Severe Asthma Burden by Blood Eosinophil Count and Total IgE Level

A substantial burden of asthma exacerbations occur across increased blood eosinophil counts (BEC) and total immunoglobulin E (IgE) levels in patients with severe asthma not receiving biologics or systemic corticosteroids, according to the results of a real-world study presented at the American College of Allergy, Asthma & Immunology (ACAAI) Annual Scientific Meeting, held virtually from November 13 to15.

Asthma exacerbation frequency is associated with increased BEC; however, few studies have examined the frequency of asthma exacerbations by total IgE levels in patients with severe asthma. Therefore, researchers examined the association between highest BEC and total IgE and annualized rates of asthma exacerbations, emergency department visits, and hospitalizations in patients not receiving biologics or systemic corticosteroids via the CHRONICLE study (ClinicalTrials.gov Identifier: NCT03373045). CHRONICLE is an observational study of adult patients with severe asthma treated by allergists/immunologists or pulmonologists in the United States and who receive biologics, maintenance systemic corticosteroids, or who experience uncontrolled asthma on high-dose inhaled corticosteroids with additional controllers.

Of the 1884 patients enrolled in this study between February 2018 and February 2020, 1196 patients did not receive biologics or systemic corticosteroids. Of these patients, 584 had BEC and 266 had total IgE levels reported, and the researchers found that higher BEC (≥300) and total IgE were associated with higher rates of asthma exacerbations, emergency department visits, and hospitalizations.

“Consistent with previous studies, higher BEC was associated with higher exacerbation rates,” the researchers concluded. “Additionally, total IgE <30 (linked to ineligibility for anti-IgE treatment per approved dosing criteria) was associated with higher exacerbation risk; this novel observation warrants further study.”

Reference

Ambrose C, Lugogo N, Soong W, et al. Real-world burden of specialist-treated severe asthma by blood eosinophil count and total immunoglobulin E level. Presented at: the American College of Allergy, Asthma & Immunology (ACAAI) Annual Scientific Meeting (Virtual Experience); November 13-15, 2020. Abstract P204.