Pathology

General Disease Processes

 

General pathology concepts apply to most or all diseases to varying degrees.

• inflammation
• degeneration
• necrosis
• apoptosis
• etc

WebPath is a great online resource for examples of pathology, both gross and histological.

 

Granulomas

Granulomas are congregations of macrophages and lymphocytes that develop in various settings of chronic inflammation, including M tuberculosis infection and Crohn's disease

 

 

Immune Conplexes

form from antibody-antigen binding

if not cleared by phagocytosis, can be deposited in tissues

Can be caused by

persistent, low grade bacterial, viral, parasitic antigens

autoimmune disease

allergic reaction

repeated inhalation of antigens from molds, plants, animals

Symptoms typically appear days to weeks after antigen exposure

• fever
• weakness
• renal
• edema
• swollen lymph nodes

 

Raji Cell Test

Raji Cells are derived from Burkitt's lymphoma and express both Fc IgG receptors and complement receptors

It is used to detect immune complexes

 

 

 

Delayed-Type Hypersensitivity

Dealyed type hypersensitivity (DTH), also called Type IV hypersensivity, takes 24-48 hours to occur.

DTH is a cell-mediated response in which APCs present antigen to memory CD4+ Th1 cells, causing rapid expression of interferon-gamma and inducing angry macrophage transformation.

The best-known example of DTH is the response to M. tuberculosis during the Mantoux skin test.