Standard of care prior to abacavir therapy per FDA. Predict risk of abacavir hypersensitivity syndrome. Relevant to most populations.
- Patient Preparation
- Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).
- Specimen Preparation
- Transport 3 mL whole blood. (Min: 1 mL)
- Storage/Transport Temperature
- Unacceptable Conditions
- Plasma or serum. Heparinized specimens.
- Ambient: 72 hours; Refrigerated: 2 weeks; Frozen: 1 month.
Characteristics: Abacavir sulfate is a nucleoside reverse transcriptase inhibitor (NRTI) used for the treatment of HIV.
Abacavir hypersensitivity reaction is characterized by fever, rash, malaise, gastrointestinal, and respiratory symptoms.
Symptoms typically appear within the first six weeks of treatment, worsen with each subsequent abacavir dose, and may be severe or fatal.
Inheritance: Autosomal dominant.
Cause: Abacavir hypersensitivity is strongly associated with the HLA-B*57:01 allele. The mechanism is related to drug-specific activation of T lymphocyte killer cells.
Allele Tested: Presence or absence of the HLA-B*57:01 allele.
Allele Frequency: Southwest Asian 11 percent, Other Asian 0-6.7 percent, European 6.8 percent, South American 2.6 percent, Middle Eastern 2.5 percent, Mexican 2.2 percent, African 1 percent.
Clinical Sensitivity: 100 percent for immunologically confirmed hypersensitivity reaction.
Methodology: Polymerase Chain Reaction (PCR) and Fluorescence Monitoring.
Analytical Sensitivity and Specificity: Greater than 99 percent.
Limitations: Alleles other than HLA-B*57:01 will not be evaluated. This test does not distinguish between heterozygote and homozygote carriers. Diagnostic errors can occur due to rare sequence variations. Risk of therapeutic failure or adverse reactions with abacavir may be affected by genetic and non-genetic factors that are not detected by this test. This result does not replace the need for therapeutic drug or clinical monitoring.
Counseling and informed consent are recommended for genetic testing. Consent forms are available online.
|Component Test Code*||Component Chart Name||LOINC|
- Abacavir hypersensitivity genotyping
- Abacavir Sensitivity
- HLA-B 5701 Genotype, Abacavir Hypersensitivity, Saliva