Nasal metachromatic cells in infancy in relation to the appearance of atopic disease during the first 6 years of life.

The relationship between the appearance of nasal metachromatic cells (basophils and mast cells) during the first 18 months of life and the development of respiratory and other allergic diseases up to 6 years of age was studied prospectively in 67 children. Follow-up was done at 3, 6, 9, and 18 months and 6 years. Of the 31 children who had detectable metachromatic cells in the nasal mucosa during infancy, 18 had atopic manifestations at 6 years (58%), two were probably atopic (6%), and 11 (36%) were nonatopic. The corresponding numbers for the 33 children without detectable metachromatic cells during infancy were 10 atopic (30%), two probably atopic (6%), and 21 nonatopic (64%) at 6 years (P < 0.05). Children having detectable nasal metachromatic cells at every examination were more often allergic than children with no detectable cells at any time during the 6-year follow-up period (P < 0.05). In contrast, nasal metachromatic cells were equally commonly demonstrated at 6 years in children with and without current atopic manifestations. We conclude that metachromatic cells appear at an earlier age in the nasal mucosa of atopic than nonatopic infants. The observation further supports the existence of a primary immunologic abnormality in atopic patients as related to allergic inflammatory responses. The diagnostic efficacy of this marker was too low, however, to be clinically useful as a predictor of allergy.