Blistering skin disorders 2

Question 1

What are integrins important in?

Answer 1

cell-cell and cell-matrix adhesion

Question 2

Where are integrins found?

Answer 2

Transmembrane

Question 3

What structure are integring?

Answer 3

Heterodimers with alpha and beta chains

Question 4

Differences in different integrins?

Answer 4

The alpha and beta subtypes that are used

Question 5

Lateral adherence meaning?

Answer 5

Cell-cell

Question 6

Basal adherence meaning?

Answer 6

Cell to matrix

Question 7

Which alpha beta subtypes are used for lateral and basal integrin mediated adherence?

Answer 7

alpha2 beta1
alpha3 beta1

Question 8

Which alpha beta subtypes are used for hemidesmosomes?

Answer 8

alpha6 beta4

Question 9

Role of hemidesmosomes?

Answer 9

Specialised junctional complexes that attach the basal cells of the epidermis to the underlying basement membrane

Question 10

Integrins ligands?

Answer 10

Laminins and fibronectin

Question 11

What do the integrins in the basement membrane attach to?

Answer 11

Laminins (in the basement membrane)

Question 12

What do laminins in the basement membrane attach/link to?

Answer 12

Collagen fibres

Question 13

Role of type VII collagen fibres?

Answer 13

Holding cells down onto the basement membrane

Question 14

Two pemphigus subtypes and their frequency?

Answer 14

P. Vulgaris - common form
P. Foliaceous - 10% of cases

Question 15

Pemphigus symptoms?

Answer 15

Blisters on skin and mucosal surfaces
Oral blisters, ulcers and erosions

Question 16

Why do pemphigus blisters develop into cutaneos lesions?

Answer 16

They are flaccid blisters that are easily broken

Question 17

Pemphigus mortality?

Answer 17

5-19% (especially in elderly)

Question 18

Main difference between P. Vulgaris and P. Foliaceous?

Answer 18

Where the split in the epidermis occurs

Question 19

Where does the epidermis split in P. Vulgaris?

Answer 19

Suprabasal blister
Gap between the basal cells and the stratum spinosum

Question 20

Where does the epidermis split in P. Foliaceous?

Answer 20

Subcorneal split
Below the stratum corneum and above the granular layer

Question 21

Which causes stronger blisters, P. Vulgaris or P. Foliaceous?

Answer 21

P. Vulgaris as there is more layers on the surface of the blister

Question 22

Why are the blisters in P. Foliaceous thinner than those in P. Vulgaris

Answer 22

In P. Foliaceous the split in the epidermis is higher up, so only the stratum corneum makes up the blister surface

Question 23

What is anantholysis?

Answer 23

losing the cell-cell contacts, so the cells begin to round up and fall apart

Question 24

What type of disease is pemphigus?

Answer 24

Autoimmune disease

Question 25

In pemphigus, what are the autoantibodies formed against?

Answer 25

Epitopes on amino terminal of desmoglein

Question 26

In pemphigus, which specific desmogleins are the antibodies formed against?

Answer 26

P. Vulgaris--> Desmoglein 3 (and 1 a bit) P. Foliaceous--> Desmoglein 1

Question 27

Which autoantibodies are responsible for P. Vulgaris and P. Foliaceous?

Answer 27

P. Vulgaris--> IgG antibodies P. Foliaceous--> IgG4 antibodies

Question 28

Where in the epidermis does the antibody in P. Vulgaris bind?

Answer 28

The lower epidermis, where desmoglein 3 is expressed

Question 29

Where in the epidermis does the antibody in P. Foliaceous bind?

Answer 29

Superficial epidermal layers

Question 30

What happens to the epidermis without the adhesion molecules?

Answer 30

The cells fall apart and the layers split