[Bronchoalveolar lavage in childhood: technical aspects and reference values]

(BAL) has been increasingly used in recent years also in children. In paediatric pulmonary diseases, however, interpretation has proved difficult in the absence of standard reference values for BAL in childhood. It is the purpose of the present publication to discuss the methodological aspects of BAL in childhood and to proviced criteria by means of standard reference values for the assessment of BAL in paediatric patients. In a group of 50 children aged 3 to 15 years with healthy lungs, who were subjected to BAL during an elective surgical intervention, we examined both cellular and non-cellular components of the BAL. Whereas the percentage of macrophages and lymphocytes in the total population did not differ significantly from the standard values in adults, the absolute and relative granulocyte count was found to be elevated in children under 8 years of age. The CD4/CD8 quotient of BAL was 0.7 on the average, and hence clearly below the standard reference values defined for adults. In the non-cellular components we found an increase in the level of all proteins from plasma, whereas locally produced proteins did not differ from the findings in healthy adults. The total phospholipid content of BAL was markedly enhanced in children below 8 years of age and decreased with increasing age. These differences between children and adults should be taken into account when interpreting pathological findings. They are the basis for better defining the ranking of BAL in paediatric pulmonary diseases.