Trypsinogen (Blood)

Does this test have other names?

Immunoreactive trypsinogen, IRT

What is this test?

This test measures the amount of trypsinogen in the blood. Trypsinogen is a chemical made by the pancreas. It's usually made in small amounts to help with digestion.

In premature babies or babies who had a stressful birth, levels of trypsinogen in the blood may be higher than normal. High levels of trypsinogen in a newborn may mean the baby has cystic fibrosis (CF). To find health problems early, trypsinogen is checked as part of a routine newborn health screening.     

Why do I need this test?

Routine newborn screening is done for all babies to check for a variety of different blood parts, including trypsinogen.  

In children and adults, a high level of trypsinogen can be a sign of a pancreas problem. You may need this test if your healthcare provider thinks that you have pancreatic disease or insufficiency.

What other tests might I have along with this test?

As part of a newborn screening, other blood components will be measured.

If you're having the test because of a possible pancreas problem, you may also need other tests. These include:

• Pancreatic function test

• Pancreatic enzymes (such as amylase and lipase) test

• Fecal matter composition test

What do my test results mean?

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

In general, a level of trypsinogen that's higher than normal could mean that a newborn has CF. Babies with high levels usually have a second test several weeks after birth to confirm the diagnosis.

In an older child or an adult, a high level of trypsinogen can mean a disorder of the pancreas.

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.

For a newborn, a sample of blood is usually taken from the heel. It is placed on a special card and sent to a lab.

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. A newborn may feel a small amount of discomfort for a short time when the heel is pricked. Afterward, the site may be sore.

What might affect my test results?

Trypsinogen levels can rise throughout the day and be higher after a meal.

How do I get ready for this test?

For newborns, no special preparation is needed for a trypsinogen test.  

Children and adults may need to fast for 8 hours before the test. Your healthcare provider will give you specific instructions. Be sure your provider knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illegal drugs you may use.