HLA-B*5801 Genotype, Allopurinol Hypersensitivity, Varies
Use
The identification of individuals carrying the HLA-B*58:01 allele allows healthcare providers to assess the risk of severe cutaneous adverse reactions (SCAR) associated with allopurinol treatment. Allopurinol is prescribed for conditions such as gout, Lesch-Nyhan syndrome, and recurrent urate kidney stones, but it can pose a significant risk of SCAR in individuals with this allele. Genotyping for HLA-B*58:01 is recommended for those vulnerable ethnic groups, such as Han Chinese, Korean, Thai, and African American patients, prior to initiating allopurinol treatment, to avoid these severe reactions.
Special Instructions
Informed consent is required for New York clients. The test can be performed on specimens such as whole blood or saliva, and special handling is required for cord blood with maternal specimen to check for maternal cell contamination. Thus, a maternal blood sample is needed if testing cord blood for accurate results.
Limitations
The test may not accurately reflect the recipient's genotype if the specimen was obtained from a patient who received a non-leukoreduced blood transfusion or allogeneic transplant. The assay might detect other rare alleles and may fail if the extracted DNA does not meet the necessary quality or quantity, especially for saliva samples. Alternatively, specific gene regions that could not be analyzed will be reported. The impact of stem cell or liver transplantation on SCAR risk is not defined.
New York Approved
Methodology
PCR-based (Real-Time PCR)
Biomarkers
LOINC Codes
- 79711-8
- 79711-8
- 93308-5
- 69047-9
- 48767-8
- 85069-3
- 62364-5
- 18771-6
Result Turnaround Time
3-5 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
3 mL
Minimum Volume
Not provided
Container
Lavender top (EDTA)
Collection Instructions
Invert several times to mix blood. Send whole blood specimen in original tube. Do not aliquot. Whole blood from umbilical cord is acceptable.
Patient Preparation
A previous hematopoietic stem cell transplant or liver transplant from an allogenic donor will interfere with testing.
Storage Instructions
Specimens are preferred to be received within 4 days of collection. Ambient (preferred) 4 days/Refrigerated 4 days/Frozen 4 days.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 4 days |
| Refrigerated | 4 days |
| Frozen | 4 days |