{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,11,7]],"date-time":"2026-11-07T02:53:03Z","timestamp":1794019983681,"version":"4.8.0"},"reference-count":55,"publisher":"FapUNIFESP (SciELO)","issue":"7","license":[{"start":{"date-parts":[[2024,1,1]],"date-time":"2024-01-01T00:00:00Z","timestamp":1704067200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2024,1,1]],"date-time":"2024-01-01T00:00:00Z","timestamp":1704067200000},"content-version":"am","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2024,1,1]],"date-time":"2024-01-01T00:00:00Z","timestamp":1704067200000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Cad. Sa\u00fade P\u00fablica"],"abstract":"<jats:p>Abstract: The Brazilian Unified National Health System (SUS) has incorporated newborn screening for cystic fibrosis since 2001. The protocol involves two samples of immunoreactive trypsinogen (IRT1\/IRT2). This study aims to analyze fixed and floating values at the first and second IRT (IRT1\/IRT2) cutoff points and assess the accuracy of the IRT\/IRT methodology in a population from Northeastern Brazil. Descriptive, individual-level data from the newborn screening reference service data system (2013-2017) were used in this observational population study. The sensitivity, specificity, and positive predictive values (PPV) for the protocol were calculated. The best cutoff point was determined using the Youden\u2019s index. The previous year\u2019s cut-off values for the IRT1 and IRT2 99.4-, 99.5-, 99.6-, and 99.7-percentiles were utilized for the floating cutoff. During the studied period, 840,832 newborns underwent screening for cystic fibrosis, obtaining 49 cystic fibrosis diagnoses: 39 by newborn screening (79.6%) and 10 (20.4%) by clinical suspicion (false negative). The sensitivity, specificity, and PPV of the protocol totaled 79.6%, 99.9%, and 6.1%, respectively. No proposed cutoff for IRT1 performed better than the current one. IRT2 performed similarly to the current protocol at a cutoff point of 90ng\/mL, showing the appropriate sensitivity and specificity while reducing the frequency of false positives. The protocol to screen newborns for cystic fibrosis had low sensitivity, a predictive positive value, and a high number of false positives and negatives. A floating cut point for IRT1 or IRT2 seems to constitute no viable option. However, changing the IRT2 cut point from 70ng\/mL to 90ng\/mL seems to have advantages and should undergo consideration.<\/jats:p>","DOI":"10.1590\/0102-311xen150623","type":"journal-article","created":{"date-parts":[[2024,8,23]],"date-time":"2024-08-23T12:15:53Z","timestamp":1724415353000},"source":"Crossref","is-referenced-by-count":2,"title":["IRT\/IRT as a newborn cystic fibrosis screening method: optimal cutoff points for a mixed population"],"prefix":"10.1590","volume":"40","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3625-4080","authenticated-orcid":false,"given":"Carolina","family":"Godoy","sequence":"first","affiliation":[{"name":"Universidade Federal da Bahia,  Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1419-7284","authenticated-orcid":false,"given":"Pedro Paulo","family":"Brito","sequence":"additional","affiliation":[{"name":"Escola Bahiana de Medicina e Sa\u00fade P\u00fablica,  Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0371-9104","authenticated-orcid":false,"given":"Tatiana","family":"Amorim","sequence":"additional","affiliation":[{"name":"Associa\u00e7\u00e3o de Pais e Amigos dos Excepcionais,  Brasil; Universidade do Estado da Bahia,  Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4916-8483","authenticated-orcid":false,"given":"Edna L\u00facia","family":"Souza","sequence":"additional","affiliation":[{"name":"Universidade Federal da Bahia,  Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7068-3319","authenticated-orcid":false,"given":"Ney","family":"Boa-Sorte","sequence":"additional","affiliation":[{"name":"Universidade Federal da Bahia,  Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"530","published-online":{"date-parts":[[2024]]},"reference":[{"issue":"4","key":"ref1","doi-asserted-by":"crossref","first-page":"S80","DOI":"10.1590\/S0021-75572008000500012","article-title":"Triagem neonatal o que os pediatras deveriam saber","volume":"84","author":"Le\u00e3o LL","year":"2008","journal-title":"J Pediatr (Rio J.)"},{"key":"ref2","series-title":"Triagem neonatal biol\u00f3gica: manual t\u00e9cnico","year":"2016"},{"key":"ref3","doi-asserted-by":"crossref","first-page":"281","DOI":"10.1136\/thoraxjnl-2012-201589","article-title":"Determining the optimal newborn screening protocol for cystic fibrosis","volume":"67","author":"Southern KW","year":"2012","journal-title":"Thorax"},{"key":"ref4","doi-asserted-by":"crossref","first-page":"820","DOI":"10.1016\/j.jcf.2021.02.006","article-title":"Defining key outcomes to evaluate performance of newborn screening programmes for cystic fibrosis","volume":"20","author":"Munck A","year":"2021","journal-title":"J Cyst Fibros"},{"key":"ref5","first-page":"s17","article-title":"Gu\u00eda de diagn\u00f3stico y tratamiento de pacientes con fibrosis qu\u00edstica: actualizaci\u00f3n.","volume":"119","year":"2021","journal-title":"Arch Argent Pediatr"},{"key":"ref6","doi-asserted-by":"crossref","first-page":"2195","DOI":"10.1016\/S0140-6736(20)32542-3","article-title":"Cystic fibrosis","volume":"397","author":"Shteinberg M","year":"2021","journal-title":"Lancet"},{"key":"ref7","doi-asserted-by":"crossref","first-page":"18","DOI":"10.3390\/ijns6010018","article-title":"Newborn screening for CF across the globe - where is it worthwhile","volume":"6","author":"Scotet V","year":"2020","journal-title":"Int J Neonatal Screen"},{"key":"ref8","series-title":"Registro Brasileiro de Fibrose C\u00edstica: ano 2020."