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Human leukocyte antigen B (HLA-B) 57:01

The HLA-B is a gene that is involved in your immune system.  More than 1000 versions (or variants) exist for the HLA-B gene, and each one is identified by a series of numbers.  One of these variants, HLA-B*57:01 is relatively uncommon, but when a patient with that variant is exposed to the medication abacavir, there is a high risk of developing a skin reaction to abacavir.  This skin reaction is also known as a “hypersensitivity reaction.” 

People are classified into 2 categories based on whether or not they have inherited the HLA-B*57:01 variant.

Priority HLA-B genotype

  • HLA-B*57:01 positive – These patients have inherited at least one HLA-B*57:01 variant.  The HLA-B*57:01 variant occurs in about 6% of individuals of European or Asian descent.
    • Drugs that may need to be avoided or have their doses decreased:
      • Abacavir is an anti-viral medication used in the treatment of HIV infections.  Abacavir should be avoided in patients who are HLA-B*57:01 positive because of the increased risk of developing skin hypersensitivity reactions. 

Routine HLA-B genotype.  Most medicines don’t need to be adjusted based on the following genotypes:

  • HLA-B*57:01 negative – These patients have not inherited one of the HLA-B*57:01 variants.  For these patients, there is no need to avoid any medicines based on HLA-B*57:01 status alone.

More information for healthcare professionals

Legal Disclaimer: This page is intended to provide implementers with guidance on establishing a clinical pharmacogenetic program at their institution. Information contained on this page is for information and educational purposes only. Although reasonable efforts have been made to ensure that the information provided on this page is current, complete and, where appropriate, based on scientific evidence, St. Jude Children's Research Hospital makes no assurances as to whether the provided information will at all times be current or complete. St. Jude Children's Research Hospital, in offering this document, is not providing medical advice or offering a consultative opinion, and is not establishing a treatment relationship with any given individual. You, therefore, should not substitute information contained herein for your own professional judgment, nor should you rely on information provided herein in rendering a diagnosis or choosing a course of treatment for a particular individual.