Cystic Fibrosis Diagnosis in Newborns, Children, and Adults

Carlo Castellani, MD; Barry Linnane, MB, BCh, BAO, DCH, MRCPI, MRCPCH, MD; Iwona Pranke, PhD; Federico Cresta, MD; Isabelle Sermet-Gaudelus, MD, PhD; Daniel Peckham, MD


Semin Respir Crit Care Med. 2019;40(6):701-714. 

In This Article

IRT: The Basics

Of the digestive enzymes, trypsin is the only one produced solely by the pancreas.[71] The major form in blood is trypsinogen. The acinar cells of the pancreas secrete enzymatically inactive trypsinogen, which is then activated to trypsin. Current methods for measuring IRT in dried blood spots use an immunohistochemistry "sandwich" technique.[71] IRT present in a sample binds to a monoclonal antibody attached to a solid matrix. A second, labeled, antibody then binds with the IRT molecule and colorimetry or fluorometry is used to measure the amount of labeled antibody from which the concentration of IRT is derived.[71]