Hypersensitivity Mechanism Examples Treatment
Type I Allergen binds to IgE, leading to mast cell degranulation • Skin: eczema • General treatment methods:
and inflammatory mediator release such as: • Infection: helminths (IgE & eosinophil degranulation) Corticosteroids: suppress transcription of proinflammatory genes
Histamine, serotonin, prostaglandins, TNFα, leukotrienes • Systemic: peanut allergy Sodium cromoglicate: inhibits mast cell degranulation
Antihistamine
Severe symptoms: Montelukast: leukotriene receptor antagonist
Vasodilation + vasopermeability increase → BP decrease + ARDS Omalizumab - anti-IgE
Type II IgG autoAb binds to self cells, leading to activation of • HDN
complement or macrophage/neutrophil phagocytosis • Transplantation/transfusion reactions
• Streptococcal endocarditis
• Goodpasture's syndrome/anti-GBM (autoimmune) - autoAb targets collagen
IV & damages lung/kidney basement membrane
Type III IgG, IgM forms immune complexes → causes obstruction • SLE (autoimmune) - autoAb against self-DNA & chromatin molecules Corticosteroids (prednisolone) Contraind: hydralazine, isoniazid, procainamide
Macrophages/complement/neutrophils damage • Rheumatoid arthritis
endothelial cells whilst clearing the immune complex • Farmer's lung/pigeon fancier's disease
• Glomerulonephritis
Type IV T cells bind to peptide-MHC leading to macrophage • TB & granuloma
activation • Acute graft rejection (transplant)
• Coeliac disease (autoimmune) - response to gluten causing gut inflammation
• Hashimoto's thyroiditis (autoimmune) - T cells attacks thyroid gland -
hypothyroidism • Levothyroxine (replaces thyroxine as an analogue) - activates nuclear receptors
to increase thyroid hormone levels
Type V Stimulatory autoAb leads to cells functioning at higher • Graves' disease - agonistic Ab binds to TSHR* - leads to hyperthyroidism
rate by binding to hormone/neurotransmitter receptors • Myasthenia gravis - autoAb binds to ACh in muscle leading to muscle
weakness & fatigue
*anti-TSHR - autoAb produced for thyroid stimulating hormone receptor
I^MD Page 1
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller dan001. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $5.22. You're not tied to anything after your purchase.