36 Questions
What is the primary mechanism by which the body's immune system mistakes its own healthy tissues as foreign and attacks them in autoimmune disease?
Loss of immunological tolerance to self
What is the main function of positive selection in central tolerance?
Sends survival signals to T cells that respond weakly to self MHC peptide
What is the outcome when self-reactive T cells fail to receive signal 2 during anergy induction?
They become anergic and fail to proliferate
What is the primary mechanism by which regulator T cells suppress immune responses?
Through the action of cytokines
What is the site where central tolerance takes place?
Thymus
What is the outcome of negative selection in central tolerance?
Removal of T cells that strongly recognize self MHC and peptide
What is the first step in the given protocol for an anaphylactic emergency?
Remove obstacles from the patient's airways
What is the recommended dose of adrenaline for an anaphylactic emergency?
0.5/1mg IM
What type of autoimmune response is a type II hypersensitivity reaction?
Antibody mediated response
What is the typical timescale for a type II hypersensitivity reaction?
2-24 hours
What is the mechanism of action in autoimmune haemolytic anaemia?
Opsonisation and phagocytosis of erythrocytes
What type of autoimmune response is a type III hypersensitivity reaction?
Immune complex mediated response
What is the typical timescale for a type III hypersensitivity reaction?
Hours-days
What is the mechanism of action in systemic lupus erythematosus?
Immune complex deposition
What type of autoimmune response is a type IV hypersensitivity reaction?
Cell mediated response
What is the typical timescale for a type IV hypersensitivity reaction?
2-3 days
What is the process by which antigens of infectious agents stimulate cross-reactive B and T cells?
Molecular mimicry
What is the enzyme responsible for citrullination in rheumatoid arthritis?
PAD
What is the second signal required for B cell activation?
Type I interferon binding to IFN receptor
What is the type of hypersensitivity reaction that is mediated by IgE and causes anaphylaxis?
Type I hypersensitivity reaction
What is the typical timescale of a type I hypersensitivity reaction?
0-2 hours
What is the primary function of TLRs in B cell activation?
Induction of type I interferon production
What is the outcome of anaphylaxis if left untreated?
All of the above
What is the treatment for mild anaphylaxis?
All of the above
What is the result of the binding of IgE and Fc receptor on mast cells?
Degranulation and histamine release
What is the definition of a hypersensitivity reaction?
An excessive immune response that damages tissue
What is the mechanism by which activated T cells are eliminated to prevent tissue damage?
Through interactions between Fas and FasL
What is the main difference between an immune response and an autoimmune response?
The duration of the response
Which of the following is an example of an organ-specific autoimmune disease?
Hashimoto's thyroiditis
Why do females have a higher prevalence of autoimmune diseases?
Due to the incomplete inactivation of X chromosomes
What is the purpose of central tolerance and negative selection?
To reduce the number of self-reactive B and T cells
What is the function of Treg cells in autoimmune responses?
To inhibit Th responses to self-antigens
What is the disease associated with a mutation in Treg cells?
IPEX
What does GWAS stand for?
Genome-wide association studies
What enzyme is associated with Rheumatoid Arthritis?
PAD
Why is negative selection not 100% effective in removing self-reactive T cells?
Because it would leave a space for pathogens to mimic human structures
Learn about autoimmune diseases, including how they occur, types of tolerance, and the role of T and B cells. Understand the mechanisms that lead to autoimmune responses.
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