Prevalence of HLA-B*1502 Allele in South Indian Epileptic and Non Epileptic Population (S26.005)

Abstract

Objective: To study the prevalence of HLA-B*1502 in epileptic South Indian population and healthy age and sex matched controls. Background Carbamazepine (CBZ) and Phenytoin (PHY) are associated with life-threatening hypersensitivity reactions like Stevens–Johnson syndrome (SJS) and Toxic Epidermal Necrolysis (TEN). Chung et al. identified an association between carbamazepine-induced SJS/TEN and HLA-B*1502. The prevalence of HLA-B*1502 in South India in epileptic and non epileptic population is reported for the first time. Design/Methods: This is a single center, prospective, cross sectional study. After an informed consent, 7 ml of blood in ethylene diamine tetra acetic acid (EDTA) was collected from 164 patients on CBZ, 78 on phenytoin and 100 healthy controls. DNA separation were done using Qiagen kits and purified DNA samples were used for HLA-B*1502 genotyping by conventional Polymerase Chain Reaction amplification and gel electrophoresis, using Olerup HLA-B*1502 kits by SSOP (Sequence Specific Oligopeptide) method. Results: There were 165 men and 177 women with a mean age of 31.83 years. 164 patients were on CBZ in whom 33 tested positive for HLA-B*1502 and 27 developed SJS. Out of 78 on PHY, 11 tested positive for HLA-B*1502 and 7 developed SJS. Seven of the 100 healthy controls tested positive for HLA-B*1502. The prevalence of HLA-B*1502 allele in the epileptic group was 18.20% compared to 7% in the non epileptic population. The Positive Predictive Value for development of SJS/TEN on exposure to CBZ and PHY were 81.81 % and 63.63 % respectively. Conclusions: There is a high prevalence HLA-B*1502 allele in South Indian epileptic population on Carbamazepine and Phenytoin (18.20 %)when compared to the non epileptic population (7 %). There is a strong association of HLA-B*1502 allele and the developmment of SJS in South Indians. It is mandatory to test for HLA-B*1502, prior to initiation of Carbamazepine and Phenytoin therapy in this population. Disclosure: Dr. Sivakumar has nothing to disclose. Dr. Venkatesan has nothing to disclose.