Block 2 Lecture 5 -- Hypersensitivity and Immunodeficiency Flashcards
What is the target Ag in autoimmune hemolytic anemia? What is the mechanism of disease?
erythrocyte membrane proteins (Rh)
– RBC opsonization
What is the target Ag in thrombocytopenic purpura? What is the mechanism of disease?
platelet membrane proteins
– platelet opsonization
What is the target Ag in pemphigus vulgaris? What is the mechanism of disease?
proteins in epidermal junctions
– Ab-mediated protease activation, adhesion disruption
What is the target Ag in Goodpasture’s syndrome? What is the mechanism of disease?
noncollagenous protein in kidney and lung
– complement- and Fc-mediated inflammation
What is the target Ag in acute rheumatic fever? What is the mechanism of disease?
Strep antigen
– inflammation and macrophage activation
What is the target Ag in myasthenia gravis? What is the mechanism of disease?
AchR
– inhibition of Ach binding
What is the target Ag in Graves’ disease? What is the mechanism of disease?
TSH receptor
– stimulation of TSH receptor
What is the target Ag in t2dm? What is the mechanism of disease?
insulin receptor
– insulin blockage
What is the target Ag in pernicious anemia? What is the mechanism of disease?
IF of gastric parietal cell
– dysfunctional IF
What is the clinical manifestation of autoimmune hemolytic anemia?
hemolysis, anemia
What is the clinical manifestation of thrombocytopenic purpura?
bleeding
What is the clinical manifestation of pemphigus vulgaris?
skin vesicles (bullae)
What is the clinical manifestation of goodpasture’s syndrome?
nephritis, lung hemorrhage
What is the clinical manifestation of acute rheumatic fever?
myocarditis, arthritis
What is the clinical manifestation of myasthenia gravis?
weak muscles and paralysis
What is the clinical manifestation of Graves disease?
hyperthyroidism
What is the clinical manifestation of insulin-resistant diabetes?
hyperglycemia
What is the clinical manifestation of pernicious anemia?
abnormal erythropoiesis, anemia
What is the target Ag in vasculitis caused by ANCA? What is the mechanism of disease? What is the clinical manifestation?
neutrophil granule proteins
- neutrophil degranulation and inflammation
- nephritis and lung hemorrhage
What is the target Ag in SLE?
DNA, nucleoproteins
What is the target Ag in polyarteritis nodosa?
HBV surface Ag
What is the target Ag in post-strep glomerulonephritis?
Strep wall ag
What is the target Ag in serum sickness?
various proteins…?
What is the clinical manifestation of SLE?
nephritis, arthritis, vasculitis
What is the clinical manifestation of polyarteritis nodosa?
vasculitis
What is the clinical manifestation of post-strep glomerulonephritis
nephritis
What is the clinical manifestation of serum sickness?
arthritis, vasculitis, nephritis
How might hypersensitivity be caused?
1) autoimmunity
2) reactions to microbes
3) reactions against environmental antigen
What is type I hypersensitivity?
Immediate, IgE-mediated
What is Type II hypersensitivity?
Ab-mediated
– IgM + IgG against cell surface or extracellular matrix
What is Type III hypersensitivity?
Immune complex-mediated
– circulating Abs and immune complexes of circulating Ags
What is the result of type I hypersensitivity?
degranulation of mast cells and mediators
What is the result of type II hypersensitivity?
- opsonization
- phagocytosis
- complement
- cell function abnormalities
What is the result of type III hypersensitivity?
- complement- and Fc-mediated leukocyte activation
- - clotting
What is type IV hypersensitivity?
T-cell-mediated
delayed type IV or T-cell-mediated cytolysis
What occurs in delayed type IV hypersensitivity?
CD4’s activate macrophages, secrete cytokines = inflammation
What occurs in T-cell mediated cytolysis?
CD8’s kill directly, secrete cytokines = inflammation
What diseases are due to type 4 delayed-type hypersensitivity?
- t1dm
- MS
- RA
- Crohn’s
- skin contact sensitivity
When does tissue damage begin in delayed-type hypersensitivity?
24-48 hours after initial response
damage due to products of macrophages