Immunology Flashcards
Which chromosome do you find HLA on?
Chromosome 6
What is HLA?
A locus of genes that encodes for the proteins on the surface of cells that regulate the immune response.
What do class 1 (A, B and C ) HLA molecules do?
Present peptides from within the cell (eg if the cell becomes infected with a virus it will bring fragments of the cell to the surface so that the cell can be recognised as infected and can be destroyed)
What do class 2 HLA molecules do?
Present antigens from outside the cell to the T lymphocytes. These antigens then stimulate multiplication of T helper cells which then stimulate antibody producing B cells to produces antibodies.
What suppresses self antigens?
Regulatory T cells
What does HLA class 3 do?
Encodes for the components of the complement system
What other autoimmune disease are associated with graves disease?
Hashimotos thyroiditis Autoimmun pernicious anaemia Addisons Vitiligo Myasthenia Gravis
What other autoimmume disease is associated with SLE?
Primary sjogrens
How does the damage occur in autoimmune diseases?
Circulating auto antibodies recruit other components of the immune response (complement, phagocytes, NK cells) to attack certain sites
What type of hypersensitivity reaction is SLE?
Type 3 (Immune complex mediated)
Describe briefly the pathophysiology of SLE
- Autoantibodies to cell nuclei produced (anti DNA, ANA and anti Ro/La)
- These then form immune complexes which are deposited in the small vessels in the skin, joints and kidneys.
- This then results in complement activation in this area and inflammation which leads to the recruitment of other cells.
What is a normal titre of ANA in a healthy person?
Less than 1:80
What conditions are anti Ro/La most specific for?
SLE and sjogrens
What auto antibody is most associated with scleroderma?
Anti centromere antibody
In what diseases would you expect to see Anti Jo -1 antibody?
Polymyositis, dermatomyositism polymyositis scleroderma.
