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HLA-B*5701 Typing

HLA-B*5701 Typing

Test Highlight

HLA-B*5701 Typing


Clinical Use

  • Guide selection of antiretroviral drugs

  • Assess risk of hypersensitivity reaction to abacavir therapy

Clinical Background

Abacavir therapy is used to treat patients with HIV infection; however, it is associated with significant risk (2% to 9% of cases) of hypersensitivity reaction.1 Such reactions are typically characterized by skin rash, fever, malaise, nausea and other gastrointestinal symptoms, dyspnea, cough, and other respiratory symptoms. Life-threatening symptoms occur with less frequency and may include anaphylaxis and liver, kidney, or respiratory failure.1

Researchers have confirmed that a specific human genetic variation, known as HLA-B*5701, is associated with susceptibility to abacavir hypersensitivity.2,3 Pharmacogenetic screening for the HLA-B*5701 allele is recommended for abacavir-naïve patients and before reinitiation of abacavir treatment.1,4-7 Selection of a non-abacavir regimen would then be recommended for patients with the HLA-B*5701 allele.

Thus, HLA-B*5701 testing has the potential to significantly improve patient care by allowing for a more informed use of abacavir treatment.8


This test uses polymerase chain reaction (PCR) followed by hybridization with sequence-specific oligonucleotide probes to detect the HLA-B*5701 allele.

Interpretive Information

Presence of the HLA-B*5701 allele indicates that the patient is at high risk of abacavir hypersensitivity reaction1 and that abacavir should not be prescribed.7 Testing should only be performed once, and results should be documented in the patient’s medical record.


  1. Ziagen® [prescribing information]. Research Triangle Park, NC: GlaxoSmithKline; 2008.

  2. Mallal S, Nolan D, Witt C, et al. Association between presence of HLA-B*5701, HLA-DR7, and HLA-DQ3 and hypersensitivity to HIV-1 reverse-transcriptase inhibitor abacavir. Lancet. 2002;359:727-732.

  3. Rauch A, Nolan D, Martin A, et al. Prospective genetic screening decreases the incidence of abacavir hypersensitivity reactions in the Western Australian HIV cohort study. Clin Inf Dis. 2006;43:99-102.

  4. FDA Alert [7/24/2008]. Information on Abacavir (marketed as Ziagen) and abacavir-containing medications. Available at: http://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/

ucm094302.htm. Accessed June 19, 2009.

  1. Mallal, S, Phillips E, Carosi G, et al. HLA-B*5701 screening for hypersensitivity to abacavir. N Engl J Med. 2008;358:568-579.

  2. Saag M, Balu R, Phillips E, et al. High sensitivity of human leukocyte antigen-b*5701 as a marker for immunologically confirmed abacavir hypersensitivity in white and black patients. Clin Infect Dis. 2008;46:1111-1118.

  3. Panel on Antiretroviral Guidelines for Adults and Adolescents.Guidelines for the use of antiretroviral agents in HIV-1-infected adults and adolescents.Department of Health and Human Services. February 12, 2013. http://aidsinfo.nih.gov/contentfiles/lvguidelines/adultandadolescentgl.pdf. Accessed May 1, 2013.

  4. Phillips EJ. Genetic screening to prevent abacavir hypersensitivity reaction: are we there yet? Clin Inf Dis. 2006;43:103-105.

Content reviewed 07/2013

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