Before starting allopurinol in a patient of Han Chinese descent, screening for which HLA allele is recommended to predict the risk of severe cutaneous adverse reactions such as Stevens-Johnson syndrome and toxic epidermal necrolysis?
- A HLA-B*1502
- B HLA-B*5701
- C HLA-B*5801 ✓
- D HLA-DQB1*0602
Correct answer: C. HLA-B*5801
Explanation
HLA-B*5801 is strongly associated with allopurinol hypersensitivity syndrome, including SJS, TEN and DRESS, particularly in Han Chinese, Thai and Korean populations, so testing is advised before starting the drug in these groups. HLA-B*1502 predicts carbamazepine-induced SJS, HLA-B*5701 predicts abacavir hypersensitivity, and HLA-DQB1*0602 relates to narcolepsy risk, making these the standard distractor alleles.
Reference: Goodman and Gilman's The Pharmacological Basis of Therapeutics, 13th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.