HLA-B*58:01 Genotyping, Allopurinol Hypersensitivity
Also known as: HLA B5801
Use
The HLA-B*58:01 genotyping test is designed to identify patients at increased risk for severe cutaneous adverse reactions (SCAR) to allopurinol, a drug commonly used to treat hyperuricemia and gout. SCAR includes conditions like Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), which can be life-threatening. The presence of the HLA-B*58:01 allele shows a strong association with allopurinol-induced SCAR, leading to recommendations for testing before initiating allopurinol therapy. Due to the severe nature of SCAR, which has a high mortality rate, identifying the allele can guide safer use of allopurinol, particularly in populations with higher allele frequencies.
Special Instructions
Not provided.
Limitations
The test only identifies the presence of the HLA-B*58:01 allele and does not provide information about other genetic or non-genetic factors influencing allopurinol hypersensitivity. Copy number variations of HLA-B*58:01 are not reported. Other rare or novel alleles may yield false positive or negative results, and additional clinical factors should be considered in conjunction with test results.
New York Approved
Methodology
PCR-based (PCR)
Biomarkers
No genes
Gene
LOINC Codes
- 79711-8 - HLA-B*58:01 Bld/T Ql
Result Turnaround Time
3-7 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
5 mL
Minimum Volume
3 mL
Container
Lavender (EDTA), Pink (K2EDTA), or Yellow (ACD Solution A or B)
Storage Instructions
Refrigerated.
Causes for Rejection
Specimens collected in green (sodium or lithium heparin).
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 72 hours |
| Refrigerated | 1 week |
| Frozen | Unacceptable |
Other tests from different labs that may be relevant