Southern KW, Munck A, Pollitt R, Travert G, Zanolla L, Dankert-Roelse J, Castellani C; ECFS CF Neonatal Screening Working Group (2007) A survey of newborn screening for cystic fibrosis in Europe. J Cyst Fibros 6:57–65. https://doi.org/10.1016/j.jcf.2006.05.008

Article  CAS  Google Scholar 

Massie RJ, Curnow L, Glazner J, Armstrong DS, Francis I (2012) Lessons learned from 20 years of newborn screening for cystic fibrosis. Med J Aust 196:67–70. https://doi.org/10.5694/mja11.10686

Article  PubMed  Google Scholar 

Hale JE, Parad RB, Dorkin HL, Gerstle R, Lapey A, O’Sullivan BP, Spencer T, Yee W, Comeau AM (2010) Cystic fibrosis newborn screening: using experience to optimize the screening algorithm. J Inherit Metab Dis 33:S255–S261. https://doi.org/10.1007/s10545-010-9117-3

Article  CAS  PubMed  Google Scholar 

Fibrosis C, Foundation; Borowitz D, Parad RB, Sharp JK, Sabadosa KA, Robinson KA, Rock MJ, Farrell PM, Sontag MK, Rosenfeld M, Davis SD, et al (2009) Cystic Fibrosis Foundation practice guidelines for the management of infants with cystic fibrosis transmembrane conductance regulator-related metabolic syndrome during the first two years of life and beyond. J Pediatr 155:S106–S116. https://doi.org/10.1016/j.jpeds.2009.09.003

Article  Google Scholar 

Munck A, Mayell SJ, Winters V, Shawcross A, Derichs N, Parad R, Barben J, Southern KW; ECFS Neonatal Screening Working Group (2015) Cystic fibrosis screen positive, inconclusive diagnosis (CFSPID): a new designation and management recommendations for infants with an inconclusive diagnosis following newborn screening. J Cyst Fibros 14:706–713. https://doi.org/10.1016/j.jcf.2015.01.001

Article  Google Scholar 

Ren CL, Borowitz DS, Gonska T, Howenstine MS, Levy H, Massie J, Milla C, Munck A, Southern KW (2017) Cystic fibrosis transmembrane conductance regulator-related metabolic syndrome and cystic fibrosis screen positive, inconclusive diagnosis. J Pediatr 181S:S45–S51. https://doi.org/10.1016/j.jpeds.2016.09.066

Article  PubMed  Google Scholar 

Terlizzi V, Claut L, Tosco A, Colombo C, Raia V, Fabrizzi B, Lucarelli M, Angeloni A, Cimino G, Castaldo A et al (2021) A survey of the prevalence, management and outcome of infants with an inconclusive diagnosis following newborn bloodspot screening for cystic fibrosis (CRMS/CFSPID) in six Italian centres. J Cyst Fibros 20:828–834. https://doi.org/10.1016/j.jcf.2021.03.015

Article  CAS  PubMed  Google Scholar 

Munck A, Berger DO, Southern KW, Carducci C, de Winter-de Groot KM, Gartner S, Kashirskaya N, Linnane B, Proesmans M, Sands D, European CF Society Neonatal Screening Working Group (ECFS NSWG) et al (2022) European survey of newborn bloodspot screening for CF: opportunity to address challenges and improve performance. J Cyst Fibros 10:S1569–1993. https://doi.org/10.1016/j.jcf.2022.09.012

Bianchimani C, Dolce D, Centrone C, Campana S, Ravenni N, Orioli T, Camera E, Mergni G, Fevola C, Bonomi P, Taccetti G, Terlizzi V (2022) Impact of pancreatitis-associated protein on newborn screening outcomes and detection of CFTR-related metabolic syndrome (CRMS)/cystic fibrosis screen positive, inconclusive diagnosis (CFSPID): a monocentric prospective pilot experience. Int J Neonatal Screen 8:46. https://doi.org/10.3390/ijns8030046

