Immunology

Question 1

Hypersensitivity reaction Type I - describe

Answer 1

Fast response
< 1h after exposure
Mediated by IgE
Ie. Anaphylaxis, asthma

Question 2

Hypersensitivity reaction II - describe

Answer 2

IgM, IgG, Complement mediated
Ig bind to host cell antigen perceived as foreign
Release of cytotoxic mediators
Ie. Autoimmune haemolytic anaemias, ITP

Question 3

Hypersensitivity reaction III - describe

Answer 3

IgG mediated
IgG binds to antigens -> immune complex
Immune complex deposits in vessel wall -> inflammatory mediators
Ie. SLE, RA

Question 4

Hypersensitivity reaction IV - describe

Answer 4

T cell mediated
Delayed hypersensitivity
Antigen presented by APCs -> T cell sensitised -> Memory T cell activated on re-exposure -> activation of macrophages
Ie. Contact dermatitis, MS, Graft rejection

Question 5

Hypersensitivity Type V - describe

Answer 5

Antibody binds cell surface ligands -> prevents cell signaling
Ie. Myasthenia Gravis, Graves Disease