and progression of lung disease in children with cystic fibrosis.

BACKGROUND

The impact of on lung disease in young children with cystic fibrosis is uncertain.

AIMS

To determine if positive respiratory cultures of species are associated with: (1) increased structural lung injury at age 5 years; (2) accelerated lung function decline between ages 5 years and 14 years and (3) to identify explanatory variables.

METHODS

A cross-sectional analysis of association between positive bronchoalveolar lavage (BAL) cultures and chest high-resolution CT (HRCT) scan findings at age 5 years in subjects from the Australasian Cystic Fibrosis Bronchoalveolar Lavage (ACFBAL) study was performed. A non-linear mixed-effects disease progression model was developed using FEV% predicted measurements at age 5 years from the ACFBAL study and at ages 6-14 years for these subjects from the Australian Cystic Fibrosis Data Registry.

RESULTS

Positive BAL cultures at age 5 years were significantly associated with increased HRCT scores for air trapping (OR 5.53, 95% CI 2.35 to 10.82). However, positive cultures were not associated with either FEV% predicted at age 5 years or FEV% predicted by age following adjustment for body mass index z-score and hospitalisation secondary to pulmonary exacerbations. Lung function demonstrated a non-linear decline in this population.

CONCLUSION

In children with cystic fibrosis, positive BAL cultures at age 5 years were associated contemporaneously with air trapping but not bronchiectasis. However, no association was observed between positive BAL cultures on FEV% predicted at age 5 years or with lung function decline between ages 5 years and 14 years.