A patient on carbamazepine for trigeminal neuralgia develops a maculopapular rash 3 weeks after starting therapy. HLA genotyping prior to treatment could have predicted this risk. The HLA allele associated with carbamazepine-induced Stevens–Johnson syndrome in Han Chinese is:

• A HLA-A*31:01
• B HLA-B*57:01
• C HLA-B*15:02 ✓
• D HLA-DRB1*07:01

Explanation

HLA-B*15:02 is strongly associated with carbamazepine-induced Stevens–Johnson syndrome and toxic epidermal necrolysis in Han Chinese, Thai, and other Southeast Asian populations, with a very high positive predictive value. Regulatory agencies in these populations now recommend HLA-B*15:02 screening before carbamazepine initiation. HLA-A*31:01 is associated with maculopapular exanthema and DRESS from carbamazepine particularly in European and Japanese populations. HLA-B*57:01 predicts abacavir hypersensitivity. HLA-DRB1*07:01 is associated with lapatinib-induced hepatotoxicity.

Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.