immunoreactive trypsin

Full Definition

Immunoreactive trypsin (IRT) is a pancreatic enzyme that serves as the primary biochemical marker for cystic fibrosis screening in newborns. Elevated levels in dried blood spots indicate potential pancreatic dysfunction characteristic of cystic fibrosis, though elevations can also occur in other conditions or stress states. IRT screening typically involves age-adjusted cutoff values, and positive results usually trigger second-tier DNA analysis or repeat testing to improve screening specificity and reduce false positive rates.

Usage

Usage note: May be abbreviated as IRT in technical documentation; hyphenate the compound adjective.

In Context

• "Elevated immunoreactive trypsin levels prompted genetic testing for cystic fibrosis mutations." — Laboratory report
• "The screening algorithm used age-specific immunoreactive trypsin cutoffs to reduce false positives." — Technical protocol