Barben J, Castellani C, Munck A, Davies JC, de Winter-de Groot KM, Gartner S, Kashirskaya N, Linnane B, Mayell SJ, McColley S, European CF Society Neonatal Screening Working Group (ECFS NSWG) et al (2021) Updated guidance on the management of children with cystic fibrosis transmembrane conductance regulator-related metabolic syndrome/cystic fibrosis screen positive, inconclusive diagnosis (CRMS/CFSPID). J Cyst Fibros 20:810–819. https://doi.org/10.1016/j.jcf.2020.11.006

Gonska T, Keenan K, Au J, Dupuis A, Chilvers MA, Burgess C, Bjornson C, Fairservice L, Brusky J, Kherani T et al (2021) Outcomes of cystic fibrosis screening-positive infants with inconclusive diagnosis at school age. Pediatrics 1(148):e2021051740. https://doi.org/10.1542/peds.2021-051740

Ooi CY, Castellani C, Keenan K, Avolio J, Volpi S, Boland M, Kovesi T, Bjornson C, Chilvers MA, Morgan L et al (2015) Inconclusive diagnosis of cystic fibrosis after newborn screening. Pediatrics 135:e1377–e1385. https://doi.org/10.1542/peds.2014-2081

Article  PubMed  Google Scholar 

Bombieri C, Claustres M, De Boeck K, Derichs N, Dodge J, Girodon E, Sermet I, Schwarz M, Tzetis M, Wilschanski M et al (2011) Recommendations for the classification of diseases as CFTR-related disorders. J Cyst Fibros 10:S86-102. https://doi.org/10.1016/S1569-1993(11)60014-3

Article  CAS  PubMed  Google Scholar 

Castellani C, De Boeck K, De Wachter E, Sermet-Gaudelus I, Simmonds NJ, Southern KW; ECFS Diagnostic Network Working Group (2022) ECFS standards of care on CFTR-related disorders: updated diagnostic criteria. J Cyst Fibros 21:908–921. https://doi.org/10.1016/j.jcf.2022.09.011

Article  CAS  Google Scholar 

Johnson F, Southern KW, Ulph F (2019) Psychological impact on parents of an inconclusive diagnosis following newborn bloodspot screening for cystic fibrosis: a qualitative study. Int J Neonatal Screen 15:23. https://doi.org/10.3390/ijns5020023

Article  Google Scholar 

Tosco A, Marino D, Polizzi S, Tradati V, Padoan R, Giust C, Fabrizzi B, Taccetti G, Merli L, Terlizzi V (2023) A multicentre Italian study on the psychological impact of an inconclusive cystic fibrosis diagnosis after positive neonatal screening. Children (Basel) 10:177. https://doi.org/10.3390/children10020177

Article  PubMed  Google Scholar 

Ginsburg DK, Salinas DB, Cosanella TM, Wee CP, Saeed MM, Keens TG, Gold JI (2022) High rates of anxiety detected in mothers of children with inconclusive cystic fibrosis screening results. J Cyst Fibros 15:S1569-1993. https://doi.org/10.1016/j.jcf.2022.12.002

Article  CAS  Google Scholar 

Terlizzi V, Claut L, Colombo C, Tosco A, Castaldo A, Fabrizzi B, Lucarelli M, Cimino G, Carducci C, Dolce D et al (2021) Outcomes of early repeat sweat testing in infants with cystic fibrosis transmembrane conductance regulator-related metabolic syndrome/CF screen-positive, inconclusive diagnosis. Pediatr Pulmonol 56:3785–3791. https://doi.org/10.1002/ppul.25683

Article  PubMed  Google Scholar 

The Sweat Test Recommendations from Italian Cystic Fibrosis Society (SIFC) Sweat Test Working Group—Third Ed. (2022) Available online: https://www.sifc.it/wp-content/uploads/2022/06/Raccomandazioni-Italiane-sul-Test-del-Sudore-_Aprile-2022.pdf . Accessed on 31 May 2023

