Cord serum IgE: an insensitive method for prediction of atopy

Summary Cord total serum IgE has been advocated as a screening test to detect infants at high risk of allergy who would be suitable for preventive measures. In a population based prospective study to look at the predictive capacity of cord IgF and family history of atopy 1111 one‐year‐old infants were followed‐up. Cord IgE was measured using the EIA ultra technique (Pharmacia, Uppsala, Sweden). Atopic symptoms developed in 255 (23%) at one year, 183 (16·5%) had probable atopy (clinical disorder but negative skin prick test (SPT)) and 72 (6·5%) had definite atopy (clinical disorder with positive SPT), There was no difference in the mean cord IgE levels in infants with or without atopic manifestations. The cut‐off for IgF was taken at 0·6 ku/1. The specificity of the test was 92% but the sensitivity was only 8·5%. The positive and negative predictive values were 24% and 78% respectively. Family history of atopy is far more sensitive in detecting infants at risk of atopy and little is added by knowledge of cord IgE.