},{"key":"ref9","doi-asserted-by":"crossref","first-page":"734","DOI":"10.1097\/MOP.0000000000000683","article-title":"Newborn screening in the developing countries","volume":"30","author":"Therrell BL","year":"2018","journal-title":"Curr Opin Pediatr"},{"key":"ref10","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1016\/0009-8981(81)90145-5","article-title":"Neonatal screening for cystic fibrosis, using immunoreactive trypsin assay in dried blood spots","volume":"113","author":"Crossley JR","year":"1981","journal-title":"Clin Chim Acta"},{"key":"ref11","doi-asserted-by":"crossref","first-page":"653","DOI":"10.1016\/S2213-2600(16)00053-9","article-title":"Newborn screening for cystic fibrosis","volume":"4","author":"Castellani C","year":"2016","journal-title":"Lancet Respir Medicine"},{"key":"ref12","doi-asserted-by":"crossref","first-page":"205","DOI":"10.1080\/14737159.2017.1288100","article-title":"Newborn screening for cystic fibrosis can one algorithm fit all?","volume":"17","author":"Caggana M","year":"2017","journal-title":"Expert Rev Mol Diagn"},{"key":"ref13","article-title":"Portaria n\u00ba 822, de 6 de junho de 2001. Institui, no \u00e2mbito do Sistema \u00danico de Sa\u00fade, o Programa Nacional de Triagem Neonatal - PNTN.","year":"2001","journal-title":"Di\u00e1rio Oficial da Uni\u00e3o"},{"key":"ref14","series-title":"Manual de normas t\u00e9cnicas e rotinas operacionais do Programa Nacional de Triagem Neonatal.","year":"2002"},{"key":"ref15","article-title":"Portaria GM\/MS n\u00ba 1.369, de 6 de junho de 2022. Altera e inclui procedimento relacionado a Triagem Neonatal na Tabela de Procedimentos, Medicamentos, \u00d3rteses, Pr\u00f3teses e Materiais Especiais (OPM) do Sistema \u00danico de Sa\u00fade (SUS) e estabelece recurso do Bloco de Manuten\u00e7\u00e3o das A\u00e7\u00f5es e Servi\u00e7os P\u00fablicos de Sa\u00fade - Grupo de Aten\u00e7\u00e3o Especializada, a ser incorporado ao limite financeiro de M\u00e9dia e Alta Complexidade (MAC), de Estados.","year":"2022","journal-title":"Di\u00e1rio Oficial da Uni\u00e3o"},{"key":"ref16","doi-asserted-by":"crossref","first-page":"5204","DOI":"10.1080\/14767058.2021.1875443","article-title":"Analysis of national coverage of neonatal cystic fibrosis screening in Brazil from 2008 to 2017","volume":"35","author":"Sadigurschi G","year":"2022","journal-title":"J Matern Fetal Neonatal Med"},{"key":"ref17","doi-asserted-by":"crossref","first-page":"32","DOI":"10.3390\/ijns5030032","article-title":"Initial evaluation of prospective and parallel 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State, Brazil","volume":"36","author":"Maciel LMZ","year":"2020","journal-title":"Cad Sa\u00fade P\u00fablica"},{"key":"ref21","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1016\/j.jped.2022.04.002","article-title":"Five-year performance analysis of a cystic fibrosis newborn screening program in northeastern Brazil","volume":"99","author":"Godoy C","year":"2023","journal-title":"J Pediatr (Rio J)"},{"key":"ref22","doi-asserted-by":"crossref","first-page":"2045","DOI":"10.1007\/s11033-018-4361-y","article-title":"Description of rare mutations and a novel variant in Brazilian patients with cystic fibrosis a case series from a referral center in the Bahia State","volume":"45","author":"Mota LR","year":"2018","journal-title":"Mol Biol Rep"},{"key":"ref23","doi-asserted-by":"crossref","first-page":"489","DOI":"10.1016\/j.jcf.2020.07.007","article-title":"K162E - a rare and uncategorized CFTR variant causing cystic fibrosis.","volume":"20","author":"Souza 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DAS","year":"2017","journal-title":"Genetica"},{"key":"ref38","doi-asserted-by":"crossref","first-page":"1006","DOI":"10.1002\/ppul.24026","article-title":"Cystic fibrosis identification and frequency of mutations in a mixed population from a low-income region in Northeastern Brazil","volume":"53","author":"Mota LR","year":"2018","journal-title":"Pediatr Pulmonol"},{"key":"ref39","doi-asserted-by":"crossref","first-page":"00109","DOI":"10.1183\/23120541.00109-2017","article-title":"Early diagnosis from newborn screening maximises survival in severe cystic fibrosis","volume":"4","author":"Tridello G","year":"2018","journal-title":"ERJ Open Research"},{"key":"ref40","doi-asserted-by":"crossref","first-page":"927","DOI":"10.1002\/ppul.26279","article-title":"Variation in cystic fibrosis newborn screening algorithms in the United States","volume":"58","author":"Rehani MR","year":"2023","journal-title":"Pediatr 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