Ankylosing Spondylitis

Ankylosing spondylitis (AS) is a chronic, inflammatory arthritis in the spondyloarthritis family that primarily targets the spine and sacroiliac joints. It often begins in adolescence or early adulthood and can cause inflammatory back pain, morning stiffness, and reduced spinal flexibility. Some people also develop enthesitis (inflammation where tendons/ligaments attach to bone), uveitis (eye inflammation), or symptoms linked to psoriasis or inflammatory bowel disease (IBD).

Because imaging findings can lag behind symptoms, blood tests help build ... See more

Because imaging findings can lag behind symptoms, blood tests help build the diagnostic picture and monitor inflammation over time. Ulta Lab Tests offers convenient access to HLA-B27 genetic testing and inflammatory markers(CRP, ESR), plus supporting labs you can review with your clinician. Order online, visit a nearby draw site, and get fast, secure results to guide next steps.

Signs & Symptoms (When to consider testing)

Inflammatory back pain: starts before age 45, lasts ≥3 months, improves with activity, worsens with rest/night, morning stiffness ≥30 minutes.
Sacroiliac pain: deep buttock pain (often alternating sides).
Limited spinal mobility: reduced ability to bend/twist; loss of chest wall expansion.
Peripheral involvement: hip/shoulder pain, enthesitis (heel, Achilles), dactylitis (“sausage” digits).
Extra-articular features: uveitis/iritis (painful red eye, light sensitivity), psoriasis, IBD.
Systemic clues: fatigue, low-grade fever during flares, sleep disturbance.
Family history: relatives with AS, reactive arthritis, psoriasis, or IBD.

Related terms users search for: ankylosing spondylitis blood test, HLA-B27 test, spondyloarthritis labs, inflammatory back pain testing, sacroiliitis.

Why These Tests Matter

What AS labs can do

Detect active inflammation (CRP, ESR) to support an inflammatory pattern.
Identify genetic association with HLA-B27, which increases the likelihood of AS in the right clinical context.
Help differentiate spondyloarthritis from mimics (e.g., rheumatoid arthritis, infection).
Provide baseline and trend data for monitoring disease activity over time.

What they cannot do

Confirm AS on their own or show structural damage—imaging (X-ray/MRI) and clinical evaluation are required.
Predict severity or future spinal fusion.
Replace a specialist assessment when AS is suspected.

What These Tests Measure (at a glance)

HLA-B27: genetic marker associated with AS and related spondyloarthropathies (positive ≠ automatic diagnosis; negative ≠ rule-out).
CRP (C-reactive protein), ESR: objective inflammation markers; often elevated during flares.
CBC: context for systemic inflammation (e.g., anemia of chronic disease).
ANA, RF, anti-CCP: usually negative in AS; positivity may suggest other autoimmune diseases (e.g., lupus, rheumatoid arthritis).
CMP: general health context (electrolytes, liver/kidney function) that can influence care decisions.

Optional supportive testing based on symptoms: stool or other labs related to IBD; dermatologic evaluation for psoriasis.

How the Testing Process Works

Order online: select an AS-focused panel (HLA-B27 CRP/ESR) or individual markers.
Visit a local lab: quick blood draw at a nearby patient service center.
Get results fast: most results are available within 24–48 hours in your secure account.
Review with your clinician: combine labs with symptoms, exam, and imaging (sacroiliac X-ray or MRI).

Interpreting Results (general guidance)

HLA-B27 positive: raises likelihood of AS when paired with classic symptoms; many carriers never develop AS.
Elevated CRP/ESR: supports active inflammation and helps track flares or response to care.
RF/anti-CCP negative: favors spondyloarthritis over rheumatoid arthritis (not absolute).
Normal labs: do not exclude AS—some people have normal CRP/ESR yet clear imaging findings.

Always interpret results with a qualified healthcare professional.

Choosing Panels vs. Individual Tests

Broad screening (undifferentiated inflammatory back pain): choose a spondyloarthritis screen combining HLA-B27 CRP/ESR CBC.
Targeted add-ons: if RA or lupus is on the differential, consider RF/anti-CCP/ANA.
Monitoring (established AS): repeat CRP/ESR to follow disease activity as advised by your clinician.

