Type III Hypersensitivity Flashcards
Immune (Antigen-Antibody) Complex Disease is
Antigen is typically from a pathogen.
Complexes filtered out or precipitate
Complement activation – classical pathway.
Attracts neutrophils.
Promotes inflammation
Type III Hypersensitivity is
The presence of immune complexes leads to damage of the host tissue.
Immune (Antigen-Antibody) Complex Disease
Mechanism by which hyper type 3 happens
Antibody binds to antigen
All of this can be normal and help destroy the antigen
Large amounts of complexes cause excessive activation and disease.
May cause local or systemic effects
How does antibody bind to antigen in hyper type 3
Some antibodies then bind and activate complement.
Attracts neutrophils
Bind macrophages and mast cells
Release molecules that stimulate inflammation
Release of variety of mediators that damage blood vessels and tissue
Sites most commonly affected by hyper 3
Lungs (local)
Kidneys, joints (systemic)
Hyper pnumotitis is caused by
Inhaled antigen
Heat tolerant bacteria growing on damp hay produce small spores that are inhaled into lungs.
Hypersensitivity Pneumonitis causes and treatment
Antigen-antibody complexes deposited into the lungs.
Whole lung is affected
-5-10 hours after exposure to moldy hay
Inflammation
-Fibrosis in chronic cases
Steroids may be beneficial.
Difference of type i and type iii
Differences from asthma in cats?
Type of inflammatory cell?
Eosinophils in asthma
Neutrophils in type III hypersensitivity
Response to bronchodilators?
Both respond.
Examples of type iii reactions
Recurrent Airway Obstruction (RAO or Heaves) and Inflammatory airway disease (IAD) of horses
Allergic Pneumonitis of cattle (Atypical Interstitial Pneumonia of Cattle, Hypersensitivity Pneumonitis) and people (Farmer’s Lung)
Clinical signs of type iii hyper Pneumonitis and treatment
Cough
Increased RR
Wheezing
Treatment?
Remove contact with allergen
Corticosteroids
Bronchodilators
Blue eyes in dogs is
Corneal edema and uveitis following infection of canine herpes (Canine Adenovirus 1)
Disease
Vaccination (older types) – modified live vaccine.
Blue eyes is caused by
Immune Complexes deposited in capillaries around iris – Neutrophils are attracted to the area.
Clinical signs occur 1-3 weeks following infection
Self-resolution once the virus has been cleared.
Glomerulonephritis is
Immune complexes are deposited in the glomeruli
Get trapped in glomerular capillaries.
Kidney damage occurs.
Need a continuous source of antigen.
See proteinuria without evidence of UTI.
Biopsy required to confirm diagnosis.
Glomerulonephritis disease that causes it
Chronic viral or bacterial disease
EIA of horses
Pyometra in dogs
Heartworm in dogs
Lyme disease
Feline leukemia virus
Glomerulonephritis treatments
Treat primary cause
Corticosteroids?
ACE inhibitors?
