SCREENING FOR CYSTIC-FIBROSIS BY DRIED BLOOD SPOT TRYPSIN ASSAY

Abstract

Immunoreactive trypsin was measured in dried blood specimens from 14,000 infants. A 2nd test was performed in 0.2% of the population in whom blood trypsin levels were > 80 ng/ml. Five infants with cystic fibrosis were then detected, with only 1 case of persistent hypertrypsinemia in whom this diagnosis could not be established. No false-negative test results have yet been identified. Seventeen infants with cystic fibrosis were tested in the first 2 wk of life, only one of whom had a blood trypsin concentration < 80 ng/ml.