Test Catalog

Test

Code
X970
Name
HLA-B5801 BY PCR
Notes
Description

Also known as: X970, HLA-B*5801, HLAB58, HLA-B58, Allopurinol
Orderable Code: X970
Test Contains (LOINC): HLA-B5801 by PCR (79711-8)
Sample Type: Whole Blood
Preferred Container: EDTA (Lavender Top) Tube
Sample Volume: 3.0 mL
Minimal Sample Volume: 1.0 mL minimum, does not allow for repeat testing
Handling Instructions: Refrigerate specimen after collection.
Client Transport Temperature: Refrigerated
Specimen Stability: Ambient: 7 Days; Refrigerated: 1 Month; Frozen: 1 Month
Unsuitable Specimen: Heparinized specimens.
Frequency: Monday, Wednesday, Friday
Expected Turn Around: 6 – 8 Days
Responsible Dept: Reference Lab
Referral Lab: SRL
Referral Lab Code: X970
CPT: 81380
Methodology: PCR and sequence specific oligonucleotide (SSO) probes
ADDITIONAL INFORMATION
Allopurinol is a widely used drug for hyperuricemia-related diseases such as gout, recurrent urate kidney stones, and Lesch-Nyhan syndrome. Allopurinol is one of the most common causes of severe cutaneous adverse reactions (SCAR), which encompasses drug hypersensitivity syndrome, Stevens-Johnson syndrome (SJS), and toxic epidermal necrolysis (TEN). These reactions have a reported mortality of up to 25% or greater. In individuals taking allopurinol, the presence of the HLA-B*58:01 allele has been strongly associated with allopurinol-induced SCAR. Frequency of the HLA-B*58:01 allele varies with ethnicity, with a frequency of 6% to 7% in Asian populations (particularly higher in southeast Asians), and approximately 1% in Caucasian populations. Guidelines from the Clinical Pharmacogenomics Implementation Consortium (CPIC) recommend HLA-B*58:01 genotyping be performed when considering prescribing allopurinol, and that allopurinol should not be prescribed to patients who test positive for the allele due to the increased risk of SCAR. In addition, guidelines developed by the 2012 American College of Rheumatology for Management of Gout also recommend that HLA-B*58:01 testing should be considered in select patient subpopulations at an elevated risk for allopurinol-induced SCAR. REFERENCES: Saito Y, Stamp L, Caudle K, et al: Clinical Pharmacogenetics Implementation Consortium (CPIC) guidelines for human leukocyte antigen B (HLA-B) genotype and allopurinol dosing: 2015 update. Clin Pharmacol Ther. 2016; 99(1): 36-7 Khanna D, Fitzgerald J, Khanna P, et al: 2012 American College of Rheumatology guidelines for management of gout. Part 1: systematic nonpharmacologic and pharmacologic therapeutic approaches to hyperuricemia. Arthritis Care Res. 2012; 64:1431-1446 Hershfield MS, Callaghan JT, Tassaneeyakul W, et al: Clinical Pharmacogenetics Implementation Consortium guidelines for human leukocyte antigen-B genotype and allopurinol dosing. Clin Pharmacol Ther. 2013; 93(2):153-158
Compliance Statement
FDA cleared or approved assay