Flashcards in Hypersensitivity and Autoimmunity Deck (34)
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1
What is type 1 hypersensitivity?
- When the body recognises an environmental antigen as a pathogen
2
What does type 1 hypersensitivity release?
IgE
3
What cells are triggered by type 1 hypersensitivity?
- Mast cells
- Blood basophils
4
What happens during sensitisation?
- The allergen is shown to a T helper cell by an APC
- B cells then differentiate
5
What do B cells produce during sensitisation?
IgE
6
What occurs if the patient is exposed to the antigen after sensitisation?
- Mast cells release cytokines
- Allergic reaction results
7
What is type 2 hypersensitivity?
Body's antibodies bind to antigens on its own cells
8
What can happen if penicillin binds to blood cell?
Antibodies are produced in response to the antigens on that cells surface
9
What can IgG and IgM antibodies trigger?
Complement system
10
What does the activation of the complement system cause?
Lysis
11
What is type 3 hypersensitivity?
When the body forms immune complexes
12
What are immune complexes?
When antibodies stick together in a clump
13
With regards to concentration, how do immune complexes form?
- Low conc. of antibody
- High conc. of antigen
14
What causes type 4 hypersensitivity?
CD4 helper T cells recognise a foreign antigen
15
What do these CD4 helper T cells release?
Cytokines
16
What does the release of these cytokines cause?
Inflammatory response
17
How fast does the early phase response react?
Within minutes
18
What is released during the early phase response?
- Histamine
- Heparin
- Chemotactic factors
19
What cell releases the chemicals in the early phase response?
Mast cell mediators
20
What is released during the late phase response?
- Prostaglandins
- Leukotrines
21
What cytokines are released in the late phase response?
Th2 cytokines
22
What cells are the mediators of the late phase response?
Eosinophils
23
What 2 complexes can form during type 3 hypersensitivity?
- Localised
- Systemic
24
What is localised type 3 complexes and how is it cleared?
- Inflammation of nearby tissue
- Cleared by macrophages
25
What is an autoimmune disease?
Disorder caused by organ damage of the immune system targeting self antigens
26
What 5 factors can result in an autoimmune disease?
- Genetic factors
- Immune regulatory factors
- Hormonal factors
- Environmental factors
- Other
27
What are the pathogenic mechanisms of autoimmune disease?
- Cell mediated
- Antibody mediated
- Antibody + compliment
- Immune complex mediated
- Accumulation of innate compounds
28
Name 3 autoimmune thyroid diseases
- Hashimoto's thyroiditis
- Thyroxicosis
- Primary myxoedema
29
Name an autoimmune stomach disease
Pernicious anaemia
30
