Avaliação da colonização pulmonar e do estado nutricional em crianças e adolescentes com fibrose cística, antes e após a triagem neonatal

Abstract

Introduction: Cystic Fibrosis (CF) is a genetic disease of the exocrine glands, autosomal recessive, which involves multiple organs and cause great diversity of clinical problems arising from the change in function of the protein transmembrane conductance regulator. Newborn screening is important for early diagnosis of the disease, but it is not known for sure, if it interferes in the cycle infection and lung inflammation, or alter the morbidity and mortality. Objective: To evaluate the benefits of neonatal screening in children and adolescents with CF in relation to pulmonary colonization by pathogenic bacteria, pulmonary function (FEV1/FVC), nutritional status (weight and height) and Shwachman clinical-radiological score, comparing the group of patients who were diagnosed through newborn screening (NBS) with the conventional diagnosis group (CD). Methodology: Cross-sectional study with of 101 patients from the outpatient CF Hospital das Clinicas, of Minas Gerais Federal University (UFMG), with confirmed diagnosis of cystic fibrosis and who had done airway cultures (sputum or aspirated trachea). These data were updated until September 2011. The variables describing the population (sex, origin, diagnosis, age), clinical (Shwachman score) and functional (FEV1/FVC), comparing patients diagnosed by newborn screening (NBS) and patients with conventional diagnosis (CD). The results of the cultures were evaluated for the presence of some bacterias: Staphylococcus aureus sensitive or resistant to methicillin (MSSA or MRSA), Pseudomonas aeruginosa (PA), mucoid Pseudomonas aeruginosa (PAM), and Burkholderia cepacia complex (BCC). Results: Mean age was 52.03 months (SD + 27.47), with 16.8% of patients born in Belo Horizonte and 46.5% were male. Among patients diagnosed by newborn screening, more than 90% were diagnosed before 3 months of life, while over 70% of patients with conventional diagnosis were diagnosed with more than 1 year of life. Patients with NBS had better nutritional status, evaluated by weight (79.1% of NBS patients above the 10th percentile for weight, p = 0.02) and better Shwachman score, compared to CD patients (85% of patients with scores above 80 points, p <0.02). There was no statistically significant difference in relation to height and pulmonary function (p> 0.05). The age of first colonization by different bacteria ranged from the NBS group and CD group, found MSSA age of acquisition of less than 6 months from 67.2% in the first group and 2.9% in the second group (p <0.01), in patients with PA these values were 17.9% and 2.9% respectively (p <0.01). The CD group had a higher frequency of chronic colonization with PA than the group of NBS, (53% and 31.3% respectively, p <0.02) and greater frequency of positive cultures for MRSA (32.3% and 13.4% respectively) and BCC (14.7% and 9% respectively) Conclusion: Newborn screening allows the early diagnosis of CF, providing adequate nutritional status. Regarding the lung colonization, there is no delay in the acquisition of pathogenic bacteria, but this appears to be intermittent colonization in most cases.