Elevated cord serum IgE increases the risk of aeroallergen sensitization without increasing respiratory allergic symptoms in early childhood

Background Increasing prevalence of allergic disorders has focused attentio n on primary prevention. There is a need to improve the accuracy of early-l ife predictors of atopy so that the at-risk population can be accurately de fined and preventive measures instituted. Objective The predictive capacity of elevated cord IgE, with or without fam ily history of atopy, to allergic symptoms and skin prick test (SPT) sensit ization is evaluated in a birth cohort followed up prospectively for 4 year s. Methods A birth cohort of 1456 consecutively born children was recruited in 1989, Data were collected on family history of atopy and cord serum total IgE (cord IgE) was measured. Of these, 1218 children were seen in the clini c at 4 years to determine the development of symptoms and signs of allergic disease and 981 were skin tested to a range of common food and aeroallerge ns. Results Of 1218 children reviewed at age 4years, 218 (17.8%) had symptoms o f respiratory allergy and, of those skin tested (n = 981),192 (19.6%) react ed positively. Twice as many children with elevated cord IgE (greater than or equal to 0.5 kU/L) at birth became sensitized to aeroallergens by age 4 years (34.8% vs 17.3%, P < 0.001). Positive predictive value (PPV) of eleva ted cord IgE for the development of aeroallergen sensitization was better t han that of family history of atopy (34.8 vs 22.6%). Combining paternal ato py with elevated cord IgE substantially increased the predictive capacity ( PPV 77.8%). Cord IgE levels did not correlate with clinical asthma or rhini tis at age 4years and PPV for allergic respiratory symptoms remained poor a t all cutoffs, Conclusion Cord IgE is better than family history for predicting atopy as d efined by allergen sensitization and this predictive value can be further i ncreased by combining cord IgE with paternal atopy.