Term
| Caused by deposition of immune complexes (IgG and/or IgM) |
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Definition
| Type lll hypersensitivity |
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Term
| Mechanism of type lll hypersensitivity? |
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Definition
| activation of complement -> recruitment of neutrophils, vasodilation, edema -> tissue damage |
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Term
| Localized antigen reacts with circulating IgG forming localized immune complexes |
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Definition
| Localized type lll hypersensitivity |
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Term
| What is a skin localized type 3 hypersensitivity? |
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Definition
Arthus reaction
May occur during desensitization (allergy immunotherapy) |
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Term
| What is an example of lung localized type 3 sensitivity? |
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Definition
| Hypersensitivity pneumonitis in cattle exposed to moldy hay |
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Term
| What is an example of eye localized type 3 hypersensitivity? |
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Definition
| Blue eye-during canine adenovirus 1 infection; deposition of immune complexes in the uvea and corneal endothelium |
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Term
| What causes the circulating immune complexes in systemic type 3 hypersensitivity? |
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Definition
| Caused by persistent antigen exposure or delayed clearance |
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Term
| What determines clinical signs in systemic type 3 hypersensitivity? |
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Definition
| Determined by location of immune complex deposition |
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Term
| What determines the location of the immune complex deposition in systemic type 3 hypersensitivity? |
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Definition
| Location determined by size, antigen (charge, glycosylation), and physical nature of blood flow |
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Term
| What are some predilection sites in systemic type 3 hypersensitivity? |
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Definition
| Glomeruli (glomerulonephritis), synovial membrane (synovitis/arthritis), skin capillaries and arterioles (vasculitis) |
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Term
| Caused by deposition of immune complexes in the glomerular basment membrane (GBM) |
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Definition
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Term
| In situ formation of immune complexes against intrinsic antigens (e.g. podocyte process) or planted antigens (e.g. DNA, microbial molecules) |
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Definition
1. membranous glomerulopathy
2. immune complexes on subepithelial side of GBM
3. granular appearance on immunofluorescence |
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Term
| Antibodies directed against diffusely distributed GBM antigens |
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Definition
| antibodies bind along GBM-linear pattern |
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Term
| Deposition of circulating immune complexes |
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Definition
1. antigen may be nuclear antignes (SLE) or microbial (streptococus, others)
2. location of immune complexes depens on antigen (charge, size) |
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Term
| What is a mechanism for glomerulonephritis |
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Definition
| Immune complexes alone or with complement and neutrophils affect the integrity of the GBM -> proteinuria -> chronic glomerulonephritis -> loss of glomeruli, tubulointerstitial fibrosis, end stage renal disease |
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