The Effect of Inhaled Ciclesonide Treatment on Systemic Markers of Immune Function in Horses.
Authors: Page Allen E, Johnson Mackenzie, Parker Jordan L, Jacob Olivia, Swan Melissa, Adam Emma
Journal: Journal of equine veterinary science
Summary
Inhaled ciclesonide offers a meaningful advantage over systemic dexamethasone for managing equine asthma: whilst both drugs effectively control respiratory inflammation, dexamethasone significantly suppresses key immune markers (granzyme B and interferon-γ) in whole blood and even after immune stimulation with Concanavalin A, whereas ciclesonide treatment produced no measurable systemic immunosuppression in this 18-horse trial. Researchers randomly assigned horses across three groups—untreated controls, ciclesonide-treated, and dexamethasone-treated—and measured mRNA expression of selected immune genes daily plus at specific timepoints after in vitro immune challenge, with statistical significance set at P < 0.05. The critical finding is that dexamethasone demonstrated dose-dependent suppression of cytotoxic and interferon responses, whereas ciclesonide-treated horses showed immune profiles indistinguishable from controls. For practitioners managing horses with recurrent airway obstruction, this suggests inhaled ciclesonide may be the preferable choice when long-term asthma control is needed, particularly for performance horses or those with concurrent infection risk, since maintaining robust systemic immunity could reduce vulnerability to secondary bacterial or viral complications whilst effectively managing lower airway disease.
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Practical Takeaways
- •Ciclesonide is a suitable alternative to dexamethasone for managing equine asthma without the risk of systemic immunosuppression
- •If using dexamethasone for asthma control, be aware it will suppress systemic immune markers (granzyme B, interferon-γ); consider duration and frequency of treatment
- •Inhaled corticosteroid therapy with ciclesonide allows local airway treatment while minimizing systemic immune effects, improving clinical safety
Key Findings
- •Dexamethasone treatment significantly decreased steady-state whole-blood expression of granzyme B and interferon-γ compared to untreated controls
- •Dexamethasone suppressed granzyme B expression in ConA-stimulated samples compared to controls, indicating continued immunosuppressive effect
- •Ciclesonide treatment produced no significant effects on immune markers measured, suggesting low immunosuppression risk
- •Inhaled ciclesonide appears safer than dexamethasone for equine asthma treatment from systemic immunosuppression perspective