Diagnosis and Testing
How do I get tested for ankylosing spondylitis?
There are several blood tests available to check for inflammation markers and the presence of the HLA-B27 gene. Having the HLA-B27 gene doesn’t mean you will develop AS. Fewer than 1 of 20 people with HLA-B27 actually develop symptoms of AS. The diagnosis of AS is made on the basis of a combination of symptoms, physical examination findings, lab results, and imaging.
More Diagnosis and Testing Content
Is there newborn testing for ankylosing spondylitis?
Newborn screening is a blood test done to help identify certain health issues that would not otherwise be seen as early in newborns. Symptoms of ankylosing spondylitis typically appear in adolescence or early adulthood and most people who have the disease get symptoms before age 30. Therefore testing for AS is not typically indicated until an individual begins developing signs or symptoms of the disease.
Who else in my family should I test for ankylosing spondylitis?
Although ankylosing spondylitis (AS) can occur in more than one person in a family, it is not a purely genetic disease. The cause of AS is unknown. Most likely it is a combination of genes and the environment that play a role in determining the risk of developing AS. The main gene associated with a risk for getting AS is called HLA-B27. Having the HLA-B27 gene doesn’t mean you will develop AS. Therefore testing for AS is not indicated until an individual begins developing signs or symptoms of the disease.
How is ankylosing spondylitis diagnosed?
The diagnosis of ankylosing spondylitis (AS) depends on a number of factors including signs and symptoms, physical examination, family history, laboratory tests, imaging studies that include x-ray and MRI to confirm the involvement of the joints in the hip (sacroiliac joint). Due to the wide-range of symptoms, which can occur from patient to patient, a doctor must make the diagnosis-typically a rheumatologist. Genetics plays an important role in ankylosing spondylitis (AS). Greater than 90% of patients with AS have an important marker, called HLA-B27, on their white blood cells. Your doctor may order blood test to check for inflammation markers and the presence of the HLA-B27 gene. But note that only ~20% of those with the specific HLA-B27 gene will experience inflammatory conditions like AS. In order to diagnose AS, you doctor - typically a rheumatologist - will take into account the physical exam including X-rays, family history of AS, and the presence of the HLA-B27 gene. X-rays are used to confirm the involvement of the joints in the hip (sacroiliac joint).