Delayed Hypersensitivity Testing (DHT) Flashcards
Throughout your body you have a large amount of ________ that are able to recognize many different antigens in your body.
T cells
Healthy people will normally react to how many of the DHT antigens?
At least one of the two antigens.
Name the 5 indications for a physician to order a delayed hypersensitivity skin testing?
Assess the immunocompetence of malnourished patients to determine risk of sepsis and mortality.
In pre and post- surgery patients to assess their immune system to determine risk of sepsis and mortality.
In medical subspecialties to assess candidates for specific immunosuppressive medications or chemotherapy.
For clinical staging of patients infected with HIV.
To evaluate cell-mediated immunity in patients with possible immunodeficiency.
What are the possible causes of false negative reactions?
The patients was never exposed/infected with the antigen.
Patients is too old or too young.
Patient has a viral infection.
Patient has a suppressed immune system.
The DHT antigen solutions are weak or outdated.
Improper placement of antigen by placing it too deep.
Recent live virus vaccines.
What are 4 reasons for getting false positive reactions?
Patients scratched/rubbed/agitated the area.
Patient applied lotions or soaps.
Patient applied cologne or perfumes.
The wrong diluent was used when preparing antigen.
What the strengths used in a first strength anergy panel?
20 PNU
What are the strengths used in a second strength anergy panel?
200 PNU
How far apart should the antigens be placed in DHT?
Separated by at least 5 cm.
What is the term used for the area you are measuring in a delayed hypersensitivity skin test?
Induration
What is the classification under the Gell and Coombs classification system?
Type 4 hypersensitivity reaction
