Blood concentrations of pancreatitis associated protein in neonates: relevance to neonatal screening for cystic fibrosis.
OBJECTIVE
To determine whether pancreatitis associated protein (PAP) is a marker for cystic fibrosis which could be used in neonatal screening for the disease.


METHODS
PAP was assayed on screening cards from 202,807 neonates. Babies with PAP > or = 15 ng/ml, or > or = 11.5 ng/ml and immunoreactive trypsinogen (IRT) > or = 700 ng/ml were recalled for clinical examination, sweat testing, and cystic fibrosis transmembrane regulator (CFTR) gene analysis.


RESULTS
Median PAP value was 2.8 ng/ml. Forty four cases of cystic fibrosis were recorded. Recalled neonates (n = 398) included only 11 carriers. A receiver operating characteristic curve analysis showed that PAP above 8.0 ng/ml would select 0.76% of babies, including all those with cystic fibrosis, except for one with meconium ileus and two with mild CFTR mutations. Screening 27,146 babies with both PAP and IRT showed that only 0.12% had PAP > 8.0 ng/ml and IRT > 700 ng/ml, including all cases of cystic fibrosis.


CONCLUSIONS
PAP is increased in most neonates with cystic fibrosis and could be used for CF screening. Its combination with IRT looks promising.
D000209:Acute-Phase Proteins / Q000032:analysis*; D000951:Antigens, Neoplasm; D015415:Biomarkers / Q000097:blood; D014408:Biomarkers, Tumor; D003550:Cystic Fibrosis / Q000097:blood / Q000175:diagnosis* / Q000235:genetics; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics; D006801:Humans; D007231:Infant, Newborn; D037181:Lectins, C-Type; D015997:Neonatal Screening / Q000379:methods*; D000073718:Pancreatitis-Associated Proteins; D011237:Predictive Value of Tests; D011446:Prospective Studies; D014362:Trypsinogen / Q000097:blood