Which HLA allele has been linked to an increased risk of hypersensitivity to abacavir?

HLA-B*5701 is the allele specifically associated with an increased risk of hypersensitivity reactions to abacavir, an antiretroviral medication used primarily in the treatment of HIV infection. Individuals who carry this allele have a significantly greater likelihood of experiencing serious hypersensitivity reactions, which can include symptoms such as fever, rash, gastrointestinal issues, and respiratory difficulties.

This link is clinically important, as screening for HLA-B*5701 before starting abacavir therapy is recommended to prevent these potentially life-threatening reactions. Pharmacogenetic testing for this allele has become an integral part of HIV management, allowing healthcare providers to tailor treatment plans effectively and enhance patient safety.

In contrast, other HLA alleles mentioned do not have a specific association with abacavir hypersensitivity in the same well-documented manner. Each of those alleles is linked to different conditions or drug responses but does not play a role in the hypersensitivity reactions induced by abacavir. Hence, HLA-B*5701 is identified as the crucial genetic marker in this context.