Validation of a Rapid, Robust, Inexpensive Screening Method for Detecting the HLA-B*58:01 Allele in the Prevention of Allopurinol-Induced Severe Cutaneous Adverse Reactions

ABSTRACT

The HLA B*5801 allele has been worldwide reported as a pharmacogenetic susceptibility to allopurinol-induced severe cutaneous adverse reactions (SCARs). To prevent these life-threatening conditions, the American College of Rheumatology hingly recommended that the HLA-B*5801 be screened prior to the initiation of allopurinol therapy. Therefore, we developed a rapid, robust, inexpensive screening method using SYBR® Green real time PCR to detect the HLA-B*5801 allele. A total of 119 samples were tested. The assay has a sensitivity of 100% (95% CI 69.15%-100%), a specificity of 100% (95% CI 96.67%-100%), a positive predictive value of 100% (95% CI 69.15%-100%) and a negative predictive value of 100% (95% CI 96.67%-100%). HLA-B*5801 genotyping results showed 100% agreement with those obtained from Luminex SSO/SBT/SSP. The lowest limit of detection of this method is 0.8 ng/µL of DNA. The unit cost of the test is only $3.8 USD. This novel screening test using SYBR® real time PCR would be appropriate to identify individuals with the HLA-B*5801 allele for the prevention of allopurinol-induced SCARs.