Race, ancestry, and development of food-allergen sensitization in early childhood.

Abstract

We examined whether the risk of food-allergen sensitization varied according to self-identified race or genetic ancestry. We studied 1104 children (mean age: 2.7 years) from an urban multiethnic birth cohort. Food sensitization was defined as specific immunoglobulin E (sIgE) levels of ≥ 0.35 kilo-units of allergen (kUA)/L for any of 8 common food allergens. Multivariate logistic regression analyses were used to evaluate the associations of self-identified race and genetic ancestry with food sensitization. Analyses also examined associations with numbers of food sensitizations (0, 1 or 2, and ≥ 3 foods) and with logarithmically transformed allergen sIgE levels. In this predominantly minority cohort (60.9% black and 22.5% Hispanic), 35.5% of subjects exhibited food sensitizations. In multivariate models, both self-reported black race (odds ratio [OR]: 2.34 [95% confidence interval [CI]: 1.24-4.44]) and African ancestry (in 10% increments; OR: 1.07 [95% CI: 1.02-1.14]) were associated with food sensitization. Self-reported black race (OR: 3.76 [95% CI: 1.09-12.97]) and African ancestry (OR: 1.19 [95% CI: 1.07-1.32]) were associated with a high number (≥ 3) of food sensitizations. African ancestry was associated with increased odds of peanut sIgE levels of ≥ 5 kUA/L (OR: 1.25 [95% CI: 1.01-1.52]). Similar ancestry associations were seen for egg sIgE levels of ≥ 2 kUA/L (OR: 1.13 [95% CI: 1.01-1.27]) and milk sIgE levels of ≥ 5 kUA/L (OR: 1.24 [95% CI: 0.94-1.63]), although findings were not significant for milk. Black children were more likely to be sensitized to food allergens and were sensitized to more foods. African ancestry was associated with peanut sensitization.