Type II And III Hypersensitivity

Question 1

Type II hypersensitivity mechanism

Answer 1

Antibodies (IgG or IgM) directed at cells resulting in complement activation, ADCC or receptor dysfunction

Question 2

Examples of type II hypersensitivity (6)

Answer 2

• Autoimmune hemolytic anemia
• Autoimmune thrombocytopenia
• Goodpastures syndrome
• Hyperacute graft rejection
• Mesthenia gravis
• Graves’ disease

Question 3

Autoimmune hemolytic anemia

Answer 3

Anti RBC antibodies that cause lysis through complement

Question 4

Autoimmune thrombocytopenia

Answer 4

Anti-platelet antibodies

Question 5

Myasthenia Gravis

Answer 5

Loss of muscle control due to autoantibodies against acetylcholine receptors

Question 6

Grave’s disease

Answer 6

Overproduction of thyroid hormone due to stimulation by autoantibodies

Question 7

Goodpastures disease

Answer 7

Autoantibodies against collagen IV

Question 8

Type III hypersensitivity mechanism

Answer 8

Ag-Ab complexes become trapped in blood vessels, especially in the joints, skin, and kidney

Question 9

Example of type III hypersensitivity

Answer 9

• Systemic Lupus erythematosus
• Post-streptococcal glomerulonephritis
• Serum sickness
• Drug rxns
• tetanus vaccination or toxin exposure to those who are immunized
• Hypersensitive pneumonitis (Farmer’s lung or Bird Fancier’s disease)

Question 10

Systemic lupus erythematosus

Answer 10

Complexes of IgG and nuclear antigens, including DNA. Complexes trapped in skin kidneys and joints

Question 11

Post-streptococcal glomerulonephritis

Answer 11

• Circulating anti-strep abs combined with strep antigen trapped in glomeruli

Question 12

Serum sickness

Answer 12

Getting sick after multiple infusions of serum from different species (ex: anti snake venom serum from horse)