Race Adjusted for Social and Environmental Disparities Is the Principal Determinant of T2HIGH Inflammation in Children With Severe Asthma.

BACKGROUND

Robust T-helper 2 (T2) inflammation drives a phenotype noted for difficult symptoms in children with asthma. Past studies show that Black children have greater T2 inflammation than White children. However, it is not clear how disparate social and environmental factors inform this difference.

OBJECTIVE

To examine the fundamental factors that differentiate T2HIGH and T2LOW inflammation phenotypes in children with severe, treatment-refractory asthma.

METHODS

Children underwent bronchoscopy and measures of blood T2 markers. T2HIGH children (n = 202) had blood or lung lavage (bronchoalveolar lavage [BAL]) eosinophilia and specific IgE to ≥1 allergen; T2LOW (n = 249) had neither. Factors associated with T2HIGH inflammation were examined with multivariable logistic regression and neural network (NN) models.

RESULTS

The T2HIGH phenotype was dominant by 5 years of age. Children with T2HIGH inflammation, compared with T2LOW, were older, had greater self-reported Black race, lower household income, greater hospital admissions, lower forced expired volume in 1 second, and greater BAL granulocytes. In regression models, Black race and ethnicity had the highest odds ratio (OR, 95% confidence interval) of T2HIGH inflammation adjusted for social and environmental disparities (OR: 2.88, 1.79-4.64, P < .001, E-estimate 5.2) and clinical outcomes (OR: 3.84, 2.19-6.73, P < .001, E-estimate 7.14). These results were repeatable with NN models, although age performed better than Black race in the social/environmental analysis.

CONCLUSIONS

In children with severe asthma, Black race confers the highest odds for T2HIGH inflammation adjusted for demographic, social, environmental, and clinical factors. Race and ethnicity and the magnitude of T2 inflammation should guide the treatment of children with severe asthma.