Autoimmune diseases Flashcards
What are the two types of autoimmune diseases.
1- organ specific
2-non-organ specific.
define autoimmunity
where the immune system attacks own tissue.
Autoimmune diseases are due to the effects of
1-Genes- genetically predispose you to a condition
2-Environment
3-Immune regulation- if it breakdown results in autoimmunity.
In which region of the human genome is most common susceptibility for autoimmune conditions.
HLA.
What is the role of MHC 1
detect foreign activity in all cells.
What is the role of MHC 2
Professional cells take up antigens from tissue and present to T cells.
Where are B cells produced
bone marrow
Where are T cell produced
thymus.
What is central tolerance
B cells and T cells acquire receptors and are tested against self antigens to see which ones react.
Where does central tolerance take place.
bone marrow and thymus
What is peripheral tolerance.
removing B and T cells from the peripheral blood which are not tolerant to self antigens.
T regulatory cells- help in this process.
Which T cells are involved in peripheral tolerance
T regulatory cells.
Causes of autoimmunity expect genetics
- sex due to hormones (women greater than men)
- Age-autoimmunity more common in elderly.
- Sequestered antigens- antigens of body parts not in contact with immune system.
- Environment.
How do auto reactive B cells cause autoimmunity
directly cytotoxic, activation of complement, interfere with normal physiological function
How do auto reactive T cells cause autoimmunity
directly cytotoixc, inflammatory cytokine production or activate B cells.
Other than genetic factors which lifestyle factor helps trigger rheumatoid arthritis.
smoking.
2 major types of autoimmune thyroid disease.
Hashimoto’s thyroiditis
Grave’s disease.
How does hashimotos cause thyroiditis and is it hyper to hypothyroidism
Antibodies destroy the thyroid follicles
This causes hypothyroidism.
How does grave’s cause autoimmune thyroid condition and is it hyper or hypothyroidism.
antibodies stimulate the thyroid
autoantibody mimics TSH
Symptoms of hyperthyroidism
weight loss, excessive sweating, hot even in cold weather, anxiety, lack of sleep, diahorrhea, puffy face, sparse eyebrows especially in the lateral 1/3
symptoms of hypothyroidism
tierd, difficult concentrating., decline in memory, constipation, weight gain, cold in hot weather.
What is myasthenia gravis
Autoantibody, which binds to Ach receptor in the synapse of the neuromuscular junction and inhibits functioning.
Often due to a tumour on the thymus so once removed symptoms resolve.
What is pernicious anaemia.
unable to absorb b12 often due to autoantibodies binding intrinsic factor and therefore B12 cannot bind you intrinsic factor it cannot be absorbed.
Treatment is B12 injections
Macrocytic anaemia.
What is the name given to non organ specific connective tissue diseases
connective tissue diseases.
How is systemic lupus caused?
Antinuclear antibodies.
nuclei are usually sequestered antigen.
defect in apoptosis results in nuclei being exposed and autoantibodies forming.
symptoms and signs of SLE
Photosensitive Malar Rash- leaves nasal avail fold. Multiple mouth ulcers Arthralgia- pain in joints. Alopecia sharp chest pain (pleural effusion)
How does exposure to sun affect SLE and normal people differently
Sunlight causes cell death- undergo apoptosis and nuclei antigens come to the cell surface, in normal person no effect just get sunburnt in SLE person due to ANA rash is caused
What organs can SLE involve that makes it a multi organ condition
Kidney: lupus nephritis
Immune complexes deposit, causing complement activation and inflammation, the glomerulus leaks causing renal function loss, scarring and irreversible renal failure.
Lung: Pleurisy / Pleural Effusion
Brain: Cerebral Lupus, seizures, strokes etc.
What is the test for SLE diagnosis
Antinuclear antibodies
What is the treatment for SLE
immunosuppression
What type of antibodies are found in vasculitis
Anti-neutrophil cytoplasmic antibodies (falsely activate neutrophils)
How do Anti-neutrophil cytoplasmic antibodies cause vasculitis.
Neutrophils are falsely activated and leave blood into tissue to fight no infection
Inflammation is around the blood vessel this is why you don’t get blood flow and purpaae.
3 types of vasculitis
- Microscopic Polyangiitis (MPA)
- Granulomatosis with Polyangiitis (GPA)
- Eosinophilic Granulomatosus with Polyangiitis (EGPA)
define polyanagitis
inflammation of blood vessels anywhere.
define granuloma
mass of inflamed tissue.
Granulomatosis with Polyangiitis can cause destructive lesions on
- Nose
- Sinuses
- Trachea
- Lung
- Orbits
Signs and symptoms of vasculitis.
all have polyangitis
some have granulomas- destructive masses of chronic inflammatory tissue often in upper airway or lung but can cavitate.
How do you diagnose vasculitis
• Anti-Neutrophil Cytoplasmic Antibodies (ANCA)
What is the treatment for vasculitis
immunosuppression
What causes scleroderma
• Anti-Nuclear Antibodies
Primary phenomenon in scleroderma
Raynaurds- fingers go white.
more common in women and runs through families.
What is scleroderma
Autoimmunity leads to ischaemia and fibrosis
Signs and symptoms of scleroderma
- Digital ulcers due to tightening and ischaemia
- Lung fibrosis- honey comb appearance on CT
- Skin fibrosis and tightening.
what organs can be involved in scleroderma
• Fibrosis may also affect lungs, gut, kidneys
What is the treatment for scleroderma
immunosuppression
