Tuesday, December 14, 2010
7:46 AM | Posted by Shams Burki | Edit Post
A. ELISA (Enzyme-linked immunosorbent assay)
B. FACS ( Fluorescence activated cell sorting)
C. RAST (Radioallergosorbent Test)
D. RID (Radial immunodiffusion)
E. Western blot
The correct answer is E. The Western blot is the most appropriate test for confirmation of HIV infection. It identifies several different antibodies against HIV (anti- gp120, -gp41, -p24, and -p17). The initial HIV test this patient had was most likely an ELISA. The ELISA (choice A) can be used to detect p24
antibody in the patient, but is not as specific as the Western blot.
Fluorescence activated cell sorting (choice B) is a technique used to separate and count specific numbers and types of cells in a sample. An example of this would be to count the number of B cells and T cells in a specific blood sample.
RAST testing (choice C) is used to determine the level of specific IgE present in a patient that reacts with a specific allergen that has been applied to a disk or glass bead.
Radial immunodiffusion (choice D) is an excellent test used for quantitation of immunoglobulin levels in patients. This is used to determine the IgG, IgM and IgA levels in patient's serum. This test cannot be used to measure levels of IgD or IgE because these two immunoglobulins are at such low levels a more sensitive test such as RIA (radioimmunoassay) or EIA (enzyme-linked immunoassay) must be used.