title: Rapid detection of HLA-A*31:01 allele in DNA and blood samples using loop-mediated isothermal amplification.
abstract: BACKGROUND
  The human leucocyte antigen (HLA) allele, HLA-A*31:01, is a biomarker for adverse cutaneous reactions to carbamazepine, a first-line antiepileptic drug.
  
  
  OBJECTIVE
  To develop a platform that can rapidly detect the HLA-A*31:01 allele in blood samples to facilitate pretreatment screening.
  
  
  METHODS
  A novel protocol based on loop-mediated isothermal amplification (LAMP) was designed and optimized. It was applied to purified genomic DNA samples derived from B-cell lines with known HLA genotypes, and to DNA and whole blood samples collected from patients with epilepsy, in whom HLA-A genotypes were determined by sequence-based typing.
  
  
  RESULTS
  The turnaround time for the LAMP-based protocol was < 45 min. In the DNA samples derived from B-cell lines (n = 66), the sensitivity, specificity, positive predictive value and negative predictive value of the LAMP-based protocol for detecting HLA-A*31:01 were 1·00 [95% confidence interval (CI) 0·88-1·00], 0·95 (95% CI 0·82-0·99), 0·94 and 1·00, respectively. The LAMP-based protocol produced the same results in the DNA and whole blood samples collected from patients (n = 34). Its sensitivity, specificity, positive predictive value and negative predictive value in detecting HLA-A*31:01 in the patient samples were 1·00 (95% CI 0·57-1·00), 0·97 (95% CI 0·83-0·99), 0·83 and 1·00, respectively.
  
  
  CONCLUSIONS
  The findings demonstrated the feasibility of accurately detecting HLA-A*31:01 in DNA and whole blood samples using a LAMP-based protocol. Given its rapid turnaround time, this novel platform has the potential to be adapted into a point-of-care screening test.
authors.affiliation: Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong SAR, China.
authors.forename: Y K
authors.initials: YK
authors.lastname: Cheung
authors.forename: M
authors.initials: M
authors.lastname: Kwok
authors.forename: E
authors.initials: E
authors.lastname: Chan
authors.forename: P
authors.initials: P
authors.lastname: Kwan
mesh_terms: D000483:Alleles; D000927:Anticonvulsants / Q000009:adverse effects*; D015415:Biomarkers / Q000032:analysis / Q000097:blood; D002220:Carbamazepine / Q000009:adverse effects*; D002460:Cell Line; D004247:DNA / Q000032:analysis*; D003875:Drug Eruptions / Q000175:diagnosis; D042241:Early Diagnosis; D004827:Epilepsy / Q000188:drug therapy; D005240:Feasibility Studies; D006580:Genetic Carrier Screening / Q000379:methods; D015234:HLA-A Antigens / Q000032:analysis* / Q000097:blood / Q000235:genetics; D006801:Humans; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D019095:Point-of-Care Systems; D012680:Sensitivity and Specificity
chemical_list: D000927:Anticonvulsants; D015415:Biomarkers; D015234:HLA-A Antigens; C069527:HLA-A31 antigen; D002220:Carbamazepine; D004247:DNA