HLA‑B27 is a genetic marker found on the surface of white blood cells.

Its presence is strongly associated with ankylosing spondylitis, reactive arthritis, psoriatic arthritis, and certain types of uveitis.

Clinical uses include:

Supporting diagnosis of spondyloarthropathies in patients with chronic back pain or arthritis.

Identifying individuals at higher genetic risk for autoimmune conditions.

Assisting in differential diagnosis of inflammatory joint and eye diseases.

The test does not confirm disease on its own but provides supportive evidence when correlated with clinical findings and imaging.

Analyte: HLA‑B27 antigen on white blood cells (detected via flow cytometry or molecular methods).

Normal Result: Negative (HLA‑B27 not present).

Abnormal Findings:

Positive HLA‑B27: Indicates genetic predisposition to ankylosing spondylitis and related disorders.

Not all individuals with HLA‑B27 develop disease; clinical correlation is essential.

Clinical Use:

Provides a genetic marker for autoimmune risk assessment.

Helps guide diagnosis, prognosis, and treatment planning.

Supports rheumatology, orthopedics, ophthalmology, and internal medicine evaluations.