Infection

HLA-B27 — The Gene Marker Behind Stubborn Back Pain

HLA-B27 is an inherited tissue type. Carrying it raises the risk of ankylosing spondylitis, reactive arthritis and recurrent inflammation of the eye, but most carriers never develop any of them: around one in ten people in Sweden carries HLA-B27, and only a small proportion become ill. The test therefore supports a diagnosis when symptoms already point that way, and cannot confirm or exclude disease on its own.

Why Test HLA B-27 Test?

Consider this test if you've got chronic back pain that gets better with movement and worse with rest, recurring eye inflammation, joint swelling after an infection, or a family history of ankylosing spondylitis. It helps narrow down what's going on and guides the next steps.

What Do High HLA B-27 Test Levels Mean?

A positive result means you carry HLA-B27. You're at higher risk for ankylosing spondylitis, reactive arthritis, psoriatic arthritis, IBD-related arthritis, and anterior uveitis. But — and this is important — many HLA-B27 carriers live their whole lives without developing any of these. The result matters most when combined with your actual symptoms.

What Do Low HLA B-27 Test Levels Mean?

Negative means HLA-B27 wasn't found. That makes these conditions less likely, but doesn't completely rule them out — a small number of people with these conditions are HLA-B27 negative. Other diagnostic tools may still be needed.

Symptoms to Watch For

  • Chronic lower back pain and morning stiffness
  • Pain that improves with activity and worsens with rest
  • Recurring eye inflammation (redness, pain, light sensitivity)
  • Joint swelling, especially after an infection
  • Heel pain or Achilles tendon inflammation
  • Fatigue

Who Should Get Tested?

  • People with chronic back pain and stiffness that improves with exercise
  • Those with recurring eye inflammation (anterior uveitis)
  • Anyone with joint pain or swelling after a gut or urogenital infection
  • Those with a family history of ankylosing spondylitis
  • People with psoriatic arthritis or IBD with joint involvement

How to Prepare for Your Test

No special preparation needed. Standard blood test. Bring valid ID.

Frequently Asked Questions

Does a positive HLA-B27 mean I have ankylosing spondylitis?
No. HLA-B27 increases the risk but doesn't confirm the diagnosis. Many carriers never develop the condition. Your symptoms, imaging, and clinical assessment are needed for a definitive answer.
Is HLA-B27 inherited?
Yes. It can be passed from parent to child, with roughly a 50% chance per child if one parent carries it.
Can HLA-B27-related conditions be treated?
Absolutely. While there's no cure for conditions like ankylosing spondylitis, physical therapy, anti-inflammatory meds, and biologic therapies can effectively manage symptoms and slow progression.
NW

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Wellth Team

Wellth

Our content is written and reviewed by Wellth, and fact-checked against peer-reviewed research and current Swedish clinical guidelines.

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Medical Disclaimer

The information on this page is provided for informational purposes only and does not constitute professional medical advice, diagnosis, or treatment. Wellth provides health information and testing services but is not a substitute for clinical care. Always consult a qualified healthcare provider if you have questions about a medical condition. If you are experiencing severe or urgent symptoms, contact your doctor or call 1177 Vårdguiden. Blood test results should be interpreted by a qualified healthcare professional in the context of your complete medical history.