Macrophage populations in CF and disease control BAL were assessed by multicolour flow cytometry. BAL inflammatory indices were collected as part of the AREST-CF programme.
Small macrophages were present in CF (n = 35, mean 36 卤 12%of BAL macrophages) but not significantly different to the respiratory disease controls (n = 7, mean 40 卤 21%). Number of small macrophages correlated significantly with number of BAL neutrophils (r = 0.44, p < 0.01) but not infection or IL-8.
In paediatric patients small macrophages are not unique to CF, but their establishment as the dominant phenotype in adults may be due to chronicity of inflammation and infection.