hypersensitivities

• immediate hypersensitivity cells

  IgE, mast cells, complement, basophils
• antibody mediated hypersensitivity cells

  IgG and IgM
• immune complex mediated hypersensitivity cells

  IgG and IgM
• atopy

  tendency of some people to produce IgE mediated hypersensitivity reactions
• immediate hypersensitivity process

  exposure means IL-4 produces Th2 and IgE. IgE sensitises mast cells. on subsequent exposure, mast cells secrete mediators. this causes immediate hypersensitivity (vasoactive amines and lipid mediators) and the late phase reaction (recruits eosinophils)
• antibody mediated hypersensitivity process

  antibody mediated destruction of cells, complement activation, activation of ADDC, activating or blocking antibodies
• graves disease

  overproduction of thyroid hormones (antibody mediated hypersensitivity)
• myasthenia Gravis


  antibody inhibits binding of acetylcholine to acetylcholine receptor. causes muscle weakness and paralysis (antibody mediated hypersensitivity)
• haemolytic disease of newborn

  Rh- mother has Rh+ daughter, on subsequent pregnancy, if the baby is Rh+, it will get haemolytic anaemia (antibody mediated hypersensitivity)
• immune complex mediated hypersensitivity

  antibodies bind to circulating antigens to form immune complexes, that deposit in blood vessels. this causes injury and disease
• localised immune complex mediated hypersensitivity

  arthus lung and farmers lung
• systemic immune complex mediated hypersensitivity

  lupus, serum sickness, rhematoid arthritis
• lupus

  immune complexes are formed but arent cleared from circulation
• serum sickness

  immunisation of the host by non-human serum proteins
• cell mediated hypersensitivity process

  delayed onset due to T cell activation by APCs and migration to site of infection. CD4 T cells cause inflammation, macrophage activation and enzymes cause tissue destruction, and CD8 cells kill cells
• contact hypersensitivity

  hapten penetrates skin and binds to self proteins, and is taken up by dendritic cells. the dendritic cells present to Th1 (these secrete IFN-y and cytokines). mediators of inflammation are released
• rheumatoid arthritis

  immune system attacks lining of joints, causing inflammation and joint damage, eventually bone erosion and joint deformity. inflammation is mediated by Th1 and Th17 cells
• tumour necrosis factor

  normal physiology, inflammation, and immune homeostasis
• etanercept

  neutralisation of TNF for treatment of Rheumatoid arthritis. reduces TNF levels, dampens inflammation, reduces IL-1 and IL-6 levels, and reduces bone erosion