[Newborn Screening on Cystic Fibrosis in Germany: Comparison of the new Screening Protocol with an Alternative Protocol].

Abstract

Background For the new cystic fibrosis (CF) newborn screening program in Germany the Federal Joint Committee (G-BA) implemented a new screening protocol using immunoreactive trypsinogen (IRT) as first and pancreatitis associated protein (PAP) as second tier. Gene analysis with a panel of 31 CFTR-mutations is used as third tier to increase the positive predictive value (PPV) which is known to be low in pure biochemical IRT/PAP protocols. Methods For post hoc analysis the data pool (n=372 906) of a study evaluating a pure biochemical IRT/PAP protocol was used for assessment of the 3-step G-BA protocol in comparison with an alternative screening protocol recommended by the authors. The difference between the 2 protocols is the procedure when IRT>99.9th percentile. In the G BA protocol PAP and DNA analysis will be by-passed while in the alternative protocol only the PAP step will be circumvented. Results Both 3-tier IRT/PAP+SN/DNA protocols did not lose sensitivity due to addition of genetic analysis when the results were compared to those of the 2-tier biochemical IRT/PAP protocol. However, the protocols provide different results regarding PPV. The G-BA protocol showed with 351 a much higher number of false-positively detected newborns (PPV 20.2%) when compared to 31 false-positively detected newborns in the alternative protocol (PPV 69.6%). Conclusions The G-BA protocol had a worse performance when compared with the alternative protocol recommended by the authors. The higher number of false-positively detected newborns using the G-BA protocol will lead to more consultations including sweat tests, will create more anxiety in parents, and will result in higher costs after screening.

• Authors: Olaf Sommerburg, Mirjam Stahl, Jutta Hammermann, Jürgen G Okun, Andreas Kulozik, Georg Hoffmann, Marcus Mall
• Journal: Klinische Padiatrie (Klin Padiatr) Vol. 229 Issue 2 Pg. 59-66 (Mar 2017) ISSN: 1439-3824 [Electronic] Germany
• Vernacular Title: Neugeborenenscreening auf Mukoviszidose in Deutschland: Vergleich des neuen Screening-Protokolls mit einem Alternativprotokoll.
• PMID: 28444650 (Publication Type: Comparative Study, Journal Article)
• Copyright: © Georg Thieme Verlag KG Stuttgart · New York.

Chemical References

• CPB1 protein, human
• Carboxypeptidase B
• Trypsin

Topics

• Carboxypeptidase B (genetics)
• Cross-Sectional Studies
• Cystic Fibrosis (epidemiology, genetics, prevention & control)
• DNA Mutational Analysis
• False Positive Reactions
• Female
• Genetic Testing
• Germany
• Humans
• Infant, Newborn
• Male
• Neonatal Screening (methods)
• Trypsin (genetics)