Lecture 20: Chronic Inflammation Flashcards
What is the time period of acute inflammation?
Hours - days
What type of immunity is acute inflammation?
Innate immunity
What is the time period of chronic inflammation?
Weeks-months-years.
What type of immunity is chronic inflammation?
Innate & adaptive immunity.
What are 3 outcomes of Acute inflammation?
- Resolution
- Repair
- Chronic inflammation
What is granulation tissue?
Granulation tissue is reddish connective tissue that forms on the surface of a wound when the wound is healing.
Key features of chronic inflammation?
Inflammation of prolonged duration.
Concomitant tissue destruction and repair.
Mononuclear inflammatory cells.
Fibrosis.
What causes chronic inflammation to arise?
Progression from acute e.g. helicobacter pylori.
Recurrent episodes of acute e.g. chronic cholecystitis.
Persistent infection by certain microorganisms (difficult to remove).e.g. TB, leprosy
Prolonged exposure to potentially toxic agents (endogenous e.g. bone, exogenous e.g. asbestos fibres, sutures).
Autoimmunity e.g. Hashimoto’s thyroiditis.
Unknown e.g. Crohn’s disease, ulcerative colitis, sarcoidosis
Effects of Chronic inflammation due to prolonged exposure to toxic agents which are difficult to phagocytose?
asbestos body
Interstitial fluid
Macrophages’ journey in the body:
Bone marrow (Pluripotent stem cell - Myeloid stem cell)
Blood (Monocyte)
Tissues (Macrophage to Microglia, Kupffer cells, Alveolar macrophages, Osteoclasts or Activated macrophages)
how does chronic inflammation affect granulation tissue?
New blood vessels (angiogenesis)
Collagen deposition by fibroblasts -> scar
What is granuloma?
Granuloma= collection of activated epithelioid macrophages (pink cytoplasm, indistinct cell membranes, oval nucleus)
May also contain multinucleate giant cells
What surrounds granuloma?
Surrounded by mononuclear leucocytes
Are granuloma’s caseating or non- caseating?
Can be either
6 types of granulomatous inflammation?
Bacterial (TB, leprosy, syphilis, cat-scratch)
Parasitic (schistosomiasis)
Fungal (histoplasma, cryptococcus)
Inorganic metals or dust (silicosis, berylliosis)
Foreign body (suture, vascular graft)
Unknown (sarcoidosis, ulcerative colitis)
Give the five key characteristics of inflammation:
1) redness (rubor)
2) heat (calor)
3) swelling (tumor)
4) pain (dolor)
5) loss of function
How does repair take place in acute inflammation?
organisation using granulation tissue
True or false: chronic inflammation uses both innate and adaptive immune responses
True
What three immune cells are most abundant in chronic inflammation?
1) macrophages
2) lymphocytes
3) plasma cells
Give 3 common systemic complications associated with chronic inflammation:
1) amyloidosis
2) cachexia
3) anaemia
What is amyloidosis?
deposition of a amyloid protein in organs
What is cachexia?
extreme wasting and malnutrition
What causes fibrosis in chronic inflammation?
concomitant tissue destruction and repair
Give 5 circumstances where chronic inflammation arises:
1) progression from acute inflammation
2) recurrent episodes of acute inflammation
3) persistent infection by microorganisms
4) prolonged exposure to potentially toxic agents
5) autoimmune
What shape nuclei do macrophages have?
bean shaped
What differentiation takes place in bone marrow in the process of forming macrophages?
pluripotent stem cells differentiate into myeloid stem cells
What do myeloid stem cells differentiate into while in the blood which goes onto form macrophages?
monocyte
What is the name of a monocyte in tissue?
macrophage
What kind of nuclei do lymphocytes have?
spherical mononucleate
What are plasma cells?
antibody producing cells
What kind of nuclei do plasma cells have?
spotty, clock face nuclei
How do eosinophils appear under a microscope?
like a tomato wearing sunglasses
How do macrophages activate T lymphocytes?
by presenting it with a specific antigen and with cytokines
What do T cells release which recruits more macrophages?
INF-gamma
How do activated T lymphocytes and macrophages cause further inflammation?
they release TNF and other inflammatory mediators
What are the two components of granulation tissue?
1) angiogenesis
2) collagen deposition by fibroblasts
What is a granuloma?
A collection of activated epithelioid histiocytes
What are epithelioid macrophages?
macrophages that have an epithelial shape with pink cytoplasms, indistinct cell membranes and oval nuclei
What cells often surround granulomas?
mononuclear leukocytes (lymphocytes and plasma cells)
What cells other than epithelial macrophages and mononuclear leukocytes are found at the centre of granulomas?
multi-nucleate giant cells (fusion of multiple macrophages)
What are the two types of granulomas?
1) caseating
2) non-caseating
What is a caseating granuloma?
It is a cheese-like necrosis, typically a feature of a granuloma of TB
What makes up the outermost layer of a granuloma?
fibroblasts producing collagen
Give 3 bacterial diseases associated with granulomatous inflammation:
1) tuberculosis
2) leprosy
3) syphilis
Give an example of a parasitic disease associated with granulomatous inflammation:
schistosomiasis
Give 2 fungal disease associated with granulomatous inflammation:
1) histoplasma
2) cryptococcus
Give an example of a dust that can cause granulomatous inflammation:
silica dust causing silicosis
Give two examples of foreign bodies associated with granulomatous inflammation:
1) sutures
2) vascular grafts
