ARUP's Laboratory Test Directory

HLA-B*5701 Associated Variant Genotyping for Abacavir Sensitivity : 2002429

Mnemonic: HLA-B5701

Methodology: Polymerase Chain Reaction/Fluorescence Monitoring
Performed: Tue, Fri
Reported: 4-10 days
Specimen Required: Collect: Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).

Specimen Preparation: Transport 3 mL whole blood. (Min: 1 mL)

Storage/Transport Temperature: Refrigerated.

Stability (collection to initiation of testing): Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable
Reference Interval:
By report
Interpretive Data: Background Information for HLA-B*5701 Associated Variant Genotyping for Abacavir Sensitivity:
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.
Incidence: HLA-B*5701 allele frequency varies by ethnicity: Indian 0.20, Thai 0.11, Caucasian 0.08, African American 0.02, Asian (rare).
Inheritance: Autosomal dominant.
Penetrance: 98 percent.
Cause: Abacavir hypersensitivity is strongly associated with the HLA-B*5701 allele. The mechanism is related to drug-specific activation of T lymphocyte killer cells.
Variant Tested: Single nucleotide polymorphism (SNP) rs2395029 in the HCP5 gene which is in linkage disequilibrium with HLA-B*5701.
Clinical Sensitivity and Specificity: 98 and 99 percent respectively, for immunologically confirmed hypersensitivity reaction.
Methodology: Polymerase chain reaction and fluorescence monitoring.
Analytical Sensitivity and Specificity: 99 percent for prediction of HLA-B*5701 carrier status by SNP rs2395029 genotyping.
Limitations: Rare diagnostic errors may occur due to primer site mutations. Rare recombination events between HCP5 SNP rs2395029 and HLA-B*5701 may occur. Alleles other than HLA-B*5701 will not be evaluated. Non-genetic factors that may affect drug sensitivity are not identified.

This test is performed pursuant to an agreement with Roche Molecular Systems, Inc.



Counseling and informed consent are recommended for genetic testing. Consent forms are available online at www.aruplab.com.

Refer to Statement C under Testing Information at http://www.aruplab.com.
CPT Code(s): 83891 Isolation; 83898 Amplification; 83896 x2 Nucleic acid probe; 83912 Interpretation and report - Additional CPT code modifiers may be required for procedures performed to test for oncologic or inherited disorders.
Cross References: Abacavir Sensitivity (HLA-B*5701 Associated Variant Genotyping for Abacavir Sensitivity)
 
 

 

 

 
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