FAQs

What is ankylosing spondylitis?
A chronic inflammatory arthritis that targets the spine and sacroiliac joints, causing inflammatory back pain, stiffness, and reduced mobility. It belongs to the spondyloarthritis family.

Which blood tests support an AS evaluation?
HLA-B27, CRP, and ESR are most relevant. CBC provides context, while RF/anti-CCP/ANA help rule in/out other autoimmune diseases.

Does a positive HLA-B27 mean I have AS?
No. HLA-B27 increases risk but is not diagnostic. Some people with AS are HLA-B27 negative.

Are CRP and ESR always high in AS?
No. They may be normal, especially outside of flares. Normal markers don’t exclude AS.

How is AS diagnosed?
By combining symptoms, exam, imaging (X-ray/MRI of sacroiliac joints/spine), and supportive labs.

Do I need a referral to order tests?
No referral is required to order through Ulta Lab Tests. Share results with your clinician for diagnosis and care planning.

How quickly will I get results?
Most AS-related labs post within 24–48 hours after your blood draw.

Internal Links & Cross-References

Arthritis Testing Hub
Rheumatoid Arthritis
Psoriatic Arthritis
Osteoarthritis
All Arthritis Tests
Key Tests: HLA-B27 • CRP • ESR • CBC • ANA • RF • anti-CCP

Available Tests & Panels

Tip: Start with a spondyloarthritis/AS screen (HLA-B27 CRP/ESR CBC). Add ANA/RF/anti-CCP if your clinician is also considering other autoimmune arthritis.

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HLA-B27 Antigen Test

The HLA-B27 Antigen Test detects the presence of the HLA-B27 protein on white blood cells, which is linked to autoimmune conditions. A positive result may indicate higher risk for ankylosing spondylitis, reactive arthritis, or other spondyloarthropathies. Doctors order this test to investigate chronic back pain, joint inflammation, or autoimmune family history. Results provide critical insight into genetic predisposition, immune system activity, and inflammatory disease risk.

Specimen Type: Blood

Collection: Blood Draw

$143.21
$60.95
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HLA-B27 DNA Typing

$564.95
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Complete Blood Count with Differential and Platelets - CBC Test Most Popular

The Complete Blood Count with Differential and Platelets Test is a comprehensive blood test that checks red blood cells, white blood cells, hemoglobin, hematocrit, and platelets. The differential analyzes types of white blood cells to detect infections, anemia, clotting abnormalities, immune conditions, and certain cancers. This essential test is often ordered for routine health exams, diagnosis, and monitoring treatment progress.

Specimen Type: Blood

Collection: Blood Draw

Also Known As: CBC Test, CBC with Differential and Platelets Test, CBC w/Diff and Platelets Test, Full Blood Count Test, Complete Blood Count Test

$50.50
$21.95
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C-Reactive Protein Test Most Popular

The C-Reactive Protein (CRP) Test measures CRP levels in blood to detect inflammation in the body. Elevated CRP may indicate infections, autoimmune disorders, or chronic diseases such as arthritis, cardiovascular disease, or inflammatory bowel disease. Doctors use this test to assess acute illness, monitor treatment response, and evaluate risk for heart disease. The CRP test provides key insight into inflammation, immune health, and overall wellness.

Specimen Type: Blood

Collection: Blood Draw

Also Known As: CRP Test, Inflammation Test

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Sed Rate Test Most Popular

The Sed Rate Test, also called the ESR Test, measures how quickly red blood cells settle in a sample of blood. A faster rate may signal inflammation caused by infections, autoimmune diseases, arthritis, or other chronic conditions. Doctors use this test to investigate unexplained fever, joint pain, or muscle aches, and to monitor inflammatory disorders such as lupus or rheumatoid arthritis. The Sed Rate Test provides important insight into overall inflammatory activity.

Specimen Type: Blood

Collection: Blood Draw

Also Known As: Erythrocyte Sedimentation Rate Test, ESR Test, Sedimentation Rate Test, Westergren Sedimentation Rate Test

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Ankylosing Spondylitis Tests: What You Need to Know

Ankylosing Spondylitis affects approximately 0.2-0.5% of the population in the US. There is a prevalence of Ankylosing Spondylitis in patients who are positive for the HLA-B27 gene.

The precise cause of Ankylosing Spondylitis is currently unknown. There are ongoing advancements in research, as well as Ankylosing Spondylitis tests. This helps to better understand this inflammatory disease and treatments.