Scurati-Manzoni E, Fossali EF, Agostoni C, Riva E, Simonetti GD, Zanolari-Calderari M, Bianchetti MG, Lava SA (2014) Electrolyte abnormalities in cystic fibrosis: systematic review of the literature. Pediatr Nephrol 29:1015–1023. https://doi.org/10.1007/s00467-013-2712-4

Article  PubMed  Google Scholar 

Farrell PM, White TB, Ren CL, Hempstead SE, Accurso F, Derichs N, Howenstine M, McColley SA, Rock M, Rosenfeld M et al (2017) Diagnosis of cystic fibrosis: consensus guidelines from the cystic fibrosis foundation. J Pediatr. 181S:S4-S15.e1. https://doi.org/10.1016/j.jpeds.2016.09.064

Bombieri C, Claustres M, De Boeck K, Derichs N, Dodge J, Girodon E, Sermet I, Schwarz M, Tzetis M, Wilschanski M et al (2011) Recommendations for the classification of diseases as CFTR-related disorders. J Cyst Fibros Suppl 2:S86-102. https://doi.org/10.1016/S1569-1993(11)60014-3

Article  Google Scholar 

LeGrys VA, Yankaskas JR, Quittell LM, Marshall BC, Mogayzel PJ Jr, Foundation CF, Foundation CF (2007) Diagnostic sweat testing: the Cystic Fibrosis Foundation guidelines. J Pediatr 151:85–89. https://doi.org/10.1016/j.jpeds.2007.03.002

Article  PubMed  Google Scholar 

Anagnostopoulou P, Latzin P, Jensen R, Stahl M, Harper A, Yammine S, Usemann J, Foong RE, Spycher B, Hall GL et al (2020) Normative data for multiple breath washout outcomes in school-aged Caucasian children. Eur Respir J 55:1901302. https://doi.org/10.1183/13993003.01302-2019

Article  PubMed  Google Scholar 

Hardaker KM, Panda H, Hulme K, Wong A, Coward E, Cooper P, Fitzgerald DA, Pandit C, Towns S, Selvadurai H, Robinson PD (2019) Abnormal preschool lung clearance index (LCI) reflects clinical status and predicts lower spirometry later in childhood in cystic fibrosis. J Cyst Fibros 18:721–727. https://doi.org/10.1016/j.jcf.2019.02.007

Oude Engberink E, Ratjen F, Davis SD, Retsch-Bogart G, Amin R, Stanojevic S (2017) Inter-test reproducibility of the lung clearance index measured by multiple breath washout. Eur Respir J 50:1700433. https://doi.org/10.1183/13993003.00433-2017

Article  PubMed  PubMed Central  Google Scholar 

Frey U, Stocks J, Coates A, Sly P, Bates J (2000) Specifications for equipment used for infant pulmonary function testing. ERS/ATS Task Force on Standards for Infant Respiratory Function Testing. European Respiratory Society/ American Thoracic Society. Eur Respir J 16:731–740. https://doi.org/10.1034/j.1399-3003.2000.16d28.x

Article  CAS  PubMed  Google Scholar 

Terlizzi V, Parisi GF, Ferrari B, Castellani C, Manti S, Leonardi S, Taccetti G (2022) Effect of dornase alfa on the lung clearance index in children with cystic fibrosis: a lesson from a case series. Children (Basel) 9:1625. https://doi.org/10.3390/children9111625

Article  PubMed  Google Scholar 

Flume PA, Mogayzel PJ Jr, Robinson KA, Goss CH, Rosenblatt RL, Kuhn RJ, Marshall BC (2009) Cystic fibrosis pulmonary guidelines: treatment of pulmonary exacerbations. Am J Respir Crit Care Med 180:802–808. https://doi.org/10.1164/rccm.200812-1845PP

Article  PubMed  Google Scholar 

Beydon N, Davis SD, Lombardi E, Allen JL, Arets HG, Aurora P, Bisgaard H, Davis GM, Ducharme FM, Eigen H, American Thoracic Society/European Respiratory Society Working Group on Infant and Young Children Pulmonary Function Testing et al (2007) An official American Thoracic Society/European Respiratory Society statement: pulmonary function testing in preschool children. Am J Respir Crit Care Med 175:1304–45. https://doi.org/10.1164/rccm.200605-642ST

