Ocular Immunology Flashcards
name the compliment factor anaphylatoxins
C3a and C5a
What coats the pathogenic or antigenic cell surfaces to promote phagocytosis in the compliment pathway, and what is this called?
C3b. Opsonization
what is the membrane attack complex
complement-derrived complex that inserts into cell membranes to form pores inducing lysis
mechanism of action of corticosteroids
inhibit phospholipase A2, preventing the formation of arachidonic acid
mechanism of action of NSAIDs
inhibit cyclooxygenase, thereby preventing prostaglandin synthesis
what binds MHC class I molecules, and what types of pathology are generally controlled by this mechanism
CD8+ T-cells, which then kill tumor and virus-infected cells directly (cell-mediated immunity)
what binds MHC class II molecules, and what types of pathology are generally controlled by this mechanism
CD4+ T cells. phagocytosed bacterial and fungal components
role of CD4+ cells in humoral immunity
activation of B cells to switch from IgM to IgG, IgA, and IgE producing plasma cells
Types of hypersensitivity w/ examples
I: anaphylaxis / immediate hypersensitivity (allergic conjunctivitis)
II: cytotoxic antibodies (target antigens expressed on patient’s own cells; ex. myasthenia gravis, ABO incompatibility)
III: Immune complex reactions (SLE)
IV: delayed cell-mediated reactions (mediated by previously-primed CD4+ cells; PPD skin test, most uveitides)
V: stimulatory hyersensitivity (example = TED)
what differentiates the different subclasses of immunoglobulins
heavy chain moeties
Name the immunoglobulin(s) that:
- are strong compliment inducers
- is the primary immunoglobulin in mucosal secretions
- stimulates mast cell degranulation
- IgM and IgG3
- IgA
- IgE
what is a chronic Arthus reaction
antigenic persistence in tissues leading to chronic inflammatory reaction (may play a role in RA and other autoimmune diseases)
What is the Goldmann-Witmer coefficient? What value is significant?
ratio of antibody produced at a host site versus passively leaked from the blood. > 3 is significant
Antibodies to which virus have been indicated in Fuchs heterochromic uveitis?
Rubella
time frame for onset of Type IV hypersensitivity
12-48 hours
Uveitic example of Th1 and Th2 delayed hypersensitivity reactions?
Th1: sympathetic ophthalmia
Th2: toxocara (mediated by IL4, IL5, IgE)
primary inflammatory cell in acute inflammation
neutropil
Inflammatory mediators most responsible for atopic keratoconjunctivitis?
For allergic conjunctivitis?
eosinophils
IgE and mast cells
Is the compliment cascade is an example of innate or adaptive immunity?
innate
Most uveitis is cell-mediated or humoral?
cell mediated (mostly Th1)
what subtype of inflammatory cells are Langerhans cells?
dendritic
Most common cause of hypopyon in general ophthalmology practice?
HLA-B27
Is Behcet’s uveitis classically a hot or a quiet eye?
quiet
birdshot HLA?
HLA A29
