Immunopathology Flashcards
(29 cards)
What is type II hypersensitivity?
Direct antibody binding to cells
What is type III hypersensitivity?
Deposition of antigen-antibody complexes
What is type IV hypersensitivity?
T lymphocytes and macrophage mediated hypersensitivity
Is IgE the only thing that can activate a mast cell?
No, a number of other molecules can activate a Mast cell
Describe the process of a Type I hypersensitivity reaction
- Antigen processed by DC
- Th2 is stimulated
- B cell+ antigen differentiates into plasma cell
- Plasma cell makes IgE
- IgE binds FcRe on mast cells
What are the two phases of type I reactions?
Immediate response: release of pre-formed mediators
Delayed response: Mast cell begins synthesis of other soluble mediators
The delayed response is more dangerous
What are the primary mediators?
- Biogenic amines
- chemotactic mediators
- enzymes
- Proteoglycans
What are the secondary mediators?
Leukotrienes
Prostaglandins
Platelet activating factor
Cytokines
What do eosinophil release?
Major basic protein (causes mast cell degranulation)
LTC4
Peroxidase Arylsulphylase
Platelet activating factor
What is severe urticaria
Cold/heat induced mast cell degranulation
What are the structural changes you will observe in a chronic asthmatic?
- Epithelial shedding
- Gland hyperplasia
- Basement membrane pseudothickening
- Muscle hyperplasia
- Inflammatory infiltrate
If incompatible blood types are mixed, what determines whether acute vs. delayed hemolysis will occur?
If previous exposure to different antibodies has occurred in the past, response will be acute. With no previous exposure, hemolysis will be delayed
Antiblood antibodies are typically what type of immunoglobulin?
IgM
What causes erythroblastosis fetalis?
When an Rh+ baby is born to an Rh- mother. This causes immunological attack on the baby’s erythrocytes. Baby responds by generating lots of erythroblasts, but eventually cannot compensate. Type II
What is goodpasture’s disease?
Anti-Type IV collagen antibody. Causes renal failure and hemoptysis Type II
What is rheumatic fever?
After streptococci infection, immunological attack of those same antibodies to self antigens of the heart. Causes heart valve vegetations, Aschoff bodies, and Anischkow bodies. Type II hypersensitivity
What is grave’s disease?
Hyperthyroidism caused by antibodies to TSH receptors, causing constant stimulation of the thyroid gland
What is responsible for causing most of the damage in Type III hypersensitivity reactions?
Neutrophils, which do most of the damage
What is post-streptococcal glomerulonephritis? What type if hypersensitivity rxn is this?
Nodules of complexes form in basement membrane with a loss of neutrophils. PMNs enter glomerular tufts. Lumpy bumpy basement membrane. Type III.
What is vasculitis?
Loss of smooth muscle with necrosis and thrombosis of vessels. Type III
What is a type IV hypersensitivity reaction?
Attack of antigen-specific and sensitized T cells accompanied by macrophages
What causes granulomatous formation?
A type IV hypersensitivity rxn that persists and becomes chronic
What mediates a delayed type hypersensitivity rxn (type IV)?
CD4+ cells and macrophages
What cells are responsible for T cell mediated cytotoxicity?
CD8+ cells
For tumors or viruses
