Ankylosing spondylitis is an incurable inflammatory disease of unknown origin that typically affects the spine and low back. Because ankylosing spondylitis is progressive and systemic it can impact many different parts of the body including joints and organs. Click through this slideshow to learn the facts about several myths related to this common disease.
Myth #1: Ankylosing spondylitis is rare
Fact: In the United States, a disease is rare if it affects fewer than 200,000 people. Ankylosing spondylitis is part of a class of diseases called spondyloarthritis, which affects an estimated 2.7 million American adults, making it more common than multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS) and rheumatoid arthritis (RA) combined. The exact number of people with ankylosing spondylitis in the Unites States remains unknown.
Myth #2: Ankylosing spondylitis is genetic
Fact: The cause of ankylosing spondylitis remains unknown. The disease can affect multiple people in the same family but is likely caused by a mix of multiple genetic and environmental factors that have yet to be fully identified. Genetic markers that have been identified include HLA-B27, ERAP1, IL1A, IL23R, the presence of which can increase the likelihood of being diagnosed. It remains unclear how and to what extent these genes contribute to the chance of developing ankylosing spondylitis.
Myth #3: If you have HLA-B27 you have ankylosing spondylitis
Fact: Testing for HLA-B27 can help confirm a suspected ankylosing spondylitis diagnosis, but is not a reliable predictor. The HLA-B27 gene, a variation of the human leukocyte antigen-B complex, is present in about 90 percent of people who have ankylosing spondylitis; 10 percent of those with the disease do not have the gene. Additionally, HLA-B27 occurs in over six percent of the general population, the majority of whom will never develop ankylosing spondylitis.
Myth #3: HLA-B27, part two
There is no single diagnostic test for ankylosing spondylitis, which is generally diagnosed after reviewing a combination of variables not limited to: imaging, inflammation levels in the blood, genetic markers, family history, and symptoms. The hallmark feature of ankylosing spondylitis is inflammation in the sacroiliac joints. Importantly, ankylosing spondylitis presents differently in every person, making it difficult to rely on a rigid set of diagnostic criteria.
Myth #4: Ankylosing spondylitis is a man’s disease
Fact: Ankylosing spondylitis affects all genders but exact ratios are unknown; currently more men are understood to be diagnosed, but the ratio is declining as women are being diagnosed at a faster rate. Women can experience a longer delay in being diagnosed because symptoms can be different than those traditionally associated with the disease. Patient communities report that some physicians still believe women cannot get ankylosing spondylitis.
Myth #5: Ankylosing spondylitis will always cause spinal fusion
Fact: Ankylosing spondylitis is characterized by inflammation in the sacroiliac joints and often the joints of the spine. As the disease progresses bone spurs can form and in severe cases complete spinal fusion can occur and force the spine into a hunched, rigid position called kyphosis. Treatments for ankylosing spondylitis are meant to slow down progression of the disease and reduce the chance of bone spur formation and fusion.
Myth #6: Ankylosing spondylitis is just back pain
Fact: Ankylosing spondylitis is a systemic, or whole body, inflammatory disease that can affect multiple parts of the body including joints and organs. The disease primarily affects the spine and specifically the sacroiliac joints, but it can also cause inflammation and pain in peripheral joints and cause damage to the eyes, heart, lungs, kidneys, and other organs. In addition, the disease can cause significant fatigue and affect sleep and cognitive function.