively clear nuclei
Where can interferon gamma come from that causes problems?
Endotoxin on bacteria (LPS)
What are the cytokines that direct macrophages to kill? To repair?
Kill = IFN-gamma Repair = IL-4, others
What do macrophages secrete if given the repair signal?
Growth factors
Angiogenic factors
What happens in chronic inflammation to macrophages?
Live longer d/t continuous signals
What do macrophages secrete when they get the kill signal (IFN-gamma)? (4)
ROS
NO
IL-1
TNF-alpha
What are the systemic effects of TNF/IL-1? (3)
Fever
Leukocytosis
Acute phase proteins
What are the results of chronic inflammation?
Ongoing tissue destruction can activate inflammatory cascade, leading to coexistence of both acute and chronic inflammation
What are the social factors that can contribute to chronic inflammation?
All the good things in life, +physical and emotional stress
What are the two stimuli that lymphocytes can be mobilized by?
Infections or trauma
What is the relationship between T cells and macrophages?
Reciprocal activation
What are the cytokines that activate T cells?
interleukins
What happens when T cells are activated via presentation? (Th 17 pathway specifically)
Differentiation to a certain type of T cell.
If th17, then secrete TNF, IL-17, and other cytokines, causing further activation of macrophages
How are macrophages encouraged to form giant cells?
Through IL-4, and IFN-gamma secretion
What are the cytokines secreted by macrophages that stimulate T cells?
IL-12
Are eosinophils mononuclear cells? How do they appear?
No–have three to four nuclei, and are pinky
What is the chemokine that recruits eosinophils?
Eotaxin
What is the function of Eotaxin?
Recruit eosinophils
What is Major basic protein (MBP)?
The protein in the pinky granules of eosinophils, that fight against parasites
Do mast cell participate in chronic or acute inflammation?
Both
What causes mast cells to be “armed”?
When they have bound an IgE ab by the Fc region
What do mast cells release? (2)
Histamine and PG
When are mast cells helpful?
Parasitic infections
What is diagnostic of acute and chronic inflammation?
Chronic markers + PMNs
What is the role of plasma cells in the damage seen in chronic inflammation?
Produce antibodies toward self tissue
How do mast cells contribute to the damage seen in chronic inflammation?
Elaborating cytokines, such as TNF
