Neonatal cystic fibrosis screening

Alternative names:

cystic fibrosis screening, neonatal; immunoreactive trypsinogen

Normal values:

The predicted value of a normal or negative test is an immunoreactive trypsinogen value less than 140 ng/dl.

Note: ng/dl = nanograms per deciliter

What abnormal results mean:

Abnormal results, and the strength of the test in predicting CF is based on where your child's test results fall in relation to the values of all tested children to date and if the test is positive on repeat examination.

If you child's level of immunoreactive trypsinogen is greater than 140 ng/dl on the first screen, the test result is considered positive. If your child's level is 120 ng/dl on the second screen, the second test result is also considered positive.

While these two test results indicate CF may exist, a sweat test with a positive result confirms the diagnosis.

Note: ng/dl = nanograms per deciliter