It is a surface antigen, known as Human Leukocyte Antigen B27, fully expanded and referred to in medical literature as HLA-B27.
Why is HLA-B27 Test Done?
This test is performed to find out whether HLA-B27, which can cause autoimmune diseases in the human body, is present in the body.
When is the HLA-B27 Test Performed?
Testing can be done for many different reasons. It can be done especially in men over the age of 30 if they are experiencing pain and chronic inflammation. This test is done if you show signs of stiffness in various parts of the body, such as back, neck and chest.
Which Samples Are Taken?
Taking a blood sample from a vein in any of your arm is sufficient for the HLA-B27 test.
What Are We Testing?
The main purpose of performing this test is to understand whether HLA-B27 (human leukocyte antigen) is found in the white blood cells. Every person has an inherited amount of HLA antigens on the surface of white blood cells and other cells. HLA antigen is divided into two different groups. The first of these is called Class I, and the second is Class II. The combination of different species within these groups creates an individual-specific HLA combination.
This HLA-B27 (human leukocyte antigen) is a suite of proteins that allows the body's immune system to recognize its own cells.
HLA-B27 found in the blood sample indicates a number of autoimmune diseases. Various diseases develop with the presence of HLA-B27 (human leukocyte antigen). One of the most common of these diseases is ankylosing spondylitis. More than 90% of ankylosing spondylitis (AS) patients are HLA-B27 positive. HLA-B27 is between 40% and 70% positive in cases with isolated acute anterior uveitis.
In addition, approximately 80% of patients with Reiter's syndrome and juvenile rheumatoid arthritis are HLA-B27 positive. In these patients, the main cause of the disease is not HLA-B27, but when the patient population is examined, it stands out as a high factor. In addition to the diseases listed above, HLA-B27 can also be found in inflammatory bowel disease or some other chronic diseases.
How and When Are Samples Used?
The HLA-B27 test is primarily used to confirm various chronic diseases. At the same time, HLA-B27 test is performed to diagnose Reiter's syndrome, suspected ankylosing spondylitis (AS) or anterior uveitis and to make sure. This test is used as evidence by collecting laboratory tests, findings, to clarify the diagnosis of specific autoimmune diseases (such as ankylosing spondylitis or Reiter's syndrome). In addition, HLA-B27 does not provide a treatment method that can be applied to diagnose or eliminate a disease. Ankylosing spondylitis (AS) and Reiter's syndrome are chronic diseases seen in men rather than women. These chronic diseases start to show their first symptoms at an early age (average 30).
Symptoms include inflammation of skin lesions, inflammation of the urethra, and pain of ankylosing spondylitis. In most cases, the symptoms of these autoimmune diseases are hidden.
For example, anterior uveitis is seen with inflammations that sometimes show symptoms in one eye and sometimes in both eyes. In addition, it takes several years for profound degenerative changes in bones and joints to be visible in x-ray results.
HLA-B27 (human leukocyte antigen) may also be a test used to evaluate and examine conditions that cause chronic joint pain, stiffness, or inflammation. In addition to such situations, HLA-B27 may be requested for evaluation of recurrent uveitis cases caused by a known disease process.
What do the results of the HLA-B27 test mean?
Not all people may have HLA-B27. If a patient has HLA-B27 and chronic pain, degenerative changes in bones or signs of inflammation, the HLA-B27 test performed afterwards supports different diseases. It may indicate the presence of ankylosing spondylitis (AS), Reiter's syndrome, and various autoimmune diseases. In this case, if the patient; If a man is in his mid-40s and shows symptoms, the HLA-B27 result is certain to be positive. This is unlikely in people who do not have the specific symptoms mentioned above or who do not have HLA-B27-related disease in their pedigree. However, this does not help to predict any autoimmune disease that may occur in the person. If there is no relevant disease in people, it is difficult to predict predictions such as the course of the disease, the type of the disease or which organs it will affect in the presence of HLA-B27. In cases where there is no HLA-B27, there is no such relationship. But it does not mean that it cannot carry the symptoms mentioned earlier. Many people with these diseases have a negative HLA-B27 test result.
What Is Underlying Autoimmune Diseases?
In different situations, the underlying cause of autoimmune diseases is unknown. In Salmonella, Yersinia, Chlamydia, Ureaplasma, Campylobacter and some Reiter syndromes, there is a significant relationship between a microorganism and the onset of infection and disease. The similarity between the HLA-B27 antigen and the antigens on different microorganism surfaces causes the immune system to fight the tissues. At the same time, these microorganisms initiate the fight against the patient's own tissues. Autoimmune disease occurs after the infection is removed.
Are There Different Topics I Should Know?
If your family members have a disease affecting the spinal joints developed due to HLA-B27, you also have the HLA-B27 antigen.
You are most likely at risk of contracting a similar disease. Because the presence of HLA antigens is investigated by genetic means.
The production of these antigens is controlled by pairs of genes that come from the mother and father to the children. Thanks to the methods developed in our age, it has become possible to separate this antigen into subgroups.