3 chronic inflammation Flashcards
Chronic inflammation is the host response to an ..1…. Trying to manage the …2… with some success ?
1 = insult
2 = insult
Chronic inflammation can …1… but also …2…
- last a long time (lifetime of patinet)
- resolve
Chronic inflammation can last a long time but also resolve but often with what ?
results that can be troublesome to the patient
List 4 possible troubles to a patient because of chronic inflammation
- fibrosis and malfunction of the organ
- deformity e.g. rheumatoid arthritis
- gradual organ destruction e.g tuberculosis
- pain
Host defences and response to chronic inflammation include ?
- natural barriers (skin , mucous membranes)
- innate immunity -> non-specific immune responses (phagocytic cells [neutrophils, macrophages], thier products)
- adaptive immunity -> specific immune responses (antibodies, lymphocytes)
How does acute insult lead to possible resolution or repair and scarring ?
- acute insult
- acute inflammation
- damage slight ? -> no -> chronic inflammation -> repair & scarring
- damage slight ? -> yes -> possible resolution
2 ways chronic inflammation arise?
- may ‘take over’ from acute inflammation
- may arise gradually without an obvious acute phase
How does chronic inflammation arise if it ‘takes over’ from acute inflammation ?
- insult / damage is too severe to be resolved within a few days
- or following persistent or recurrent acute episodes
How does chronic inflammation arise gradually without an obvious acute phase ?
- some chronic infections (e.g. hepatitis, B, C, Tuberculosis, leprosy)
- autoimmune conditions (e.g. RA)
- unknown aetiology / idiopathic
Clinical definition of ‘chronic’
> 6 weeks
Clinical features of chronic inflammation?
may be similar to acute inflammation :
* pain (dolor)
* loss of function
* rubor (redness)
* swelling (tumor)
* heat (calor)
On inspection what tissue is seen in chronic inflammation
granulation
what is chronic inflammation characterised by ?
microscopic appearances which are much more variable than acute inflammation
An important characteristic of chronic inflammation is ?
the predominant type of cell present
6 typical features of chronic inflammation in terms of microscopic appearances ?
[Question to CE are polymorphs neutrophils]
- macrophages
- lymphocytes
- plasma cells
- absence of polymorphs (cells with more than one morphology e.g. granulocytes , neutrophils !!)
- proliferation of fibroblasts with collagen production leading to fibrosis
- angiogenesis (formation of new blood vessels from pre-existing vessels)
Where are macrophages derived from ?
blood monocytes
Which inflammation type are macrophages important in ?
both acute and chronic
Functions of macrophages
- phagocytosis and destruction of debris & bacteria
- Processing and presentation of antigen to immune system (APCs)
- synthesis of cytokines e.g. interleukins, TNF
- control of other cells by releasing : EGF, FGF, PDGF
- induce fibrosis and angiogenesis needed for healing
What is EGF ?
epidermal growth factor
what is FGF ?
fibroblast growth factors
what is PDGF ?
platelet-derived growth factor
What are 3 growth factors that macrophages need to release to control other cells ?
- EGF = epidermal growth factor
- FGF = fibroblast growth factor
- PDGF = platelet-derived growth factor
Name 3 cells under the term ‘lymphocytes’
- B-cells
- T-cell
- NK cells
% of cicrulating leukocytes that lymphocytes constitute of ?
25 - 33 %
diameter of lymphocytes ?
~ 10 µm
Why are B- and T- lymphocytes unusual in terms of their genomic DNA?
it undergoes somatic rearrangements to create a vast repertoire of cell surface receptors
How many years can memory B-cells live for ?
many
How do lymphocytes appear in blood smears ?
spherical with thin strip of cytoplasm surrounding a regularly-shaped nucleus
How do B-lymphocytes create a repertoire of antibodies to be able to recognise a vareity of antigens ?
‘shuffle’ the DNA encoding their immunoglobulins
What will happen if a B-cell is presented to a foreign antigen that it ‘recognises’ ?
It will proliferate (under the control of T-helper cells) to form a population of plasma cells producing antibodies specific for that antigen
What a long-lived memory B-lymphocytes able to do ?
expand again following re-exposure to the antigen
Where do T-lymphocytes originate and mature in ?
originate -> bone marrow
mature -> thymus or in adults spleen
what happens to T-lymphocytes when they mature in the thymus or spleen ?
undergo rearrangement of their T-cell receptor genes
What do CD4+ (T helper) cell induce ?
proliferation and differentiation of T&B cells, and activate macrophages
What do T-cytotoxic (CD8+) cells induce ?
apoptosis in cell that present foreign antigens in the correct MHC context by punching holes in the plasma membrane and injecting perforins or granzyme
NK cells produce ..1…. and are an important component of ..2…
- a rapid response to viral infection
- innate immunity
what do NK cells recognise ?
“stressed” cells like tumour cells
What’s the mechanism of killing that NK cells have ?
similar to cytotoxic T cells but without the requirement for MHC presentation
Apart from macrophages, lymphocytes (B&T), NK cells what other cells are involved in the chronic inflammatory response ?
- plasma cells
- eosinophils are related to neutrophils
- fibroblasts / myofibroblasts
Plasma cells are differentiated ….1….. lymphocytes
usually implies considerable …2…
- antibody - producing B
- chronicity
Name some conditions in which trigger eosinophilia
- allergic reactions
- parasite infestations
- some forms of vasculitis
- some tumours
Fibroblasts / myofibroblasts are recruited by ..1…. and make …2…
- macrophages
- collagen and elastin
In the bladder wall where are massive eosinophilia found ?
around schistosome eggs
what are giant cells ?
multinucleate cells made by fusion of macrophages
3 types of recognised giant cells?
- langhans giant cell -> tuberculosis
- foreign body type -> adaptive/memory immunity NOT involved
- touton type -> pale cytoplasm = lipid phagocytosed
In touton giant cell what does the pale cytoplasm indicate ?
lipid phagocytosed
when does frustrated phagocytosis occur ?
when a cell (usually macrophage) attempts to engulf a larger particle but is unable to complete the process whcih can lead to the formation of giant cells
What pathology do T-cell mediated immunity usually involve ?
Langhans type giant cell
How is the nuclei in Langhans giant cell arranged ?
around the periphery of the giant cell
- How is the nuclei of foreign body type giant cell arranged ?
- often seen when what is present e.g. ?
- randomly in cell
- foreign body is present e.g. surgical suture
How is the nuclei of a touton giant cell arranged ?
In a ring structure towards the centre of the cell