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What to Know About AMA Tests

Medically Reviewed by Dan Brennan, MD on June 07, 2021

Your cells have energy centers called mitochondria. They’re the powerhouses that fuel the functions of most cells in your body. Antimitochondrial antibodies (AMAs) are substances that are present in your blood when your body tries to attack its own cells. ‌

This is also known as an autoimmune disorder, and it is a serious health condition. It means that your body is turning against itself, confusing your own healthy cells with a disease or foreign material. 

If that happens, AMAs will be present inside your blood. Doctors usually see AMAs in the blood of people with a liver disease called primary biliary cholangitis (PBC), which used to be called primary biliary cirrhosis. 

What Is an AMA Test?

An AMA test checks for the presence of antimitochondrial antibodies in a blood sample that you're asked to provide. The test can help answer lots of questions about your health and ensure that you get proper treatment recommendations.

Who May Need an AMA Test?

A doctor may order an AMA test if you have symptoms that are common with PBC or another autoimmune disorder. The symptoms could be: ‌

  • Fatigue 
  • Chronic itchy skin (pruritus)
  • Pain in the muscles and joints
  • Abdominal pain
  • Weight loss
  • Nausea
  • Yellowing of the skin and eyes (jaundice)
  • Decreased appetite
  • Fluid buildup around the feet, ankles, or abdomen 
  • Dry mouth 
  • Dryness in the eyes  ‌

Almost 19 out of 20 people who have primary biliary cholangitis will test positive for AMAs in their blood. PBC is a disease that affects the liver. ‌

Your liver makes bile for several reasons, such as ensuring smooth digestion, getting rid of toxins, and disposing of cholesterol. The liver releases bile through ducts. PBC damages the ducts and keeps the bile inside the liver, which causes scarring.

Over time, the scarring impairs the function of the liver and can eventually lead to liver failure. PBC is common in women ages 35 to 60.‌

How Is the Test Performed?

Before the test. Make sure you tell your doctor about all medicines, drugs, or supplements you take prior to the test. That includes any nonprescription or illegal substances. All substances can affect your results.   

Your health care provider may instruct you to not eat or drink for six hours before the test. That will help ensure your results are accurate. Otherwise, there’s usually no special preparation for this test. 

At the test. A lab staffer or other medical professional makes a small puncture mark in your vein with a needle and withdraws blood. 

Everyone’s tolerance to pain is different. Some people may only feel a small prick of the needle, while others may find it more painful. Afterward, the site may be sore or throb slightly. 

Risks. There are some risks involved with having a blood sample taken. You may feel lightheaded afterward, especially if you were required to fast before the test. Fainting after having blood drawn is also fairly common. 

Blood pooling under the skin, or hematoma, is also a risk. Infection is possible whenever there’s a break in the surface of your skin. 

After the test. Often, after the blood analysis is completed, medical staff will call you and explain the results of your test. You may not get a diagnosis immediately after your AMA test. It's possible your doctor may want to search further and get a clearer picture of your medical condition. 

What Do Your AMA Test Results Mean?

A doctor or similarly qualified medical professional tests for AMA by studying your blood sample. The test detects how much AMA, if any, is in your blood.  

An AMA test result is considered normal when it doesn’t detect any AMAs. But testing negative doesn’t always rule out the disease either. Five to 10 percent of people with PBC don’t have AMAs in their blood.

‌If you test positive for AMAs, the test results will also tell you what level, or titer, you have. But testing positive for AMAs in your blood doesn’t always mean you have PBC. AMAs can also show up when you have the following autoimmune conditions:‌

  • Lupus
  • Scleroderma
  • Rheumatoid arthritis
  • Thyroiditis 

An AMA test alone doesn't always offer a complete picture of your health. A doctor may order others if they need more information or clarity. Other possible tests include: ‌

  • Albumin
  • IgM level
  • Bilirubin
  • C-reactive protein (CRP)
  • Prothrombin time (PT) 
  • Alkaline phosphatase (ALP)
  • Smooth muscle antibodies (SMI)
  • Antinuclear antibodies (ANA)
  • GGT

‌Imaging scans of the liver or a liver biopsy may also be recommended before confirming a diagnosis of PBC. ‌ ‌

Those results will usually be taken into account along with other tests and symptoms you’re experiencing. All this information will help your doctor make a proper diagnosis. 

WebMD Medical Reference

Sources

SOURCES: 

LabTests Online: “Antimitochondrial Antibody and AMA M2.”

Mayo Clinic: “Primary biliary cholangitis.”

Mount Sinai: “Antimitochondrial antibody.”

PBCers Organization: “Antimitochondrial Antibodies (AMA).”

University of Rochester Medical Center: “Antimitochondrial Antibody and Antimitochondrial M2 Antibody.”

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