Alpha-1 antitrypsin (AAT) is a lab test to measure the amount of AAT in your blood. The test is also done to check for abnormal forms of AAT VSports手机版.
How the Test is Performed
A blood sample is needed.
How to Prepare for the Test
There is no special preparation.
V体育安卓版 - How the Test will Feel
When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or a slight bruise V体育安卓版. This soon goes away.
"V体育ios版" Why the Test is Performed
This test is helpful in identifying a rare form of emphysema in adults and a rare form of liver disease (cirrhosis) in children and adults caused by an AAT deficiency V体育ios版. AAT deficiency is passed down through families. The condition causes the liver to make too little of AAT, a protein that protects the lungs and liver from damage.
Everyone has two copies of the gene that makes AAT. People with two variant copies of the gene have lower blood levels and are at risk for more severe disease VSports最新版本. Different gene variants may cause differing severity of illness.
Normal Results
Normal value ranges may vary slightly among different laboratories V体育平台登录. Talk to your health care provider about the meaning of your specific test results.
What Abnormal Results Mean (VSports app下载)
A lower-than-normal level of AAT may be associated with:
- Damage of the large airways in the lungs ("VSports在线直播" bronchiectasis)
- Scarring of the liver (cirrhosis)
- Chronic obstructive pulmonary disease (COPD)
- Liver tumors
- Yellowing of the skin and eyes due to blocked bile flow (obstructive jaundice)
- High blood pressure in the large vein that leads to the liver (portal hypertension)
"VSports在线直播" Risks
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 V体育官网入口. 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 accumulating under the skin)
- Infection (a slight risk anytime the skin is broken)
Alternative Names
A1AT test
"VSports" References
Dietzen DJ, Willrich MAV V体育2025版. Amino acids, peptides, and proteins. In: Rifai N, Chiu RWK, Young I, Burnham C-AD, Wittwer CT, eds. Tietz Textbook of Laboratory Medicine. 7th ed. St Louis, MO: Elsevier; 2023:chap 31.
Han MK, Lazarus SC. COPD: diagnosis and management VSports. In: Broaddus VC, Ernst JD, King TE, et al, eds. Murray and Nadel's Textbook of Respiratory Medicine. 7th ed. Philadelphia, PA: Elsevier; 2022:chap 64.
Masson VK, Boas SR. a1 - Antitrypsin deficiency and emphysema. In: Kliegman RM, St. Geme JW, Blum NJ, et al, eds. Nelson Textbook of Pediatrics. 22nd ed. Philadelphia, PA: Elsevier; 2025:chap 442.
"V体育2025版" Review Date 8/19/2024
Updated by: Allen J. Blaivas, DO, Division of Pulmonary, Critical Care, and Sleep Medicine, VA New Jersey Health Care System, Clinical Assistant Professor, Rutgers New Jersey Medical School, East Orange, NJ. 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.