Read on to learn more about Ankylosing Spondylitis and the effects it has on the body.

What Is Ankylosing Spondylitis?

Ankylosing Spondylitis is a long-term, chronic condition. It causes inflammation in the spine and other parts of the body.

Over time, the inflammation can cause new bone to form. This can lead to the small bones in your spine fusing, causing pain, stiffness, and hunching.

Symptoms can start in teenagers and early adults. This inflammatory disease is more common in men than ... See more

Ankylosing Spondylitis affects approximately 0.2-0.5% of the population in the US. There is a prevalence of Ankylosing Spondylitis in patients who are positive for the HLA-B27 gene.

Read on to learn more about Ankylosing Spondylitis and the effects it has on the body.

What Is Ankylosing Spondylitis?

Ankylosing Spondylitis is a long-term, chronic condition. It causes inflammation in the spine and other parts of the body.

Over time, the inflammation can cause new bone to form. This can lead to the small bones in your spine fusing, causing pain, stiffness, and hunching.

Symptoms can start in teenagers and early adults. This inflammatory disease is more common in men than women.

Types of Ankylosing Spondylitis

There are 7 different types of Ankylosing Spondylitis:

Enteropathic Arthritis (EnA)

Along with the typical symptoms, this also includes inflammatory bowel disease. The typical diseases are Crohn's, undifferentiated colitis, and ulcerative colitis.

There are other symptoms included. Such as abdominal pain, weight loss, chronic diarrhea, and/or blood in the stool.

Juvenile Spondyloarthritis (JSpA)

This is when the symptoms of Ankylosing Spondylitis begin in childhood. They may also look to the other types of Ankylosing Spondylitis for diagnosis.

Psoriatic Arthritis (PsA)

Causes frequent pain and swelling in the smaller joints of the hands and feet. Most will also have a psoriasis rash and swelling in the digits.

Reactive Arthritis (ReA)

You will start with infections in the intestines and urinary tract. Then the inflammation will start to dominate. Inflammation can occur in the mucus membranes, bladder, skin, eyes, joints, and genitals.

This can cause recurrent symptoms and subsides in 3-12 months. This tends to recur over time, and most patients will develop chronic forms of arthritis over time.

Undifferentiated Spondyloarthritis (USpA)

USpA doesn't fit within the other categories above.

They may have heel pain, knee swelling, and iritis. There is a lack of back pain, infections, intestinal symptoms, and psoriasis.

Axial Spondyloarthritis (AxSpA)

One of the two newer forms of Ankylosing Spondylitis. It causes inflammation in the hips and/or spine, causing inflammatory back pain.

Peripheral Spondyloarthritis (pSpA)

This form causes inflammation across joints and tendons outside of the spine and sacroiliac joints.

Affected areas include the shoulders, knees, ankles, feet, wrists, hands, and elbows. This can also cause inflammation of the tendons and ligaments, especially in the bones, fingers, and toes.

Almost everyone that has Psoriatic Arthritis will have this category of disease. Patients with the other categories may fit into this category also.

Symptoms of Ankylosing Spondylitis

The most common symptoms which are not categorized as above are:

Back Pain and Stiffness

The back pain and stiffness can feel worse in the early hours of the morning. Symptoms may improve with warmth or gentle exercise and movement.

You may find you are waking in the early hours in a lot of pain and unable to get back to sleep.

Early Stage Symptoms

In the very early stages, some have a mild fever, loss of appetite, and discomfort.

You may find symptoms started around your teenage years or early 20s.

Inflammation

Inflammation can be in the spine and pelvis, also other areas such as joints.

Areas that can have inflammation are the shoulders, heels, hips, and ribs. You may find there is inflammation in the small joints of the hands and feet.

Pain and Discomfort

As there are areas of inflammation in the body, this can also cause pain.

Swelling and heat from the areas may happen, especially in the smaller joints such as fingers.

The pain is more common in the early hours of the morning. Or after a period of time staying still.

Spinal Fusion

Over time, the spine may start to fuse together, giving a hunch-back appearance. You may need surgery long-term.

Diagnosis

A visit with a Rheumatologist is the first step in your diagnosis of Ankylosing Spondylitis.

