Lactentes com fibrose cística do programa de triagem neonatal do Rio de Janeiro: avaliação clínica, microbiológica e radiológica

Abstract

Cystic fibrosis (CF) is a progressive, genetic disease that affects 1:2500 caucasian live births. Diagnosis criteria are well defined and newborn screening programs (NBS) using immunoreactive trypsinogen (IRT) has been widely established worldwide and, more recently, in Brazil. Newborn infants with high risk of presenting CF are identified by NBS and, once diagnosis is confirmed, follow up and management must be initiated early. The benefits of NBS for CF have been studied and show evidences of improvement in nutritional status and lung function in infants, beside the contribution for long term survival. High resolution computed tomography (HRCT) is a sensitive method for detecting structural lung abnormalities. HRCT evaluation through reproducible scoring systems can be used to quantify chest computed tomography (CT) findings in cystic fibrosis (CF) patients. The aim of the study was to describe early HRCT findings according to a validated score system in cystic fibrosis infants diagnosed through newborn screening (NBS) followed at Instituto Nacional de Saúde da Mulher, da Criança e do Adolescente Fernandes Figueira – FIOCRUZ. This is a cross-sectional study including NBS infants with CF born between 2013-2017. Clinical, nutritional and microbiological data were evaluated at the moment of diagnosis. The subjects were submitted to HRCT scans within the first year after diagnosis, when clinically stable. The CT scans were evaluated through the modified Bhalla score. 35 patients were included in the study, with male predominance and mean age at diagnosis was 3.8 months. Regarding clinical presentation, 20% were asymptomatic, while respiratory signs were present in 45.7% and digestive in 65.7%, with anthropometric data revealing nutritional risk in 68.5% of patients. Microbiological data showed that 51.4% of patients had no CF pathogenic bacteria in respiratory secretion, while 17.1% presented Pseudomonas aeruginosa isolation and 31.4% showed other pathogenic bacteria. 32 subjects were submitted to HRCT scans. The mean total modified Bhalla score was 3.6 ± 2.1 and 93.8% scans were abnormal. Bronchial wall thickening was the most common parameter (90.6%), followed by collapse/consolidation (59.4%), mosaic attenuation/perfusion (50%), bronchiectasis (37.5%) and mucus plugging (15.6%). Bronchial wall thickening was diffuse in most patients. A substantial proportion of infants diagnosed with CF after detection by NBS already have evidence of lung disease. P. aeruginosa colonization was associated to higher Bhalla scores, highlighting the importance of this CF pathogen in early structural lung disease. The presence of bronchial wall thickening in most subjects in such early age patients may already reflect the presence of airway inflammatory process. Detection and quantification of structural abnormalities through modified Bhalla score may contribute to acknowledgment lung disease before clinically apparent.