26650 HLA B27 Disease Association (006924)

​​​Ankylosing Spondylitis

B27 Disease Association

Disease Association Testing​

​HLA-B27

​Evaluate spondyloarthritis and other disorders associated with HLA-B27.

​Hemolysis, clotted specimen, tube other than EDTA Lavender Top Tube (LTT)

​LabCorp will evaluate the integrity of all specimens and their suitability for testing.

​Regarding whole blood specimens, an adequate test requires the presence of intact lymphocytes at the time of testing. Even taking appropriate precautions, an occasional specimen will not be satisfactory for testing. In such cases, fresh blood should be drawn for retesting.​​

​HLA-B27 is strongly associated with ankylosing spondylitis (Marie-Strumpell disease). HLA-B27 shares homology with a Klebsiella protein and may imply a bacterial pathogenesis to ankylosing spondylitis. A patient with consistent clinical and radiographic findings who is B27-positive has a greater chance of having or developing ankylosing spondylitis than a negative patient. The antigen is not causative, however, and 10% of normal subjects are B27-positive. This test should not be considered a screening procedure for ankylosing spondylitis. The antigen is less strongly associated with Reiter syndrome and other arthritides than with ankylosing spondylitis. It has been linked with congenital deficiency of C₄ and C₂, and with adrenal hyperplasia.

The generic sequence coding for HLA-B27 is probed and reported as either P (positive) if it is present or N (negative) if it is absent.