Histocompatibility antigen test
HLA typing; Tissue typingA histocompatibility antigen blood test looks at proteins called human leukocyte antigens (HLAs). These are found on the surface of almost all cells in the human body. HLAs are found in large amounts on the surface of white blood cells. They help the immune system tell the difference between body tissue and substances that are not from your own body.
How the Test is Performed
Blood is drawn from a vein. You may feel slight pain or a sting when the needle is inserted. Afterward, there may be some throbbing.
Blood is drawn from a vein
Venipuncture is the collection of blood from a vein. It is most often done for laboratory testing.
Read Article Now Book Mark ArticleHow to Prepare for the Test
You do not need to prepare for this test.
Why the Test is Performed
The results from this test can be used to identify good matches for tissue grafts and organ transplants. These may include kidney transplant or bone marrow transplant.
Kidney transplant
A kidney transplant is surgery to place a healthy kidney into a person with kidney failure.
Read Article Now Book Mark ArticleBone marrow transplant
A bone marrow transplant is a procedure to replace damaged or diseased bone marrow with healthy bone marrow stem cells. Bone marrow is the soft, fatt...
Read Article Now Book Mark ArticleIt may also be used to:
- Diagnose certain autoimmune disorders. Drug-induced hypersensitivity is an example.
- Determine relationships between children and parents when such relationships are in question.
- Monitor treatment with some medicines.
Normal Results
You have a small set of HLAs that are passed down from your parents. Children, on average, will have half of their HLAs match half of their mother's and half of their HLAs match half of their father's.
It is unlikely that two unrelated people will have the same HLA makeup. However, identical twins may match each other.
Some HLA types are more common in certain autoimmune diseases. For example, HLA-B27 antigen is found in many people (but not all) with ankylosing spondylitis and Reiter syndrome.
Autoimmune diseases
An autoimmune disorder occurs when the body's immune system attacks and destroys healthy body tissue by mistake. There are more than 80 autoimmune d...
Read Article Now Book Mark ArticleHLA-B27 antigen
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 (...
Read Article Now Book Mark ArticleAnkylosing spondylitis
Ankylosing 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...
Read Article Now Book Mark ArticleReiter syndrome
Reactive arthritis is a type of arthritis that follows an infection. It may also cause inflammation of the eyes, skin and urinary and genital system...
Read Article Now Book Mark ArticleRisks
There is little risk involved with having your blood taken. Veins and arteries vary in size from one person to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight, but may include:
- Fainting or feeling lightheaded
- Multiple punctures to locate veins
- Hematoma (blood buildup under the skin)
- Excessive bleeding
- Infection (a slight risk any time the skin is broken)
References
Bray R, Sullivan C, 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.
Monos DS, Rajalingam R. The major histocompatibility complex. In: Rich RR, Fleisher TA, Schroeder HW, Weyand CM, Corry DB, Puck JM, eds. Clinical Immunology: Principles and Practice. 6th ed. Philadelphia, PA: Elsevier; 2023:chap 5.
Wang E, Adams S, Stroncek DF, Marincola FM. Human leukocyte antigen and human neutrophil antigen systems. In: Hoffman R, Benz EJ, Silberstein LE et al, eds. Hematology: Basic Principles and Practice. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 114.
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Blood 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 test
illustration
-
Blood 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 test
illustration
Review Date: 1/24/2023
Reviewed By: Anna C. Edens Hurst, MD, MS, Associate Professor in Medical Genetics, The University of Alabama at Birmingham, Birmingham, AL. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.