Flashcards in Allergy (core immunology) Deck (25)
What is hypersensitivity?
Undesirable reaction by the normal immune system (direct against non-harmful antigens) in a PRE-SENSITIZED host.
What antibodies are present in type 2 cytotoxic hypersentivity? How do they act?
-IgG and IgM act against antigen at the cell surface.
-They activate complement and phagocytosis.
-leads to cell lysis and necrosis
what diseases are associated with type 2 cytotoxic hypersensitivity?
1) Erythroblastosis fetalis (mother's WBCs attack fetal RBCs)
(antibodies attack basement membrane in lungs and kidneys leading to bleeding and renal failure)
What is Erythroblastosis fetalis and what type of hypersenitivity is it related to ?
-related to Type 2 cytotoxic hypersensitivity
-Mother's WBCs attack fetal RBCs
What is good pasture's nephritis/syndrome? what type of hypersensitivity is it related to?
Related to type 2 cytotoxic hypersensitivity.
-antibodies attack basement membrane in lung and kidney. leads to bleeding and renal failure.
What is type 3 immune complex hypersensitivity?
IgG and Igm antibodies form complexes with soluble antigens. Leading to precipitation and deposition.
What are the signs of type 3 immune complex hypersensitivity?
How long does it take for type 3 hypersensitivity reaction to start?
What diseases are associated with type 3 immune complex hypersensitivity
(systemic Lupus Erythmatosus)
What is Type 4 delayed hyersensitivity?
CD4+ T cells recognise the antigen in association with MCH class 2 proteins.
-The T cells secrete cytokines which stimulate an immune response.
-CD8 T cells kill cells on contact.
What is a sign of type 4 delayed hypersensitivity?
Erythema induration (redness and inflammation)
What is a common antigen of type 4 hypersensitivity?
-metals e.g. nickel
What disease is associated with type 4 hypersensitivity?
What is the immune response to parasitic disease?
1) Increased level of IgE
3) CD4+ T cells
What is the Type 1 IgE mediated hypersensitivity response?
- IgE antibody mediated mast cell and basophil degranulation
-releases histamine and inflammatory mediators
What cell types are involved in the late type 1 hypersensitivity reaction?
what is their role?
Eosinophils and T cells
T cells - release cytokines >>stimulate antibody production also cause inflammation
What are the features of allergic rhinitis?
-Nasal congestion and inflammation
-tonsilar and adenoidal enlargement
What are the features of asthma?
what causes allergic rhinitis?
-house dust mite
what is the treatment for allergic rhinitis
What stimulates athma?
house dust mite
fumes (non allergic stimuli)
What is atopic dermatitis?
inflammation of the skin
What are the features of atopic dermatitis?
crackling of skin
Give signs/symptoms of anaphylaxis, include skin, GI, respiratoru, cardiovascular and neuro reactions.
Skin - itchy and flushing
GI - oral tingling >>abdo pain>>diarrhoea
Respiratory - throat tingling >>severe wheeze
Cardiovascular - tachycardia>>>cardiac arrest
Neurological - irritability>>light headedness >>loss of consciosness