NEJM：CF患儿感染支气管肺炎的危险因素

　　澳大利亚学者的一项研究显示，支气管肺泡灌洗（BAL）液体中的中性粒细胞弹性蛋白酶的活性与囊性纤维化（CF）患儿早期支气管肺炎相关。相关论文于2013年5月23日在线发表于《新英格兰医学杂志》（N Engl J Med）。 

　　该研究纳入127例在新生儿筛查中被诊断为CF的婴儿，在孩子3个月，1岁和3岁时，分别进行胸部CT扫描和BAL。用纵向数据来决定危险因素与3个月到3岁支气管肺炎发病率的关系。

　　结果显示，支气管肺炎的时点患病率从3个月的29.3%增加到3岁时的61.5%。多变量分析显示，支气管肺炎的危险因素有胎粪性肠梗阻(OR=3.17; 95%CI=1.51-6.66; P=0.002)，CT和BAL时的呼吸道症状(OR=2.27; 95%CI=1.24-4.14; P=0.008)、BAL液体中的中性粒细胞弹性蛋白酶的活性(OR=3.02; 95%CI=1.70-5.35; P<0.001)和呼气相CT气体捕集(OR=2.05; 95%CI=1.17-3.59; P=0.01)均相关。3个月时BAL液体中的中性粒细胞弹性蛋白酶的活性与支气管肺炎相关（在两个或以上顺序扫描中呈现），12个月时的相关性为7倍，3岁时的相关性为4倍。

Risk Factors for Bronchiectasis in Children with Cystic Fibrosis
Background
Bronchiectasis develops early in the course of cystic fibrosis, being detectable in infants as young as 10 weeks of age, and is persistent and progressive. We sought to determine risk factors for the onset of bronchiectasis, using data collected by the Australian Respiratory Early Surveillance Team for Cystic Fibrosis (AREST CF) intensive surveillance program.
Methods
We examined data from 127 consecutive infants who received a diagnosis of cystic fibrosis after newborn screening. Chest computed tomography (CT) and bronchoalveolar lavage (BAL) were performed, while the children were in stable clinical condition, at 3 months and 1, 2, and 3 years of age. Longitudinal data were used to determine risk factors associated with the detection of bronchiectasis from 3 months to 3 years of age.
Results
The point prevalence of bronchiectasis at each visit increased from 29.3% at 3 months of age to 61.5% at 3 years of age. In multivariate analyses, risk factors for bronchiectasis were presentation with meconium ileus (odds ratio, 3.17; 95% confidence interval [CI], 1.51 to 6.66; P=0.002), respiratory symptoms at the time of CT and BAL (odds ratio, 2.27; 95% CI, 1.24 to 4.14; P=0.008), free neutrophil elastase activity in BAL fluid (odds ratio, 3.02; 95% CI, 1.70 to 5.35; P<0.001), and gas trapping on expiratory CT (odds ratio, 2.05; 95% CI, 1.17 to 3.59; P=0.01). Free neutrophil elastase activity in BAL fluid at 3 months of age was associated with persistent bronchiectasis (present on two or more sequential scans), with the odds seven times as high at 12 months of age and four times as high at 3 years of age.
Conclusions
Neutrophil elastase activity in BAL fluid in early life was associated with early bronchiectasis in children with cystic fibrosis. (Funded by the National Health and Medical Research Council of Australia and Cystic Fibrosis Foundation Therapeutics.)