Ankylosing spondylitis is a chronic inflammatory disorder that mainly affects the spine.
Lower back pain is not necessarily a rare phenomenon: 80 percent of U.S. adults suffer from low back pain at some point in their lives, according to the National Institute of Neurological Disorders and Stroke. But for many of those Americans, the pain can be alleviated by getting a new mattress, or fixing their lifting form.
This is not the case for people with ankylosing spondylitis, or AS. “Ankylosing spondylitis is a chronic inflammatory disorder that mainly affects the spine,” says Jessica Patel, MD, a rheumatologist at Mount Sinai Hospital in New York City. “It affects the flexibility and mobility of the back and other joints as well.” In fact, ankylosis and spondylitis come from the Greek words for “crooked” and “vertebra,” respectively.
Ankylosing spondylitis is a type of arthritis, and is the most common condition within the spondyloarthritis family, according to the American College of Rheumatology. Spondyloarthritis also includes axial spondyloarthritis (which creates lower back pain) and peripheral spondyloarthritis (which causes pain and swelling in joints other than the spine, such as the hands, elbows, shoulders, knees, and feet). It’s possible to be diagnosed with multiple types of spondyloarthritis.
Symptoms of Ankylosing Spondylitis
“Ankylosing spondylitis primarily affects large joints in the body, particularly where there are a lot of ligament attachments to bone,” says Themistocles Protopsaltis, MD, spine surgeon at NYU Langone Hospital.
A key feature of AS is the inflammation of the sacroiliac joints, which is where the spine meets the pelvic bone. “There are really strong ligaments here [in the sacroiliac joints],” says Dr. Protopsaltis. “Those ligaments and those attachments to those ligaments can become inflamed as the immune system attacks the attachment.”
The inflammation can make these joints painful and stiff. Over time, the vertebrae may fuse together (which is known as ankylosis) and make the spine inflexible, according to the Arthritis Foundation (AF). “At the very end of the disease, you can have very little joint pain, but now you have a joint that doesn’t move anymore,” says Dr. Protopsaltis.
The inflammation and pain may spread to the hips, shoulders, chest, neck, and even the organs, especially the eyes and bowels. Around 26 percent of people with AS also suffer from inflammatory bowel disease and as much as 40 percent also have uveitis (an eye disease), according to a 2014 article in Hip & Pelvis journal.
Possible Causes of Ankylosing Spondylitis
The cause of AS inflammation is unknown, but researchers have some theories. “Ankylosing spondylitis is an autoimmune disease,” says Dr. Protopsaltis. “It’s theorized to be something that occurs after an infection, where the body might attack an infecting organism. It then recognizes different parts of the joints as similar to that infecting organism and attacks those joint surfaces.”
Doctors also know that genetics play a role in the development of this arthritis. Most people with AS have a gene known as HLA-B27.
The role of HLA-B27 in the development of AS is pretty clear: This gene is found in 90 percent of caucasians with AS, but only 8 percent of caucasians without AS, according to AF. That said, you can get AS without having this gene, and having the HLA-B27 doesn’t guarantee you’ll develop AS: Only 1 in 20 people with the gene get AS, according to the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS).
Additionally, researchers have identified two more genes—IL23R and ERAP1—that may increase the risk of developing AS, according to NIAMS.
Just short of half a million Americans live with AS, and it affects more men than women. “Ankylosing spondylitis often affects people at a younger age,” says Dr. Patel. Symptoms usually begin in the late teens or early 20s, or at least before age 45. Learn more about risk factors for AS here.
Treatment for Ankylosing Spondylitis
AS has no cure, but medications can help manage symptoms and prevent the progression of the disease. Lifestyle changes can help reduce inflammation and lessen symptoms. Eating a healthy and anti-inflammatory diet, not smoking, and exercising are recommended. In rare cases, doctors may use surgery to straighten the spine.
Learn more about treatment for ankylosing spondylitis here.
“If you have back pain and you’re concerned about it being an inflammatory arthritis or ankylosing spondylitis, I would talk to your doctor and they will give you a referral to a rheumatologist,” says Dr. Patel.