Munck A, Bourmaud A, Bellon G, Picq P, Farrell PM; DPAM Study Group (2020) Phenotype of children with inconclusive cystic fibrosis diagnosis after newborn screening. Pediatr Pulmonol 55:918–928. https://doi.org/10.1002/ppul.24634

Article  Google Scholar 

Gunnett MA, Baker E, Mims C, Self ST, Gutierrez HH, Guimbellot JS (2023) Outcomes of children with cystic fibrosis screen positive, inconclusive diagnosis/CFTR related metabolic syndrome. Front Pediatr 11:1127659. https://doi.org/10.3389/fped.2023.1127659

Article  PubMed  PubMed Central  Google Scholar 

Ginsburg D, Wee CP, Reyes MC, Brewington JJ, Salinas DB (2022) When CFSPID becomes CF. J Cyst Fibros 21:e23–e27. https://doi.org/10.1016/j.jcf.2021.06.012

Article  PubMed  Google Scholar 

Tosco A, Castaldo A, Colombo C, Claut L, Carnovale V, Iacotucci P, Lucarelli M, Cimino G, Fabrizzi B, Caporelli N et al (2022) Clinical outcomes of a large cohort of individuals with the F508del/5T;TG12 CFTR genotype. J Cyst Fibros 21:850–855. https://doi.org/10.1016/j.jcf.2022.04.020

Article  CAS  PubMed  Google Scholar 

Terlizzi V, Padoan R, Claut L, Colombo C, Fabrizzi B, Lucarelli M, Bruno SM, Castaldo A, Bonomi P, Taccetti G, Tosco A (2020) CRMS/CFSPID subjects carrying D1152H CFTR variant: can the second variant be a predictor of disease development? Diagnostics (Basel) 10:1080. https://doi.org/10.3390/diagnostics10121080

Article  CAS  PubMed  Google Scholar 

Terlizzi V, Mergni G, Centrone C, Festini F, Taccetti G (2020) Trend of sweat chloride values in a cohort of patients carrying CFTR mutations of varying clinical consequence: is there a risk of increasing sweat chloride over time? Pediatr Pulmonol 55:1089–1093. https://doi.org/10.1002/ppul.24721

Article  PubMed  Google Scholar 

Hatton A, Bergougnoux A, Zybert K, Chevalier B, Mesbahi M, Altéri JP, Walicka-Serzysko K, Postek M, Taulan-Cadars M, Edelman A et al (2022) Reclassifying inconclusive diagnosis after newborn screening for cystic fibrosis. Moving forward J Cyst Fibros 21:448–455. https://doi.org/10.1016/j.jcf.2021.12.010

Article  CAS  PubMed  Google Scholar 

Salinas DB, Ginsburg DK, Wee CP, Saeed MM, Brewington JJ (2023) Gradual increase in sweat chloride concentration is associated with a higher risk of CRMS/CFSPID to CF reclassification. Pediatr Pulmonol 58:1074–1084. https://doi.org/10.1002/ppul.26296

Article  PubMed  Google Scholar 

Terlizzi V, Fevola C, Ferrari B, Castellani C, Santini G, Innocenti D, Masi E, Bonomi P, Lombardi E, Taccetti G (2023) Lung clearance index in children with cystic fibrosis previously diagnosed with CRMS/CFSPID: a monocentric prospective experience. Pediatr Pulmonol. https://doi.org/10.1002/ppul.26442. Epub ahead of print. PMID: 37133232

Kasi AS, Wee CP, Keens TG, Salinas DB (2020) Abnormal lung clearance index in cystic fibrosis screen positive, inconclusive diagnosis (CFSPID) children with otherwise normal FEV1. Lung 198:163–167. https://doi.org/10.1007/s00408-019-00307-3