Ankylosing spondylitis is an autoimmune disease. This means that the body’s immune system becomes confused and attacks the healthy tissue, such as the joints. This can lead to much pain and inflammation. People with this condition have new bone growth in the spine, which can lead to stiffness of the back and neck. While the exact mechanism that leads to ankylosing spondylosis is not clear, genes are thought to contribute to this problem.
Scientists have discovered a gene called HLA-B27, that is in around 90% of Caucasians with ankylosing spondylosis. This suggest an important genetic link in the disease. In addition, some studies have found that bacteria could possibly influence the disease and its development.