Hypersensitivity

Question 1

what are hypersensitivity disorders

Answer 1

incorrect immune response causing damage to self - includes allergy and autoimmune disease

Question 2

which type of hypersensitivity is each disorder

Answer 2

I - immediate hypersensitivity
II - direct cell effects
III - immune complex mediated
IV - delayed hypersensitivity

Question 3

type I hypersensitivity causes what

Answer 3

allergy

Question 4

what causes allergy to arise

Answer 4

IgE mediated response to external antigen (allergen)

Question 5

what are examples of allergens

Answer 5

foods, asthma, pollen, eczema, drugs

Question 6

what is the hygiene hypothesis

Answer 6

that increasing cleanliness can lead to increased allergy in children - prevention of Th1 cells differentiating into Th2 cells

Question 7

does the first exposure to an allergen cause an allergic reaction

Answer 7

No, second exposure causes reaction. B cells produce IgE and allergen is cleared but on second encounter of allergen histamine is released from IgE

Question 8

what is the immediate response of exposure to an allergen

Answer 8

muscle spasm
mucosal inflammation
inflammatory cell infiltrate

Question 9

what is the management of allergy

Answer 9

allergen avoidance
anti-inflammatory
block mast cell activation

Question 10

type II hypersensitivity involves activation of what

Answer 10

IgM or IgG antibodies reacting to surface antigens

Question 11

what are two examples of type II hypersensitivity

Answer 11

blood transfusions

Good Pastures syndrome

Question 12

what is Good Pastures syndrome

Answer 12

autoimmune disease affecting kidneys and lungs.

due to genetic susceptibility and environmental triggers

Question 13

what is the treatment for Good Pastures syndrome

Answer 13

ICS, smoking cessation

Question 14

what are three functions of antibodies

Answer 14

act as opsonins for phagocytosis
activates NK cells and eosinophils
activates complement system

Question 15

what is the bodys response to type III hypersensitivity

Answer 15

leukocyte accumulation and inflammation

Question 16

what is an example of type III hypersensitivity

Answer 16

hypersensitivity pneumonitis/extrinsic allergic alveolitis

Question 17

what type of conditions cause extrinsic allergic alveolitis

Answer 17

farmers lung, malt workers lung, cheese workers

Question 18

what organisms commonly cause EAA

Answer 18

aspergillus - inhalation of mould etc can leave deposits within the bronchioles and alveoli

Question 19

what is the treatment of EAA

Answer 19

antigen avoidance
reduce inflammation through ICS
reduce production of antibody through immunosuppression

Question 20

what is a side effects of immunosuppression/anti-TNF therapy

Answer 20

reactivation of latent TB

Question 21

type IV hypersensitivity is delayed type true/false

Answer 21

true

Question 22

how long does it take after exposure to experience symptoms from EAA

Answer 22

4-6 hours

Question 23

how long does it take after exposure to experience symptoms from an allergen

Answer 23

immediate, minutes to an hour

Question 24

how long does it take after exposure to experience symptoms from type IV hypersensitivity

Answer 24

days

Question 25

what are examples of non-autoimmune type IV hypersensitivity

Answer 25

sarcoidosis

TB

Question 26

which lymphocyte causes type IV hypersensitivity

Answer 26

T cells

Question 27

what is the pathophysiology of type IV hypersensitivity

Answer 27

inhalation of antigen causes macrophages and T cells in the parenchyma causing granuloma formation

Question 28

what is the management of sarcoidosis

Answer 28

many patients spontaneously improve

can treat with ICS to block T cell activation