THE CYTOLOGIC EVALUATION OF LIPID-LADEN ALVEOLAR MACROPHAGES AS AN INDICATOR OF ASPIRATION PNEUMONIA IN YOUNG-CHILDREN

Gastroesophageal reflux with aspiration of feedings in infants and you ng children may be involved in the development of chronic lung damage. Our laboratory has utilized tracheal aspirates stained with oil red O to identify and quantitate lipid-laden alveolar macrophages as a mark er of such aspiration. During the last 10 years, we have evaluated 244 tracheal aspiration smears in children. Although a few patients were up to 3 years old, the vast majority were infants. The cytologist look ed for the presence of and the number of oil red O-positive macrophage s on tracheal aspirate smears. The specimens were easily assigned grad es of absent (grade = 0), low positive (grade 1: 1-25 lipid-laden macr ophages), moderate positive (grade 2: 26-50 lipid-laden macrophages), and high positive (grade 3: >50 lipid-laden macrophages). The grade wa s then correlated with the positive or negative clinical diagnosis of gastroesophageal reflux with aspiration. We believe the cytologic eval uation and grading of oil red O-stained tracheal aspirates for lipid-l aden macrophages is valuable in identifying these patients with gastro esophageal reflux and aspiration.