HLA-B27抗原

定义

HLA-B27 is a blood test to look for a protein that is found on the surface of white blood cells. The protein is called human leukocyte antigen B27 (HLA-B27).

Human leukocyte antigens (HLAs) are proteins that help the body's immune system tell the difference between its own cells and foreign, 有害物质. They are made from instructions by inherited genes.

选择的名字

Human leukocyte antigen B27; Ankylosing spondylitis-HLA; Psoriatic arthritis-HLA; 反应性关节炎-HLA

How the Test is Performed

A blood sample is needed. Most of the time, blood is 从静脉中抽出 located on the inside of the elbow or the back of the hand.

How to Prepare for the Test

No special steps are needed to prepare for the test.

How the Test will Feel

When the needle is inserted to draw blood, you may feel moderate pain, or only a prick or stinging sensation. Afterward, there may be some throbbing.

Why the Test is Performed

Your health care provider may order this test to help determine the cause of joint pain, 刚度, 或肿胀. The test may be done along with other tests, including:

• Anti-cyclic citrullinated peptide (CCP) antibody
• c反应蛋白
• Erythrocyte sedimentation rate (ESR)
• 类风湿因子
• x射线

HLA测试 is also used to match donated tissue with a person's tissue who is getting an organ transplant. For example, it may be done when a person needs a 肾移植 or bone marrow transplant.

正常的结果

A normal (negative) result means HLA-B27 is absent.

What Abnormal Results Mean

A positive test means HLA-B27 is present. It suggests a greater-than-average risk for developing or having certain autoimmune disorders. An autoimmune disorder is a condition that occurs when the immune system mistakenly attacks and destroys healthy body tissue.

A positive result can help your provider make a diagnosis of a form of arthritis called spondyloarthritis. This kind of arthritis includes the following disorders:

• Ankylosing spondylitis
• 与以下疾病有关的关节炎 克罗恩病 或者溃疡性结肠炎
• Psoriatic arthritis (arthritis associated with psoriasis)
• 反应性关节炎
• Sacroiliitis (inflammation of the sacroiliac joint)
• 葡萄膜炎

If you have symptoms or signs of spondyloarthritis, a positive HLA-B27 test may help confirm the diagnosis. However, HLA-B27 is found in some normal people and does not always mean you have a disease.

风险

风险 from having blood drawn are slight, but may include:

• 大出血
• Fainting or feeling lightheaded
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)

参考文献

Bray R, Sullivan HC, Krummey S, Gebel HM. Human leukocyte antigen: the major histocompatibility complex of humans. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24日艾德. Philadelphia, PA: Elsevier; 2022:chap 50.

Lienesch DW. Spondyloarthritis. In: Wing EJ, Schiffman FJ, eds. Cecil Essentials of Medicine. 10日艾德. Philadelphia, PA: Elsevier; 2022:chap 80.

McPherson RA, Massey HD. Overview of the immune system and immunologic disorders. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24日艾德. Philadelphia, PA: Elsevier; 2022:chap 44.

Reveille JD, Ridley LK. Spondyloarthritis. In: Rich RR, Fleisher TA, Schroeder HW, Weyand CM, Corry DB, Puck JM, eds. Clinical Immunology: Principles and Practice. 6日艾德. Philadelphia, PA: Elsevier; 2023:chap 58.