Autoimmune Diseases Flashcards
What are autoimmune diseases??
They are diseases triggered by loss of immunologic tolerance to self antigens which can cause systemic or organ damage.
Pathogenesis of autoimmune diseases?
Autoimmune response is mediated by autoreactive B and T lymphocytes responsible for the production of soluble mediators and autoantibodies.
These will lead to tissue damage that maybe systemic or organ specific.
List the infections mechanisms of autoimmune diseases?
Molecular mimicry
Epitope spreading
Bystander activation
Constant activation of immune system
Super antigens
Clearance deficiencies
What is molecular mimicry?
This occurs when there is an activation of b and T lymphocytes as a result of an infection but the cells are not able to identify self antigens from those similar to infectious agents.
Epitope spreading is also known as?
Antigenic determinant.
What is epitope spreading?
In this case, the autoimmune diseases is as a result of the spatial proximity and similarity btw self epitopes and epitope of microorganisms.
Explain Bystander activation.
This is the activation and clonal expansion of auto t cells activated by cytokines released during inflammatory response to an infection.
These favour the inflammatory process and leads to an aggressive response leading to exacerbations in pts with AD.
Explain Super antigen activation of autoimmune diseases?
Super antigens are proteins produced by viral, bacteria or pathogens.
They have the ability to link the TCR to the MHC expressed on any cell.
They are not restricted to MHC class 2 so they can activate cytotoxic t cells in large quantities.
They activate a large quantity of T cells without antigen processing.
What are the pathogens associated with systemic lupus erythomatosus?
CMV, EBV
What mechanisms does CMV use to cause SLE?
Molecular mimicry.
What mechanisms does EBV use to cause SLE?
Molecular mimicry.
Bystander activation.
Complement deficiencies.
Which pathogens cause antiphospholipid syndrome?
EBV, clostridium.
They use molecular mimicry.
Which pathogens cause type 1 diabetes?
CMV,
Saccharomyces.
Cerevisaia.
Rheumatoid arthritis is caused by??
E. Coli
K. Pneumonia
EBV
Retrovirus
P. Mirabilis…… They use molecular mimicry.
Which pathogens cause multiple sclerosis?
EBV
Acenebacter
Pseudomonas….. They use molecular mimicry.
