HLA’s or Human Antigen Leukocytes are proteins found on the surface of white blood cells. Although most HLAs protect the body from harm, HLA-B27 is a specific type of protein that contributes to immune system dysfunction. The presence of HLA-B27 on your white blood cells can cause your immune system to attack the healthy cells that contain it. When this occurs, it can result in an autoimmune disease, such as juvenile rheumatoid arthritis. The B27 refers to a particular protein that helps white blood cells determine the good cells from the harmful agents in the body. A test for this antigen determines whether or not the protein is present.
One way to reach a diagnosis of ankylosing spondylitis is by having the blood checked for the HLA-B27 gene. It’s reported that not more than 2% of people born with the HLA-B27 gene will eventually develop ankylosing spondylitis. A negative HLA-B27 test means you do not carry the antigen and further tests would be needed if you are experiencing joint pain or inflammation. A positive HLA-B27 test means that although you are much more likely to have an autoimmune disorder.
You may also not have any disease since a small amount of persons carry the protein but not have signs of disorder. Again, further testing would be needed to determine whether or not you actually are experiencing symptoms of any disorder. Further testing such as Rheumatoid factor, x-rays, and C – reactive protein tests would possibly be needed in a diagnosis.
An abnormal result on this test may be caused by:
- Ankylosing spondylitis
- Arthritis related to Crohn’s disease or ulcerative colitis
- Psoriatic arthritis (arthritis associated with psoriasis)
- Reactive arthritis or Reiter’s syndrome
- Sacroiliitis (inflammation of the sacroiliac joint)
- Uveitis
Symptoms
- joint pain
- inflammation of the joints and/or urethra accompanied by skin lesions
- stiffness or swelling of the spine, neck, or chest
- recurring inflammation of the structures of the eye
Test options
HLA B27 Genetic marker screen
Learn more about HLA B27
http://www.healthline.com/health/hla-b27-antigen#Overview1
http://www.nlm.nih.gov/medlineplus/ency/article/003551.htm
https://www.rheumatology.org/Practice/Clinical/Patients/Diseases_And_Conditions/Reactive_Arthritis/