A physical exam will take place, including imaging tests, MRI, and x-ray scans.

You will also have blood tests performed that are likely to include a test for the HLA-B27 antigen, a test for rheumatoid arthritis, and the following inflammation markers:

1. - Erythrocyte sedimentation rate (ESR), also known as Sed Rate by Modified Westergren (ESR)
2. - C-reactive protein (CRP)
3. - Plasma viscosity (PV)

Your healthcare professional will also check your medical history to understand when the pain and problems started. Blood tests in addition to those noted above may be ordered to understand what is causing the inflammation and identify other conditions such as anemia that may exacerbate arthritis.

A few diagnostic criteria that your healthcare professional will consider along with your lab tests; may vary based on where you live.

The onset of pain before 45 years of age
Chronic and persistent pain (lasting more than 3 months)
Back pain and stiffness, which is worse in the early morning
Pain and stiffness easing with movement and exercise
Fatigue as well as the presence of inflammation

Other symptoms, such as inflammation elsewhere in the body—particularly the eye and digestive tract will be evaluated.

Available Ankylosing Spondylitis Tests

You can order blood tests directly through Ulta Lab Tests to check for Ankylosing Spondylitis. Your tests results are returned quickly in 1 to 2 days for most tests.

The Ankylosing Spondylitis tests most often recommended include the HLA-B27 Antigen Test, C-reactive protein, CBC, and an ESR blood test.

The HLA-B27 Antigen Test measures the presence of HLA-B27. Ankylosing spondylitis is ten times more common among individuals with HLA-B27 than individuals without this antigen, and HLA-B27 is found in 90% of patients with ankylosing spondylitis.

The C-reactive protein (CRP) and Erythrocyte sedimentation rate (ESR) blood tests measure the level of inflammation in your body. While a Complete Blood Count (CBC) is ordered to help rule out other conditions with similar symptoms.

The HLA-B27 DNA Typing test is available to evaluate the genetic risk for Ankylosing Spondylitis, uveitis, and several other autoimmune disorders.

Treating and Managing Ankylosing Spondylitis

From medication to lifestyle changes, there are ways you can manage Ankylosing Spondylitis. Once you have your test results, you can look to managing your condition.

Medications such as NSAIDs (non-steroidal anti-inflammatory drugs) are conventional medications along with DMARDs (disease-modifying antirheumatic drugs). Painkillers can be prescribed to manage pain.

Physical therapy can help you manage the pain and ease the stiffness. Exercise is also another way to relieve the pain and keep your spine mobile.

Lifestyle changes such as a healthy diet and avoiding inflammatory foods.

Keeping an eye on your inflammation levels is a good way to monitor how your body reacts to the new medications. Blood tests ordered from Ulta Lab Tests are a good way to keep on track without the long waiting periods.

Frequently Asked Questions

Here are three frequently asked questions about the condition.

Are There Certain Exercises I Should Do?

There are some specific exercises that can help with movement and pain. A physiotherapist will be able to offer advice on the best options for you.

Do I Need to Follow a Special Diet?

There is no specific diet, but having a healthy diet will benefit you long term. It is suggested to avoid nightshades which are inflammatory foods.

Am I Able to Consider Complementary Therapies?

Before you agree to any complementary therapies, seek advice from your specialist. There are complementary therapies such as chiropractic treatment and acupuncture to consider.

Should I Get a Blood Test?

Blood tests are a quick and reliable way to find the answers you need to identify the cause and monitor inflammation's impact on your organs.

You can order the blood tests you are looking for at a low price with Ulta Lab Tests. Our tests are organized by condition so that you can quickly select and order your tests. You can quickly have your specimen collected and receive your results in 24-48 hours for most tests with a local lab.

Testing with Ulta Lab Tests is fast, reliable, and you're able to request any blood test you need, including Ankylosing Spondylitis tests.

If you suspect you have Ankylosing Spondylitis, find peace of mind by testing for Ankylosing Spondylitis with Ulta Lab Tests. There's no need to wait weeks for an appointment at your doctor's office, go back and forth from the doctor to the lab, or worry about scheduling a second appointment to get your test results.

Ulta Lab Tests make it easy to get blood tests. Order the lab tests needed to help diagnose Ankylosing Spondylitis and to monitor your condition.

You order your tests, and we will do the rest.

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