Ankylosing Spondylitis- An Overview

Ankylosing Spondylitis- An Overview

Ankylosing Spondylitis is an inflammatory condition that affects young adults, occurs more in males, and affects the spine, sacroiliac joints, and large joints (ex. Hip). Ankylosing means “rigid” or fusion.

Spondy means “spine”. Spondylitis is inflammation of the spine. The patient may have inflammation followed by fusion of the spine and the sacroiliac joints. Other large joints (ex. Hip) may be affected, so the patient may complain of morning stiffness, low back pain, and maybe hip pain. The pain associated with Ankylosing Spondylitis gets better with exercises and not with rest. There is a difference between Reheumatoid arthritis and Ankylosing Spondylitis. Rheumatoid arthritis affects the synovial lining of joints and affects predominantly the cervical spine. Ankylosing Spondylitis affects ligaments, tendons, discs, and some joints, but it will affect the entire axial spine. Ankylosing Spondylitis is part of the seronegative spondyloarthropathy. This means that the rheumatoid factor is negative. Although the rheumatoid factor is negative, the HLA-B27 is positive. Ankylosing Spondylitis is a systemic problem that involves the immune system. It is almost like rheumatoid arthritis, but with a negative rheumatoid factor. Risk Factors of Ankylosing Spondylitis would include a young male with a positive family history + HLA-B27 gene positive. The HLA-B27 is part of the immune system. It is an antigen that will be on the surface of the cell. HLA-B27 probably has the same amino acid sequence as the protein produced by bacteria (klebsiella pneumonia), by food, or by other things. When the immune system identifies this protein and it goes through the blood stream, then these T-cells can recognize that antigen that protein is on the surface of cells (HLA-B27). Then the T-cells recruit other cells to attack it. Everything that contains HLA-B27 (tendons, ligaments, joints, etc) will be attacked because they think it is a bad protein.

The protein produced by the bacteria for example or by the HLA-B27 have the same sequence and the immune system cannot tell the difference between both of them so it is an autoimmune disease. These patient will have fusion of the spine. The spine will not have any free movement. The patient will complain of gradual stiffening of the spine and limited chest wall expansion. Less than 2 cm of chest wall expansion is more diagnostic than the HLA-B27 blood test. Ankylosing Spondylitis is a difficult condition to diagnose and there will be a “Bamboo Spine” seen on the x-ray. There will be sacroiliac joint involvement which is a characteristic for Ankylosing Spondylitis. There will also be fusion of the SI joint. There may be systemic autoimmune disease that will cause fever and malaise. There will be uveitis (redness and inflammation of the eye). There will be aorta inflammation that may lead to aortic aneurysm if the aorta is dilated or aortic regurgitation. The patient may have depression. When you do the blood test, it will be HLA-B27 positive. The sedimentation rate and CRP could be high. Treatment of Ankylosing Spondylitis uses things that decrease inflammation such as anti-inflammatory medications, physical therapy to improve flexibility and strength of the spine and joints, or TNF alpha blocking agents.