Association of HLA-B*1502 allele with carbamazepine-induced toxic epidermal necrolysis and Stevens-Johnson syndrome in the multi-ethnic Malaysian population.

Background: Carbamazepine (CBZ), a frequently used anticonvulsant drug, is one of the most common causes of life-threatening cutaneous adverse drug reactions such as toxic epidermal necrolysis (TEN) and Stevens-Johnson syndrome (SJS). Recent studies have revealed a strong association between HLA-B*1502 and CBZ-induced TEN/SJS in the Taiwan Han Chinese population.

Objectives: This study is aimed to investigate the association between human leucocyte antigens (HLA) and CBZ-induced TEN/SJS in the multi-ethnic Malaysian population.

Methods: A sample of 21 unrelated patients with CBZ-induced TEN/SJS and 300 race-matched, healthy controls were genotyped for HLA-A, -B and -DR using polymerase chain reaction (PCR). Allele frequencies were compared.

Results: HLA-B*1502 was present in 75.0% (12/16) of Malay patients with CBZ-induced TEN/SJS but in only 15.7% (47/300) of normal controls (odds ratio 16.15, 95% confidence interval 4.57-62.4; corrected P-value  = 7.87 × 10(-6) ), which suggests a strong association between HLA and CBZ-induced TEN/SJS. Additionally, HLA-B*1502 was found in all three Chinese and two Indian patients. Existing data show that frequencies of the HLA-B*1502 allele are generally much higher in Asian populations than in White European populations, which explains the higher incidences of SJS and TEN in Asian countries.

Conclusions: HLA-B*1502 is strongly associated with CBZ-induced TEN/SJS in the Malay population in Malaysia, as has been seen in Han Chinese in Taiwan. This indicates that the genetic association apparent in the incidence of CBZ-induced TEN/SJS is linked with the presence of HLA-B*1502, irrespective of racial origin. Screening of patients for this genetic marker can help to prevent the occurrence of TEN/SJS.