Autoimmunity Flashcards
What is autoimmunity?
immune reaction to self tissues/Ags
How does autoimmune disease occur?
failure of tolerance; failure of:
selection process (central tolerance)
anergy (peripheral tolerance)
apoptosis
Which type of patients are prone to autoimmune disease?
lack of Fas-mediated killing of self-reactive cells
What is a organ specific autoimmune disease?
type I diabetes
What is a non organ specific autoimmune disease?
lupus
What is another reason for autoimmune disease?
genetic predisposition
some MHC association
What is the MHC/HLA Allotype association for ankylosing spondylitis?
B27
risk: > 150
What is the MHC/HLA Allotype association for Narcolepsy?
DQ6
Risk >40
Why does a person autoimmune?
release of sequestered antigens
-Ags that show up later in life
-Ags confined to specialized organs get exposed to immune cells
brain, testes, eye, etc
loss of suppression – lack of Tregs/Ts cells
cross-reactive antigens
post-streptococcal infection
altered self-antigens - chemical or viral infections
break” of tolerance
due to combination of above mechanisms?
Who is more sucesptlbe to AID, women or men?
women
What are reasons females are more susceptible to AID?
females produce more Abs than males
females have higher CD4 cell counts
in mice, females favor a Th1 response
—-good for some infections, bad for AID where inflammation may play a role
—-Is this response true for humans??
sex hormones
What is the effect sex hormones have on the immune system?
in mice, can “switch” female Th1 response to Th2 by injection of testosterone
sex hormones can affect gene expression (and immune system activation)
during pregnancy, much of the female immune response is shifted towards Th2
- fetus is a “graft”…Th1 responses play a role in graft rejection
- SLE, with a strong Ab component, is exacerbated during pregnancy
What effect an glucocorticoids?
general are immunosuppressive
used in autoimmiune diseases
