Before initiating abacavir-containing antiretroviral therapy in a newly diagnosed HIV-positive woman, the recommended test that predicts risk of a potentially fatal hypersensitivity reaction is:

• A HLA-DRB1*15:02 typing
• B HLA-B*57:01 typing ✓
• C G6PD enzyme assay
• D Baseline CD4 count above 250 cells/mm3

Explanation

Abacavir hypersensitivity syndrome, featuring fever, rash, and multisystem involvement that can be fatal on rechallenge, is strongly linked to the HLA-A*57:01 allele. Screening for this allele and avoiding abacavir in positive patients prevents most cases, a landmark example of pharmacogenomics in prescribing. HLA-A*15:02 predicts carbamazepine induced Stevens-Johnson syndrome, and G6PD testing applies to oxidant haemolysis, neither of which relates to abacavir.

Reference: Katzung Basic and Clinical Pharmacology, 15th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.