Skip to content

HLA-B*57:01 Genotype

Published: July 27, 2026Updated: August 25, 2026

The HLA-B*57:01 genotype is a genetic marker used to predict adverse reactions to certain medications, such as abacavir in HIV treatment.

Quick summary

HLA-B*57:01 predicts hypersensitivity reactions to specific drugs like abacavir.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 25, 2026Editorial policy

Key facts at a glance

Units
genotype
Clinical utility
predictive
Result kind
qualitative
FDA-cleared
Roche HLA-B*5701, Abbott HLA-B*5701, Thermo Fisher HLA-B*5701
interpretation: {"text":"The patient does not carry the HLA-B*57:01 allele and is at low risk for hypersensitivity reactions to abacavir.","label":"0–0 (Negative)"}; {"text":"The patient carries the HLA-B*57:01 allele and is at high risk for hypersensitivity reactions to abacavir.","label":"1–1 or 1–0 (Positive)"}

The HLA-B*57:01 allele is a genetic variant of the Human Leukocyte Antigen (HLA) system, which plays a crucial role in the immune response. This biomarker is particularly important in pharmacogenomics for its association with hypersensitivity reactions to specific drugs.

Testing for HLA-B*57:01 is essential before initiating treatment with abacavir, an antiretroviral medication used in HIV therapy. Patients who are positive for this allele have a significantly higher risk of developing a severe hypersensitivity reaction to the drug.

Identifying the HLA-B*57:01 genotype prior to drug administration allows for personalized treatment plans, thereby preventing potential adverse events and improving patient safety and treatment outcomes.

Frequently asked questions

What is the significance of the HLA-B*57:01 test?
The test is crucial for identifying patients at risk of severe hypersensitivity reactions to abacavir, an antiretroviral medication used in HIV treatment.
How is the HLA-B*57:01 test performed?
The test is typically performed using genetic sequencing or PCR-based methods on a blood or saliva sample.
  1. 1
    Clinical Pharmacogenetics Implementation Consortium (CPIC) Guidelines for HLA-B Genotype and Abacavir DosingSource
  2. 2
    FDA Drug Safety Communication: Abacavir and HLA-B*5701 TestingSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 25, 2026. · Read our editorial policy