Human Leukocyte Antigen B27 (HLA-B27)

The HLA-B27 test works by detecting the presence of the HLA-B27 antigen on the surface of white blood cells, typically using a blood sample. In the laboratory, the test is performed using techniques such as flow cytometry or polymerase chain reaction (PCR). Flow cytometry uses labeled antibodies that specifically bind to the HLA-B27 protein, allowing detection and quantification of positive cells. PCR, on the other hand, identifies the HLA-B27 gene directly by amplifying DNA sequences associated with this antigen. A positive result indicates that the patient carries the HLA-B27 marker, which, when correlated with clinical symptoms, can aid in the diagnosis of autoimmune and inflammatory conditions such as ankylosing spondylitis and other spondyloarthropathies.

The HLA-B27 test identifies the presence of the HLA-B27 antigen on leukocytes using a blood sample. This genetic marker is strongly associated with certain autoimmune and inflammatory conditions, including ankylosing spondylitis, reactive arthritis, and other spondyloarthropathies. Detection of HLA-B27 can support the diagnosis of these disorders in patients presenting with clinical features such as chronic joint pain, stiffness, or inflammatory symptoms.