Combining immunoreactive trypsinogen and pancreatitis-associated protein assays, a method of newborn screening for cystic fibrosis that avoids DNA analysis.
OBJECTIVE
To evaluate the performance of a strategy in which, after immunoreactive trypsinogen (IRT) determination, genetic analysis is replaced by a biological test, the pancreatitis-associated protein (PAP) enzyme-linked immunosorbent assay (ELISA).


METHODS
The French newborn screening program includes cystic fibrosis (CF) screening by the IRT/CFTR mutation strategy. PAP was assayed on screening cards, in parallel with IRT, in all newborns from 5 French regions (n = 204,749). Analysis of PAP values in CF and non-CF newborns with elevated IRT allowed direct comparison between the current strategy and the proposed IRT/PAP strategy.


RESULTS
A protocol in which newborns with IRT >50 ng/mL and PAP >1.8 ng/mL and those with IRT >100 ng/mL and PAP >1.0 ng/mL are directly recalled for sweat testing would have the same performance as the IRT/CFTR mutation strategy.


CONCLUSIONS
The IRT/PAP strategy is an alternative for CF newborn screening, which avoids the drawbacks of genetic analysis and is cheaper and easier to implement than the current IRT/CFTR mutation strategy.
Sarles
Jacques
J
Service de Pédiatrie Multidisciplinaire, Pediatrics Department, Hôpital de la Timone, Marseille, France. jacques.sarles@ap-hm.fr
Berthézène
Patrice
P
Le Louarn
Christian
C
Somma
Claude
C
Perini
Jean-Marc
JM
Catheline
Michael
M
Mirallié
Sophie
S
Luzet
Karine
K
Roussey
Michael
M
Farriaux
Jean-Pierre
JP
Berthelot
Jacques
J
Dagorn
Jean-Charles
JC
D000951:Antigens, Neoplasm / Q000097:blood*; D014408:Biomarkers, Tumor / Q000097:blood*; D003550:Cystic Fibrosis / Q000097:blood / Q000175:diagnosis* / Q000235:genetics; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics*; D004252:DNA Mutational Analysis; D005602:France; D006801:Humans; D007231:Infant, Newborn; D037181:Lectins, C-Type / Q000097:blood*; D015997:Neonatal Screening / Q000191:economics / Q000379:methods*; D000073718:Pancreatitis-Associated Proteins; D012680:Sensitivity and Specificity; D013545:Sweat Glands / Q000503:physiopathology; D014362:Trypsinogen / Q000097:blood*
D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; C505032:CFTR protein, human; D037181:Lectins, C-Type; D000073718:Pancreatitis-Associated Proteins; C000612141:REG3A protein, human; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D014362:Trypsinogen