What are the other Names for this Test? (Equivalent Terms)
- Human Leukocyte Antigen B27 Blood Test
What is HLA-B27 Blood Test? (Background Information)
- Human leukocyte antigen (HLA) proteins are immune complexes on the surfaces of most human cells. They are recognized by the cluster of differentiation (CD) proteins on the surfaces of certain white blood cells, called T lymphocytes
- In non-humans, HLA proteins are called major-histocompatibility (MHC) complexes. More information is available about MHCs than HLAs, because non-human immune systems are less complex and easier to study than human immune systems
- The MHC class I equivalents of HLAs include HLA-A, HLA-B, and HLA-C. They are present on all cells with a nucleus and they display samples from a cell’s internal environment to cytotoxic T cells
- Cytotoxic T cells contain CD8. If they detect abnormalities in the HLA-A/B/C-displaying cell, they destroy it. Cytotoxic T cells constitute the body’s cell-mediated immunity, which defends from threats by virus-infected and cancerous cells
- The MHC class II equivalents of HLAs include HLA-DP, HLA-DM, HLA-DOA, HLA-DOB, HLA-DQ, and HLA-DR. They are present only on the surfaces of cells that are active engulfers or phagocytes, of other cells. These cells display fragments of what they have engulfed to helper T cells. Helper T cells contain CD4 and they activate B cells to mount an immune response. They also produce memory cells
- HLA-B27 is a version of HLA-B. It is clinically significant, because it is associated with various autoimmune disorders. The instructions for HLA-B27 are encoded on the HLA-B27 gene
- The HLA-B27 Blood Test is a test to detect the presence of HLA-B27 on the surfaces of nucleated cells. It is used to assess the likelihood of autoimmune diseases associated with HLA-B27
What are the Clinical Indications for performing the HLA-B27 Blood Test?
Following are the clinical indications for performing the HLA-B27 Blood Test:
- Joint pain and stiffness
- Eye inflammation
- Trouble urinating
- Swollen fingers or toes
How is the Specimen Collected for HLA-B27 Blood Test?
Following is the specimen collection process for HLA-B27 Blood Test:
Sample required: Blood
Process: Insertion of a needle into an arm vein.
Preparation required: No special preparation is needed prior to the test.
What is the Significance of the HLA-B27 Blood Test Result?
The presence of HLA-B27 in blood may indicate:
- Ankylosing spondylitis
- Juvenile rheumatoid arthritis
- Reiter’s syndrome
- Psoriatic arthritis
The laboratory test results are NOT to be interpreted as results of a "stand-alone" test. The test results have to be interpreted after correlating with suitable clinical findings and additional supplemental tests/information. Your healthcare providers will explain the meaning of your tests results, based on the overall clinical scenario.
Additional and Relevant Useful Information:
- The HLA-B27 Blood Test is not diagnostic tool. The presence of HLA-B27 does not definitively indicate that an autoimmune disorder is present. It is only associated with certain disorders
Certain medications that you may be currently taking may influence the outcome of the test. Hence, it is important to inform your healthcare provider, the complete list of medications (including any herbal supplements) you are currently taking. This will help the healthcare provider interpret your test results more accurately and avoid unnecessary chances of a misdiagnosis.