When a person tests positive for HLA-B27, he or she may have symptoms such as inflammation, chronic pain and progressive changes in the bones. Inflammation may affect several areas, including the joints, eyes, spine, chest, eyes and the neck. A positive result indicates the presence of human leukocyte antigen B27, or HLA-B27.
A HLA-B27 is a medical test that is performed to determine the presence of a protein that is found on the surface of the white blood cells. This test is usually recommended by a doctor when a person is suffering from an autoimmune disorder, recurrent uveitis or chronic pain in the neck, chest, eyes or joints. The test is not performed as part of a diagnosis, but it helps to add information, which is necessary in determining if a person has an autoimmune disorder due to the presence of HLA-B27, as stated by Labs Test Online.
There is no special preparation prior to the test. During the test a blood sample is drawn from the body, usually from a vein, and taken to the lab for testing. This test is usually performed to determine the cause of pain, swelling and stiffness, as stated by the National Institute of Health's MedlinePlus. Others tests that may be carried out alongside HLA-B27 include X-rays, C-reactive protein and rheumatoid factor.