Associations between genetic ancestry and allergic outcomes at 10 years among Black children

Elevated IgE levels, a higher prevalence of allergic disorders, and a higher incidence of asthma have been reported among Black children compared with White children. Racial classification is a social construct that is partially influenced by genetic ancestry. The factors contributing to racial health disparities remain uncertain but likely reflect complex interactions between genetic susceptibility and environmental exposures.

To assess the associations of genetic ancestry with allergic disorders, IgE production, and lung function among Black children.

Prospective data from the Wayne County Health, Environment, Allergy, and Asthma Longitudinal Study (WHEALS) birth cohort were analyzed. Race was assigned by maternal report, and Black, non-Hispanic/non-Arabic children were identified (n = 345, 53.3% male). Genome-wide continental percent African ancestry (PAA) was estimated. Associations between PAA and longitudinal total IgE trajectory (from birth to age 10), allergic sensitization, allergic disorders, and spirometry at 10 years were examined. Models were adjusted for confounders, including available variables associated with social determinants of health.

A total of 102 participants (56%) were sensitized to 1 or more allergens; 47 (27.5%) had asthma. Each 10-percentage-point increase in PAA was associated with a 68% increased risk of asthma (relative risk [RR], 1.68; 95% CI, 1.16-2.45; P = .007), a 30% higher risk of sensitization to common allergens (RR, 1.30; 95% CI, 1.04-1.63; P = .019), and a decrease in forced expiratory volume in 1 second (FEV1%) predicted by 2.67% (β -2.57; 95% CI, -5.19 to 0.06; P = .055). No association was identified between PAA and total IgE trajectory (P = .11).

Among Black children, PAA is associated with an increased risk of asthma, allergen-specific IgE sensitization, and decreased lung function at 10 years.