HLA-B15:02

HLA-B15:02
Identifiers
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HLA-B15:02 is a specific allele of the HLA-B gene, which is part of the human Major Histocompatibility Complex (MHC) class I molecules. These molecules play a critical role in the immune system by presenting peptide antigens to T cells.

Structure and Function

HLA-B15:02 is a variant of the HLA-B gene, which encodes a protein that is expressed on the surface of almost all nucleated cells. The primary function of HLA-B15:02, like other HLA class I molecules, is to present endogenous peptides, typically derived from proteins synthesized within the cell, to CD8+ T cells. This presentation is crucial for the immune system's ability to recognize and eliminate infected or malignant cells.

Clinical Significance

HLA-B15:02 is most notably associated with an increased risk of severe cutaneous adverse reactions (SCARs) to certain medications, particularly carbamazepine. Individuals carrying the HLA-B15:02 allele are at a significantly higher risk of developing Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) when treated with carbamazepine. This association is particularly prevalent in certain Asian populations, where the allele frequency is higher.

Pharmacogenomics

Due to the strong association between HLA-B15:02 and adverse drug reactions, genetic testing for this allele is recommended before initiating carbamazepine therapy in individuals of Asian descent. This is an example of pharmacogenomics, where genetic information is used to guide drug therapy to improve safety and efficacy.

Population Genetics

The frequency of the HLA-B15:02 allele varies significantly among different populations. It is most commonly found in Southeast Asian populations, including Han Chinese, Thai, and Malaysian individuals. The allele is rare in European and African populations.

Research and Future Directions

Ongoing research is focused on understanding the molecular mechanisms by which HLA-B15:02 contributes to drug hypersensitivity. Studies are also exploring the potential for developing alternative therapies that do not trigger adverse reactions in individuals with this allele.

Also see

• HLA-B
• Major Histocompatibility Complex (MHC)
• Stevens-Johnson syndrome
• Toxic epidermal necrolysis
• Pharmacogenomics