Immunology of autoimmune disease Flashcards
(35 cards)
What is a monogenic disorder?
Single gene defect which causes the autoimmune disease.
Rare.
What is IPEX syndrome?
Immune dysregulation Polyendocrinopathy Enteropathy and X-linked inheritance syndrome.
What kind of inheritance does IPEX syndrome have?
Fatal autosomal recessive disorder
When does IPEX syndrome present?
Early childhood
What are the symptoms of IPEX syndrome?
IDDM Malabsorption Eczema Autoimmune thyroid and haemolytic anaemia Severe infections
What is the pathogenesis of IPEX syndrome?
Mutation in FOXP3 gene which is essential to develop T cells.
What does HLA stand for?
Human Leukocyte Antigen complex
What does HLA do?
???
On the surface of antigen and recognises peptides.
What are the 3 types of class I HLA?
HLA-A, HLA-B and HLA-C.
What are the specialised class II HLA?
HLA-DR
HLA-DQ
HLA-DP
True or False.
Each person has only 1 type of HLA molecule
False.
Each individual possesses 2 variants of each HLA molecule.
In what way is HLA like an enzyme?
Like lock and key mechanism.
Only a few peptides can bind to a specific molecule
What is the susceptible allele of ankylosing spondyltitis?
HLA B27
What is the susceptible allele of rheumatoid arthritis?
HLA-DR4
Which rheum disease is a type III hypersensitivity diseases?
SLE
What is a type III hypersenstivity?
Antibody-antigen complex deposition in the small vessels activating complement and macrophages to the site.
Which antibody is characterised in SLE?
ANA- anti nuclear antibodies.
What are the clinical features of SLE?
?? malar rash fatigue arthralgia weight loss depression
What other diseases is anti-ANA associated with?
Scleroderma
Sjogrens
When would you find an anti-centromere antibody?
Systemic sclerosis/ CREST.
What is the classical pathway of complement?
Centres around C3.
Formation of antibody-antigen complexes.
Why would you use C3 as a marker for disease?
It measures unactivated C3.
If C3 levels are low then C3 has been used up and would be a good marker of disease activity.
What other investigations would you do if still not sure from bloods?
Biopsy for presence of immune complexes
How does glomerulonephritis in SLE differ from that in Goodpastures (a type II)?
Goodpastures glomerulonephritis has a linear deposition of IgG on basement membrane.
SLE is bumpy.
