Screening for Cystic Fibrosis among Newborns in Norway by Measurement of Serum/Plasma Trypsin-Like Immunoreactivity: Results of a 2-Year Pilot Project

Abstract

A pilot project for neonatal screening for cystic flbrosis (CF) by measuring trypsin-like immunoreactivity (TLI) in liquid serum or plasma samples was carried out in Norway from May 1982 to December 1984. A total of 72,320 newborns was screened. Twelve infants were recalled for sweat testing; 11 were confirmed to have CF. One infant had normal sweat sodium and chloride levels and no clinical symptoms. The incidence of CF in this study was 1:6574, and the recall rate for second blood samples was 0.6%. No false-negative cases have yet been reported. The level of TLI was affected by the use of heparin in plasma preparation, being reduced by about 20% as compared to serum levels.

Key Words:

• Cystic flbrosis
• neonatal screening
• trypsin-like immunoreactivity