B27 Blood Test Results Fully Explained

B27 Blood Test Results Fully Explained

The B27 blood test is used to either confirm a suspected diagnosis of juvenile rheumatoid arthritis, reactive arthritis, or similar condition, or strengthen an existing diagnosis. Although this blood test is not considered to be definitive in the results that it provides, it is an influential piece of the diagnostic puzzle when combined with symptoms and other testing.

When To See a Doctor About the B27 Blood Test

Many of the conditions that are detected by the B27 blood test are autoimmune disorders. With the exception of juvenile arthritis, the first symptoms tend to appear when someone reaches their early 30’s. When stiffening of the spin, inflammation, joint pain, or a persistent stiff neck or chest are felt, then this could indicate the presence of ankylosing spondylitis (AS). Children who experience the symptoms of arthritis should also be seen immediately.

If there is inflammation in one or both eyes, then this may indicate the presence of anterior uveitis and this can also be detected by the B27 blood test. Anyone with chronic pain in the neck, face, joints, or spine should consider speaking with their medical provider about the benefits of having this test ordered.

It is not uncommon for additional blood tests to be ordered with the B27 test, including tests that measure an individual’s rheumatoid factor.

What Do My B27 Blood Test Results Mean?

Men under the age of 40 are the most susceptible to an autoimmune disease that will create a positive B27 blood test result. A diagnosis may be received after the test results come back if certain symptoms or degenerative changes have also been discovered during the medical examination. If the test is positive without certain signs or symptoms, then additional testing may be ordered to help pin down a diagnosis.

If the B27 blood test comes back as negative, then this means the markers it detects were not present in the sample given. A negative test is not confirmation that an autoimmune disease is not present at that time. It is possible to have a positive test and not have an autoimmune disease and it is possible to have a negative result, but still have a disease.

Certain antigens that are detected by the B27 blood test are also determined by genetics. Certain genes control their production, so if one person in a family develops an autoimmune disease that is related to the B27 test and tests positive, it increases the chances of all other family members having the same thing happen.

Here’s What You Need to Know

Although men under 40 are the most likely to be affected by diseases that are detected by the B27 blood test, women and men outside of the age demographic may also develop these autoimmune disorders. The symptoms are typically milder outside of the key demographic and in women may barely be noticeable.

There are more than 70 different subtypes of B27 that have been discovered to date. How each subtype may increase or decrease the risk of autoimmune disease development is not use known, but genetic testing on this marker can let people know early on whether or not they are at risk of developing a disease at some point in their life.

This is not considered a routine blood test. Although the blood draw will typically happen at a local provider, the test must usually be sent to a reference laboratory to be completed. This may cause a delay in test results because of the need to ship the sample.

Not everyone will benefit from having the B27 blood test being ordered, especially those who have a family history of genetic markers that would generate a positive result. In the United States, it is estimated that about 6% of the population has genetic markers in place that would generate a positive test result. It is most useful to determine the possibility of risk in the development of an autoimmune disease when there are signs and symptoms that indicate it has developed, especially for all men under the age of 40.

Inflammatory bowel diseases may also generate a positive test result, as can other chronic conditions. That is why a careful interpretation of results is necessary.

Be sure to talk about all of the advantages and disadvantages about what a B27 blood test result could mean for an individualized medical history and discuss results with a local medical provider. That is the best way to determine what course of treatment may be helpful now and into the future.