Age-dependency of surfactant phospholipids and surfactant protein A in bronchoalveolar lavage fluid of children without bronchopulmonary disease.

Whilst alterations in surfactant components of bronchoalveolar lavage fluid (BALF) have been described in a variety of pulmonary diseases in adults, no information is available on the surfactant composition in children beyond the neonatal period. In order to obtain reference values for the paediatric age group, we have studied phospholipid profiles of BALF in children without pulmonary disease. The study population consisted of 38 children aged 3-15 yrs (mean +/- SD 8 +/- 4 yrs) undergoing elective surgery for nonpulmonary illnesses. Surfactant composition was analysed by high pressure liquid chromatography using both an ultraviolet and a light-scattering detector. Total phospholipid concentration was higher in children under 8 yrs of age and decreased with age. In contrast, the total protein concentration remained constant throughout the age range. No age-related changes in the relative composition of phospholipid fractions could be observed. Surfactant protein A concentrations were highly variable in all age groups. This study provides the first data on surfactant components in bronchoalveolar lavage fluid of healthy children and will be the basis for future studies of children with pulmonary diseases.