Hypersensitivity

Question 1

What is hypersensitivity?

Answer 1

Excessive immune response that cause damage

Question 2

What can cause hypersensitivity?

Answer 2

Infectious agents
Environment
Self antigens

Question 3

Are all infectious agents capable of triggering hypersensitivity?

Answer 3

No

Question 4

Give an example of a virus which causes hypersensitivity.

Answer 4

Influenza

Can trigger major cytokine secretion

Question 5

Give an example of an environmental substance which may trigger hypersensitivity.

Answer 5

Dust

May enter lower respiratory tract, trigger antibody response

Question 6

Which Ig is associated with farmer’s lung?

Answer 6

IgG

Question 7

What happens when environmental substances are small enough to diffuse through skin?

Answer 7

Can trigger delayed hypersensitivity response

Question 8

What can Nickel do on contact?

Answer 8

Contact dermatitis

Question 9

What is the onset of type I hypersensitivity like?

Answer 9

Rapid onset
IgE mediates adaptive immune response
Mast cell and eosinophils mediate innate immune response

Question 10

What is the onset of type II hypersensitivity like?

Answer 10

Rapid onset
IgG mediates adaptive immune response
Complement and phagocytes mediate innate immune response

Question 11

What is the onset of type III hypersensitivity like?

Answer 11

Slow onset (hours)
IgG mediates adaptive immune response
Complement and neutrophils mediate adaptive immune response

Question 12

What is the onset of type IV hypersensitivity like?

Answer 12

Very slow onset (2-3 days)
T cell mediates adaptive immune response
Macrophages mediate innate immune response

Question 13

What kind of hypersensitivity is peanut and dust allergies?

Answer 13

Type I

Environmental triggers

Question 14

What kind of hypersensitivity is Farmer’s lung?

Answer 14

Type III

Environmental trigger

Question 15

What kind of hypersensitivity are immune haemolytic anaemias?

Answer 15

Type II

Question 16

What kind of hypersensitivity is SLE?

Answer 16

Type III

Autoimmune issue

Question 17

What kind of hypersensitivity is Coeliac disease?

Answer 17

Type IV

Question 18

What kind of hypersensitivity is contact dermatitis?

Answer 18

Type IV

Question 19

What kind of hypersensitivity usually mediates allergy?

Answer 19

Type I

Question 20

Describe the process of Type I hypersenitivity.

Answer 20

Environmental factors
TH2 cells produce IL4 which induces production of IgE
Mast cell degranulation

Question 21

What does atopy mean?

Answer 21

Basically another word for allergy

Immediate hypersensitivity reactions mediated by IgE

Question 22

Can atopy be inherited?

Answer 22

Yes
Atopy traits can be passed on
May not be same allergy as parents

Question 23

What is the allergen in penicillin allergy?

Answer 23

Beta-lactam

Question 24

What are some symptoms of systemic allergy?

Answer 24

Low BP
Angioedema
Airway obstruction

Question 25

What are some symptoms for allergy in the airways?

Answer 25

``` Reversible bronchial obstruction Discharge Sneezing Nasal obstruction Allergic conjunctivitis ```

Question 26

What are some symptoms of allergic reactions on the skin?

Answer 26

Itchy oedema Lip swelling Itchy inflammation

Question 27

What does filaggrin do?

Answer 27

Maintain epithelial barriers, moisturising surfaces and controlling pH

Question 28

What is filaggrin?

Answer 28

Protein expressed by keratinocytes

Question 29

What do mast cells produce?

Answer 29

Prostaglandins and leukotrienes through COX and lipo-oxygenase pathways

Question 30

Does allergy raise or lower BP?

Answer 30

Lower | Often severe drop

Question 31

Is there mucus secretion in asthma?

Answer 31

Yes | Contributes to airflow obstruction

Question 32

How do we test for allergies?

Answer 32

Skin-prick | Positive control could be histamine and negative control could be saline

Question 33

What is anaphylaxis?

Answer 33

``` Mast cells and leukotrienes produced Vasodilation and increased vascular permeability Fluid shifts to extra-vascular space Fall in vascular tone Drop in BP Mast cells release histamines ```

Question 34

What is Rhesus?

Answer 34

IgG develops during pregnancy and crosses placenta | Causes haemolytic disease

Question 35

What is the most common cause of hyperthyroidism?

Answer 35

Graves disease

Question 36

Which gene is associated with Graves disease?

Answer 36

HLA allele DR3

Question 37

How are large complexes cleared?

Answer 37

Broken down by complement

Question 38

What is a possible cause of slow complex formation in nephrotic syndrome?

Answer 38

Hep B

Question 39

What is a possible cause of rapid complex formation in nephrotic syndrome?

Answer 39

Strep infection

Question 40

Describe immune complex disease in the kidney.

Answer 40

Common cause of renal failure | Glomerulonephritis including nephrotic syndrome and nephritis

Question 41

What is nephrotic syndrome?

Answer 41

Protein leaks into urine Gradual development Renal failure

Question 42

How does nephritis present?

Answer 42

Rapid onset renal failure Blood and protein in urine Hypertension

Question 43

What role does Tissue Necrosis Factor play in hypersensitivity?

Answer 43

Secreted by macrophages and T cells and causes much of the tissue damage in delayed hypersensitivity

Question 44

How does hypersensitivity affect RA?

Answer 44

TH1 and TH17 infiltrate synovium | TNF and IL-17 attract neutrophils which damage synovium

Question 45

How do inflammatory cells affect MS?

Answer 45

TH1 and TH17 cells and macrophages develop in the affected nervous tissue The inflammatory lesions cause the reversible, relapsing disability typical of early MS