Aberrant immune response Flashcards
what is hypersensitivity type 1
an excessive immune response
what is responsible for hypersensitivity type 1
IgE and mast cells largely
describe the response in hypersensitivity type 1
resting mast cells have granules that contain histamines
when a stimulus arrives, the mast cell releases the histamines and other inflammatory compounds
IgE antigen complex binds with stimulus -> triggers degranulation event
granule contents expunged
what is hypersensitivity type IV mediated by
T cells
Which hypersensitivity types are antibody mediated
I (IgE)
II (IgG/ IgM)
III (IgG/ IgM)
give an example of type 1 hypersensitivity
seasonal hay fever, food allergies, drug allergies, local and systemic anaphylaxis
give an example of type II hypersensitivity
red blood cell destruction after blood transfusion with mismatched blood types
give an example of type III hypersensitivity
rheumatoid arthritis
give an example of type IV hypersensitivity
type I diabetes
what is an organ-specific autoimmune disease
autoimmune attack of self-antigens of a given organ
damage to organ structure and function
what is a non-organ specific autoimmune disease
widespread self-antigens are targets for autoimmune attack
damage affects structures such as blood vessels, cell nuclei etc
autoimmunity definition
a misdirected immune response that occurs when the immune system goes awry and attacks the body itself
describe type I diabetes as an autoimmune disease
organ specific
alpha cell -=> glucagon
delta cell -> somatostatin
beta cell -> insulin
effector T cell recognises peptides produced by ß cell specific proteins and triggers apoptosis
- insulin can no longer be produced
describe grave’s disease as an autoimmune disease
organ-specific (thyroid gland)
thyroid hormones regulated by TSH
weight loss, sweating
triggering auto-antibodies bind the the TSH receptor and continuously trigger production of TH
describe the normal functioning of TSH
Thyroid hormones regulated by thyroid-stimulating hormones (TSH) from pituitary gland
TSH binds to receptor + stimulates synthesis of thyroid hormones
- Negative feedback loop then switches of TSH production
Homeostatic control
describe TSH control in someone with Grave’s disease
non-regulated activating auto0antibodies that bid the the TSH receptor
leads to overstimulation of thyroid hormones
describe asthma as an autoimmune disease
inflammatory/ structural cells -> mediators -> effects
- narrowed airway
- muscle contraction, mucus production, inflammation
describe the pathophysiology of asthma
chronic inflammation of the lower airways
thickening of BM
increased goblet cell activity
smooth muscle hypertrophy/ thickening
epithelial shedding
airway occlusion (mucosal plug)
mucosal infiltration of T cells/ eosinophils/ others
describe covid-19 as it progresses to an autoimmune disease
viral infection
SARS-CoV-2
hyperinflammatory state
- some patients
- more associated with poor outcomes
- result of immune system overworking
‘cytokine storm’
list some risk factors that contribute to the cytokine storm
COPD (lung disease)
CAD (coronary artery disease)
obesity (BMI >40)
diabetes
chronic kidney disease
old age (>60)
