HLA-B27 Test: Overview, Procedure and Result

A blood test called an HLA-B27 test identifies HLA-B27 proteins. Although most HLAs shield your body against damage, HLA-B27 is a particular kind of protein that impairs the immune system. In such a scenario, the immune system may assault your white blood cells, which are otherwise healthy. Even while carrying the HLA-B27 protein alone does not always mean that a person has an autoimmune illness, it nevertheless increases their risk of developing several immune-mediated health conditions.

What is HLA-B27?

HLAs are proteins that assist the body's immune system in distinguishing between the body's cells and external microbes. They are produced using instructions provided by inherited genes. Your body creates a protein known as human leukocyte antigen B27 that helps your immune system recognise foreign materials that are regarded as harmful to the body. 

To safeguard your body from potential harm, human leukocyte antigens seek to eliminate any cell they identify as "foreign and unsafe." However, individuals with the HLA-B27 antigen are considered prone to contracting diseases like autoimmune hepatitis, ankylosing spondylitis, juvenile rheumatoid arthritis, rheumatoid arthritis type II, lupus erythematosus, or Crohn's disease. Geographical location affects the prevalence of the HLA-B27 allele in individuals, with individuals living in northern latitudes having a higher prevalence. 

What is The HLA-B27 Test Procedure?

The procedure for the HLA-B27 test is similar to standard blood-drawing techniques. Trained employees administer it in the clinic using a tiny needle. Typically, they use a small needle to draw blood from your arm. Your blood is drawn from a vein inside your elbow or the back of your hand and put in a tube before being transported to a lab for testing. No additional preparation is required. However, remember to consult your doctor before taking any medications. 

Mild discomfort, soreness/swelling at the injection site, or lightheadedness are the adverse effects seen during the test. The wait time for results is 4–8 days. The length of time depends on the technology being employed, like Flow Cytometry, Sequence-Specific Oligonucleotide Probes (SSOP), or Polymerase Chain Reaction (PCR).

Common Illnesses Due to HLA-B27

When a patient experiences acute or persistent pain and inflammation in their chest, spine, neck, eyes, or joints and their doctor detects an autoimmune condition linked to the existence of HLA-B27, only then may an HLA-B27 test be prescribed. When diagnosing ankylosing spondylitis (AS) and other HLA-B27-related illnesses, doctors frequently depend on their clinical observations and the result of the HLA-B27 test because any unprecedented changes might not be seen for a few years. The HLA-B27 test in this situation does not provide a diagnosis, but it does provide additional information that can either increase or decrease the possibility that the individual has ankylosing spondylitis.

Arthritis is another common illness caused by HLA-B27. It includes inflammation of the vertebrae or spinal joints, which can lead to chronic, ongoing pain and discomfort. Individuals may also suffer from ankylosis, where portions of the spine fuse in a permanent and immovable posture. HLA-B27 is also considered the hallmark of the genetic component of spondyloarthritides, and about 90% of patients with AS carry this antigen.

Understanding The HLA-B27 Test Results 

The test procedure, your age, sexuality, health history, and other factors may affect the test findings. Ask your healthcare practitioner to interpret your test findings for you. A negative test result indicates that the white blood cells in an individual do not have HLA-B27. If you get a positive impact, your blood has HLA-B27 in it. In that case, you could be more susceptible to developing autoimmune conditions, including reactive arthritis and ankylosing spondylitis. 

Remember, though, that a positive test does not always indicate that you have an autoimmune disease; it might indicate arthritis, ankylosis, or other disorders as well. When considering seeking therapy for an autoimmune condition, you should consider your symptoms, clinical examination, and other blood and urine tests. 

What are The Risks of HLA-B27 Test?

Although no preparation is required for the HLA-B27 test, it is advised to let the doctor know before the test if you are taking any drugs or medications, have any underlying medical issues, or have any allergies. Ensure that you follow the doctor's detailed directions. 

People who undergo the HLA-B27 test hold minimal risks. Some people may experience discomfort when their blood is taken. During the trial, you could have pain at the puncture site, and afterwards, you might experience slight discomfort or throbbing. All blood tests include the following risks:

• Multiple needle stick marks as a result of difficulty getting a sample
• A puncture site infection and profuse bleeding
• Fainting or experiencing dizziness
• Hematoma (blood collecting under the skin) 

An HLA–B27 positive patient having HLA antibodies has substantially little threat in donating blood. However, such individuals are not qualified to donate whole blood, which has plasma or plasma blood products like platelets. 

Conclusion

The HLA-B27 test determines if human leukocyte antigen is present or absent. Ankylosing spondylitis (AS), reactive arthritis, juvenile rheumatoid arthritis (JRA), and occasionally anterior uveitis can all be identified by the HLA-B27 blood test. However, the HLA-B27 test is not a conclusive tool for making a diagnosis or excluding a condition. The results of the test should not be interpreted as proof of whether you have an autoimmune condition or not, whether they are positive or negative. Only individuals who have symptoms need to undergo this test. But be sure that all of the medications, vitamins and supplements you use are disclosed to your healthcare professional. This includes any over-the-counter medications you may use. 

If you are experiencing similar symptoms or have been advised by your doctor to undergo the HLA-B27 test, book a test at Metropolis Healthcare.