General and Systemic Histopathology, C601&C602
In this laboratory we
will be looking at examples of diseases that begin as, or principally involve,
abnormal activation of the immune system. Clearly, the immune system participates
to a degree in all forms of disease, most of the time on behalf of the good
guys. Here we will see what can happen when our tissues become the object
of interest and destruction by our own immune system. We will see examples
of both direct assault and what might be termed "innocent bystander" injury.
This would be a good time to review the topic of hypersensitivity and the
four major classes of this type of injury. In a most distilled form the categories
are:
| Type I | IgE mediated histamine release. An example would be an anaphylactic response to a bee sting. |
| Type II | Antibodies produced to "self antigens." For example lupus erythematosus or an autoimmune hemolytic anemia. |
| Type III | Antigen-antibody complex disease. In this instance, the antigen is "non-self," but the complexes are passively absorbed onto bodily tissues and immune system destroys the "innocent bystander." An example would be streptococcal induced glomerulonephritis. |
| Type IV | T-cell mediated hypersensitivity. The best example I can think of is tuberculosis |
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| Slide 25, Hashimoto's thyroiditis. | Slide 168, skin with amyloid. | Slide 169, skin with amyloidosis. | Slide 190, Kaposi's sarcoma of skin. |
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I'd like to take the quiz now. | |
| Slide 190, Kaposi's sarcoma of skin, | Slide 175, kidney with graft vs host reaction. |