Cystic fibrosis: when neonatal screening is unsatisfactory for early diagnosis

• Published in: Revista Brasileira de Saúde Materno Infantil 2024, Vol.24
• Main Authors: Godoy, Carolina, Radel, Igor, Mota, Laís Ribeiro, Santos, Marília Augusta, Terse, Regina, Souza, Edna Lúcia
• Format: Article
• Language: English
• Subjects: Cystic fibrosis; Delayed diagnosis; Diagnostic errors; Newborn screening; PEDIATRICS; Public health policy
• ISSN: 1519-3829; 1806-9304; 1806-9304
• DOI: 10.1590/1806-9304202400000235-en

Abstract Introduction: cystic fibrosis newborn screening must enable its earlier diagnosis, which may enhance outcomes. This study was a series case of delayed-diagnosis children submitted to cystic fibrosis newborn screening. Description: fourteen children were included; eight (57.1%) were due to false-negative screening, while six (42.9%) were due to processing errors. Two samples collected after 30 days of life were incorrectly classified as negative, and four infants with a positive test could not be located due to screening processing errors. Cystic fibrosis diagnosis was confirmed at a median (IQR) age of 5.3 (4.2-7.4) months. Poor nutritional status was the most prevalent clinical sign at diagnosis, being present in 78.6% of infants. The mean (SD) weight-for-length and length-for-age Z-scores were -3.46 (0.84) and -3.99 (1.16), respectively. Half of the children had Pseudo-Bartter syndrome, and 42.9% had breathing difficulties. Twelve children (85.7%) required hospitalization, with a median (IQR) length of stay of 17.0 (11.5-26.5) days. Discussion: newborn screening had some faults, from incorrect collections to inefficient active search. Early identification of these children in which screening was unsatisfactory is essential, emphasizing the importance and efforts to not miss them. In the case of a failed test, healthcare professionals must be prepared to recognize the main symptoms and signs of the disease. Resumo Introdução: a triagem neonatal para fibrose cística deve contribuir para diagnóstico precoce e melhor prognóstico da doença. O estudo é uma série de casos com lactentes submetidos à triagem, porém com diagnóstico tardio da doença. Descrição: quatorze crianças foram incluídas; oito (57,1%) com triagem falso-negativo e seis (42,9%) com erros processuais na triagem neonatal. Duas amostras foram coletadas tardiamente, sendo incorretamente classificadas como negativas e quatro lactentes com triagem positiva não foram localizados, por erros na busca ativa. Confirmou-se o diagnóstico da fibrose cística com idade mediana (IIQ) de 5,3 (4,2-7,4) meses. O Comprometimento nutricional precoce foi o sinal clínico mais prevalente ao diagnóstico, presente em 78,6% das crianças. Os Z escores médios (SD) do peso para altura e altura para idade foram -3,46 (0,84) e -3,99 (1,16), respectivamente. Metade das crianças teve síndrome de Pseudo-Bartter e 42,9% dificuldade respiratória. Doze crianças (85,7%) precisaram hospitalização com tempo mediano de permanê