HLA-B

HLA-B is a gene that provides instructions for making a protein that plays a crucial role in the immune system. HLA-B is part of a family of genes called the human leukocyte antigen (HLA) complex. The HLA complex helps the immune system distinguish the body's own proteins from proteins made by foreign invaders such as viruses and bacteria.

Function

The HLA-B gene belongs to the HLA class I group. These genes produce proteins that are found on the surface of almost all cells. The HLA-B protein attaches itself to a protein fragment (antigen) inside the cell. This complex moves to the cell's surface, where it is recognized by the immune system. If the immune system recognizes the antigen as foreign, it triggers a response to attack the infected cells.

Role in Disease

Certain variations of the HLA-B gene are associated with an increased risk of developing specific diseases. For example, a particular version of the HLA-B gene, HLA-B27, is associated with a higher risk of developing ankylosing spondylitis, a form of chronic inflammation of the spine. Another variant, HLA-B57, is associated with a slower progression of HIV infection to AIDS.

Genetic Testing

Genetic testing can identify the specific variations of the HLA-B gene. This information can be used to determine a person's risk of developing certain conditions, to predict the course of disease, or to guide treatment.

See Also

• Human leukocyte antigen
• Ankylosing spondylitis
• HIV/AIDS