Ocular Immunology and Immune-Related Disorders of the External Eye

Question 1

mechanism of action of Xiidra (lifitegrast)

Answer 1

inhibits the integrin LFA-1 from binding its ligand ICAM-1, thereby preventing T-cell adhesion to endothelial cells and migration to inflamed tissue

Question 2

what are the sentinel cells of the ocular immune system?

Answer 2

Langerhans cells

Question 3

Name 5 factors that contribute to the immune privilege of the cornea

Answer 3

1. absence of blood vessels
2. absence of lymphatics
3. Presence of anti-inflammatory mediators such as TGF-beta
4. Presence of Fas ligand (CD95) which induces apoptosis of activated lymphocytes
5. Exposure to anti-inflammatory mediators of anterior chamber such as corticosteroids

Question 4

True or False: the normal cornea can

1. have an acute allergic reaction
2. generate an Arthus reaction (type III hypersensitivity reaction)
3. participate in humoral immune response
4. participate in cellular immune response
5. Wessely immune ring

Answer 4

1. false (no mast cells)
2. false (no blood vessels)
3. true (lymphocytes from limbus)
4. true (lymphocytes from limbus)
5. true

Question 5

IL-1 and TNF-alpha are up- or down-regulated in DES?

Answer 5

both upregulated

Question 6

which ocular/periocular tissues are part of the MALT (mucosa-associated lymphouid tissue)?

Answer 6

conjunctiva and lacrimal gland

Question 7

What immunoglobulin is responsible for much of the humoral immunity of the conjunctiva? What cell is responsible for much of the cellular immunity of the conjunctiva?

Answer 7

IgA; CD4+ T cells

Question 8

% of patients with necrotizing scleritis who have a systemic immunologic or connective tissue disease?

Answer 8

50%

Question 9

what is rheumatoid factor?

Answer 9

an autoantibody (IgG, IgA, or IgM) targeted against epitopes of the Fc portion of IgG

Question 10

associations for c-ANCA and p-ANCA

Answer 10

c-ANCA: Wegener’s granulomatosis (granulomatosis with polyangiitis)
p-ANCA: small vessel vasculitis

Question 11

What types of immune-mediated keratoconjunctivitis are specific to predominance of each of the following inflammatory mediators?

1. neutrophils
2. lymphocytes and monocytes
3. eosinophils
4. basophils and mast cells
5. keratinized epithelial cells

Answer 11

1. acute or subacute ocular surface inflammation
2. chronic toxic or allergic conjunctivitis
3. acute allergic conjunctivitis
4. vernal conjunctivitis
5. OCP, SJS, severe DES, GVHD