Mononuclear cell reactivity to food allergens in neonates, children and adults

A model of antigen-specific T-cell proliferative responses based on recipro cal patterns of responses to dietary and inhalant allergens has been sugges ted, the former being frequent in infancy but rare in adults, whereas the l atter are preserved and expand between infancy and adulthood. We have evalu ated the age-related variations of mononuclear cell reactivity to food alle rgens. The cord blood mononuclear cells (CBMC) of 30 neonates without famil y history of atopy and the peripheral blood mononuclear cells (PBMC) of 20 healthy children and of 40 healthy adults were stimulated in vitro with bet a-lactoglobulin (BLG) or ovalbumin (OVA) and the cultures were harvested af ter 7 days. Neonates, children and adults were compared for the percentages of positive responses and for the magnitude of response. Adult subjects sh owed significantly lower percentages of positive responses and reduced magn itude of response than those observed in neonates and children either in BL G or in OVA cultures. We have not observed a decrease of food allergen mono nuclear cell reactivity between neonates and children for the frequency of positive responses. The magnitude of response of neonates was significantly lower than that of children in BLG cultures. Our results seem to confirm t he loss of mononuclear cell reactivity to food allergens in adult age. Howe ver, other reports show conflicting data. We suggest that a rigorous standa rdization of the methodological steps of in vitro mononuclear cell stimulat ion with allergen is necessary.