HLA B-27 (PCR)
🧬 Marker for Ankylosing Spondylitis📋 Test Specifications
- Report Turnaround: 3rd Working Day.
- Sample Required: EDTA Whole Blood (Purple Top).
- Methodology: Real-Time PCR (Molecular).
- Fasting Required: No.
- Accuracy: High Sensitivity & Specificity.
What is the HLA-B27 PCR Test?
This test uses advanced PCR (Polymerase Chain Reaction) technology to detect the presence of the HLA-B27 gene on the surface of your white blood cells. This genetic marker is strongly associated with a group of autoimmune disorders known as Spondyloarthropathies, which cause chronic inflammation in the joints and spine.
Unlike standard Flow Cytometry methods, the PCR method is molecular-based, offering superior accuracy in detecting the gene.
🔴 Link to Ankylosing Spondylitis (AS)
Ankylosing Spondylitis is a condition where the spine fuses together over time. About 90% of people with Ankylosing Spondylitis test positive for the HLA-B27 gene. Doctors prescribe this test if you have:
- Chronic back pain or morning stiffness (especially in young adults).
- Inflammation in the eyes (Uveitis) with redness and pain.
- Joint pain and swelling (Arthritis).
Why PCR is better than Flow Cytometry?
While Flow Cytometry looks for the antigen protein, PCR looks for the DNA itself. This means PCR eliminates False Positives or Indeterminate results that can happen due to cross-reactivity with other HLA types (like HLA-B7). PCR gives a definitive Detected or Not Detected result.
When is this Test Recommended?
This test helps in the diagnosis of several autoimmune conditions:
- Ankylosing Spondylitis (AS): Spine inflammation.
- Reactive Arthritis: Joint pain triggered by an infection.
- Juvenile Rheumatoid Arthritis: Arthritis in children.
- Anterior Uveitis: Recurrent eye inflammation.
Test Procedure
- Collection: A standard blood draw from the vein.
- Preparation: No special preparation or fasting is needed.
- Privacy: Genetic data is handled with strict confidentiality.
Frequently Asked Questions (FAQ)
No. Being HLA-B27 positive means you have a higher risk (genetic predisposition). Many people have the gene but never develop arthritis. A diagnosis is made based on symptoms + X-rays + this test result.
Yes. The HLA-B27 gene is inherited from parents. If you test positive, there is a 50% chance your children may inherit the gene.
The report will be available on the 3rd Working Day after sample collection.
Disclaimer: This test detects a genetic risk factor. It is not a standalone diagnosis for any disease. Results must be interpreted by a Rheumatologist.