Module 7: Type II Flashcards
Another name for Type II
cytotoxic
tissue damage due to
binding of IgG or IgM Ab to cell surface antigens
4 mechanisms of tissue damage
CLEARANCE of opsonized target cell by macrophages
INTERFERENCE of normal cell function due to antibody binding to a receptor site
COMPLEMENT MEDIATED LYSIS of the target cell
damage to local tissues due to INFLAMMATORY RESPONSE
Clearance of the opsonized target cell by macrophages
macrophage has Fc receptors
Antibody binds to antigen
Macrophage binds to antibody/antigen complex
Antibody coated cell is removed by macrophages
3 examples of Clearance of opsonized target cells by macrophages
Autoimmune hemolytic anemia (AIHA)
Rh Hemolytic Disease of the Newborn (Rh HDN)
Immune Thrombocytopenic Purpura (ITP)
Autoimmune hemolytic anemia (AIHA)
Antibody that is reactive at 37deg. and it attaches to pts RBC (macrophages come and kill RBC)
Rh Hemolytic Disease of the Newborn (Rh HDN)
If a D neg mom is carrying a D pos baby (inherited from dad)
If D pos cells leak back into mom, mom may produce Anti D Ab. Ab can pass back through placenta and attach to babies D pos cells (removed by macrophages)
Immune Thrombocytopenic Purpura (ITP)
Pts make Ab against their own PLT
Removed by macrophages
2 examples of Interference of normal cell function due to the Ab binding to a receptor site
Graves disease
Myasthenia gravis
Graves disease
Ab mimics TSH
Ab binds to TSH receptor on thyroid
Results in constant and uncontrolled production of T3 and T4 by the thyroid
Myasthenia gravis
autoantibody binds to the acetylcholine receipts at the neuromuscular junction
Binding blocks normal signal transmission (Binding of Ach) and results in muscle weakness
example of Complement mediated lysis of the target cell
ABO incompatible blood transfusion
Leads to binding of complement by the Ab coated donor cell
If complement cascade proceeds to completion, intravascular hemolysis is the result
Damage to local tissues due to the inflammatory response
lysosomal enzymes released by cells of the immune response may damage local tissue
Example of Damage to local tissues due to the inflammatory response
Good pasture’s syndrome
AutoAb against basement membrane collagen binds to the basement membrane of the kidney and/or pulmonary alveolar membrane of the lungs
Auto Ab binds complement, activates cascade and promotes inflammation
The phagocyte becomes frustrated and releases their lysosomal contents