Immune Mediated Conditions

Question 1

What are the types of Oral LP?

Answer 1

• Erosive- has potential to become malignant and is most painful (biopsy)
• Reticular
• Papular
• Atrophic
• Bullous
• Plaque like

Question 2

How does skin LP present?

Answer 2

raised bumps and papules that are red/purple with white lesions on top (commonly seen in wrist flex areas and legs)

Question 3

When may you biopsy lichen planus?

Answer 3

If patient smokes

If symptoms

Question 4

What is the cause of white lesions?

Answer 4

Thickening of epithelium (hyperplasia) and keratin formation (may be para- remains of nucleus still present)

Question 5

How does LP appear histologically?

Answer 5

 Destruction of basal cell layer- by proteases and cytokines
 Some cells undergo apoptosis (programmed/natural cell death)- civet cells
 Band of inflammatory cells is present (known as blue band- hugging)-
 Epitheliotropism- antigen is present in cells and pulls T cells up into the epithelium
 Saw tooth rete pegs are present- not often seen in oral mucosa
 Increased keratinisation
 Hyperplasia of epithelium (sometimes atrophy)

Question 6

What immune cells are present in hugging blue band? Why is this immune reaction taking place?

Answer 6

T cells- CD8+ cytotoxic

Macrophages

-> autoimmune condition- body doesn’t recognise this as normal self and causes reaction

Question 7

What type of hypersensitivity reaction is LP?

Answer 7

Type 4- cell mediated (delayed) hypersensitivity is associated with T cells

Question 8

How is LP/lichenoid reaction distinguished from SLE?

Answer 8

Diagnosis decided on by history and clinical appearance

Question 9

How is LP managed?

Answer 9

• Avoid triggers
• Non SLS toothpaste
• Corticosteroids may be used depending on type or symptoms- spray, mouthwash, systemic
• Laser or surgical removal of lesions

Question 10

What is the name of central white striae in lichenoid reaction?

Answer 10

Wickham’s

Question 11

What are the causes of lichenoid tissue reactions?

Answer 11

Amalgam fillings (replace with composite)

Food/drink additives

Medications

Atopy- multiple allergies

Question 12

What are the histological features of lichenoid reactions?

Answer 12

• Blue band underneath epithelium (not as dense as in LP)
• Hyperplasia of epithelium
• Keratinisation
• Basal cell destruction and apoptosis
• Epitheliotropism
• Perivascular cuffing in deeper part of the tissue- chronic inflammatory cells surrounding BVs
• Thick rete pegs

Question 13

What is meant by vesiculobullous?

Answer 13

Mixture of small and large blisters

Question 14

What happens to lesion in Pemphigus when it ruptures?

Answer 14

Often leaves painful ulcer

Question 15

How does epithelium appear in Pempigus vulgaris clincally?

Answer 15

Ragged

Red

Ulcerated

Question 16

What causes reaction in Pemphigus?

Answer 16

Autoantibody reaction toward antigen on desmoglian 3 protein of desmosomes

Question 17

What are the histological features of pemphigus?

Answer 17

• Presence of intra-epithelial split (cells separate leaving spaces to fill with fluid)
• Basal layer is still firmly attached to underlying Lamina Propria (hemidesmosomes are unaffected)
• Acantholysis- cells separate due to destruction of desmosomes
• Tzank cells- cells that have detached and fallen into epithelium
• Lamina propria inflammation- mast cells, plasma cells, macrophages, eosinophils

Question 18

Why is there a high level of mortality in untreated pemphigus/pemphigoid?

Answer 18

Loss of fluid

Secondary infection of lesions

Question 19

Where is a biopsy for pemphigus/GOID taken?

Answer 19

Peri-lesional- must be taken from non-ulcerated tissue in the area surrounding lesion (may be the opposite side)
 One piece of tissue is put in formalin (fixed by regular H/E)
 One piece must be frozen or placed in meckels- to allow immunofluorescence

Question 20

What type of hypersensitivity reaction occurs in Pemphigus?

Answer 20

Type 2 hypersensitivity reaction (cytotoxic)
 Caused by IgG antibodies and complement (C4b and C5a- draw in polymorphs which release MMPs, enzymes causing breakdown of connective tissue)
 Loss of surface epithelium will cause even more inflammation

Question 21

How does direct immunofluorescence for pemphigus work?

Answer 21

 IgG antibody against desmoglian 3 attached to florescent molecule is applied to biopsy which then combines with antigen (gives fishing net pattern within epithelium)

Question 22

What is indirect immunofluorescence and its use?

Answer 22

measures patients’ serum and level of antibodies within
 Good at checking response to treatment- the number would come down
 Measured using ELISA technique

Question 23

How is Pemphigus treated?

Answer 23

Corticosteroids

Monoclonal antibodies

Question 24

Which conditions is desquamative gingivitis seen in?

Answer 24

LP

Pemphigus

Pemphigoid

Question 25

What are the types of pemphigoid?

Answer 25

Bullous- generally affects skin Mucous membrane- affects eye and oral cavity (also oesophagus and nasal cavity) Cicatricial- associated with scarring (can cause blindness)

Question 26

What do IgG antibodies target in pemphigoid?

Answer 26

Hemi-desmosomes in basal layer -> Blisters occur underneath the epithelium -> Tougher blisters but still tend to rupture (can leave an ulcer-like lesion

Question 27

Which condition is more common out of pemphigus/pemohigoid

Answer 27

Pemphigoid

Question 28

What are the similarities and differences between Pemphigoid and Angina Hemorhagica Bullosa?

Answer 28

Both may contain blood in blisters if BVs are near lesions Pemphigoid recurs and does not fully heal

Question 29

What are the histological feature of Pemphigoid?

Answer 29

 Blister forms underneath epithelium- no acantholysis  Presence of neutrophils  T2 hypersensitivity reaction- c3b and c5a (draws up polymorphs and mast cells- release MMPs causing tissue destruction)  Macrophages- phagocytosis  Plasma cells  No Tzank cells- as there is no destruction of desmosomes

Question 30

How does Pemphigoid appear on DI?

Answer 30

Fluorescent line