A 35-year-old man with newly diagnosed HIV (CD4 450 cells/µL, HIV RNA 35,000 copies/mL) is starting ART. The HLA-B*5701 test is performed before initiating which drug?
- A Efavirenz
- B Abacavir ✓
- C Tenofovir disoproxil fumarate
- D Dolutegravir
Explanation
Abacavir (ABC) can cause a potentially fatal hypersensitivity reaction (ABC HSR) in individuals carrying the HLA-B*5701 allele (present in approximately 5–8% of Caucasians, less common in Africans). The PREDICT-1 trial established that HLA-B*5701 screening before initiating abacavir eliminates immunologically confirmed ABC HSR. HLA-B*5701 testing is therefore mandatory before prescribing abacavir-containing regimens. Efavirenz is associated with CNS side effects and teratogenicity; tenofovir with nephrotoxicity; dolutegravir with neural tube defects in periconception use. None require HLA testing.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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