HLA-B27 Test Purpose, Procedure, Results and more with Free Updates
Human leukocyte antigen B27 (HLA-B27) is a protein located on the surface of white blood cells. An HLA-B27 test is a blood test that identifies HLA-B27 proteins.
Human leukocyte antigens (HLA) are proteins commonly found on white blood cells. These antigens help your Immune System identify the differences between healthy body tissue and foreign substances that can cause an infection.

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| Also Known as | HLA-B27, Human Leukocyte Antigen B27, HLA-B27 Antigen, Ankylosing spondylitis-HLA, Psoriatic arthritis-HLA, Reactive arthritis-HLA, B27, Human lymphocyte antigen B27, Human Leukocyte A Antigen, Histocompatibility Leukocyte A Antigen, LY27, |
| Test Purpose | An HLA-B27 test is a blood test that identifies HLA-B27 proteins |
| Test Preparations | No need any Preparation |
| Test Components | HLA-B27 Antigen |
| Specimen | 4 ML (2 ML Min.) Whole Blood In 1 Lavender Top (EDTA) / Green Top (Sodium Heparin) Tube. |
| Stability Room | 24 hours |
| Stability Refrigerated | N/A |
| Stability Frozen | N/A |
| Method | Flow Cytometry |
| Download Report | Download Report |
Why get tested
The presence of HLA-B27 is associated with certain autoimmune and immune-mediated diseases, including:
- Ankylosing spondylitis, which causes inflammation of the bones of the spine
- Reactive Rrthritis, which causes inflammation of the joints, urethra, and eyes, and sometimes skin lesions
- Juvenile Rheumatoid Arthritis
- Anterior Uveitis, which causes swelling and irritation in the middle layer of the eye
A doctor may order the HLA-B27 test to monitor the progression of these and other autoimmune diseases.
When to get tested
Symptoms that might prompt a doctor to order the test include:
- Joint pain
- Stiffness or swelling of the spine, neck, or chest
- Inflammation of the joints or urethra accompanied by skin lesions
- Recurring Inflammation in the eye
Sample required
- A sample of blood drawn from a vein in your arm
- 4 ML (2 ML Min.) Whole Blood In 1 Lavender Top (EDTA) / Green Top (Sodium Heparin) Tube.
Preparation for Test:
No need any Preparations
Normal Result:
- Normal: Negative
- Abnormal : Positive
Positive HLA-B27 is seen in :
- Ankylosing Spondylitis: 95%
- Reiter’s Syndrome (Reactive Arthritis): 80%
- Psoriatic Arthritis (Spondylitis with Psoriasis): 70%
- Enteropathic Arthritis (Spondylitis with Inflammatory Bowel Disease): 50%
- Incidence in general population without disease: 6-8%
Related Tests:
If your HLA-B27 antigen test is positive, you may need other tests to help confirm a diagnosis of an autoimmune disease. You may have tests such as:
- Erythrocyte sedimentation rate (ESR) which may show you have inflammation
- C-reactive protein, which also can look for inflammation
- Joint X-rays or MRI
- Urine test
Understand Your Test Results:
Understand your B27 Test Results
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