Dr. Protopsaltis is a surgeon specializing in orthopedic and spine surgeries at NYU Langone Health.
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Ankylosing Spondylitis is
an inflammatory arthritis.
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So it's an inflammation that can attack
different joints in the body, the spine,
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the hip, the knees.
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It can also attack part of the eye and
parts of the bowel.
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So you can have a variety of symptoms.
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And it tends to occur in patients in
their teenage years and up until their
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40s as the first time when they get signs
and symptoms of ankylosing spondylitis.
00:00:25,904 --> 00:00:31,886
00:00:31,886 --> 00:00:35,280
Ankylosing spondylitis is
an autoimmune disease.
00:00:35,280 --> 00:00:39,140
So it's theorized to be
something that occurs after
00:00:39,140 --> 00:00:43,974
an infection where the body might
attack an infecting organism.
00:00:43,974 --> 00:00:48,772
It then recognizes different parts
of the joins as similar to that
00:00:48,772 --> 00:00:53,032
infecting organism and
attacks those joints surfaces.
00:00:53,032 --> 00:00:56,640
Ankylosing spondylitis primarily
affects large joints in their body,
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particularly where there are a lot
of ligament attachments to bone.
00:01:00,300 --> 00:01:05,866
Like in the joints between the pelvis and
the spine, the sacroiliac joints here.
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There are really strong ligaments here
that attach between the iliac bone and
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the sacrum bone.
00:01:11,434 --> 00:01:15,303
And those ligaments and
those attachments to those ligaments can
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become inflamed as the immune
system attacks the attachment.
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And that inflammation and
pain induced by the inflammatory response
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can present to the patient like
a low back problem, a back ache.
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And as the disease progresses,
the pain can become more chronic,
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it can become more persistent,
it can become more severe.
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And then things can get to a point
where pain starts to recede and
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the joints start to ossify or
calcify and fuse together.
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And then at the very end of the disease
you could have very little joint pain,
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but now you have a joint
that doesn't move anymore.
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So in the case of the spine,
you don't want to fuse in a position
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where you're crooked, or bent forward,
or your head isn't in a good posture.
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And so later chronic manifestations of
a disease involve fusion of the spine,
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but it's optimal for you to have
good posture if that is to occur.
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Patients that have ankylosing
spondylitis can still live full and
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vibrant lives and
do all the activities that they want to.
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But what they should know is that it's
best if they try to lead a lifestyle
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that's as healthy as possible.
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Because the treatment, which can include
just the physical therapy, stretching,
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or medications, might prevent the disease
from becoming more chronic and
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severe manifestation of
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Low back pain fact sheet. Bethesda, MD: National Institute of Neurological Disorders and Stroke. (Accessed on April 12, 2021 at https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Fact-Sheets/Low-Back-Pain-Fact-Sheet.)
Moon KH, Kim YT. Medical treatment of ankylosing spondylitis. Hip Pelvis. 2014 Sep;26(3):129-35.
Overview of ankylosing spondylitis. Encinos, CA: Spondylitis Association of America. (Accessed on April 12, 2021 at https://www.spondylitis.org/Ankylosing-Spondylitis.)
Overview of types of spondylitis. Encinos, CA: Spondylitis Association of America. (Accessed on April 12, 2021 at https://www.spondylitis.org/Types-of-Spondylitis.)
Spondyloarthritis. American College of Rheumatology, 2013. (Accessed on September 19, 2018 at https://www.rheumatology.org/I-Am-A/Patient-Caregiver/Diseases-Conditions/Spondyloarthritis.)
What causes ankylosing spondylitis? Bethesda, MD: National Institute of Arthritis and Musculoskeletal and Skin Diseases. (Accessed on April 12, 2021 at https://www.niams.nih.gov/health-topics/ankylosing-spondylitis#tab-causes.)What is ankylosing spondylitis? Atlanta, GA: Arthritis Foundation. (Accessed on April 12, 2021 at https://www.arthritis.org/about-arthritis/types/ankylosing-spondylitis/what-is-ankylosing-spondylitis.php.)