• when innate system cannot handle infection/antigen
• responds by producing antibodies and activates T lymphocytes (humoral immunity)

• body does not differentiate between self and foreign cells or antigens
• Activation of T and B lymphocytes occurs
• autoimmune disease occurs

• occurs due to:
  • exposure of T cells to previous antigens (lens protein)
  • molecular mimicry by invasive pathogens (strop pyogenes: rheumatic heart disease)
  • inappropriate expression of MHC on cells that normally do not express this (b-cells)
  • Rheumatoid arthritis
  • systemic lupus erythematousus
  • multiple sclerosis
  • insulin dependent diabetes  

• extensive tissue damage reaction to minimal stimuli / past stimuli
• 4 types

• Immediate 
• IgE mediated occurs as a tissue mediated mast cell response
• anaphylaxis, asthma, hay fever, insect bite)
• Humoral

• antigen-antibody complex formed
• IgG/IgM ( due to improper cross matching and penicillin reaction to allergic patients)
• Humoral

• Elevated levels of Ag-Ab complexes deposited on basement membranes. 
• components C5a, C3a, and C4a are produced resulting in rash, glomeruonephritis, arthritis. 
• symptoms occur after 3-4 day
• Humoral

• Delayed hypersensitivity reaction
• Cell mediated (unlike other types which are humoral)
• contact hypersensitivity

important for formation of T cell transcription factor which synthesize interleukins

• inhibited by Cyclosporins & Tacrolimus

Monoclonal Antibodies 

(MABS)

• genes of immunoglobulins which are manipulated to develop 'humanized' monoclonal antibodies directed against therapeutic targets

• Reactions caused by: Penicillin, Iodide, Phenytoin, Sulfonamides
• skin rash, edema, fever, glomerulonephritis, eosinophilia, anaphylactoid reaction

• allergy testing
• triple response (redness, wheal, flare)

• Immediate steroids cause immunosuppression
• antihistamines ↓ the allergic response
• supportive therapy: oxygen, antipyretics, antiinflammatory, analgesics, antivenoms, antidotes
• Desensitization of drugs: start with small dose and increase