The significance of fat-filled macrophages in the diagnosis of aspiration associated with gastro-oesophageal reflux.

Tracheal aspirates from 46 children were examined for the presence of fat-filled macrophages. They had no history suggestive of gastro-oesophageal reflux. The number of positive results from this group (46%) was compared with the number of positive results (73%) in a group of 40 children with proven gastro-oesophageal reflux. The difference in proportion of positive results between the two groups was statistically significant (P less than 0.05). In addition, subgroups of subjects, negative for gastro-oesophageal reflux and lower respiratory tract disease, were compared with children who had both conditions. A slightly greater difference, although at a similar level of significance, was found. The fact that 42% of subjects without lower respiratory tract disease or gastro-oesophageal reflux had tracheal aspirates positive for fat-filled macrophages would, however, suggest that this test is of limited clinical value and may need better quantitation before it can be recommended for widespread clinical use.