Newborn screening for cystic fibrosis: Techniques and strategies

Abstract

Newborn screening for cystic fibrosis has been carried out for over 25 years, and clinical and cost benefits have been documented. There is still much variation in the methods and strategies adopted. All current screening programmes use a measurement of immunoreactive trypsin as a primary screening test, and in most, a second tier test involves analysing DNA mutations. The choice of DNA mutations depends on the genetic background in the region, and considerations of cost. Using DNA analysis as part of a screening procedure has introduced unwanted carrier detection, and protocols have now been devised in an attempt to avoid this. There are at least seven distinct protocols in use, all of which have different advantages and disadvantages, and no method or strategy will suit every region. Further careful study of performance and costs of various strategies is needed.

Neonatal screening for cystic fibrosis in São Paulo State, Brazil: a pilot study

“…The IRT method determination is the starting point for neonatal screening in all protocols used thus far (25), although IRT levels can be elevated in various situations not related to CF (11). The original IRT/IRT screening protocol was adopted in the present study in view of the ethnic heterogeneity of the Brazilian population and the need to investigate various mutations, despite the known large number of false-positive results (26,27).…”

Newborn screening for inborn errors of metabolism and endocrinopathies: an update

“…Newborn screening tests that rely solely on DNA testing are rare and can only be applied to diseases and populations that have a major mutation with a very high frequency such as the ΔF508 mutation in CF patients of northern European descent [41]. Therefore, nearly all screens for CF still use the two-tier strategy.…”

“…However, measurement of IRT has a high falsepositive rate. There are different strategies for reducing false-positive results [41]. The most promising seems to be a combination of the South Australian [179] and the UK strategy [180].…”

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

“…IRT was measured in dried blood spot using the AutoDEL-FIA Neonatal IRT-Kit (PerkinElmer Wallac, Turku, Finnland) [13][14][15]. AutoDELFIA is an automatic immunoassay system, which performs all sample and reagent handling as well as all assay stages automatically.…”