Evaluation Of Peanut Allergy In a Birth Cohort

There is relatively little information about longitudinal changes in serum peanut-specific IgE (sIgE) in children with peanut allergy and in children who are sensitized to peanut but not allergic. 288 high-risk children were enrolled in the Childhood Origins of Asthma birth cohort and were followed prospectively. Yearly questionnaires related to adverse reactions to foods were completed. Peanut allergy was defined as having an elevated sIgE (>0.35) and an adverse reaction to peanut. Serum peanut-specific IgE (UniCAP, Phadia USA) was also obtained at 1, 2, 3, 5, 6, 9, and 11 years of age. On average, 85% of children had sIgE levels measured at each interval. 245 children were included in the study at age 6 and 217 remained at age 11. 31 children were sensitized to peanut but not allergic and 11 children had peanut allergy. Group mean sIgE levels at 1, 9, and 11 years were fairly stable for children with peanut allergy (3.96, 4.55, 2.77 kU/L) and for sensitized children (0.6, 0.39, 1.11 kU/L), and overall peanut allergic children had increased sIgE levels compared to those who were sensitized (3.70 vs 0.56 p < 0.0001). In contrast to the group mean data, time-related changes in individual sIgE levels varied widely. Mean peanut sIgE levels were higher in children with peanut allergy compared to sensitized patients. Analysis of individual patterns of sIgE may yield new insights into personal and environmental factors that modify immune responses to peanut.