Eosinophil-guided therapy to shorten systemic corticosteroid duration is non-inferior to usual care of fixed duration corticosteroids in adults admitted to hospital for asthma exacerbations.

A Singaporean study, published in Thorax [link here], said 5–7 days of systemic corticosteroids for all asthma exacerbations was “an entrenched clinical practice” supported by guidelines.

However it may undermine corticosteroid stewardship and opportunities for shorter courses in some patients which would in turn reduce unnecessary corticosteroid exposure and the attendant risk of adverse events.

The open-label trial randomised 110 patients to either usual care of 5 days oral prednisolone regardless of initial blood eosinophil count or eosinophil-guided care of 3 days prednisolone if eosinophils <300 cells/µL or 5 days if ≥300 cells/µL

About 60% of the participants were considered to have eosinophilic airway inflammation versus 40% non-eosinophilic using a 300 cells/µL cut-point.

The primary outcome of treatment failure during the index admission – all due to extension of treatment duration – was experienced by 10.9% in the eosinophil-guided group and 7.3% in the usual care group.

The cumulative dose of systemic corticosteroid per patient did not significantly differ between eosinophil-guided and usual care (199.5 mg vs 188.5 mg prednisolone-equivalent, p=0.45).

However, “among those randomised to eosinophil-guided care, non-eosinophilic participants received significantly lower cumulative dose of systemic steroids compared with eosinophilic subjects (136 vs 214 mg, p=0.0004),” the study found

“In contrast, there was no significant difference in cumulative steroid dose comparing non-eosinophilic to eosinophilic subjects treated under usual care (186 vs 211 mg prednisolone-equivalent, p=0.18).”

In secondary outcomes, there were no significant differences in length of stay (2.5 v 2.7 days, p=0.68), change in asthma symptoms, additional systemic steroid use at 14 days and time to next emergency visit or admission for asthma exacerbation.

“Our trial is the first to investigate the feasibility and safety of using the blood eosinophil count to reduce systemic steroid exposure in asthma exacerbations, and we were able to demonstrate that the eosinophil-guided strategy can be used to shorten the duration of systemic corticosteroid use without compromising safety,” the study said.

“Our results indicate that using the blood-eosinophil count to guide systemic corticosteroid therapy may provide a promising strategy for personalised corticosteroid stewardship in the setting of acute exacerbations.”

They said implementation would first require validation of their study in larger, more diverse cohorts using randomised, double-blind and placebo-controlled trial design.