In children with severe asthma, significant predictors of airflow limitation (AFL) include being Black, prior intensive care unit (ICU) admission for asthma, higher-dose inhaled corticosteroid (ICS) treatment, and increased absolute blood and bronchoalveolar lavage (BAL) eosinophil count, according to study findings presented at the American College of Allergy, Asthma & Immunology (ACAAI) 2022 Annual Scientific Meeting, held November 10-14, 2022, in Louisville, Kentucky.

It is well known that AFL is predictive of poor asthma outcomes across the stages of maturation. Researchers sought to identify significant predictors of AFL in children with severe asthma from school age to adolescence (ie, 5 to 18 years of age).

The study participants, who had been diagnosed with treatment-refractory asthma, underwent spirometry and diagnostic bronchoscopy. In these individuals, AFL was defined as prebronchodilator forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) of less than 0.85 or less than 90% predicted.


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A total of 226 individuals were included in the analysis. Overall, 46% (105 of 226) of the participants had AFL. No difference was observed between the 2 groups with respect to age, gender, body mass index, or age at onset of symptoms.

Children with AFL had significantly higher total blood and bronchoalveolar lavage (BAL) eosinophil count, total IgE, and greater number of positive allergen specific serum IgE.

Results of the study showed that compared with children without AFL, those with AFL were more likely to report prior ICU admission for asthma, treatment with higher-dose ICS, and identified as Black. “Children with AFL had significantly higher total blood and bronchoalveolar lavage (BAL) eosinophil count, total IgE, [immunoglobulin E] and greater number of positive allergen specific serum IgE,” the investigators noted.

Among younger children, those who had a sensitization to at least 4 allergens experienced greater AFL; however, the opposite relationship was observed among adolescents. In a similar fashion, the effect of higher total IgE levels (ie, >130 IU/mL) on AFL was most prominent among younger children.

The study authors noted that “AFL is driven in part by allergic sensitization in the younger children whereas in older children this [is] associated more with the absence of allergic sensitization,” said the researchers.

Reference

Boyd K, Lawrence M, Borish L, Wavell K, Teague G. Impact of allergen sensitization on airflow limitation in children with severe asthmaAnn Allergy Asthma Immunol. 2022;129(5):S4. doi:10.1016/j.anai.2022.08.519

This article originally appeared on Pulmonology Advisor