Autoimmunity Flashcards
What is autoimmunity
Recognition of self antigen by person’s immune system
What is a function of bone marrow and thymus to avoid autoimmune disease
REmoval of autoantigen specific cells
Testing
Genetic rearrangement
Clonal deletion
What happens to most autoreactive cells?
Become tolerized to the self antigen as excessive presentation to autoreactive T cell will lead to anergy
What is molecular mimicry
ANtigen of a foreign pathogen creates an immune response that has a very similar molecular structure to a self antigen
Bone mounts immune response against itself
What is epitope spread?
Unactivated autoimmune cells become activated in the presence of an inflammatory response because of the high level of inflammatory cytokines and APCs
Autoantigen may be structurally different to original antigen
How can autoimmunity occur?
Cytokine dysregulation - low levels of anti-inflammatory cytokine production
Failure of deletion - failure of bone marrow or thymus to delete
What are examples of organ specific autoimmune dsieases
T1DM
Grave’s
What are examples of systemic specific autoimmune diseases
SLE, RA
What are primary immunodeficiencies?
Produce of mutation in any of a large number of genes involved in control of immune response - defective element
What is secondary immunodeficiencies
Acquired immunodeficiencies caused by other disease, malnutrition, iatrogenic, drugs
What does HIV do
Retrovirus infects CD4 T cells, dendritic cells and macrophages - leading to destruction
What is the most common HIV opportunisitc infection in the eye
CMV retinitis
