BACK TOTOP Browse A-ZSearchBrowse A-ZABCDEFGHIJKLMNOPQRSTUVWXYZ0-9 E-mail FormEmail ResultsName:Email address:Recipients Name:Recipients address:Message: Print-FriendlyBookmarksbookmarks-menuHLA-B27 antigenHuman leukocyte antigen B27; Ankylosing spondylitis-HLA; Psoriatic arthritis-HLA; Reactive arthritis-HLAHLA-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, harmful substances. They are made from instructions by inherited genes. How the Test is Performed A blood sample is needed. Most of the time, blood is drawn from a vein located on the inside of the elbow or the back of the hand. Drawn from a veinVenipuncture is the collection of blood from a vein. It is most often done for laboratory testing.ImageRead Article Now Book Mark Article 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, stiffness, or swelling. The test may be done along with other tests, including:C-reactive protein C-reactive proteinC-reactive protein (CRP) is produced by the liver. The level of CRP rises when there is inflammation throughout the body. It is one of a group of p...ImageRead Article Now Book Mark Article Erythrocyte sedimentation rate (ESR) ESRESR stands for erythrocyte sedimentation rate. It is commonly called a "sed rate. "It is a test that indirectly measures the level of certain protei...Read Article Now Book Mark Article Rheumatoid factor Rheumatoid factorRheumatoid factor (RF) is a blood test that measures the amount of the RF antibody in the blood.ImageRead Article Now Book Mark Article X-rays HLA testing 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 kidney transplant or bone marrow transplant.HLA testing A histocompatibility antigen blood test looks at proteins called human leukocyte antigens (HLAs). These are found on the surface of almost all cells...ImageRead Article Now Book Mark Article Kidney transplantA kidney transplant is surgery to place a healthy kidney into a person with kidney failure.ImageRead Article Now Book Mark Article Bone marrow transplantA bone marrow transplant is a procedure to replace damaged or destroyed bone marrow with healthy bone marrow stem cells. Bone marrow is the soft, fat...ImageRead Article Now Book Mark Article Normal Results 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 Ankylosing spondylitisAnkylosing spondylitis (AS) is a chronic form of arthritis. It mostly affects the bones and joints at the base of the spine where it connects with t...ImageRead Article Now Book Mark Article Arthritis related to Crohn disease or ulcerative colitis Crohn diseaseCrohn disease is a disease where parts of the digestive tract become inflamed. It most often involves the lower end of the small intestine and the be...ImageRead Article Now Book Mark Article Psoriatic arthritis (arthritis associated with psoriasis) Reactive arthritis Reactive arthritisReactive arthritis is a type of arthritis that follows an infection. It may also cause inflammation of the eyes, skin and urinary and genital system...ImageRead Article Now Book Mark Article Sacroiliitis (inflammation of the sacroiliac joint) UveitisUveitisUveitis is swelling and inflammation of the uvea. The uvea is the middle layer of the wall of the eye. The uvea supplies blood for the iris at the ...ImageRead Article Now Book Mark Article 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. Risks Risks from having blood drawn are slight, but may include:Excessive bleeding Fainting or feeling lightheaded Hematoma (blood accumulating under the skin) Infection (a slight risk any time the skin is broken) Open ReferencesReferencesBray 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. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 50.Chernecky CC, Berger BJ. Human Leukocyte Antigen (HLA) B-27 - blood. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures. 6th ed. St Louis, MO: Elsevier Saunders; 2013:654-655.Lienesch DW. Spondyloarthritis. In: Wing EJ, Schiffman FJ, eds. Cecil Essentials of Medicine. 10th ed. 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. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 44.Reveille JD. Spondyloarthritis. In: Rich RR, Fleisher TA, Shearer WT, Schroeder HW, Frew AJ, Weyand CM, eds. Clinical Immunology: Principles and Practice. 5th ed. Philadelphia, PA: Elsevier; 2019:chap 57.AllVideoImagesTogBlood test - illustration Blood is drawn from a vein (venipuncture), usually from the inside of the elbow or the back of the hand. A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. Preparation may vary depending on the specific test.Blood testillustrationBlood test - illustration Blood is drawn from a vein (venipuncture), usually from the inside of the elbow or the back of the hand. A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. Preparation may vary depending on the specific test.Blood testillustration Tests for HLA-B27 antigen HLA-B27 antigenHistocompatibility antigen testRelated Information Histocompatibility antigen test(Medical Test)Kidney transplant(Surgery)Bone marrow transplant(Surgery)Autoimmune disorders(Condition)Ankylosing spondylitis(Condition)Reactive arthritis(Condition) Review Date: 5/2/2021 Reviewed By: Diane M. Horowitz, MD, Rheumatology and Internal Medicine, Northwell Health, Great Neck, NY. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. 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