title: Sweat testing infants detected by cystic fibrosis newborn screening.
abstract: OBJECTIVE
  Describe and define limitations of early pilocarpine iontophoresis (sweat testing) for cystic fibrosis (CF) newborn screening (NBS).
  
  
  METHODS
  Population-based results from follow-up of CF NBS-positive newborns.
  
  
  RESULTS
  Insufficient quantity of sweat is more likely if the sweat test is done too early, but testing is generally successful after 2 weeks of age. Sweat chloride levels drop over the first weeks of life. CF carriers have higher sweat chloride concentrations than non-carriers.
  
  
  CONCLUSIONS
  Sweat testing can be performed effectively after 2 weeks of age for CF NBS-positive newborns. Earlier testing has a higher risk of insufficient sweat for completing testing.
authors.affiliation: New England Newborn Screening Program of University of Massachusetts Medical School, MA 02130, USA. richard.parad@umassmed.edu
authors.forename: Richard B
authors.initials: RB
authors.lastname: Parad
authors.forename: Anne Marie
authors.initials: AM
authors.lastname: Comeau
authors.forename: Henry L
authors.initials: HL
authors.lastname: Dorkin
authors.forename: Mark
authors.initials: M
authors.lastname: Dovey
authors.forename: Robert
authors.initials: R
authors.lastname: Gerstle
authors.forename: Thomas
authors.initials: T
authors.lastname: Martin
authors.forename: Brian P
authors.initials: BP
authors.lastname: O'Sullivan
mesh_terms: D000367:Age Factors; D000465:Algorithms; D002712:Chlorides / Q000032:analysis*; D003550:Cystic Fibrosis / Q000175:diagnosis* / Q000235:genetics; D004252:DNA Mutational Analysis; D003663:Decision Trees; D042241:Early Diagnosis; D005188:False Negative Reactions; D005189:False Positive Reactions; D005500:Follow-Up Studies; D006801:Humans; D007231:Infant, Newborn; D007478:Iontophoresis / Q000379:methods* / Q000592:standards; D016014:Linear Models; D008404:Massachusetts; D018721:Muscarinic Agonists; D015997:Neonatal Screening / Q000379:methods* / Q000592:standards; D018579:Patient Selection; D010862:Pilocarpine; D012016:Reference Values; D012017:Referral and Consultation; D012307:Risk Factors; D013542:Sweat / Q000737:chemistry*
chemical_list: D002712:Chlorides; D018721:Muscarinic Agonists; D010862:Pilocarpine