HLA-B*5701 Associated Variant Genotyping for Abacavir Sensitivity
2002429
Ordering Recommendation
Standard of care prior to abacavir therapy per FDA. Screening test to determine susceptibility to abacavir hypersensitivity syndrome.
Mnemonic
HLA-B5701
Methodology
Polymerase Chain Reaction/High Resolution Melt Analysis
Performed
Tue, Fri
Reported
4-10 days  
New York DOH Approval Status
This test is New York DOH approved.
Submit With Order
Specimen Required
Patient Preparation
  
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.  
Unacceptable Conditions
  
Remarks
  
Stability
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/High Resolution Melt Analysis.
Analytical Sensitivity and Specificity:
99 percent for prediction of HLA-B*5701 carrier status by SNP rs2395029 genotyping.
Limitations:
Diagnostic errors can occur due to rare sequence variations. 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.



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

See Compliance Statement C: www.aruplab.com/CS  
Note
 
CPT Code(s)
81381
Components
Component Test Code*Component Chart Name
2002431HLA-B*5701 Specimen
2002432HLA-B*5701 Genotyping
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • Abacavir hypersensitivity genotyping
  • Abacavir Sensitivity
  • HLA-B 5701 Genotype, Abacavir Hypersensitivity, Saliva