Hypersensitivity rxns Flashcards
Goodpasture syndrome
Type II cytotoxic HSR
SLE
Type III immune complex HSR
Tuberculin skin test
Type IV HSR
cell-mediated/delayed type hypersensitivity
Type I
IgE Mediated
Ag x-links IgE on Mast cells and basophils –> release of vasoactive mediators
Type II
Cytotoxic HSR
Ab against cell surface Ag –> complement mediated cell destruction
Type III
Immune complex-mediated HSR
Ag+ab complex onto tissue –> complement –> inflam
Type IV
Cell-mediated HSR/delayed
T(DTH) cells release cytokines –> activated macrophages or Tc cells –> direct cell damage
Serum sickness (vasculitis - fibrinoid necrosis and neutrophils in small blood vessels)
Type III immune complex HSR - dec serum C3 nd C4 due to complement consumption
Ab to foreign proteins produced
Can occur after admin of chimeric monoclonal ab (eg rituximab or infliximab) or nonhuman immunoglobulins (eg venom antitoxins)
Contact dermatitis (eg poison Ivy, nickel allergy)
Type IV HSR
cell-mediated/delayed type hypersensitivity
Mediated primarily by T lymphocytes
Graft-versus-host disease
Type IV HSR
cell-mediated/delayed type hypersensitivity
Mediated primarily by T lymphocytes
Blood transfusion reactions
Type II cytotoxic HSR
Anaphylaxis (hay fever, asthma, hives, food allergies, eczema)
Type I IgE-mediated HSR
Multiple sclerosis
Type IV HSR
cell-mediated/delayed type hypersensitivity
Arthus reaction
Type III immune complex HSR
Ag-ab complexes cause the rxn. Edema, necrosis and activation of complement
PSGN
Type III immune complex HSR
Polyarteritis nodosa
Type III immune complex HSR
Bee sting
Type I IgE-mediated HSR
Food/drug allergies
Type I IgE-mediated HSR
Myasthenia gravis
Type II cytotoxic HSR
Pemphigus vulgaris, bullous pemphigoid
Type II cytotoxic HSR
Rheumatic fever
Type II cytotoxic HSR
Pernicious anemia, autoimmune hemolytic anemia
Type II cytotoxic HSR
Graves disease
Type II cytotoxic HSR
Guillain-Barre syndrome
Type II cytotoxic HSR
hyperacute transplant rejection
Type II cytotoxic HSR (ab mediated)
acute or chronic transplant rejection
Type IV cell-mediated HSR - T(DTH) cells release cytokines –> activated macrophages or Tc cells –> DIRECT cell damage
Acute (w/in 6mo): Host T-cell sensitization against graft MHC antigens
Prevent with calcineurin inhibitors
Cardio Histo: dense mononuclear lymphocytic infiltrate with cardiac damage
Chronic Renal histo: obliterative intimal thickening, tubular atrophy, interstitial fibrosis
Candidal antigen skin test is what HSR? What does it assess the activity of?
Type IV cell-mediated/delayed HSR
Macrophages, CD4+ and CD8+ T lymphocytes
Medications like opioids, radiocontrast agents, and some abx (eg vancomycin) can trigger IgE (dependent vs independent) mast cell degranulation?
INDEPENDENT
Activate PKA and PI3 kinase –> histamine, bradykinin, heparin, and chemotactic factor release.
Note: IgE-mediated degranulation is usually assoc with environmental exposures
In lung transplant, the immune reaction of chronic rejection affect what part of the lung?
Small airways causing bronchiolitis obliterans.
Sx - dyspnea, wheezing
Henoh-Schonlein purpura is what HSR?
Type III hypersensitivity - immune complex
Deposition of IgA-containing immune complexes in small vessels –> systemic vasculitis
