An Immunology Instant
Bio 344 Immunology
brought to you by ____________________________
Name of condition, disease, or immunodeficiency:
Is this a genetic or acquired deficiency? If genetic, is it a dominant or recessive mutation?
What immunological process is disrupted or altered (Give the main hypothesis if cause
unknown)?
What main molecules/interactions are affected?
What are the symptoms of the disease?
What tests are used to diagnose the disease?
Treatment and/or vaccine:
Most interesting fact you learned about this condition:
An Immunology Instant
Bio 344 Immunology
brought to you by Christine White-Ziegler
Name of condition, disease, or immunodeficiency: Atopic dermatitis (AD)
Is this a genetic or acquired deficiency? If genetic, is it a dominant or recessive mutation?
There is probably a genetic link as patients with AD have increased serum levels of IgE and are
deficient in a cell-mediated TH1 response.
What immunological process is disrupted or altered:
Patients have both IgE and Th2 cells specific for the allergen. Allergen at the site of entry causes
cytokines to be released, either by action of allergen on immune cells (mast cells through IgE,
antigen-specific T cells) or from damaged keratinocytes (usually due to itching). Drawn by
chemokines secreted at site of allergen, allergen-specific TH2 cells home to the site of the
allergen. Cytokines produced by these TH2 cells recruit more antigen-specific cells and effector
cells (eosinophils, macrophages) to site. Effector cells degranulate, causing tissue damage and an
inflammatory response. Thus, the antigen-specific TH2 cells prolong the inflammatory response
by causing continued activation of these effector cells.
What main molecules/interactions are affected: Patients have allergen-specific TH2 cells that
prolong the inflammatory response. Increased serum IgE levels are observed and a decreased
TH1 response.
TH2 cells secrete cytokines prolong and amplify the inflammatory response. IL-5 induces the
differentiation and survival of eosinophils. IL-4 made by TH2 cells stimulates IgE isotype
switching and induces differentiation of naïve T cells to become TH2 cells.
What are the symptoms of the disease? Eczema is the main sympton, a chronic itchy,
inflammatory response, leading to local tissue damage. On the skin, a rash develops with open
lesions, itching, redness, and swelling. Symptoms can vary by route of allergen entry.
What tests are used to diagnose the disease: Besides the symptoms, patients are tested for
common allergen sensitivities as these are usually associated with AD. Also, IgE serum levels
are elevated and increase eosinophils in the blood.
Treatment and/or vaccine: Skin lotions to retain moisture, avoidance of substances that
irritatie/disrupt skin barrier (soaps,fabrics), steroidal cream that suppresses inflammatory
response, antihistamine to reduce itching.
Most interesting fact you learned about this condition:
It has been 40 years since a new class of topical medications specifically for this disease has been
introduced. However, a new class of drugs called topical immunomodulators (TIMs) will soon
be available that show promise in the treatment of moderately severe eczema. Two TIMs in
development, tacrolimus and ascomycin, are steroid-free. Tacrolimus is likely to be the first TIM
approved and available in the United States. Studies have shown that this new class of drugs will
improve or completely clear eczema in more than 80 percent of treated patients, with an
improved side-effect profile compared with topical steroids.