HLA-B48
HLA-B48 is a human leukocyte antigen (HLA) serotype within the HLA-B locus. The HLA system, also known as the major histocompatibility complex (MHC) in humans, is a gene family located on chromosome 6 that plays a crucial role in the immune system. Specifically, HLA-B48 is a Class I MHC antigen.
Class I MHC molecules are expressed on the surface of nearly all nucleated cells in the body. Their primary function is to present peptide fragments derived from intracellular proteins to cytotoxic T lymphocytes (CTLs, also known as CD8+ T cells). If a presented peptide is recognized as foreign (e.g., derived from a virus or cancer cell), the CTL will initiate an immune response to eliminate the cell.
HLA-B48, like other HLA alleles, is highly polymorphic, meaning there are many different versions (alleles) of the gene within the human population. This polymorphism is crucial for providing a broad range of peptide-binding specificities, enabling the immune system to recognize and respond to a diverse array of pathogens. Specific HLA-B48 alleles may be associated with susceptibility or resistance to certain diseases, including autoimmune disorders and infectious diseases. The association arises because different HLA-B48 variants present different peptides with varying affinity, affecting T cell activation and the overall immune response.
Genetic testing for HLA-B48 and other HLA alleles is used in various clinical settings, including:
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Transplantation: HLA matching is essential for organ and bone marrow transplantation to minimize the risk of graft rejection.
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Disease Association Studies: Researchers investigate the association of specific HLA alleles with various diseases to understand their role in disease pathogenesis.
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Drug Hypersensitivity: Certain HLA alleles are strongly associated with severe adverse drug reactions, allowing for preemptive genetic screening before drug administration.
The precise function and clinical significance of specific HLA-B48 alleles are continually being researched and refined.