Prealbumin (Blood)

Does this test have other names?

PA, transthyretin test

What is this test?

Prealbumin is a protein that is made mainly by your liver. Your body uses prealbumin to make other proteins. Prealbumin also carries thyroid hormones in the blood.

The prealbumin screen is a blood test that used to be used frequently to see if you are getting enough nutrition in your diet. This may be because you have a chronic condition. Or it may be because you have an infection or inflammation, or you suffered a trauma. 

Why do I need this test?

You may need this test if your healthcare provider thinks you may have an infection, inflammation, or poor nutrition. You may also have this test if you have had trauma. Your healthcare provider may also order this test while you are in the hospital to see if you need more nutritional or medical care as part of your treatment.

What other tests might I have along with this test?

To watch your nutritional needs, your healthcare provider might order a C-reactive protein screen. This looks for another protein in your blood. Your provider may also order tests for hemoglobin, albumin, iron, transferrin, folate, and vitamin B-12, and other electrolytes, vitamins, and minerals.

What do my test results mean?

Test results may vary depending on your age, gender, health history, the method used for the test, and other things. Your test results may not mean you have a problem. Ask your healthcare provider what your test results mean for you. 

Low prealbumin scores mean that you are likely to need a nutritional assessment. Low prealbumin scores may also be a sign of liver disease, inflammation, or tissue death (tissue necrosis). High prealbumin scores may be a sign of long-term (chronic) kidney disease, steroid use, or alcoholism.

Normal results for a prealbumin blood test are:

• Adults: 15 to 36 milligrams per deciliter (mg/dL) or 150 to 360 milligrams per liter (mg/L)

• Children: 6 to 21 mg/dL for an infant under 5 days old, 14 to 30 mg/dL for children ages 1 to 5, 15 to 33 mg/dL for children ages 6 to 9, 22 to 36 mg/dL for those ages 10 to 13, 22 to 45 mg/dL for those ages 14 to 19

How is this test done?

The test is done with a blood sample. A needle is used to draw blood from a vein in your arm or hand. 

Does this test pose any risks?

Having a blood test with a needle carries some risks. These include bleeding, infection, bruising, and feeling lightheaded. When the needle pricks your arm or hand, you may feel a slight sting or pain. Afterward, the site may be sore. 

What might affect my test results?

Infection, inflammation, or recent trauma may affect your test results. This could make them more difficult to figure out. Experts suggest that people in the hospital who are tested for prealbumin be tested twice. This should be done 3 to 5 days apart, for more accurate results.

How do I get ready for this test?

No preparation is necessary. Be sure your healthcare provider knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illicit drugs you may use.