You plan to start allopurinol in a 66-year-old man of Han Chinese ethnicity with tophaceous gout and eGFR of 34 mL/min/1.73 m2. According to ACR guidance, which step should be taken before initiating therapy because of his ancestry and renal function?
- A Administer a test dose of intramuscular corticotropin
- B Screen for the HLA-B*58:01 allele ✓
- C Confirm a normal serum IgE level
- D Perform HLA-B*15:02 genotyping
Correct answer: B. Screen for the HLA-B*58:01 allele
Explanation
Allopurinol hypersensitivity syndrome, comprising Stevens-Johnson syndrome, toxic epidermal necrolysis and DRESS, is strongly associated with the HLA-A*58:01 allele, whose carrier rate is highest in Han Chinese, Korean and Thai populations. ACR guidance recommends considering testing in these groups, particularly when renal impairment raises the risk. HLA-A*15:02 predicts carbamazepine-induced reactions, and there is no role for corticotropin test doses or IgE screening in preventing allopurinol hypersensitivity.
Reference: Katzung's Basic and Clinical Pharmacology, 15th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.