Human leukocyte antigen B*40:01 (HLA-B*40:01)

HLA-B*40:01 is a specific allele of the Human Leukocyte Antigen B (HLA-B) gene, which encodes a Major Histocompatibility Complex (MHC) class I molecule (MedlinePlus, 2022). This protein is expressed on the surface of almost all nucleated cells and plays a fundamental role in the immune system by presenting endogenous peptides to CD8+ cytotoxic T cells (NIH, 2022). HLA-B*40:01 is particularly significant in pharmacogenomics and oncology; it has been identified as a protective factor against carbamazepine-induced Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) in certain populations, while also being associated with a reduced risk of NPM1-mutated Acute Myeloid Leukemia (AML), likely due to its ability to present leukemia-specific neoepitopes (NIH, 2025; Karger, 2016). In the context of HIV treatment, the presence of this allele has been linked to the efficacy of antiretroviral regimens containing drugs like nevirapine and stavudine (ClinPGx, 2024). Furthermore, HLA-B*40:01 is a target for novel immunotherapies, such as TCR-engineered T cells, which aim to exploit its antigen-presenting capabilities to treat malignancies (NIH, 2012). Its role in drug hypersensitivity and anti-tumor immunity makes it a critical biomarker for personalized medicine.

Other names

HLA-B40HLA-B60B*40:01B*4001MHC class I antigen B*40:01B60 antigen

Antigen presentation of endogenous or drug-modified peptides to CD8+ T-cell receptors; Non-covalent binding of small molecule drugs to the antigen-presenting groove (p-i mechanism)