Association between HLA-B Alleles and Carbamazepine-Induced Maculopapular Exanthema and Severe Cutaneous Reactions in Thai Patients

The HLA-B∗15:02 allele has been reported to have a strong association with carbamazepine-induced Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) in Thai patients. The HLA-B alleles associated with carbamazepine-induced maculopapular exanthema (MPE) and the drug reaction with eosinophilia and systemic symptoms (DRESS) among the Thai population have never been reported. The aim of the present study was to carry out an analysis of the involvement of HLA-B alleles in carbamazepine-induced cutaneous adverse drug reactions (cADRs) in the Thai population. A case-control study was performed by genotyping the HLA-B alleles of Thai carbamazepine-induced hypersensitivity reaction patients (17 MPE, 16 SJS/TEN, and 5 DRESS) and 271 carbamazepine-tolerant controls. We also recruited 470 healthy Thai candidate subjects who had not taken carbamazepine. HLA-B∗15:02 showed a significant association with carbamazepine-induced MPE (P=0.0022, odds ratio (OR) (95% confidence interval [CI]) = 7.27 (2.04–25.97)) and carbamazepine-induced SJS/TEN (P=4.46×10−13; OR (95% CI) = 70.91(19.67–255.65)) when compared with carbamazepine-tolerant controls. Carbamazepine-induced SJS/TEN also showed an association with HLA-B∗15:21 allele (P=0.013; OR (95% CI) = 9.54 (1.61–56.57)) when compared with carbamazepine-tolerant controls. HLA-B∗58:01 allele was significantly related to carbamazepine-induced MPE (P=0.007; OR (95% CI) = 4.73 (1.53–14.66)) and DRESS (P=0.0315; OR (95% CI) = 7.55 (1.20–47.58)) when compared with carbamazepine-tolerant controls. These alleles may serve as markers to predict carbamazepine-induced cADRs in the Thai population.