Relationship between bronchial hyperresponsiveness and impaired lung function after infantile asthma.

Wheezing during infancy has been linked to early loss of pulmonary function. We prospectively investigated the relation between bronchial hyperresponsiveness (BHR) and progressive impairment of pulmonary function in a cohort of asthmatic infants followed until age 9 years. We studied 129 infants who had had at least three episodes of wheezing. Physical examinations, baseline lung function tests and methacholine challenge tests were scheduled at ages 16 months and 5, 7 and 9 years. Eighty-three children completed follow-up. Twenty-four (29%) infants had wheezing that persisted at 9 years of age. Clinical outcome at age 9 years was significantly predicted by symptoms at 5 years of age and by parental atopy. Specific airway resistance (sRaw) was altered in persistent wheezers as early as 5 years of age, and did not change thereafter. Ninety-five per cent of the children still responded to methacholine at the end of follow-up. The degree of BHR at 9 years was significantly related to current clinical status, baseline lung function, and parental atopy. BHR at 16 months and 5 years of age did not predict persistent wheezing between 5 and 9 years of age, or the final degree of BHR, but it did predict altered lung function. Wheezing that persists from infancy to 9 years of age is associated with BHR and to impaired lung function. BHR itself is predictive of impaired lung function in children, strongly pointing to early airway remodeling in infantile asthma.

Chest computed tomography findings in bronchopulmonary dysplasia and correlation with lung function.

OBJECTIVE: With changes in the predominant pathogenic factors in the new form of bronchopulmonary dysplasia (BPD), a different pattern of CT findings may be expected. This study aimed to (1) describe CT findings in infants with BPD and (2) correlate the CT findings with lung function abnormalities. STUDY DESIGN AND METHOD: Retrospective review of 41 very low birthweight infants with BPD, who were referred for pulmonary investigations at between 10 and 20 months after birth because of persistent respiratory symptoms, and underwent CT and lung function tests. RESULTS: None of the infants had normal CT findings. The most frequent abnormalities were hyperlucent areas (n = 36; 88%), linear opacities (n = 39; 95%), and triangular subpleural opacities (n = 26; 63%). Bronchiectasis was not seen. None of the CT abnormalities correlated with the maximum expiratory flow at functional residual capacity (VmaxFRC). In contrast, increased number of subpleural opacities and limited linear opacities were associated with low FRC and longer duration of neonatal oxygen exposure. The numbers of triangular subpleural opacities also correlated with duration of mechanical ventilation. CONCLUSIONS: Despite advances in neonatal care, many CT findings in infants with BPD are similar to those observed in the pre-surfactant era, and are still associated with duration of supplemental oxygen and mechanical ventilation. The absence of bronchial involvement in the present study was the most striking difference from previous studies.

Bronchoalveolar cells in children < 3 years old with severe recurrent wheezing.

STUDY OBJECTIVE: To determine the cell profile of BAL from infants with severe recurrent wheezing who were not acutely ill at the time of investigation, suggesting an ongoing inflammation. DESIGN AND PATIENTS: In a retrospective study, we determined BAL cell profiles for 83 children with wheezing aged 4 to 32 months (mean +/- SD, 11.3 +/- 5.5 months). Fiberoptic bronchoscopy was performed in children with severe recurrent wheezy bronchitis unresponsive to inhaled steroids. These children were compared with 17 children aged 6 to 36 months (mean, 15.1 +/- 7.5 months) with various nonwheezing pulmonary diseases. Children were included as control subjects if they had no endobronchial inflammation and no atopy. RESULTS: The BAL cell profile of young children with wheezing typically includes a significantly higher cell count (mean, 644.4 +/- 956.8 x 10(3)/mL vs 313 +/- 203.2 x 10(3)/mL, p = 0.008), a significantly higher percentage of neutrophils (mean, 9 +/- 12.1% vs 2.1 +/- 2.2%, p = 0.003), and a higher neutrophil count (mean, 43.2 +/- 81.6 x 10(3)/mL vs 7.9 +/- 11.8 x 10(3)/mL, p = 0.003), as compared with control subjects. The larger number of neutrophils in children with wheezing was not correlated with bacterial or viral infection, or with age, sex, or atopic status. In contrast to the situation in asthmatic adults, eosinophil levels were not higher in children with wheezing than in control subjects (mean, 0.09 +/- 0.27% vs 0.08 +/- 0.25%). CONCLUSION: Neutrophil-mediated inflammation in the airways appears to better characterize severe recurrent wheezing in children < 3 years old.