Hypersensitivity 2-4 Flashcards
Which complement pathway does type 2-4 work by?
Classical pathway
Which proteins are deposited in the target cell membrane during complement?
C3b and C3d
What proteins is the membrane attack complex composed of?
C5b-9
What antibodies are produced against the ABO system antigens?
IgM
What Rh carries risk for HDNB?
When a Rh+ sensitized Rh- mother carries a second Rh+ infant
How do you treat haemolytic disease?
Rhesus prophylaxis - preformed anti-RhD antibodies. Given to Rh- mothers immediately after delivery of Rh+ baby. Destroy fetal Rh+ cells before they cause sensitisation
What’s autoimmune haemolytic anaemia?
where the patient becomes sensitized to their own erythrocytes
What’s idiopathic thrombocytopenic purpura?
autoantibodies to platelets
What’s guillain-barré syndrome?
a group of autoimmune diseases characterized by inflammation, loss of myelin and loss of function in peripheral nerves
What autoantibodies are produced in myasthenia gravis?
IgG antibodies to nicotinic acetylcholine receptors
What 2 mechanisms do IgG and complement act in myasthenia gravis?
Increasing rate of turnover of Ach receptors. Partial blocking of Ach binding.
Name a treatment for myasthenia gravis?
Pyridostigmine
Where is the immune complex removed in type 3 hypersensitivity?
Liver and spleen
Name 3 ways in which immune complex formation can result from?
- Persistent infection - in addition to weak antibody response
- Inhalation of antigenic material - extrinsic antigens (moulds, animals) often seen in lungs
- Autoimmune disease - SLE
Where do platelets aggregate during immune complex inducing inflammation?
On the exposed collagen of the vessel basement membrane to form microthrombi
