HLA-B8

HLA-B8 is a human leukocyte antigen (HLA) serotype, specifically an allele of the HLA-B locus. The HLA-B locus is located within the major histocompatibility complex (MHC) on human chromosome 6. HLA-B8 is a class I MHC molecule. Class I MHC molecules present peptide fragments of intracellular proteins to cytotoxic T lymphocytes (CTLs, also known as CD8+ T cells). This interaction is crucial for immune surveillance and the elimination of cells infected with viruses or other intracellular pathogens.

The HLA-B8 antigen is associated with an increased susceptibility to a number of autoimmune diseases. These include, but are not limited to, celiac disease, dermatitis herpetiformis, primary biliary cholangitis (PBC), myasthenia gravis, and Sjögren's syndrome. The exact mechanisms by which HLA-B8 contributes to the development of these diseases are not fully understood, but are thought to involve its specific peptide-binding repertoire and its interaction with T cell receptors, potentially leading to aberrant T cell activation and autoreactivity.

Individuals inherit HLA alleles from their parents, and the HLA-B8 allele can be inherited as part of a haplotype, a group of alleles that are closely linked on the chromosome and tend to be inherited together. One well-known haplotype associated with HLA-B8 includes the alleles HLA-A1, HLA-B8, and HLA-DR3 (A1-B8-DR3). This haplotype is also associated with increased risk for autoimmune diseases.

Typing for HLA-B8 is typically performed using serological methods or molecular techniques such as PCR-based methods and sequencing. These techniques are used in clinical settings for disease association studies, organ transplantation matching, and other immunological investigations. The presence or absence of HLA-B8 can be a clinically relevant marker in the diagnosis and management of certain autoimmune disorders.