Allergy (core immunology)

Question 1

What is hypersensitivity?

Answer 1

Undesirable reaction by the normal immune system (direct against non-harmful antigens) in a PRE-SENSITIZED host.

Question 2

What antibodies are present in type 2 cytotoxic hypersentivity? How do they act?

Answer 2

• IgG and IgM act against antigen at the cell surface.
• They activate complement and phagocytosis.
• leads to cell lysis and necrosis

Question 3

what diseases are associated with type 2 cytotoxic hypersensitivity?

Answer 3

1) Erythroblastosis fetalis (mother’s WBCs attack fetal RBCs)

2)Goodpasture’s nephritis
(antibodies attack basement membrane in lungs and kidneys leading to bleeding and renal failure)

Question 4

What is Erythroblastosis fetalis and what type of hypersenitivity is it related to ?

Answer 4

• related to Type 2 cytotoxic hypersensitivity

- Mother’s WBCs attack fetal RBCs

Question 5

What is good pasture’s nephritis/syndrome? what type of hypersensitivity is it related to?

Answer 5

Related to type 2 cytotoxic hypersensitivity.

-antibodies attack basement membrane in lung and kidney. leads to bleeding and renal failure.

Question 6

What is type 3 immune complex hypersensitivity?

Answer 6

IgG and Igm antibodies form complexes with soluble antigens. Leading to precipitation and deposition.

Question 7

What are the signs of type 3 immune complex hypersensitivity?

Answer 7

vasculitis

Question 8

How long does it take for type 3 hypersensitivity reaction to start?

Answer 8

3-8hours

Question 9

What diseases are associated with type 3 immune complex hypersensitivity

Answer 9

SLE

systemic Lupus Erythmatosus

Question 10

What is Type 4 delayed hyersensitivity?

Answer 10

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.

Question 11

What is a sign of type 4 delayed hypersensitivity?

Answer 11

Erythema induration (redness and inflammation)

Question 12

What is a common antigen of type 4 hypersensitivity?

Answer 12

-metals e.g. nickel

Question 13

What disease is associated with type 4 hypersensitivity?

Answer 13

contact dermatitis

Question 14

What is the immune response to parasitic disease?

Answer 14

1) Increased level of IgE
2) tissue inflammation
3) CD4+ T cells

Question 15

What is the Type 1 IgE mediated hypersensitivity response?

Answer 15

• IgE antibody mediated mast cell and basophil degranulation

- releases histamine and inflammatory mediators

Question 16

What cell types are involved in the late type 1 hypersensitivity reaction?
what is their role?

Answer 16

Eosinophils and T cells

T cells - release cytokines&raquo_space;stimulate antibody production also cause inflammation

Question 17

What are the features of allergic rhinitis?

Answer 17

• Nasal congestion and inflammation

- tonsilar and adenoidal enlargement

Question 18

What are the features of asthma?

Answer 18

airway inflammation
oedema
mucus
Airway constriction

Question 19

what causes allergic rhinitis?

Answer 19

• house dust mite
• animal dander
• pollen

Question 20

what is the treatment for allergic rhinitis

Answer 20

• antihistamine

- nasal steroids

Question 21

What stimulates athma?

Answer 21

house dust mite

fumes (non allergic stimuli)

Question 22

What is atopic dermatitis?

Answer 22

inflammation of the skin

Question 23

What are the features of atopic dermatitis?

Answer 23

itchin
blistering
crackling of skin

Question 24

Give signs/symptoms of anaphylaxis, include skin, GI, respiratoru, cardiovascular and neuro reactions.

Answer 24

Skin - itchy and flushing
GI - oral tingling&raquo_space;abdo pain»diarrhoea
Respiratory - throat tingling&raquo_space;severe wheeze
Cardiovascular - tachycardia»>cardiac arrest
Neurological - irritability»light headedness&raquo_space;loss of consciosness

Question 25

what are the major food allergens?

Answer 25

• cow’s milk
• egg
• legumes
• fish
• seafood
• grains