IgE and atopic allergy in newborns and infants with a family history of atopic disease.

Serum IgE levels were studied in 2 groups of children with a family history of atopic disease, 30 in whom the mother only and 38 in whom both parents had atopic disease. IgE antibodies were determined with Phadebas RAST Test and serum IgE with Phadebas IgE Test and Phadebas PRIST at 0, 3, 9, 12 and 18 months of age. There was no correlation between the serum IgE levels in mothers and their newborns. RAST tests were frequently positive in maternal sera but no positive RAST test was found in the newborns. Obvious and probable atopic disease developed during the observation period in 42.1% of the children with a double family history of atopic disease. In 75% of these the serum IgE level was above the upper limit of normal on an average 6 months before the onset of atopic symptoms. An elevated IgE level without atopic symptoms during the observation period occurred in only one child. It is concluded that the serum IgE in newborns seems to be of foetal origin and that the determination of serum IgE in infants is of value in predicting atopic allergy.