Lecture 25: Immunodeficiency, Autoimmunity and autoinflammation Flashcards
What are the two main mechanisms of the innate immune system?
1) complement cascade
2) neutrophil and dendritic cell action
True or false: the innate immune system produces memory cells
True
What is the main mechanism of the adaptive immune system?
antibody production
True or false: the adaptive immune system produces memory cells
False
What is the name given to the proteins that opsonise pathogens?
acute phase proteins
What are autoinflammatory diseases>
clinical disorders caused by defects or dysregulation of the innate immune system characterised by recurrent or continuous inflammation
Give a common presentation of autoinflammatory disease:
neutrophilic urticarial dermatosis
What is the name of the inflammasome associated with a range of autoinflammatory diseases?
NLRP3 inflammasome
Give 3 autoinflammatory diseases associated with the NLRP3 inflammasome in order of increasing severity:
1) FCAS
2) Muckle Wells Syndrome
3) NOMID
What is arthralgia?
joint pain
Give three symptoms of FCAS:
1) cold induced rash
2) conjunctivitis
3) arthralgia
Give three symptoms of Muckle Wells Syndrome:
1) hives
2) sensorineural deafness
3) amyloidosis
Give two symptoms of NOMID:
1) progressed and chronic meningitis (including deafness and visual + intellectual damage)
2) destructive arthritis
How does a mutation of the NLRP3 gene cause autoinflammatory disease?
it over-activates the NLRP3 inflammasome, promoting proteolytic cleavage, maturation and secretion of pro-inflammatory cytokines interleukin 1-beta and 18
What 2 interleukins does the NLRP3 inflammasome secrete?
1) IL-1-beta
2) IL-18
What causes autoimmune diseases?
antibodies or lymphocytes produced against substances naturally present in the body
Give 5 causes of autoimmune disease:
1) genetics
2) immune regulation
3) environment
4) sex (hormonal influence)
5) age
Are autoimmune diseases more common in men or women?
women
Where in the body do lymphocytes undergo positive and negative selection to ensure tolerance to body cells is developed?
Thymus
What cells ensure our immune system isn’t overactive or attacking body cells?
regulatory T cells
How do autoreactive B cells cause damage?
they are directly cytotoxic and cause activation of the complement system
How do autoreactive T cells cause damage?
they are directly cytotoxic and cause inflammatory cytokine production
What is Hashimoto’s thyroiditis?
destruction of thyroid follicles by autoimmunity
Does Hashimoto’s thyroiditis cause hyper or hypothyroidism?
hypothyroidism
Does Grave’s disease cause hyper or hypothyroidism?
hyperthyroidism
In Hashimoto’s thyroiditis, what 2 proteins do the autoantibodies mainly act against?
1) thyroid peroxidase
2) thyroglobulin
What is Grave’s disease?
inappropriate stimulation of the thyroid gland by anti-TSH autoantibodies
Give 3 common manifestations of systemic lupus erythematosus:
1) skin rash
2) erosion of joints
3) kidney failure
What structures do autoantibodies in SLE target?
connective tissue
Other than SLE, give 3 autoimmune diseases that target connective tissue:
1) scleroderma
2) polymyositis
3) Sjogrens syndrome
Define ‘immunosuppression’:
the natural or artificial process which turns off the immune response partially or fully, accidentally or on purpose
Define ‘immunodeficiency’:
the lack of an efficient immune system causing susceptibility to infections
Give 7 causes of secondary immunodeficiencies:
1) stress
2) surgery/ burns
3) malnutrition
4) cancer
5) immunosuppressive drugs e.g. cancer therapies
6) irradiation
7) AIDS
Give the most common cause of secondary immunodeficiencies:
Malnutrition
Give an example of a primary immunodeficiency disease:
SCID (severe combined immunodeficiency)
True or false: both B and T cells are affected in SCID
True
Why is it defects in T cells are more dramatic than B cells?
B cells rely on T cells for mediation and activation
What is the main symptom of immunodeficiency diseases?
recurrent infection
