Also known as: B5701« Back to test list
A specific variant of the human leukocyte antigen B57, HLA-B*57:01, is associated with severe cutaneous adverse reactions (SCAR) to the medication, abacavir.
Abacavir must never be prescribed to a patient with HLA*B57:01. Patients must be screened for this variant before being commenced on abacavir.
This test has a role in identifying patients who may benefit from avoiding a specific drug or dose, but it provides little useful information for people (including relatives) who are not taking the medications of concern. Testing of relatives is generally not recommended.
If a person has this variant, the risk of developing a severe cutaneous adverse reaction (SCAR) to abacavir is approximately 99.9%. If a person does not have this specific variant, the risk of SCAR is negligible.
Abacavir must never be prescribed to a patient with HLA*B57:01. Patients must be screened for this before being commenced on abacavir.
Analysis of the gene sequence of the HLA-B genes for the presence of this specific variant.
This test can be requested by any medical practitioner.
5 mL blood in EDTA. Specimens may be collected by the requesting practitioner or at any Sonic Healthcare pathology collection centre.
To help ensure the quality of the test, a genetic test should be done with a dedicated sample whenever possible i.e. a sample collected specifically for that test rather than a sample that is used for multiple tests.
We also recommend that the patient or another adult check the labelling of request forms and sample tubes.