Neonatal bronchial hyperresponsiveness precedes acute severe viral bronchiolitis in infants

作者：Chawes Bo L K; Poorisrisak Porntiva; Johnston Sebastian L; Bisgaard Hans^*

来源：Journal of Allergy and Clinical Immunology, 2012, 130(2): 354-+.

DOI：10.1016/j.jaci.2012.04.045

• Bronchial responsiveness
• infants
• lung function measurements
• viral bronchiolitis

Background: Respiratory syncytial virus and other respiratory tract viruses lead to common colds in most infants, whereas a minority develop acute severe bronchiolitis often requiring hospitalization. We hypothesized that such an excessive response to respiratory tract viral infection is caused by host factors reflected in pre-existing increased bronchial responsiveness.
Objective: We sought to compare bronchial responsiveness and lung function in 1-month-old neonates who later develop acute severe bronchiolitis with those who do not.
Methods: We measured infant lung n = 402) and bronchial responsiveness to methacholine (n = 363) using the raised-volume rapid thoracoabdominal compression technique before any respiratory symptoms in 1-month-old neonates from the Copenhagen Prospective Study of Asthma in Childhood birth cohort born to mothers with asthma. The children were prospectively monitored for respiratory symptoms and given a diagnosis of acute severe bronchiolitis according to a fixed algorithm.
Results: Thirty-four (8.5%) infants had acute severe bronchiolitis before 2 years of age, 21 (62%) were hospitalized, and 23 (67%) of the cases were associated with respiratory syncytial virus. Children who later had acute severe bronchiolitis irrespective of viral species had a 2.5-fold increased responsiveness to methacholine (provocative dose of methacholine producing a 15% decrease in transcutaneous oxygen pressure [PD15]) at age 1 month compared with control subjects (median PD15 in cases vs control subjects, 0.13 vs 0.33 mu mol; P = .01), whereas differences in baseline airflow were not significant for forced expiratory volume at 0.5 seconds (mean z score for cases vs control subjects, -0.18 vs -0.01; P = .36) and forced expiratory flow at 50% of forced vital capacity (mean z score for cases vs control subjects, -0.37 vs -0.09; P = .13).
Conclusion: Bronchial hyperresponsiveness in at-risk neonates precedes acute severe bronchiolitis in response to infections with respiratory tract virus. (J Allergy Clin Immunol 2012;130:354-61.)

• 出版日期2012-8