Patients on long term treatment for epilepsy with carbamazepine, need HLA-B1502 allele screening in order to avert Steven Johnson Syndrome.

Team@CMHF

Recent studies associated the HLA-B allele with carbamazepine (CBZ)-induced Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) in patients from China, Thailand and Malaysia. No association has been found in patients from Europe or Japan. Linkage summary reports from East and South-east Asia predict a highly significant odds ratio (OR) with sensitivity and negative predictive values of 92% and 98%, respectively. The higher prevalence of HLA-B(∗)1502 allele among certain Asian populations (10-15%) compared to Caucasians (1-2%) may explain a 10-fold to 25-fold higher incidence of CBZ-SJS/TEN in patients from Asia. Screening for HLA-B(∗)1502 before using CBZ can prevent SJS/TEN in certain populations, but screening may be less beneficial in populations with low HLA-B(∗)1502 allele frequency and in patients exposed to CBZ for more than 2 months. A retrospective study demonstrated that the costs of HLA-B(∗)1502 screening were less than those of SJS treatment. This article reviews possible benefits and concerns of HLA-B(∗)1502 screening in clinical practice.
Ref: http://www.docguide.com/pharmacogenetic-screening-carbamazepine-induced-severe-cutaneous-allergic-reactions?hash=80445d1a&eid=21468&alrhash=2efbb8-880279c42369cc2f8adcb48a6daaf3d2