Prealbumin (Blood)

Does this test have other names?

PA, transthyretin test

What is this test?

The prealbumin screen is a blood test to see whether you are getting proper nourishment from your diet. Specifically, the test finds out if you have been getting enough protein and if not, whether you are at risk for malnutrition or already suffering from it. Prealbumin is a protein that is made mainly by your liver. Your body uses prealbumin as a building block to make other proteins.

Why do I need this test?

You might have this test if you appear to be malnourished or if doctors want to follow your nutritional progress. Your doctor may also order this test if you are an older adult and he or she suspects you suffer from poor nutrition. Health care providers may also screen children for prealbumin if they appear undernourished. In addition, if you are in the hospital, your doctor might order this test soon after you arrive to see whether you need additional nutritional support as part of your treatment.

What other tests might I have along with this test?

To watch your nutritional needs, your doctor might order a C-reactive protein screen, which looks for another protein in your blood. If you appear to be malnourished, your health care providers may order other tests. These may include hemoglobin, albumin, iron, folate and vitamin B12, and. other electrolytes, vitamins, and minerals.

What do my test results mean?

Many things may affect your lab test results. These include the method each lab uses to do the test. Even if your test results are different from the normal value, you may not have a problem. To learn what the results mean for you, talk with your health care provider.

Low prealbumin scores mean that you are likely at risk for malnutrition and need careful assessment. 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 requires a blood sample, which is drawn through a needle from a vein in your arm.

Does this test pose any risks?

Taking a blood sample with a needle carries a small risk of bleeding, infection, or bruising. You may also feel dizzy. When the needle pricks your arm, you may feel a slight sting. Afterward, the site might be sore.

What might affect my test results?

Infection, inflammation, or recent trauma may affect your test results, making them more difficult to figure out. Experts suggest that people in the hospital be tested twice, three to five days apart, for more accurate results.

How do I get ready for this test?

No preparation is necessary.