When people are first diagnosed with a chronic inflammatory disease like ankylosing spondylitis (AS), many questions and fears come up. Some of the big ones for AS include: Will this disease make me disabled? Will it affect my posture or make me hunched over? Can it affect my life expectancy or be life-threatening?
The prognosis of a condition describes its likely course, such as whether it will remain stable, improve, or get worse over time.
Doctors and researchers are still learning about the prognosis of ankylosing spondylitis, which is a form of axial spondyloarthritis (axSpA). Axial spondyloarthritis is an umbrella term for inflammatory arthritis that primarily affects the spine and the sacroiliac (SI) joints that connect the spine to the pelvis, causing pain predominantly in the back, hips, and buttocks as well as other joints. What’s behind the inflammation? Your body’s immune system is releasing chemicals into your blood and joints that cause pain, stiffness, and eventually joint damage.
There are two main types of axSpA:
- Non-radiographic axial spondyloarthritis (nr-axSpA)
- Ankylosing spondylitis (AS) (also called as radiographic axSpA)
“Non-radiographic” means that damage to the joints is not visible on X-ray. When changes to the SI joints don’t show any changes on an X-ray, that’s known as nr-axSpA.
Once the joints are clearly damaged on an X-ray, a person can be diagnosed with AS. There is some debate as to whether non-radiographic axial spondyloarthritis is simply early-stage AS or whether they are two different diseases. Here, we will focus on the prognosis and progression of AS; you can read more here about progression in non-radiographic axial spondyloarthritis.
In this article, you can learn about how AS progresses and what factors can affect AS prognosis. You will get information to have a more informed conversation with your doctor about treating your disease to improve your symptoms and prognosis.
Ankylosing Spondylitis Progression
The symptoms and progression of AS can vary widely from patient to patient. Some people may experience mild symptoms and not much progression; others can have more serious symptoms that continue to get worse. According to the latest research, significant progression in AS may affect around 20 to 30 percent of patients.
AS starts with inflammation in the joints of the spine and pelvis and causes chronic back pain, which is known as inflammatory back pain. It has some unique traits compared with mechanical back pain, which occurs because of injuries or damage to the discs, nerves, muscles, and joints in the back. Inflammatory back pain generally:
- Starts at a young age (before age 40-45)
- Feels better with movement and exercise and gets worse with rest and inactivity
- Feels stiff first thing in the morning
- Can wake you up in the middle of the night in agony
- Comes on slowly and lasts, on and off, for three months or more
Inflammation in AS often starts in the sacroiliac joints in the pelvis and gradually begins to affect more of the spine, including the neck, over time.
As inflammation in AS endures, the joints in the spine can become damaged, causing bony growths, hardening, and fusing that can affect flexibility and mobility. In the most severe cases of AS, patients are at risk for fusion of bones in the spine, joint destruction, limited range of motion, and kyphosis (a hunched back). Other joints, such as hip and shoulder movement, can be impacted.
This kind of progression can take many years to occur. Treating AS with medication and healthy lifestyle habits may help stop this damage — more on this below.
“This is a very slowly progressive disease and takes several years for damage or fusion to occur in the joints,” says Abhijeet Danve, MD, assistant professor of clinical medicine and director of the Spondyloarthritis Program at Yale University in New Haven, Connecticut.
While there is still much room for improvement, AS is starting to be diagnosed sooner, says Kari Sutter, MD, a rheumatologist and an assistant professor the Charles E. Schmidt College of Medicine at Florida Atlantic University in Boca Raton, Florida. This means patients can start treating AS earlier, which helps limit long-term inflammation and the damage that comes with it.
“We’re intervening earlier and can stop the progression so patients are doing better,” she says.
How Ankylosing Spondylitis Affects Quality of Life
Inflammatory back pain alone — even without permanent joint damage — can have very dramatic impacts on patients’ quality of life and daily function.
