Doctor's Assessment Included
Every result includes a professional assessment from a BIG-registered doctor. For treatment decisions, discuss your results with your GP.
HLA B-27 (PCR)
HLA B-27 testing detects genetic susceptibility to spondyloarthropathies. While more common in men, women can also develop these conditions and may present with different symptom patterns.
What It Measures
This PCR test identifies the presence or absence of the HLA-B27 gene. It is a one-time genetic test — your HLA-B27 status does not change over time.
Why It Matters
HLA-B27 positivity supports the diagnosis of spondyloarthropathy in patients with inflammatory back pain. It does not diagnose any condition on its own but increases the likelihood of spondyloarthritis when symptoms are present.
When to Test
Clinicians may order the test in cases of chronic inflammatory back pain (especially in young adults), suspected ankylosing spondylitis, acute anterior uveitis, reactive arthritis, or family history of spondyloarthropathy.
Symptoms
Low Levels
A negative HLA-B27 makes spondyloarthropathy less likely but does not exclude it. Approximately 5-10% of ankylosing spondylitis patients are HLA-B27 negative.
High Levels
HLA-B27 positivity does not cause symptoms. Most HLA-B27 positive individuals never develop spondyloarthritis. The gene increases susceptibility but additional factors are needed for disease development.
Lifestyle Tips
If HLA-B27 positive with inflammatory back symptoms, early rheumatology referral is important. Regular exercise, particularly swimming and stretching, helps maintain spinal mobility. Good posture habits and smoking cessation are also important.
Frequently Asked Questions
Does HLA-B27 positive mean I have ankylosing spondylitis?
No. Only a small percentage of HLA-B27 positive individuals develop the disease. The gene increases susceptibility but most carriers remain healthy.
Is HLA-B27 hereditary?
Yes. HLA-B27 is inherited. If you carry it, there is approximately a 50% chance each child will inherit it.
What conditions are associated with HLA-B27?
Ankylosing spondylitis, reactive arthritis, psoriatic arthritis, inflammatory bowel disease-associated arthritis, and acute anterior uveitis.