Disorders of the Immune System
Allergic Reactions
![The first time the allergy-prone person runs across an allergen such as ragweed, he or she makes large amounts of ragweed IgE antibody. These IgE molecules attach themselves to mast cells. The second time that person has a brush with ragweed, the IgE-primed mast cell will release powerful chemicals, and the person will suffer the wheezing and/or sneezing, runny nose, watery eyes, and itching of allergy.](https://webarchive.library.unt.edu/eot2008/20090511012732im_/http://www3.niaid.nih.gov/NR/rdonlyres/A85E4E17-DC57-4E18-A06F-BE64D4C4C305/0/allergicReaction.jpg)
An allergic reaction occurs after plasma cells produce IgE antibody against a specific antigen and mast cells become activated. View credit information.
Autoantibodies
![Pancreas with beta cell attacked by mature T cells.](https://webarchive.library.unt.edu/eot2008/20090511012732im_/http://www3.niaid.nih.gov/NR/rdonlyres/E7BED554-2798-4033-88CE-0F216978D8DC/0/autoantibodies.jpg)
Misguided T cells can attack insulin-producing cells of the pancreas, contributing to an autoimmune form of diabetes. View credit information.
Antigen-antibody Complex
![Large and small antigen-antibody complexes trapped in the glomerular basement membrane of a kidney, between endothemelial cells.](https://webarchive.library.unt.edu/eot2008/20090511012732im_/http://www3.niaid.nih.gov/NR/rdonlyres/2C76FCAF-DD71-41CE-AB1A-998A41464B84/0/antigenAntibodyComplex.jpg)
Antigen-antibody complexes can become trapped in, and damage, the kidneys and other organs. View credit information.
AIDS Virus
![Virus DNA infects cell DNA within a T cell, with new AIDS virus budding from the T cell, virus components infecting the cell, and a new virus created from the buds.](https://webarchive.library.unt.edu/eot2008/20090511012732im_/http://www3.niaid.nih.gov/NR/rdonlyres/D72D8221-3183-4401-A059-F097FAD21528/0/aidsVirus.jpg)
The AIDS virus takes over the machinery of the T cells it infects, using the cells to make new viruses. View credit information.
back to top