Chronic inflammation Flashcards
What are the major immune cells involved in chronic inflammation?
Lymphocytes
Plasma cells
Macrophages
Natural killer cells
What is the functions of B lymphocytes in chronic inflammation?
Differentiate into plasma cells - produce antibodies against any pathogens
Act with macrophages - antigen presentation
Differentiate into memory B cells
What is the function of T cells in chronic inflammation?
Produce cytokines - attracts and activates macrophages and attracts other immune cells
Produce interferons - antiviral + attracts other cells
Cytotoxic T cells - damage/lyse other cells and destroys pathogen
What type of immunity do Natural killer cells correspond to?
Innate
Describe what macrophages do at the site of chronic inflammation.
Remove debris
Present antigens (for B cells)
Phagocytose or degranulate
Produce interferons + other chemicals
Aside from immune cells, what other cells are involved with chronic inflammation?
Fibroblasts
+ osteoblasts in bone healing
What do fibroblasts do?
Produce collagen protein for healing process
What can cause chronic inflammation?
Autoimmunity
Persistent infection/prolonged exposure to pathogens/toxins
Exogenous substances (sutures, splinters, glass etc.)
Endogenous substances that are not easily phagocytosed
Why would chronic inflammation arise from acute inflammation?
Large volume of damage
Unable to remove debris
= Unable to resolve the acute inflammation so becomes chronic
What is angiogenesis?
Formation of blood vessels
What is the purpose of granulation tissue formation?
Patches tissue defects
Replaces dead/necrotic tissue
Contracts and pulls together
Describe the sequence of events that take place with granulation tissue formation.
Angiogenesis of inflammatory mass
Plasma proteins, macrophages, fibroblasts gain access
Fibroblasts lay down collagen to repair damaged tissue, replacing inflammatory exudate
This forms granulation tissue
What negatives are associated with granulation tissue formation?
Scarring
Fibrosis can lead to other health problems
Can progress to chronic inflammation - acne etc
What is the body’s response, when it can’t phagocytose something, for example, a splinter?
Granulomatous inflammation
formation of granuloma
Granulomatous inflammations are associated with what type of hypersensitivity reaction?
Type IV
Describe (in basics) what granulomatous inflammation is.
Macrophages walling off an indigestible antigen
What cells are involved in granulomatous inflammation?
Macrophages (+ giant cells)
Neutrophils
Eosinophils
What are giant cells made from?
Fused macrophages
What are some examples of giant cells?
Langhans type
Foreign body type
Silicone associated
Warthin-Finkeldy type
What are the characteristics of Langhans type giant cells?
Classically found in TB
Nuclei ring round the outer edges of the cell
Large eosinophilic cytoplasm
Foreign body type giant cells are associated with what type of tissue?
Pyogenic (pus forming) granulation tissue
What is different in how Warthin-Finkeldy type and Langhans type look?
Langhans - nuclei on outer edges of cell
W-F - central cluster of nuclei
What are some examples of infectious granulomatous diseases?
Syphilis
Leprosy
Tuberculosis
What are examples of Non-infectious granulomatous diseases?
Rheumatoid disease
Sarcoidosis
Crohn’s disease
Describe the process of wound healing.
1) Injury > blood clotting > acute inflammation > fibrin produced
2) Growth factors + cytokines
3) Angiogenesis + Granulation tissue formation
4) Phagocytosis of fibrin
5) Fibroblasts move in > collagen
6) Contraction of scar
7) Re-epithelialisation
What vitamins are important in the wound healing process?
C and A
Bone healing is similar to that of tissue healing, except another main cell type is involved. What is it?
Osteoblasts
+ osteoclasts etc
How do cells signal that they want angiogenesis to take place?
Hypoxic cells release Vascular endothelial growth factor (VEGF) that stimulates proliferation
Enzyme secretion aids process
Leads to vascularisation of damaged tissue
What factors impair wound healing?
Dirty, gaping wound, large heamatoma
Poorly nourished, lack of vitamins C and A
Abnormal CHO metabolism, diabetes, corticosteroid therapy
Inhibition of angiogenesis
