Understanding the HLA-B27 PCR Test
What It Is: The HLA-B27 PCR (Polymerase Chain Reaction) test is a molecular technique used to detect the presence of the HLA-B27 gene, a specific type of protein found on the surface of white blood cells. This gene is associated with certain autoimmune and inflammatory conditions.
Why It's Important: The presence of the HLA-B27 gene can increase the risk of developing autoimmune diseases such as ankylosing spondylitis, reactive arthritis, psoriatic arthritis, and juvenile idiopathic arthritis. Detecting this gene helps in diagnosing and managing these conditions.
Role of HLA-B27:
Immune System Function: HLAs help the immune system recognize and respond to foreign substances. HLA-B27 can sometimes cause the immune system to attack healthy cells, leading to autoimmune diseases.
Disease Association: HLA-B27 is strongly associated with ankylosing spondylitis and other inflammatory diseases.
How the HLA-B27 PCR Test Works:
Sample Collection: A healthcare professional collects a blood sample from a vein in your arm.
Laboratory Analysis: The sample is processed in a lab where the PCR technique amplifies specific regions of the HLA-B27 gene, making it easier to detect and identify the gene.
Advantages of PCR Testing:
Increased Sensitivity: PCR testing is highly sensitive and can detect even small amounts of the HLA-B27 gene, reducing the likelihood of false negatives.
Accurate Diagnosis: PCR testing provides a precise identification of the HLA-B27 gene, aiding in the diagnosis and management of autoimmune diseases.
Why Your Doctor Might Order This Test:
Diagnosing Autoimmune Diseases: To help diagnose conditions like ankylosing spondylitis, reactive arthritis, and psoriatic arthritis.
Monitoring Disease Progression: To monitor the progression of autoimmune diseases and assess the effectiveness of treatments.
Evaluating Symptoms: If you have symptoms such as chronic back pain, joint pain, stiffness, or inflammation in the eyes, urethra, and joints, this test can help diagnose the underlying cause.
Symptoms That Might Prompt This Test:
Chronic back pain
Joint pain and stiffness
Inflammation of the eyes (uveitis)
Inflammation of the urethra