Persistence of Eosinophilic Asthma Endotype and Clinical Outcomes: A Real-World Observational Study

Abstract

Purpose Eosinophil count elevations are predictive of adverse outcomes in patients with asthma, yet little is known regarding longitudinal eosinophil patterns and their association with clinical outcomes. The goal of this study was to assess associations between longitudinal persistence of eosinophil elevations and both clinical outcomes and health care resource utilization (HCRU). Methods Data were extracted from 2 databases in the United Kingdom. Patients included were aged ≥13 years, had active asthma, and had ≥3 blood eosinophil count (BEC) recordings. Patients were categorized by BEC as: never high (all BEC ≤300 cells/µL), intermittently high (≥1 BEC >300 cells/µL but <75% of BEC >300 cells/µL), or persistently high (≥75% of BEC >300 cells/µL). Asthma exacerbations, asthma control (risk domain, overall, and full), and HCRU were evaluated for 12 months after the last BEC. Results The study population comprised 148,021 patients. Persistently high, intermittently high, and never high eosinophil patterns were detected in 13.6%, 40.5%, and 45.9% of patients, respectively. Patients with ≥1 elevated BEC were at greater risk for severe asthma exacerbations, regardless of whether the elevation was persistent (rate ratio [RR]: 1.28 [95% CI 1.24–1.33]; P < 0.001) or intermittent (RR: 1.24 [95% CI 1.21–1.27]; P < 0.001), compared with patients with no eosinophil elevations. Full asthma control was achieved by <25% of patients across eosinophil pattern groups, and HCRU did not appreciably differ, although patients with persistently high BEC had the shortest hospital stay duration among the groups. Conclusion These data suggest that elevated blood eosinophils, regardless of persistency, signify increased risk of severe asthma exacerbations.

Clinical Remission in Severe Asthma: A Pooled Post Hoc Analysis of the Patient Journey with Benralizumab

“…Consistent with evidence that eosinophilic asthma is the most common asthma phenotype, the high percentages of patients who achieved C 2 composite remission criteria also reflects that many patients enrolled in benralizumab trials have an eosinophilic component underlying their asthma; indeed, in these patients, using benralizumab as a precision approach to directly target, and almost entirely deplete, eosinophils led to clinically meaningful improvements. Patients with eosinophilic asthma or a history of elevated bEOS levels are more likely to experience asthma exacerbations or have worse lung function [6,9,45]. Exacerbations represent a substantial source of morbidity and mortality for patients with severe asthma, and they are also associated with considerable economic burden as well as a progressive decline in lung function [12,13,[46][47][48].…”

Peripheral blood eosinophilia in adult asthmatic patients and its association with the severity of asthma

“…On the contrary, various studies have found that an elevated eosinophil count is associated with severe asthma [ 9 , 35 – 37 , 54 , 55 ]. This is due to the fact that inflammation is firmly related to the existence of elevated eosinophils in the airway as well as the expression of the Th2 cytokine during allergic asthma.…”

“…Asthma endotypes can be largely classified as type 2 (T2) high or T2-low [7]. T2-high asthma is distinguished by fractional exhaled nitric oxide (FeNO) > 25 ppb, blood and airway eosinophilia (peripheral blood eosinophil levels > 300 or > 150 cells/µL, and sputum eosinophils > 2%), increased severity, and therapeutic responsiveness to Glucocorticoids and T2 inflammatory inhibitors [8,9]. During exposure to allergens, T2 inflammation coexists with eosinophilic inflammation mediated by cytokines such as interleukin (IL) -4, IL-5, and IL-13 [10,11].…”

A retrospective observational study on pheno-endotypes of severe asthma among adults attending asthma clinic in a tertiary care centre in India

“…Studies of asthmatic patients have shown that persistence of eosinophils predisposes these patients to increase the risk of severe asthma exacerbations. [ 31 ] Therefore, it is best that we target these particular phenotypes with available modalities. The benefits of use of these biologicals are better asthma control, decreased exacerbation frequency, hospitalisation, reduction in steroid use, improvement in lung functions, and overall quality of life, and this has already been shown by various meta-analyses.…”