The assay can be used to determine the presence of the HLA-B27 gene. This gene predisposes to the development of certain joint autoimmune diseases.
Many joint diseases are caused by a malfunction of the immune system. In such cases, the immune system identifies each cell in the joints as infected and attacks them in response. Immune cells, when they get into the joint cells, cause permanent inflammation.
HLA-B27, a specific protein that can be detected on the surface of white blood cells, helps identify foreign substances for the immune system.
Everyone has a unique combination of human leukocyte antigens (HLA), but the HLA-B27 gene is present in only 5-8% of the population. However, the presence of the gene does not indicate a clear predisposition to autoimmune disease, with only 2% of carriers suffering from any of the diseases it affects.
Autoimmune diseases affected by the presence of the HLA-B27 gene include Bechterew’s disease (ankylosing spondylitis, or AS), reactive arthritis (Reiter’s syndrome), arthritis associated with inflammatory bowel disease, and uveitis.