Trypsinogen: Blood Test and Levels Explained

What Is Trypsinogen?

Trypsinogen is a substance produced by the pancreas. It is an inactive form of trypsin, an enzyme that catalyzes the digestion of proteins.

Under normal conditions, small amounts of trypsinogen enter the bloodstream. Measuring trypsinogen levels in blood helps doctors understand how well the pancreas is functioning. When the pancreas is stressed, damaged, or not working properly, trypsinogen levels may rise.

The trypsinogen blood test is commonly used in newborn screening programs. Elevated trypsinogen levels in newborns may suggest cystic fibrosis, a genetic condition that affects the lungs and digestive system.

When Is Trypsinogen Testing Recommended?

The trypsinogen test is most often used during newborn screening, but it may also be ordered later in life when pancreatic disease is suspected.

Common reasons include:

• Routine newborn screening for cystic fibrosis
• Follow-up testing after abnormal newborn screening results
• Suspected pancreatic disease
• Signs of pancreatic insufficiency
• Unexplained digestive problems
• Monitoring pancreatic health

How Is Trypsinogen Testing Conducted?

Trypsinogen levels are measured using a blood test.

For adults and older children, blood is taken from a vein in the arm using a needle. The sample is sent to a laboratory to measure trypsinogen in the bloodstream.

For newborn screening, a small blood sample is usually taken from the baby’s heel. The blood is placed on a special collection card and sent to a laboratory for analysis.

Preparation for the test depends on age:

• Newborns: No preparation is required.
• Children and adults: Fasting for about 8 hours may be recommended.

Your healthcare provider will give specific instructions before the test.

What Are the Normal Trypsinogen Levels?

Normal trypsinogen levels can vary depending on age, laboratory methods, and the type of testing used.

What Do High Trypsinogen Levels Mean?

Elevated trypsinogen levels often suggest that the pancreas is under stress or not functioning normally.

Possible causes include:

• Cystic fibrosis in newborns: High immunoreactive trypsinogen levels may be an early sign of cystic fibrosis detected during newborn screening.
• Pancreatic disorders: Damage or inflammation of the pancreas can increase trypsinogen levels in the blood.
• Pancreatic insufficiency: When the pancreas cannot produce enough digestive enzymes, trypsinogen levels may rise.

Recommendations

• Follow up with confirmatory testing if screening results are abnormal.
• Monitor pancreatic function through additional laboratory tests if advised.
• Seek medical evaluation if digestive symptoms persist.
• Repeat testing may be needed to confirm results or monitor pancreatic health.

Which Specialist Should You Consult?

The appropriate specialist depends on the reason for testing.

You may be referred to:

• A pediatrician or genetic specialist for abnormal newborn screening results
• A gastroenterologist for pancreatic disorders
• A pulmonologist for cystic fibrosis management