In a study shared at the 2018 American College of Rheumatology annual meeting, researchers surveyed 235 ankylosing spondylitis patients through the ArthritisPower research registry — a partnership of the CreakyJoints arthritis patient community, researchers at the University of Alabama at Birmingham, and the Global Healthy Living Foundation (GHLF) — and found significant negative impacts on patients’ work and social lives.
Difficulty with Daily Tasks
As AS progresses, patients start to lose spinal mobility, says Dr. Sutter. This can mean reduced range of motion, such as trouble turning your head and looking to your left and right shoulders. The following types of activities can become challenging:
- Turning your head while driving (such as to change lanes or go in reverse)
- Getting dressed, such as bending over to tie shoes
- Household chores, such as cleaning and laundry
- Reaching for things overhead
- Exercise and physical activity
“Anything that requires flexing and extension of the spine can be challenging and painful,” says Hareth Madhoun, DO, a rheumatologist at The Ohio State University Wexner Medical Center in Columbus.
AS is associated with poorer health-related quality of life as well as work disability, says Jean Liew, MD, a senior fellow/acting instructor in the division of rheumatology at the University of Washington in Seattle. Having to leave a job is three times more common among people with AS than in the general population, found a study in the journal Annals of the Rheumatic Diseases. This is particularly true of those who perform manual work that involves repetitive bending and twisting. Some of this data comes from older studies from the 1990s, though. “We’re continuing to study what factors are related to work disability, and what measures can be taken to allow people with AS to continue to work with the appropriate adaptations,” says Dr. Liew.
The ArthritisPower study found that 47 percent of patients said they had to miss work because of their AS and 41 percent reported being less productive at work due to AS.
Not surprisingly, pain, fatigue, and other AS symptoms also take a toll on patients’ social lives and personal relationships. ArthritisPower research showed that 63 percent of AS patients reported that they have difficulty spending time with friends and 47 percent said they have difficulty spending time with family. This can impact mental health and mood. In fact, a large 2019 study found that having AS more than doubles the risk of depression.
Factors That Can Affect AS Prognosis and Progression
Because AS progresses differently from person to person, researchers are continuing to study which factors may help predict which patients are more likely to experience a worse prognosis. Some of these factors may include:
Sex and Age
Studies suggest that being male and being diagnosed at a younger age are associated with a worse AS prognosis. However, it is a gross misconception that AS does not affect women or that women’s AS symptoms are less serious that men’s. Read more here about AS in women.
Genetics and Family History
AS tends to run in families. Research shows that disease severity and functional impairment show a consistent pattern within families. In other words, having a family member with more severe disease can indicate how others in the family with AS will be affected.
Which genes are involved in AS is an ongoing area of research, but at least one genetic marker, called HLA-B27, has been associated with an increased risk of not only developing AS in the first place, but also having a worse prognosis. Read more here about the role of HLA-B27 and AS.
When AS affects the hips or other joints aside from those in the spine, it is associated with a poorer prognosis. The hip is affected in about a third of AS patients, says Dr. Liew.
Hip involvement appears to be a risk factor for more severe disease, including progression of disease in the spine. AS in the hip is more common in those diagnosed at younger ages, including childhood and teenage onset.
People with AS have an increased risk of other inflammatory diseases including psoriasis and inflammatory bowel disease (Crohn’s disease and ulcerative colitis). Research shows that AS patients who have such “extra-articular” (non-joint) symptoms may have greater overall disease severity.
Response to NSAIDs
Non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, are considered first-line medications for AS. Patients are typically started on NSAIDs and followed for a few months; there may be some trial and error to find the right NSAID. Not responding well to NSAIDs can be a sign of a more severe case of AS, says Dr. Sutter. These patients should go on to take biologic medications to help reduce immune system activity that is triggering inflammation.
Limited Range of Motion of the Lumbar Spine
If you have limited range of motion when you are diagnosed with AS, it may indicate a worse prognosis. “If you have limited range of motion, you may be less able to exercise and be physically active, and that raises your risk of other issues, such as cardiovascular risk or risk of falling,” says Dr. Sutter.
Having high levels of C-reactive protein, a marker of inflammation in the blood, at the time of AS diagnosis is associated with worse progression, a recent study showed.
