HLA-DR9

HLA-DR9 is a human leukocyte antigen serotype within the HLA-DR serotype group. The serotype is determined by the antibody recognition of HLA-DRB1*09 and *1001. This broad antigen group is produced by the Major Histocompatibility Complex (MHC), a gene complex in humans that plays a crucial role in immune response.

Function

HLA-DR9, like other HLA-DR antigens, is involved in the immune system's recognition of foreign substances. It presents peptides derived from extracellular proteins to T cells, which are a type of white blood cell. This presentation triggers an immune response, leading to the destruction of cells containing the foreign substance.

Association with Diseases

HLA-DR9 has been associated with several autoimmune and inflammatory diseases. These include rheumatoid arthritis, systemic lupus erythematosus, and type 1 diabetes. The exact mechanism of this association is not fully understood, but it is believed to involve the antigen's role in immune response.

Distribution

HLA-DR9 is found in varying frequencies in different populations. It is most common in East Asian populations, particularly in Japan and China. It is less common in European and African populations.

See Also

• HLA-DR
• Human leukocyte antigen
• Major Histocompatibility Complex
• Autoimmune disease