Isabel Delgado Pecellín1, Estela Pérez Ruiz2, Ana Isabel Álvarez Ríos3, Carmen Delgado Pecellín3, Raquel Yahyaoui Macías4, Laura Carrasco Hernández5, Irene Marcos Luque6, Pilar Caro Aguilera2, María José Moreno Valera7, María Esther Quintana Gallego5. 1. Unidad de Fibrosis Quística, Hospital Universitario Virgen del Rocío, Sevilla, España; Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid, España. Electronic address: idelpe@gmail.com. 2. Hospital Materno-Infantil, Hospital Regional Universitario de Málaga, IBIMA, España. 3. Servicio de Bioquímica Clínica, Sección de Metabolopatías, Hospital Universitario Virgen del Rocío, Sevilla, España. 4. UGC Laboratorio, Sección de Metabolopatías, Hospital Regional Universitario de Málaga, Instituto de Investigación Biomédica de Málaga (IBIMA), España. 5. Unidad de Fibrosis Quística, Hospital Universitario Virgen del Rocío, Sevilla, España; Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid, España. 6. Departamento de Medicina Materno-Fetal, Genética y Reproducción, Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío, Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Sevilla, España. 7. Unidad de Neumología y Alergia Pediátricas, Hospital Universitario Virgen del Rocío, Sevilla, España; Unidad de Gestión Clínica de Neonatal, Hospital Universitario Virgen del Rocío, Sevilla, España.
Abstract
INTRODUCTION: Cystic fibrosis neonatal screening (CFNS), based on double determination of immunoreactive trypsinogen ([IRT] [IRT1/IRT2]), has been available in Andalusia since May 2011. If screening is positive, a sweat test is performed, and if that is positive or inconclusive, genetic testing is requested. OBJECTIVE: To analyze CFNS, based on results from the first 4.5 years of the program. MATERIALS AND METHODS: Prospective descriptive study of neonates undergoing CFNS. IRT levels, sweat chloride, and mutations were recorded. Statistical analysis was performed using SPSS 12.0. RESULTS: Between May 2011 and December 2016, 474,953 neonates underwent CFNS. Of these, 1,087 (0.23%) had elevated IRT2. Since CFNS was introduced, 73 cases of cystic fibrosis were diagnosed; 60 were diagnosed by positive CFNS, and 13 were diagnosed by other means. In one case, the patient developed a typical clinical picture of cystic fibrosis, but had not undergone CFNS at the decision of the parents; the remaining 12 had a negative CFNS (false negatives). Of these, one patient was diagnosed before symptoms developed, as his twin brother had a positive CFNS result; another had chloride at the upper limit of normal, and was subsequently diagnosed with genetic testing before symptoms appeared; and 10 patients developed clinical signs and symptoms. Excluding patients with meconium ileus, sensitivity and specificity of the CFNS program were 85.71% and 99.78%, respectively. The incidence of the disease in Andalusia is 1/6,506 live births. CONCLUSION: These results are a basis for reflection on possible areas for improvement of the CFNS algorithm, and thought may be given to the introduction of genetic studies to increase sensitivity and reduce false positives.
INTRODUCTION:Cystic fibrosis neonatal screening (CFNS), based on double determination of immunoreactive trypsinogen ([IRT] [IRT1/IRT2]), has been available in Andalusia since May 2011. If screening is positive, a sweat test is performed, and if that is positive or inconclusive, genetic testing is requested. OBJECTIVE: To analyze CFNS, based on results from the first 4.5 years of the program. MATERIALS AND METHODS: Prospective descriptive study of neonates undergoing CFNS. IRT levels, sweat chloride, and mutations were recorded. Statistical analysis was performed using SPSS 12.0. RESULTS: Between May 2011 and December 2016, 474,953 neonates underwent CFNS. Of these, 1,087 (0.23%) had elevated IRT2. Since CFNS was introduced, 73 cases of cystic fibrosis were diagnosed; 60 were diagnosed by positive CFNS, and 13 were diagnosed by other means. In one case, the patient developed a typical clinical picture of cystic fibrosis, but had not undergone CFNS at the decision of the parents; the remaining 12 had a negative CFNS (false negatives). Of these, one patient was diagnosed before symptoms developed, as his twin brother had a positive CFNS result; another had chloride at the upper limit of normal, and was subsequently diagnosed with genetic testing before symptoms appeared; and 10 patients developed clinical signs and symptoms. Excluding patients with meconium ileus, sensitivity and specificity of the CFNS program were 85.71% and 99.78%, respectively. The incidence of the disease in Andalusia is 1/6,506 live births. CONCLUSION: These results are a basis for reflection on possible areas for improvement of the CFNS algorithm, and thought may be given to the introduction of genetic studies to increase sensitivity and reduce false positives.