Is Ankylosing Spondylitis Life-Threatening?
Ankylosing spondylitis itself isn’t directly life-threatening. But some complications and comorbidities associated with AS can be, says Dr. Liew, who conducts research on cardiovascular comorbidities in spondyloarthritis.
She says that older studies have shown that overall mortality — when you don’t look at specific causes of death — was 1.5 times higher than expected among people with AS compared to the general population. However, these studies didn’t look closely at factors that differ between people with and without AS that might be contributing to higher death rates among those of the same age and sex.
In studies that do look at specific causes of death for people with and without AS, cardiovascular disease is a major one, Dr. Liew says. People with AS have an increased risk of cardiovascular disease, including heart attacks and stroke, compared to those in the general population of the same age and sex. According to a study published in the journal Annals of Internal Medicine, AS patients had a 35 percent higher risk of dying from heart attack and a 60 percent increased risk of dying from stroke than those without AS.
This increased risk can be due to multiple different factors, including underlying inflammation that affects the cardiovascular system as well as the joints, which could potentially increase cardiovascular risk., says Dr. Liew. Lifestyle factors may also play a role, since people with AS may be less physically active.
Osteoporosis is another common comorbidity for people with AS, either due to taking steroid medication like prednisone, or from having the disease itself. While osteoporosis is generally not life-threatening, moderate to severe cases can cause fractures in the hip and spine, says Dr. Liew. These can lead to hospitalizations and complications. One study that looked at people who were hospitalized for fractures of the cervical spine (neck) showed that people who also had AS had an increased risk of death compared to those with these fractures who didn’t have AS.
Read more here about other AS comorbidities that can affect quality of life.
The Long-Term Outlook of AS: How to Protect Yourself
While the prognosis of AS is highly variable, says Dr. Liew, the good news is that you can do a lot to remain healthy and avoid progression of the condition.
Treatment for AS aims to reduce pain and symptoms, help maintain normal posture, reduce complications and comorbidities, prevent permanent damage, and improve quality of life.
“The outlook for AS is very good if addressed early in the disease course,” says Brett Smith, DO, rheumatologist with Blount Memorial Physicians Group in Alcoa, Tennessee. “With appropriate comprehensive treatment, including physical therapy and exercise, NSAIDs, and biologics, many people have preserved function and minimal pain.”
Joint damage in AS cannot be undone, but treating AS can prevent damage from occurring in the first place. Ongoing research is assessing how biologic medications, such as drugs that target immune system proteins tumor necrosis factor (TNF) and interleukin inhibitors (like IL-17) stop AS progression. Research is starting to show that these medications can help stop structural damage in AS.
“With the help of medications such as NSAIDs, TNF inhibitors, and IL-17 inhibitors, we can improve patients’ symptoms, physical function, and possibly X-ray progression significantly,” says Dr. Danve, noting that physical therapy and regular exercise is critical as well. “With ongoing research, we expect to see further advances in the diagnosis, management, and treatment of AS.”
As awareness for AS increases and patients get diagnosed and treated earlier, the prognosis for AS will certainly continue to improve.
Use Our ArthritisPower App to Manage Your AS
Join CreakyJoints’ patient-centered research registry to track your symptoms, disease activity, and medications — and share with your doctor. Learn more and sign up here.
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Interview with Abhijeet Danve, MD, assistant professor of clinical medicine, director of the Spondyloarthritis Program at Yale University in New Haven, Connecticut
Interview with Jean Liew, MD, a senior fellow/acting instructor in the division of rheumatology at the University of Washington in Seattle
Interview with Brett Smith, DO, rheumatologist with Blount Memorial Physicians Group in Alcoa, Tennessee
Interview with Hareth Madhoun, DO, rheumatologist and assistant professor of clinical medicine at The Ohio State University Wexner Medical Center in Columbus
Interview with Kari Sutter, MD, rheumatologist and an assistant professor the Charles E. Schmidt College of Medicine at Florida Atlantic University in Boca Raton, Florida
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