Developmental profiles of mucosal immunity in pre-school children

This study investigated the effect of attending pre-school on mucosal immunity. Children 3.5 to 5 years of age who attended pre-school were observed for a 10 month period. Demographic information was collected on previous childcare experiences, the home environment and clinical information relating to the child and the family. A daily illness log was kept for each child. A multivariate longitudinal analysis of the relation between immunoglobulins in saliva and age, gender, childcare experience, preschool exposure, number of siblings, environmental tobacco smoke (ETS), atopy and hospitalisation was conducted. There was a positive association of higher IgA levels with the winter season and with children being older than 4 years (P < .001), having attended childcare prior to commencing pre-school (P < .05), and having been exposed to ETS at home (P < .05). Lower IgA levels were associated with being atopic (P < .05). Higher IgG levels were associated with exposure to ETS (P < .001), while lower levels were associated to having atopy. Higher IgM levels were associated with previous childcare experience (P < .01) whilst having been hospitalised was associated with having low salivary IgM levels (P < .01). Lagged analyses demonstrated that immunological parameters were affected by the number of respiratory infections in the preceding 2 months.