Unit 3 - Autoimmunity 2 Flashcards
What are the symptoms of Type I diabetes?
- feeling very quickly
- peeing more than usual - particularly at night
- feeling very tired
- losing weight without trying
- thrush that keeps coming back
- blurred vision
- cuts and grazes that are not healing
How is type I diabetes tested for?
- urine test
- blood glucose test
Which cells are the target of the autoimmune mechanism in diabetes mellitus?
Pancreatic B cells
- islet cell antibody (ICA)
- surface reactive islet cell antibody (ICSA)
What is the prevalence of autoantibodies in diabetes mellitus patients?
ICA present in 70% of patients at diagnosis
ICA present at 4% in general population
Antibodies fix complement and possess ADCC activity that leads to lymphocyte infiltration
What genetic factors play a role in diabetes mellitus?
Genes in HLA-D significant with 90-95% of type I diabetics having DR3 or DR4 or both, compared to 50% of general population
What environmental factors play a role in diabetes mellitus?
Viral infections may precede onset of disease
- initiating injury
- altering self-antigens
- triggering autoimmune response
What is the treatment of diabetes mellitus?
Insulin replacement
why do autoimmune diseases occur ?
Autoimmune diseases occur when the immune system fails to recognize the body’s own molecules as self and attacks them, causing damage to tissues and altered organ function. Some autoimmune diseases are thought to be caused by exposure to pathogens that have antigens similar to the body’s own molecules. After this exposure, the immune system responds to body cells as though they were pathogens as well.
What are the two most common autoimmune diseases and describe how they work.
Two of the most common autoimmune diseases are type I diabetes and multiple sclerosis.
Both are localized diseases in terms of the specific body cells that are attacked by the immune system. In the case of type I diabetes, the immune system attacks and destroys insulin-secreting islet cells in the pancreas.
In the case of multiple sclerosis, the immune system attacks and destroys the myelin sheaths that normally insulate the axons of neurons and allow rapid transmission of nerve impulses.
