Hla-B27 Detection Test

HLA-B27 Detection Test

What it is

The HLA-B27 Detection Test is a genetic blood test used to check for the presence of the HLA-B27 antigen, a protein found on the surface of white blood cells. This protein plays a role in the immune system, but its presence is strongly associated with certain autoimmune and inflammatory conditions. While having HLA-B27 does not guarantee disease, it increases the risk of developing disorders such as ankylosing spondylitis and related spondyloarthropathies.

Uses

This test is used to:

• Support the diagnosis of ankylosing spondylitis, reactive arthritis, psoriatic arthritis, and juvenile idiopathic arthritis.
• Identify genetic predisposition in individuals with family history of autoimmune arthritis.
• Assist in evaluating patients with chronic back pain, joint inflammation, or unexplained arthritis.
• Guide prognosis and management of spondyloarthropathies.

Symptoms / Conditions That May Lead to the Test

Doctors may recommend this test if you have:

• Chronic back pain and stiffness, especially improving with activity but not with rest.
• Joint pain, swelling, or inflammation without another clear cause.
• Recurrent eye inflammation (uveitis/iritis).
• Skin or gastrointestinal symptoms linked with arthritis (e.g., psoriasis, inflammatory bowel disease).
• A close family member with ankylosing spondylitis or related conditions.

Abnormal Results

• Positive Result: Indicates presence of the HLA-B27 antigen. This increases the risk of developing autoimmune conditions but does not confirm a diagnosis, as many people with HLA-B27 remain healthy.
• Negative Result: Suggests absence of the HLA-B27 antigen, which lowers the likelihood of HLA-B27–associated disorders but does not completely exclude them.

Results must be interpreted in combination with clinical symptoms, imaging tests (X-rays, MRI), and other laboratory findings.

Risks

The test requires a blood sample and carries minimal risks, including:

• Mild pain, bruising, or discomfort at the puncture site.
• Rare risk of infection or dizziness after blood draw.