HLA B-27 (PCR)

HLA-B27 by PCR is a laboratory genetic test that detects the HLA-B27 gene variant using polymerase chain reaction on a blood sample. A positive result shows presence of the HLA-B27 allele, which is linked to higher risk of ankylosing spondylitis and related inflammatory arthritis. It supports—but does not confirm—diagnosis; results need clinical correlation and specialist input.

HLA‑B27 is strongly associated with ankylosing spondylitis (most cases) and is also positive in other spondyloarthropathies: reactive arthritis, psoriatic arthritis, and IBD‑associated (enteropathic) arthritis. It increases risk for acute anterior uveitis and appears in undifferentiated spondyloarthropathies and some juvenile idiopathic arthritis cases. Presence supports diagnosis but isn’t diagnostic alone; many carriers stay healthy.

HLA-B27 PCR positivity alone does not require treatment. Management depends on symptoms: assess for spondyloarthritis, uveitis or reactive arthritis and refer to rheumatology or ophthalmology. First-line therapy includes NSAIDs and physiotherapy for axial pain. Peripheral arthritis may need sulfasalazine or methotrexate; refractory or axial disease may require biologics (TNF or IL-17 inhibitors). Treat any underlying infection and monitor.

HLA‑B27 PCR costs vary by country and setting. In India it's roughly ₹800–₹3,000; in the United States about $50–$300 for private/out‑of‑pocket testing; in the UK it's usually NHS‑covered but private tests run about £30–£100. Final price depends on the lab, location, and insurance or public‑health coverage; lab techniques and bundled fees can alter costs.

HLA‑B27 positivity is not an illness itself but a genetic marker that raises risk for certain autoimmune conditions—most commonly ankylosing spondylitis, reactive arthritis and uveitis. Many people with HLA‑B27 remain healthy and never develop disease. A positive result requires clinical correlation: if you have chronic back pain, stiffness, eye pain or family history, see a clinician for evaluation and possible monitoring or referral.

Having the HLA-B27 gene doesn’t directly cause back pain, but it increases risk of inflammatory conditions—most commonly ankylosing spondylitis—that produce characteristic inflammatory back pain (young onset, morning stiffness, improves with exercise, worse at night). Many HLA-B27–positive people remain asymptomatic. A positive test supports diagnosis but isn’t definitive; clinical evaluation and imaging are needed if inflammatory back pain is suspected.