Retrospective analysis of stored dried blood spots from children with cystic fibrosis and matched controls to assess the performance of a proposed newborn screening protocol in Switzerland

Abstract

All children but one with atypical CF would have been detected with the planned two step protocol.

Comparison of two sweat test systems for the diagnosis of cystic fibrosis in newborns

“…Genomic DNA was extracted from peripheral blood cells. In a first step, the laboratory tested for 50 mutations using a Multiplex‐PCR and Amplification Refractory Mutation System (ARMS™; ELUCIGENE ® CFEU2v1 Kit) . When fewer than two mutations were detected, the entire coding sequence of the CFTR gene was screened, including intron/exon boundaries, promoter region, and tests for deletions and duplications.…”

“…The Swiss CF-NBS comprises the measurement of immunoreactive trypsinogen (IRT) in a heel prick test (Guthrie card) on the 4th day of life of all newborns in Switzerland. [26][27][28][29][30] If the IRT is above the specified cut-off (99.2 percentile), the most common CFTR mutations (initially 7, since 2013: 18) are sought. If at least one mutation is found, the newborn is screen positive.…”

“…In Switzerland, CF‐NBS was introduced in 2011 . With the implementation of the programme, the Swiss Federal Office of Public Health requested a close evaluation of the programme including the use and comparison of two different sweat test systems (Macroduct™ collection system with chloride measurement and Nanoduct™ analysis system) for the diagnostic evaluation in newborns with a positive CF‐NBS result.…”

“…5,6,15 In Switzerland, CF-NBS was introduced in 2011. [26][27][28][29][30] With the implementation of the programme, the Swiss Federal Office of Public Health requested a close evaluation of the programme including the use and comparison of two different sweat test systems (Macroduct™ collection system with chloride measurement and Nanoduct™ analysis system) for the diagnostic evaluation in newborns with a positive CF-NBS result. We therefore aimed to: 1) compare the feasibility of the two tests in infants (overall, and according to age and weight); 2) compare the diagnostic performance of the tests in identifying infants with CF; and, 3) investigate whether the diagnostic performance of the Macroduct alone could be improved by also taking the Nanoduct result into account.…”

Ventilatory response to nitrogen multiple-breath washout in infants

“…We prospectively enrolled 40 infants (16 with CF) from two ongoing studies, the Bern Infant Lung Development (BILD) cohort and the Swiss CF Newborn Screening Study. [16][17][18] The following inclusion criteria applied: white ethnicity, term delivery (37 weeks), and no known other diseases likely to affect lung function. General exclusion criteria were clinical signs of lower respiratory tract infection.…”