Immunoreactive trypsinogen, IRT, newborn screening
This test measures the amount of trypsinogen in the blood. Trypsinogen is a chemical produced by the pancreas. It is usually made in small amounts to help with digestion.
In premature babies or babies who had a stressful delivery, levels of trypsinogen in the blood may be elevated. High levels of trypsinogen in a newborn are also an indicator of cystic fibrosis (CF). To find health problems early, trypsinogen is measured as part of a routine newborn health screening.
Routine newborn screening is done for all babies to check for a variety of different blood components, 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 health care provider suspects that you have pancreatic disease or insufficiency.
As part of a newborn screening, other blood components will be measured.
If you're having the test because of a possible pancreas problem, your doctor may order other tests, including:
Pancreatic function test
Pancreatic enzymes (such as amylase and lipase) test
Fecal matter composition test
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.
In general, a level of trypsinogen that's higher than normal could mean that a newborn has cystic fibrosis or is a carrier of the disease. Infants with high levels usually have a second test several weeks after birth to confirm the diagnosis.
In an older child or an adult, an elevated level of trypsinogen can signal a disorder of the pancreas.
The test requires a blood sample, which is drawn through a needle from a vein in your arm.
Blood samples from newborns are usually taken from the heel.
Taking a blood sample with a needle carries risks that include bleeding, infection, bruising, or feeling dizzy. When the needle pricks your arm, you may feel a slight stinging sensation or pain. Afterward, the site may be slightly sore.
Trypsinogen levels can rise throughout the day and be higher after a meal.
For newborns, no special preparation is needed for a trypsinogen test.
Children and adults may need to fast for eight hours before the test. Your health care provider will give you specific instructions. Be sure your doctor 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.