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Tissue antigen B27


Alleles are alternative forms of a specific gene variant. The existence of certain alleles or combinations thereof may increase or decrease the risk of immune system disorders. HLA alleles are an example of these alleles. They do not directly cause an illness but generate a predisposition for its development. HLA alleles are congenital.

The presence of the HLA-B27 allele is particularly connected to ankylosing spondylitis. Disorders connected to the HLA-B27 allele also include various eye and systemic disorders, reactive arthritis, inflammatory gastrointestinal disorders and psoriasis-related arthritis.

About 14% of Finns are HLA-B27-positive.

When should HLA-B27 be measured?

HLA-B27 is often measured when examining ambiguous joint symptoms or prolonged back pain. The test cannot be used to diagnose an illness, but the presence of the allele strengthens the diagnosis. On the other hand, a negative result reduces the likelihood of disorders related to HLA-B27.

What does the HLA-B27 test measure?

The HLA-B27 test measures whether the HLA-B27 allele is present in the sample.

Normally, the result is:

Form of response: Positive or negative result for the HLA-B27 allele.

The presence of the HLA-B27 allele alone cannot be used to diagnose an illness, but the result supports the diagnosis and helps assess the risk of illness.

Please contact your physician or other healthcare professional if you suspect an illness or need help interpreting the results.

The presence of the HLA-B27 allele means that the risk of illnesses related to the allele is higher. The incidence of the antigen is considerably more common than the incidence of the related disorders.

The HLA-B27 allele occurs in people suffering from the following autoimmune illnesses:

  • 90–95% ankylosing spondylitis
  • 60–90% reactive arthritis
  • 50–60% inflammatory gastrointestinal disorder or inflammatory articular disease
  • 80–90% juvenile ankylosing spondylitis.

If the HLA-B27 allele is not present in the sample, it does not mean that the person cannot develop the disorders connected to the allele. About 86% of Finns do not have the HLA-B27 allele.


Fasting is not required

This examination does not require fasting